I

2ND INTERNATIONAL CONFERENCE ON ADVANCES IN MECHANICAL ENGINEERING

PROCEEDINGS BOOK

ISTANBUL, 2016

2ND INTERNATIONAL CONFERENCE ON ADVANCES IN MECHANICAL ENGINEERING

ICAME2016

10-13 MAY, 2016

YILDIZ TECHNICAL UNIVERSITY

ISBN: 978-605-65907-1-9

II

ORAL PRESENTATIONS

AUTHORS PAPER TITLE PAGE NUMBER

. EKMEKC, E. AYDAR A NEW DESIGN FOR PANEL RADIATORS USING CFD 1

E. ETKN VASCULAR STRUCTURES FOR SMART FEATURES: SELF-COOLING AND SELFHEALING 9

EL-SAYED ABD EL-AZM EL-AGOUZ

PERFORMANCE OF HUMIDIFICATIONDEHUMIDIFICATION DESALINATION UNIT

USING A DESICCANT WHEEL 16

C. WANG, M. AMER REVIEW OF ACTIVE DEFROSTING METHODS IN REFRIGERATION SYSTEMS 28

S. GARAN, I. SHYHA, F.INAM

EFFECT OF CUTTING TOOLS AND WORKING CONDITIONS ON THE

MACHINABILITY OF TI-6AL-4V USING VEGETABLE OIL-BASED CUTTING FLUIDS

34

M. S. SAHARUDN, I. SHYHA,F. INAM

VISCOELASTIC AND MECHANICAL PROPERTIES OF MULTI-LAYEREDGRAPHENE

POLYESTER COMPOSITES 41

S. ZEN, . . OLAK AKIR

GRID INDEPENDENCE ANALYSIS OF COMPUTATIONAL FLUID DYNAMICS OF A

HYDRODYNAMIC JOURNAL BEARING WITH MICROFILM LUBRICATION

46

O. ELGAD, M. BRKETT, W.M. CHEUNG

A PROPOSED MIXED METHOD METHODOLOGY TO IDENTIFY THE FACTORS IMPEDING

THE ADOPTION OF SIX SIGMA IN LIBYAN MANUFACTURING COMPANIES

49

O. AHMAD, MD. N. AL, A.CHEKMA

ADVANCES IN ZERO ENERGY TRANSPORTATION SYSTEMS 53

M. MASKANYAN, G.AHMAD, J. A. ESFAHAN

EFFECT OF TRAP AND REFLECT WALL BOUNDRY CONDITIONS ON

DEPOSITIONS AND CONCENTRATION DISTRIBUTION OF NANOPARTICLES BY

AN EULERIAN-LAGRANGIAN MODEL

59

L. MERAD, F. JOCHEM, P.BOURSON, B. BENYOUCEF

KINETIC STUDY OF THERMAL DEGRADATION OF RTM6

CONTAINING TIO2 BY THERMOGRAVIMETRY 64

O. BODUR, . . OLAKAKIR

OPTIMIZATION OF THE CRANKSHAFT JOURNAL BEARINGS IN REFRIGERATOR

COMPRESSORS 69

M. BIDEQ, K. I. JANATI, L.BOUSSHINE

STUDY OF THE ELASTIC DEFORMATION OF ROTARY CEMENT KILN USING

FINITE ELEMENT ANALYSIS 76

B. BELKACEM, B. KAMELMECHANICAL BEHAVIOUR IN STATIC TRACTION

TWO COMPOSITE FIBER GLASS/EPOXY [04] AND [0/902/0]

82

J. ZHANG, B. SUN, X LUTOOTH PROFLE TOLERANCE DESGN OF HGH-PRECSON END-TOOTHED DSC BASED ON THE

NORMAL DSTRBUTON MODEL OF PROFLE ERROR

88

III

F. BAYRAK, H. F. OZTOP, A.HEPBASL

COMPARATVE ENERGY AND EXERGY ANALYSES OF A BULDNG USNG DFFERENT HEATNG

SYSTEMS WTH SOLAR COLLECTORS 93

B. M. NASSERIMPROVEMENT OF PRODUCTIVITY IN THE

PLASTIC BAGS INDUSTRY USING SIMULATION

100

K. ABDELKADER, K.YOUCEF, T. SABHA

NUMERCAL SMULATON OF FREE VBRATONS OF MULTLAYER COMPOSTE BEAMS 105

A. S. AHCENE, C. ABDENACER, B. KAMEL, B.

BELKACEM

MECHANCAL BEHAVOR OF COMPOSTE LAMNATES SANDWCHES

FOAM-GLASS / EPOXY, UNDER 3-PONTS AND 4-PONTS STATC BENDNG

111

M. DEMIRCI, A. S. VANLI, A.AKDOGAN

EFFECTS OF HEAT TREATMENT ON MECHANICAL AND CORROSION

PROPERTIES OF MAGNESIUM ALLOYS 117

N. KURTULMUS, M. BLGL,B. AHN, A. ETNZ

HOURLY PERFORMANCE PREDICTION OF SOLAR POWERED VAPOR ABSORPTION

AIR-CONDITIONING SYSTEM 121

R. YILDIRAN, . TEKEINVESTIGATION ON COMBUSTION

AERODYNAMICS OF A PULVERIZED COAL BURNER

131

E. ERDL, A. PINARBAI EXPERIMENTAL STUDY OF AIR FLOW IN VACUUM CLEANERS 140

H. OZYURT, Z. YUMURTACI TO INCREASE PRODUCTION CAPACITY AND PROVIDE ENERGY EFFICIENCY

FOR FACTORY PRODUCTION LINE 145

M. S. ZER, L. KIRKAYAK, A.ALTINKAYNAK, O. ATA,

UUR F. TENKU

SYSTEMATIC ANALYSIS OF WASHING MACHINE FRONT BLOCK 153

H. F. ZTOP, F. SELMEFENDGL

NUMERCAL STUDY OF NATURAL CONVECTON N A PARTALLY HEATED OPEN CAVTY 158

. ESK DESIGN OF NEURAL PREDICTOR FOR VIBRATION ANALYSIS OF DRILLING MACHINE 166

L. ARRABET, I. LAMR, M.HDJEB, K. HARRAT

PILE-SOIL INTERACTION NEARBY A SLOPE BY FINITE ELEMENT METHOD 170

L. ARRABET, I. LAMR, M.HDJEB, K. HARRAT

THE BEHAVIOUR OF A DIAPHRAGM WALL ALONG A DEEP EXCAVATION IN A

SAND DUNE SUBSOIL 175

C. YILDIRIM, N. F. TMENZDL

THEORETICAL INVESTIGATION OF A SOLAR AIR HEATER ROUGHNED BY RIBS

AND GROOVES 179

. YILDIRIM, E. ARSLAN ESTIMATION OF CONTACT FORCES ON REAL-TIME

SIX LEGGED MOBILE ROBOT WITH ODE (OPEN DYNAMICS ENGINE)

185

B. KURSUNCU, H.CALISKAN, S. Y. GUVEN

PERFORMANCE OF CRYOGENICALLY TREATED AND NON-TREATED TALN

COATED CARBIDE CUTTING TOOLS WHILE FACE MILLING OF INCONEL 718

SUPERALLOY

191

U. ALIKAN, M. K. APALAKFEM ANALYSES OF LOW VELOCITY IMPACT

BEHAVIOUR OF SANDWICH PANELS WITH EPS FOAM CORE

195

K. TOUAFEK, I. TABET, A.KHELFA, H. HALOU, H. B.

C. EL HOCNE

PERFORMANCE OF A HYBRD PHOTOVOLTAC-THERMAL AR COLLECTOR- EXPERMENTAL APPROACH

202

E. ERYLDZ, A. UYSAL, E.ALTAN

A STUDY ON SHEAR STRENGTH OF SINGLE-LAP JOINTS BONDED BY NANO

GRAPHENE REINFORCED EPOXY ADHESIVE 207

PH SENSITIVE HYDROGELS AS MICROFLUIDIC

IV

N. ARBAB, M. BAGHAN, M.M. MASHHAD

VALVES: A FLUID STRUCTURE INTERACTION (FSI) APPROACH

211

. KARASU, M. O. TACI, B. AHN, H. AKILLI

STEREO PIV INVESTIGATION ON WINDWARD SIDE LEADING EDGE VORTEX OF

A YAWED SLENDER DELTA WING 215

S. BENRAMACHE, B.BENHAOUA

CHARACTERISATION OF ZNO THIN FILM PREPARED BY SOLGEL TECHNIQUE 224

O. AKIR MACHINING OF HADFIELD STEEL : AN OVERVIEW 227

U. EMROLU, M. KIYAK, E.ALTAN

EXPERIMENTAL STUDY ON TURNING WITH SELF-PROPELLED ROTARY

CUTTING TOOL 233

M. GUL, S. SU, I. UZMAY DESIGN OF COMPLIANT BISTABLE MECHANICAL SYSTEM 239

B. KURSUNCU, H.CALISKAN,S. Y. GUVEN

THE EFFECT OF MULTILAYER NANOCOMPOSITE TALSN/TSN/TALN COATING ON CUTTING FORCES IN FACE MILLING OF INCONEL 718

SUPERALLOY 244

S. YAYLA, S. YASSEN, A. B.OCLAY

CFD SIMULATION FOR DESIGNINIG TWO DIFFERENT SHAPES OF THE VENTURI

FOR SHOWING CAVITATION IN TWO PHASE FLOW 248

MUSTAFA KILIC NUMERICAL INVESTIGATION OF HEAT TRANSFER

FROM A POROUS PLATE WITH TRANSPIRATION COOLING

255

G. M. AY, M. A. SOFUOLU META ANALYSIS OF FACTORS AFFECTING SURFACE ROUGHNESS IN MILLING 265

A. YILMAZ, M. T. ERDN, T.YILMAZ

INFLUENCE OF DIFFERENT OPERATING CONDITIONS ON THE COOLING

PERFORMANCE OF TRANSCRITICAL ORGANIC RANKINE REFRIGERATION SYSTEM

271

F. MOHAMMAD, R.SEDAGHAT

CHARACTERIZING NONLINEAR VISCOELASTIC PROPERTIES OF

ELECTRORHEOLOGICAL FLUIDS 276

A. GLL, H. KUU MECHANICAL AND SOFTWARE DESIGN OF THE WAREHOUSE ROBOT 281

M. A. SOFUOLU, S. ORAK,R. A. ARAPOLU

EXPERIMENTAL INVESTIGATION OF CHATTER VIBRATION PREVENTION

METHODS IN TURNING OPERATIONS 286

C. YLMAZ, M. KANOGLUTHERMOECONOMIC OPTIMIZATION OF AN

INTEGRATED SYSTEM WITH ABSORPTION COOLING, GEOTHERMAL BINARY,

AND CLAUDE CYCLES

291

S. GRGEN, M. C. KUHANABRASIVE PROPERTIES OF SILICON CARBIDE

PARTICLES IN SHEAR THICKENING FLUID

298

N. A. KUREKCI, M.K. SEVINDIR, M. H. CUBUK

THE ECONOMIC ANALYSIS OF GRAY WATER USE IN A SAMPLE RESIDENTIAL

BUILDING 303

I. ESKI, A. KIRNAP, M.KIRNAP

CONTROLLER DESIGN FOR PATIENTS WHO HAS MALFUNCTION AT EXTREMITY 313

T. H. ETN, B. ZTRKMEN, C. YLMAZ, M. KANOGLU

PERFORMANCE ANALYSIS AND COMPARISON OF GAS LIQUEFACTION CYCLES 319

. ESKI DESIGN OF ROBUST CONTROL SYSTEM FOR

CONTROLLING TRAJECTORY OF AUTONOMOUS TRACTOR

326

M. AHBAZ, A. KENTL AN APPLICATION OF ANALYTICAL HIERARCH PROCESS ON NUMERICAL

ANALYSIS OF HEAT TRANSFER

331

V

M. AHBAZ, A. KENTL, A.EREN, C. BLK

MATERIAL SELECTION FOR INSULATION OF BUILDINGS BY MULTI-CRITERIA

DECISION MAKING METHODS 335

NEBBAL RACHD, HAMADOUCHE ABDELMALEK

EXPERIMENTAL AND NUMERICAL STUDY OF A TURBULENT FLOW IN A DUCT

PARTLY FITTED WITH ALUMINUM METALLIC FOAMS BLOCKS

340

E. B. T, F. SELMEFENDGL, H. F.

ZTOP

NATURAL CONVECTION HEAT TRANSFER IN A WATER-BASED NANOFLUIDFILLED

TRAPEZOIDAL ENCLOSURE: EFFECT OF THERMAL CONDUCTIVITY

MODELS

346

MUSTAFA ZDEMR SPRING BALANCING OF A FIVE-BAR PARALLEL

MANIPULATOR IN THE PRESENCE OF SINGULARITIES

354

GUVEN GONCA, IBRAHM OZSARI

EXERGETIC PERFORMANCE ANALYSIS OF A GAS TURBINE WITH TWO

INTERCOOLERS AND TWO REHEATERS FUELLED WITH DIFFERENT FUEL

KINDS

358

ABAN NAL, MEHMET TAHR ERDN, ARI

KUTLU

INVESTIGATION OF OPTIMUM WORKING CONDITIONS FOR TWO-EVAPORATOR

EJECTOR REFRIGERATION SYSTEM USING ALTERNATIVE REFRIGERANTS

366

A. UYSAL, E. ALTANAN EXPERIMENTAL STUDY ON DRILL TEMPERATURE IN DRILLING OF PURE

AND CARBON BLACK REINFORCED POLYMERS 371 H. GOMEZ, A. PACHECO-

VEGA PARAMETRIC ANALYSIS OF MEMBRANELESS

FUEL CELLS 376

. UKAN, A. A. YOUSIF INVESTIGATION OF APPLICABILITY OF A SOLAR

ABSORPTION COOLING SYSTEM IN ERBIL CITY OF NORTH IRAQ

384

F. ARSLAN, Y. UST, G.GONCA

PERFORMANCE ANALYSIS OF A SINGLE CYLINDER SPARK IGNITION CNG

ENGINE BY USING CFD ANALYSIS AND TWO-ZONE COMBUSTION MODEL

396

O. AKIR CHEMICAL MACHINING OF CZ128 COPPER ALLOY 404

R. YILMAZ, R. AHN, S. ATATHERMODYNAMIC ANALYSIS AND WORKING

FLUID SELECTION OF ORGANIC RANKINE CYCLE (ORC) USING ENGINEERING

EQUATION SOLVER (EES) 408

M.M. YAVUZ

OBSERVATON OF FLOW CHARACTERSTCS AND WNG SURFACE STRESS CHANGES WTH THE

USAGE OF SNUSODAL SHAPED SDE PROFLE OVER A SHARP EDGED DELTA WNG

412

M.MURAT YAVUZFNTE ELEMENT STRESS ANALYSS OF A FNNED

MCRO HEAT TUBE UNDER VAROUS REYNOLDS NUMBERS

417

M.MURAT YAVUZINVESTGATON OF HEAT TRANSFER

PERFORMANCE OF A MCRO TUBE WTH INCLUDNG CORRUGATED FNS

420

. ULUS, M. SUVEREN, S. ERKAYA

A VIBRATION BASED FAULT MODELOF GEAR SYSTEMS USING NEURAL

PREDICTOR 426

VI

S. ERKAYA, . ULUS, S.

DOAN

A NUMERICAL STUDY OF JOINT CLEARANCE EFFECTS ON A PARTLY

COMPLIANT MECHANISM

432

. PUSAT FREEZING DEGREE-HOURS IN SVAS AND ADANA 438

. DOYMAZ, A. SEYHUN KPCAK, S.PSKN

EFFECT OF PRE-TREATMENT AND AIR TEMPERATURE ON DRYING TIME OF

CHERRY TOMATO

442

YOUSSEF CHOUAB, AHMED HACHEM CHEBB,

ZOUHAER AFF, LOTF ROMDHANE

PREDICTION OF POSE ORIENTATION ERROR DUE TO THE JOINTS CLEARANCES IN THE DELTA

MANIPULATOR

447

VAMSI VEGAMOOR, MUHAMMAD SAJID,

YASSER M. AL HAMIDI, IBRAHIM HASSAN

EXPERIMENTAL STUDY OF THERMOELECTRIC CONVERSION EFFICIENCY

AND COLD SIDE THERMAL MANAGEMENT

453

A. S. KPCAK, . DOYMAZ, S. PKN

THIN-LAYER MICROWAVE DRYING KINETICS OF MANGO SLICES

462

T. TEZ, H. KUU

IMPLEMENTATION FOR A BIPED ROBOT AND DETECTION OF HIP, KNEE AND

ANKLE ANGLES IN WALKING STEP OF HUMAN USING A VIDEO CAMERA

467

S. BAKHSH, A. NKFARJAM,

H. HAJGHASSEM

SIMULATION OF MICRO CHANNEL AS SEPARATION COLUMN IN GAS CHROMATOGRAPHY SYSTEMS

473

O. BOR, . KAKA, N. TOKGZ

THE FIRST LAW ANALYSIS OF A COMBINED GAS-ORC POWER CYCLE

476

NDER KAKA, SENA

YILMAZ, NEHR TOKGZ

COMPARISON OF ANNUAL ENERGY CONSUMPTIONS OF AIR AND WATER

COOLED INDUSTRIAL COOLING SYSTEMS

482

ZGE YILMAZ, AZM

SEYHUN KIPAK, MEHMET BURN PKN, NURCAN

TURUL

INVESTIGATION OF THE ZINC METAL ADSORPTION BEHAVIOUR FROM WASTEWATER

OF WATERMELON RINDS ACTIVATED WITH ZNCL2 AND TREATED WITH MICROWAVE

488

F. T. SENBERBER, M. YLDRM, A. S. KPCAK, M.

B. PSKN, E. M. DERUN

LOW TEMPERATURE SOLID-STATE SYNTHESIS OF COPPER BORATES

493

S. KZLTAS DEMR, A. S. KPCAK, N. TUGRUL, S.

PSKN

INVESTIGATION OF TEMPERATURE EFFECT ON THE SYNTHESIS OF HYDROXYAPATITE FROM

FLUE GAS DESULFURIZATION WASTE

497

G. BALKAN, F. T. SENBERBER, M. B. PSKN, E.

M. DERUN

CHARACTERIZATION STUDY OF CENTAURIUM ERYTHRAEA USING BY UV-VIS AND ICP-OES

502

O. F. SANCAK, M. PAKSOY, S. CETN

VIBRATION REDUCTION OF AN AIRCRAFT USING SEMI ACTIVE LANDING GEAR

WITH MR DAMPER

506

AHMET UMNU, BRAHM H. GZELBEY, MEHMET V.

AKIR

ANALYSIS AND PID CONTROL OF THE STEWART PLATFORM

512

P. C. ROY, B. KUNDU THERMODYNAMIC MODELING OF PULSE TUBE REFRIGERATION SYSTEM

520

A. TUNCER, M. PAKSOY, S. CETN

SEMI ACTIVE CONTROL OF A HALF VEHICLE ROLL MOTION

527

VII

S. ILA, M. YLDRM, F. T. SENBERBER, A. S. KPCAK,

E. M. DERUN, S. PSKN

ULTRASONIC SYNTHESIS OF POTASSIUM BORATES FROM POTASSIUM CARBONATE AT 90C

533

H. CALISKAN, B.KURSUNCU A CUTTING FORCE MODEL IN MILLING OF INCONEL 718 SUPERALLOY USING

RESPONSE SURFACE METHODOLOGY

537

O. AKIR ENVIRONMENTAL IMPROVEMENTS IN PHOTOCHEMICAL MACHINING

542

E. AYDIN SURFACE CLEANING VIA DRY ICE TECHNOLOGY AND EVALUATION OF APPLICATION AREAS

548

S. ETAG, R. HASAN, N. PERERA, A.RAMADAN

NUMERICAL INVESTIGATIONS ON THE ALUMINA OXIDE IN WATER NANOFLUID

IN MICROCHANNEL

553

A. RAMADAN, R. HASAN, R. PENLNGTON, S.ETAG

ANALYTICAL AND NUMERICAL MODELLING OF SPENT FUEL COOLING PONDS

558

ABDELMADJD CHEHHAT, MOHAMED S-AMEUR,

ESSAM ABO-SERE

CFD ANALYSIS OF TURBULENT AIR FLOW IN THE TURBOCHARGER

COMPRESSOR

564

M. A. MOHAMED, E. ABO-

SERE, J. MUHAMMAD

ERROR ANALYSIS OF A PRACTICAL TECHNIQUE FOR TRANSFORMING

WELDING SEAM FEATURES TO THE ROBOT BASE COORDINATE FRAM

572

B. DORU, M. M. ZDEMIR IMPLEMENTATION OF A MINI WEATHER STATION ON ENGINE TEST ROOM

577

N. TOKGZ, E. ALI, . KAKA, M. M. AKSOY

NUMERICAL INVESTIGATIONS ON THE HEAT TRANSFER ENHANCEMENT IN

DIFFERENT CORRUGATED DUCTS USING AL2O3WATER NANOFLUID

584

E. ZTRK, . H. GZELBEY,

A.UMNU

SIMULATION OF NON-LINEAR COMPUTED TORQUE CONTROL ON SIMULINK FOR TWO LINK

SCARA TYPE MANIPULATOR

592

M. OREJAH

POWER GENERATION FROM LOW GRADE HEAT USING SIMPLE REACTION TURBINE

598

B. ETN

THE EFFECT OF AMBIENT TEMPERATURE ON PERFORMANCE OF SMPLE BRAYTON CYCLE

603

M. EREN, S. CALSKAN

EXPERIMENTAL INVESTIGATION OF THE EFFECT OF FLEXIBLE SPLITTER PLATE ON HEAT

TRANSFER ENHANCEMENT

607

MAHD MOGHM ZAND, IMMAN ISAAC HOSSEN

OPTMZED MCROSTRUCTURE SNGLE CELL TRAPPNG UTLZNG CONTACTLESS

DELECTROPHORESS

613

E. ABO-SERE, E.ORAN, O.UTCU

AERODYNAMICS CONSIDERATIONS FOR A LOW DRAG SHELL ECO-MARATHON COMPETITION CAR

617

A. KASAEAN, R.D. AZARAN, M. ARAMESH, F.

KASAEAN, O.MAHAN

EXPERMENTAL NVESTGATON ON THE PERFORMANCE OF A PARABOLC

TROUGH COLLECTOR USNG SELECTVE COATNG AND NANOFLUD

623

A. V. AKKAYA

PERFORMANCE ANALYZING OF AN ORGANIC RANKINE CYCLE UNDER

DIFFERENT AMBIENT CONDITIONS

631

M. C.FETVACI, H. K.

SRMEN

COMPUTER SIMULATION OF INVOLUTE SPUR GEARS

MANUFACTURED BY PINION-TYPE SHAPER CUTTERS

636

S. C. DORU

COMPARATIVE EVALUATION OF THE MECHANICAL PROPERTIES OF

INTERVERTEBRAL DISC: FINITE ELEMENT

642

VIII

ANALYSIS S. B. KARAKA, M. SARI

YILMAZ THE PREPARATION OF MSU-X MESOPOROUS

SILICA 647

Z. ALTA, N. UGURLUBLEK TWO- AND THREE-DIMENSIONAL TRANSIENT ANALYSIS OF FLOW AND HEAT

TRANSFER IN STRUCTURES WITH DOMICAL AND CURVED ROOFS

650

N. KARAMAHMUT MERMER, M. S. YILMAZ, O.DERE OZDEMR, M. B. PSKN

INVESTIGATION OF PROPERTIES OF HYDROPHOBIC AEROGEL

656

T. C. AHN, M. SARI YILMAZ, S.PKN

THE SYNTHESIS OF MCM-41 MESOPOROUS SILICA FROM WATER GLASS

661

N. KARAMAHMUT MERMER, S. PSKN

PREPARATION OF SILICA SOLUTION FROM SAND BY ALKALI FUSION METHOD

664

M. MACAR THE FAILURE INVESTIGATION OF AA 5059 ALUMINUM ARMOR ALLOY

667

H. AGGUMUS, A. O. AHAN, S. CETIN

SEMI ACTIVE ROBUST VIBRATION CONTROL OF STRUCTURAL SYSTEM WITH

MR DAMPER

673

T. T. GKSU, F. YILMAZ

NUMERICAL ANALYSIS ON HEAT TRANSFER ENHANCEMENT OF HELICAL

DOUBLE WIRE COIL INSERT WITH VARYING PITCH RATIOS

678

S. KAPAN, E. TURGUT

INVESTIGATION OF EFFECTS OF CIRCULAR CROSS-SECTIONAL TURBULATORS

TO HEAT TRANSFER AND PRESSURE DROP IN A CONCENTRIC HEAT EXCHANGER

683

N. KARAMAHMUT MERMER, O. DERE OZDEMR

POTENTIAL OF ZEOLITE SYNTHESIS FROM WASTE ALKALINE SOLUTION

689

T. TOR, A. S. KPCAK, E. M.

DERUN, S. PSKN

SOLID-STATE SYNTHESIS OF POTASSIUM BORATES AT 600 C FROM BORON

OXIDE AND POTASSIUM CARBONATE

692

J. GLEN, E. SERDAR REMOVAL OF A CATIONIC DYE BY A BIOMASS ADSORBENT

697

U. ZVEREN

ESTIMATING THE CALORIFIC VALUES OF LIGNOCELLULOSIC FUELS FROM

THEIR CONTENT OF HEMICELLULOSE, CELLULOSE AND LIGNIN

701

K. S. MUSHATET, H. F. OZTOP, S. E. HAMD

COMPUTATIONAL ANALYSIS OF COMBINED FORWARD FACING STEP FLOW AND

INCLINED CONTRACTION IN A CHANNEL

704

G. GONCA

APPLICATION OF A NOVEL THERMO-ECOLOGICAL PERFORMANCE CRITERION:

EFFECTIVE ECOLOGICAL POWER DENSITY (EFECPOD) TO A JOULE-BRAYTON

CYCLE (JBC) TURBINE

710

Y. E. GNEN, . ERM, M.

ARI

TB, HO AND DY CO-DOPED BISMUTH OXIDE ELECTROLYTES FOR SOLID OXIDE

FUEL CELLS

718

S. ALTUNTAS, T. DEREL

APPLICATION OF AN AGGREGATION TECHNIQUE TO FACILITY LAYOUT DESIGN

SELECTION

723

L. CHAN, I. SHYHA, D. DREYER, J. HAMLTON, P.

HACKNEY

WELD OVERLAY CLADDING REPAIR AN INVESTIGATION OF YIELD STRENGTH

VARIATION IN METALLIC SUBSTRATE

730

I. KURT, S. D. AKBAROV, S.

SEZER

EFFECT OF UNIAXIAL INITIAL STRESSES, PIEZOELECTRICITY AND THIRD

ORDER ELASTIC CONSTANTS ON THE NEAR-SURFACE WAVES IN A STRATIFIED

737

IX

HALF-PLANE S. N.MST, M. BRKETT, D.

BELL, R. PENLNGTON EXPERIMENTAL INVESTIGATION INTO ABRASIVE

CONCURRENT TRIMMING FOR MANGANIN SHUNT RESISTOR

745

F. A. LATRASH, B. AGNEW,

K. HOSSN

OPTIMAL SELECTION OF USING FLUIDS IN ORGANIC RANKINE CYCLE AT LOW

TEMPERATURE GEOTHERMAL AND BELONGING TO CHEMICAL COMPOSITIONS (HFC, HCFC, HC AND MIXTURE)

777

M. SEVER, H. YAZICI

NONLINEAR VIBRATION ANALYSIS OF OLEO PNEUMATIC LANDING GEAR

SYSTEM INTEGRATED WITH BIODYNAMIC PILOT MODEL

782

B. TURGUT, D. ERDEMR, N.

ALTUNTOP

EXAMINATION OF MECHANICAL AND THERMAL VARIATIONS

CAUSED BY THE IMPLANTOLOGY IN THE JAWBONE

788

U. CAN, . HAKKI TOPAL, A. DORUL, T. OGUN, N.

VARDAR

ON THE FORM FACTOR PREDICTION OF A DISPLACEMENT TYPE VESSEL: JBC

CASE

796

T. OGUN, A. YURTSEVEN, N. VARDAR

UNCERTAINTY ANALYSIS IN COMPUTATIONAL FLUID DYNAMICS PROBLEMS

800

A. BOZTEPE, J. GLEN, H. SARA

INVESTIGATION OF BRIQUETTING PERFORMANCE OF YENIKOY LIGNITE BY USING HUMIC ACID 806

D. AKDENZ, C. MOTOR, E. TERZ, A. K. FGEN, S. N.

KARTAL, S. PKN

THERMAL DEGRADATION CHARACTERISTICS OF PARTICLE BOARD

812

D. NCEL, B. C. FLZ, H. ERGVEN, A. K. FGEN, S.

PKN

THERMOLYSIS AND HYDROLSIS PROPERTIES OF AMMONIA BORANE

816

A. M. A. SOLIMAN, A. K. ABDEL-RAHMAN, S.

OOKAWARA

THEORETICAL INVESTIGATION OF VAPOR COMPRESSION CYCLE PERFORMANCE USING

DIFFERENT NANOMATERIALS ADDITIVES

823

K. HOSSIN, K. MAHKAMOV, G. HASHEM

COMPARATIVE ASSESSMENT OF WORKING FLUIDS FOR A LOW-TEMPERATURE SOLAR ORGANIC RANKINE CYCLE POWER SYSTEM

830

M. A. R. SHARIF IMPINGING JET HEAT TRANSFER FROM PLANE AND CURVED SURFACES:

A REVIEW

837

N. DUKHAN, A. ARBAK, . BACI

THE THERMAL ENTRY REGION OF WATER FLOW IN ALUMINUM FOAM WITH HIGH POROSITY AND

40 PORES PER INCH

852

. E. SEVER, R. YILDIRAN, E. KALYONCUOGLU, N.

JAVANI

SIMULATION AND OPTIMIZATION OF A WIND TURBINE BLADE FOR A WIND POWERED VEHICLE

TO OBTAIN THE OPTIMUM ATTACK ANGLE

858

X

A. CELIK, N. JAVANI, K. KESKIN

NUMERICAL AND ANALYTICAL STUDY OF NATURAL FREQUENCIES IN A WIND TURBINE BLADE USING FINITE ELEMENT AND ENERGY

METHODS

865

B. M. NASSER IMPROVEMENT OF PRODUCTIVITY IN THE PLASTIC BAGS INDUSTRY USING SIMULATION

872

A. DJAMILA, C. HAMDANE, R. FODIL

STUDY OF THE OF THE IMPOSED POTENTIEL EFFECT ON THE GROWTH OF ZNO

NANOSTRUCTURES ELABORATED BY CHRONOAMPEROMETRY

877

I. SEBEAN, D. FLOROIU, L. M. BABICI

CONSIDERATIONS REGARDING SUSPENSION OF RAILWAY VEHICLES WITH RUBBER SPRINGS

881

Y. KARAGZ EXPERIMENTAL INVESTIGATION OF HYDROGEN ENRICHED CHARGE WITH DIESEL

IGNITION ON ENGINE PERFORMANCE AND CO EMISSION

891

Y. KARAGZ, T. SANDALCI EFFECT OF HYDROGEN ENRICHMENT ON PERFORMANCE AND EMISSIONS OF A

DIESEL ENGINE AT DIFFERENT ENGINE LOADS

897

Y. KARAGZ EFFECT OF HYDROGEN AND OXYGEN ADDITION ON PERFORMANCE AND NOX

EMISSIONS OF AN SI ENGINE WITH WATER INJECTION

906

Y. KARAGZ, T. SANDALCI EFFECT OF DIFFERENT LEVEL HYDROGEN ADDITION ON PERFORMANCE AND

EMISSIONS OF AN CI ENGINE

917

M. S. CELLEK, T. ENGN, A. PINARBAI

2-D NUMERICAL INVESTIGATION ON THE EFFECTS OF BLADE NUMBER ON THE CENTRIFUGAL

BLOWER

926

M. S. CELLEK, K. ZERK, A. DOAN, A.OKBAZ, . AHN,

A. PINARBAI

NUMERICAL INVESTIGATION ON JOURNAL BEARING LUBRICATION

932

HAMAIDI B, OMEIRI H, MAHDJOUB H, ZEROUALI B

EFFECT OF THE ELECTRIC ARC AND MATHEMATICAL APPLICATION OF MAGNETIC

FIELD FOR DEGRADATION OF THE STRENGTH OF A SOLID USULATION MATERIAL LAC (ARCELOR

MITTAL)

937

O. ACIKGOZ, A. S. DALKILIC A NUMERICAL INVESTIGATION ON THE CONVECTIVE HEAT TRANSFER COEFFICIENT IN

RADIANT CEILING COOLING SYSTEMS

943

O. ACIKGOZ, A. S. DALKILIC NEW APPROACH ON THE DETERMINATION OF THE TOTAL HEAT TRANSFER COEFFICIENT IN

RADIANT WALL HEATING SYSTEMS

947

A. S. DALKILIC, O. ACIKGOZ EXPERIMENTAL APPARATUS DESIGN FOR STUDY OF HEAT TRANSFER AND FLOW

CHARACTERISTICS OF WATER FLOWING THROUGH INTERNALLY GROOVED TUBE

951

A. S. DALKILIC, O. ACIKGOZ EXPERIMENTAL APPARATUS DESIGN FOR STUDY OF POOL-BOILING HEAT TRANSFER

CHARACTERISTICS OF AL2O3WATER NANOFLUIDS ON A HORIZONTAL CYLINDRICAL

HEATING SURFACE

957

A. S. DALKILIC, O. ACIKGOZ CALCULATION PROCEDURE OF DOUBLE PIPE HEAT EXCHANGER DESIGN HAVING NANOFLUID FLOW

963

XI

OPENING SPEECH

DEAR OUR RECTOR, DEAN, DEPARTMENT HEAD AND AUDIENCE,

IT GIVES ME GREAT PLEASURE TO EXTEND TO YOU ALL A VERY WARM WELCOME ON BEHALF

OF THE ORGANIZING COMMITTEE. IT IS AN OPPORTUNE TIME TO HAVE COLLABORATION

WITH OTHER RESEARCHERS AND DISCUSS PROBLEMS OF MUTUAL INTEREST WITH

PARTICIPANTS FROM THE WORLD NOW.

FIRST OF ALL, WE NEED TO THANK OUR RECTOR AGAIN FOR HIS SUPPORT TO THIS

ORGANIZATION. THERE WERE OVER 350 ACCEPTED ABSTRACTS AND 20 INVITED SPEAKERS AS

THEY CAN BE SEEN FROM OUR CONFERENCE WEBSITE. UNFORTUNATELY, WE HAVE GOT 163

SUBMITTED FULL PAPERS AND POSTERS, AND 12 INVITED SPEAKERS IN OUR CONFERENCE

PROCEEDINGS. FINALLY, WE WOULD LIKE TO REVEAL THAT OUR AIM IS TO GATHER OVER

1000 PARTICIPANTS FROM ALL OVER THE WORLD IN THE NEAR FUTURE. MAKE SURE THAT WE

WILL DO OUR BEST TO REACH THIS AIM AS WE HAVE BEEN DOING FOR ALL OUR INVOLVED

SOCIAL AND SCIENTIFIC WORKS.

WE WOULD LIKE EMPHASIZE THE IMPORTANCE OF THE USE OF ENERGY SOURCES

EFFICIENTLY AGAIN HERE. WE ARE IN A NEW PERIOD WHERE WE SHOULD SURPASS

TRADITIONAL POWER GENERATING SYSTEMS, OWING TO CRITICAL ENERGETIC,

ENVIRONMENTAL AND SUSTAINABILITY SUBJECTS.

THE EXISTING ENERGY SITUATION OF THE WORLD HAS PRESENTED SOME DIFFICULTIES TO

BE SOLVED SUCH AS THE INTEGRATION OF CLEAN ENERGY GENERATION AND THE USAGE OF

EFFICIENT HIGH-POWER AND ENERGY STORAGE SYSTEMS. THE ENERGY INDUSTRY HAS TO

STRUGGLE AGAINST DIFFICULTIES BROUGHT BY THE INTEGRATION OF RENEWABLE ENERGY

SYSTEMS REGARDING WITH RELIABILITY AND STABILITY OF THE POWER GRID. IN ANY CASE,

IT BECOMES EXTREMELY SIGNIFICANT TO BENEFIT FROM ENERGY STORAGE SYSTEMS IN

ORDER TO STABILIZE AND IMPROVE THE EFFICIENCY OF THE POWER SYSTEMS USING

ULTIMATE GENERATION BATTERIES, ULTRA-CAPACITORS, HYDROGEN BASED SYSTEMS AND

XII

MECHANICAL SYSTEMS, AMONG OTHERS. RECENTLY, THE POWER ELECTRONICS SUGGESTS

EFFECTIVE WAY OUTS TO BE APPLIED TO THE NEW SPREAD ENERGY GRID IDEA.

A MICRO POWER GENERATION WITH DIESEL SYSTEMS AND RENEWABLE ENERGY IS

CONSIDERABLY DEPENDING ON INSTABILITIES DIRECTLY ATTRIBUTED TO THE

FLUCTUATIONS AND THE RANGE ABILITY OF THE RESOURCES. IT SEEMS EXTREMELY

SUGGESTED TO USE STORAGE UNITS IN ORDER TO CONFIRM THE ACCESSIBILITY OF ENERGY,

ENDURANCE AND EFFICIENCY OF THE SYSTEM. CONSISTENT WITH THE FORMULATION OF

THE PROBLEM OF ENERGY STORAGE, TIME OR REGULARITY PROPERTIES TIED TO THE

EXISTING TECHNOLOGIES SHOULD BE CONNECTED TO THE PROBLEM OF MULTI-OBJECTIVE

MANAGEMENT OF ENERGY. THE RELATED OFFERED PROPOSALS DEAL WITH STRATEGIES FOR

MANAGING ENERGY IN A POWER SYSTEM INCLUDING WIND, DIESEL ENGINE, FLYWHEEL,

BATTERY AND SUPER CAPACITOR AS HYBRIDIZATION NOMINEES.

IN CONCLUDING, I WISH YOU EVERY SUCCESS IN YOUR DELIBERATIONS AND A VERY

PLEASANT STAY IN ISTANBUL.

REGARDS,

AHMET SELIM DALKILIC

HONORARY CHAIRS

1. PROF. DR. SMAL YKSEK, (RECTOR OF YLDZ TECHNCAL UNVERSTY), TURKEY

2. PROF. DR. FARUK YT, (DEAN OF MECHANCAL ENGNEERNG FACULTY, YLDZ

TECHNCAL

UNVERSTY), TURKEY

XIII

ORGANISING COMMITTEE

1. PROF. DR. AYEGL AKDOAN EKER, YLDZ TECHNCAL UNVERSTY, TR

2. ASSOC. PROF. AHMET SELM DALKILI, YLDZ TECHNCAL UNVERSTY, TR (CONFERENCE

CHAR)

3. ASSOC. PROF. NUR BEKROLU, YLDZ TECHNCAL UNVERSTY, TR

4. ASSOC. PROF. ZDEN ARA, YLDZ TECHNCAL UNVERSTY, TR

5. ASSOC. PROF. ZEHRA YUMURTACI, YLDZ TECHNCAL UNVERSTY, TR (CONFERENCE CO-

CHAR)

6. ASSOC. PROF. DR. NHAN ETN DEMREL, YLDZ TECHNCAL UNVERSTY, TR

7. ASSST. PROF. DR. HLYA OBDAN, YLDZ TECHNCAL UNVERSTY, TR

8. ASSST. PROF. DR. NADER JAVAN, YLDZ TECHNCAL UNVERSTY, TR

9. RES. ASST. DR. ZGEN AIKGZ, YLDZ TECHNCAL UNVERSTY, TR

10. RES. ASST. OMD MAHIAN, FERDOWS UNVERSTY OF MASHHAD, IRAN

11. RES. ASST. AL CELEN , YLDZ TECHNCAL UNVERSTY, TR

12. RES. ASST. ALCAN EB, YLDZ TECHNCAL UNVERSTY, TR

13. RES. ASST. YASN KARAGZ, YLDZ TECHNCAL UNVERSTY, TR

14. RES. ASST. MEHMET SALH CELLEK, YLDZ TECHNCAL UNVERSTY, TR

XIV

SCIENTIFIC COMMITTEE

1.PROF. DR. ANTONIO CAMPO, THE UNIVERSITY OF TEXAS AT SAN ANTONIO, USA

2. PROF. DR. BALARAM KUNDU, JADAVPUR UNIVERSITY, INDIA

3. PROF. DR. DONGSHENG WEN, UNIVERSITY OF LEEDS, UNITED KINGDOM

4. PROF. DR. GODSON ASIRVATHAM LAZARUS, KARUNYA UNIVERSITY, INDIA

5. PROF. DR. ENRICO SCIUBBA, ROMA UNIVERSITY, ITALY

6. PROF. DR. EHSAN EBRAHIMNIA-BAJESTAN, GRADUATE UNIVERSITY OF ADVANCED

TECHNOLOGY, IRAN

7. PROF.DR. EIYADA ABU-NADA - KHALIFA UNIVERSITY, UNITED ARAB EMIRATES

8. PROF. DR. ERIC DIMLA, INSTITUT TEKNOLOGI BRUNEI, BRUNEI DARUSSALAM

9. PROF. DR. HAKAN F. ZTOP, FIRAT UNIVERSITY, TR

10. PROF. DR. BRAHIM ENOL, YILDIZ TECHNICAL UNIVERSITY, TR

11. PROF. DR. MEHMET KANOLU, GAZIANTEP UNIVERSITY, TR

12. PROF. DR. MOHAMED AWAD, MANSOURA UNIVERSITY, EGYPT

13. PROF. DR. NURI YCEL, GAZI UNIVERSITY, TR

14. PROF. DR. OCTAVIO GARCA VALLADARES, UNIVERSIDAD NACIONAL AUTONOMA DE

MEXICO, MEXICO

15. PROF. DR. SOMANCHI KRISHNA MURTHY, DEEMED UNIVERSITY, INDIA

XV

16. PROF. DR. TZVETELIN GEORGIEV, UNIVERSITY OF RUSE, BULGARIA

17. ASSOC. PROF. AHMET SELIM DALKILI, YILDIZ TECHNICAL UNIVERSITY, TR

18. ASSOC. PROF. NUR BEKIROLU, YILDIZ TECHNICAL UNIVERSITY, TR

19. ASSOC. PROF. ZDEN ARA, YILDIZ TECHNICAL UNIVERSITY, TR

20. ASSOC. PROF. ZEHRA YUMURTACI, YILDIZ TECHNICAL UNIVERSITY, TR

21. ASST.PROF. TOLGA TANER, AKSARAY UNIVERSITY, TR

22. ASST. PROF. HLYA OBDAN, YILDIZ TECHNICAL UNIVERSITY, TR

23. ASST. PROF. SIBEL ZORLU, YILDIZ TECHNICAL UNIVERSITY, TR

24. RES.ASSIST. YASIN KARAGZ, YILDIZ TECHNICAL UNIVERSITY, TR

CONFERENCE ON ADVANCES IN MECHANICAL ENGINEERING ISTANBUL 2016 ICAME2016 11-13 May 2016, Yildiz Technical University, Istanbul, Turkey

A NEW DESIGN FOR PANEL RADIATORS USING CFD

*smail EKMEKCIstanbul Commerce University

Engineering Faculty stanbul, Kkyal, Turkey

Emir AYDAR TUBITAK Marmara Research Center

Energy Institute Kocaeli, Gebze, Turkey

Keywords: EN442; Computational fluid dynamics; Panel radiator; Heat transfer * Corresponding author:smail EKMEKCI, Phone:+90 444 0 413 /3214 , Fax:+90 216 489 02 69

E-mail address:iekmekci@ticaet.edu.tr

ABSTRACT An experimental study was conducted in accordance with

EN442 in the standard test room in order to determine boundary conditions for computational study and verify numerical results. Tests were carried out in three different operating conditions. Turbulent natural convection coupled with thermal radiation in the test room and water flow inside the tested radiator were simulated by means of CFD together in order to compare with the experimental data obtained for this cavity at a Grashof number equal to 1.09x109. In carrying out numerical investigations, a three-dimensional, low-turbulence, two-parameter k model known as the low-Reynolds-number k turbulence model was used. Non-uniform temperature distribution on the front surface of tested panel radiator was observed. The difference between experimental and computational heat transfer rate are 1.70% in case of the excess temperatures of 50 C. Quite good results are obtained for the excess temperature of 50 C. The study shows that computational methods can be applicable in the design of new heater types. The aim of the study is the distribution of the fluid flow at each vertical duct inside panel homogeneously. High temperature gradients occur inside panel where fluid flows because of distinct values of mass flow rates at vertical ducts. It is found that the rate of heat transfer is increased by approximately 8% and weight is decreased by 17.22% using novel panel radiator compared to the rates obtained by tested panel radiator.

INTRODUCTION

Heat is transferred by the combination of conduction, convection and radiation from radiators. Many numerical and experimental studies about natural convection in an air-filled

cavity, in cavities with a thin fin or along a vertical, heated, flat plate with different Rayleigh numbers have been performed and reported with different attentions. In many of the analyses, interaction of surface radiation with natural convection is neglected.

Many researchers have tested various turbulence models for the calculations of natural convection heat transfer in a full scale room. Due to the nature of room airflow, there will always be regions (particularly near the walls) in which this number is quite small. In these regions, the viscous effects become significantly greater than any turbulent effects. Because the standard form of the k- model is valid only for high-Reynolds turbulent flow, difficulty arises. There are two ways in which the standard k- model is used for low-Reynolds flow. These methods are known as wall functions and low-Reynolds models. [4] have concluded that the low-Reynolds k-epsilon was mostaccurate but required high computing resource.

Three different turbulence models (k-epsilon,Wilcox k- model, Shear Stress Transport k- model) were assessed. They deduced that the standard Wilcox k- model more accurately predicted the velocity profile. [6] were interested in increasing efficiency of radiators. The purpose of the study, introducing outside air through the radiators themselves to increase efficiency and improve thermal comfort was tested in this study and compared to traditional arrangements by CFD simulations. [7] examined heat output of panel radiators by altering theemissivity of the wall behind. The total heat output of theradiator was 198 W with a high emissivity wall and 157 W witha low emissivity wall. This indicated that the shiny wall reducedthe heat output by 21%.

In this study, internal forced convection within radiator and buoyancy-induced flow during the test of a radiator in a test

1

room will be investigated. In our study, heat output of panel radiator will be found and simulation of air flow around panel radiator will be modeled by using computational methods. In this context, the three-dimensional Navier-Stokes equations, energy and transport equations will be numerically solved with natural convection effects and radiation heat transfer. For the radiation model, surface to surface (S2S) model based on the view factors will be employed. Numerical solutions will be performed by means of STAR-CCM+ software solving with the finite volume method of the flow and energy equations. The results obtained from computational methods will be compared with experimental results and results of characteristic equations derived in compliance with EN 442 part 2 standard. The standard thermal outputs of the panel radiator were calculated with respect to the least squares regression method mentioned in the standard. Panel-convector-convector-panel commonly used in the market was chosen for this study. Panel radiator whose dimensions are 600 mm (height) and 500 mm (length) will be investigated by using numerical methods. The aim of this study is that distribution of water in the vertical channels of panel radiator are not homogeneous. Thus, heat output of the panel radiator turns out to be less than it needs to be. If this problem can be solved, heat output of the panel radiator will be increased a lot. When this problem is tried to solve, more material will not be used. Solving nonhomogeneous distribution has not been studied in the literature yet.

EXPERIMENTAL SETUP AND FACILITY

Standard Type-22 PCCP 600mm high by 600mm length panel radiator were tested in the experiments. Tested radiator shown in Figure 1 contained top grilles and side panels. At the beginning of the test, panel radiator was attached to the core pipe with top-bottom same end (TBSE) connection specified by EN 442-2. Panel radiator was mounted 110 mm above the floor and 50 mm away from the wall described in EN 442-2. Tested radiator was connected to the circuit by using flexible connections. Flexible connections were insulated and thus all the heat loss can be assumed from the panel radiator.

Thermocouples were placed at the reference air temperature point and three additional points described in EN 442-2 to obtain the ambient air temperature readings at variouslocations during tests. Thermocouples were also placed at theinlet and outlet of the panel radiator in order to monitor desiredexcess temperature whether steady operating conditions exist ornot. Thermocouples were also placed at the internal surfaces ofthe walls excluding the wall behind the panel radiator.

Thermocouple cables were connected to terminal box shown in Figure.2 and terminal box were attached to a data acquisition system (DAQ) which was connected to a computer. Therefore, it was possible to monitor the temperature history of the system.

Figure.1: Placement of the panel radiator during a test procedure

The test chamber consists of a test room 4.0 m length x 4.0 m wide x 3.0 m high, which is constructed to the requirements contained in EN 442-2. The test chamber walls are cooled by a serpentine for water circulation. These pipes shown in Figure 3 completely cross five room walls in order to keep a room temperature of 20C. The only non-cooled wall is behind the panel radiator specified by EN 442-2. When steady state conditions are achieved the heat output of the panel radiator is determined from measurements of the water flow rate and inlet and outlet water temperature difference specified by EN 442-2 in this study. These temperatures were used to calculate the specific enthalpies as described in weighing method.

TEST PROCEDURE

The boiler heats water to a thermostatically-controlled temperature. The piping, usually made of copper, carries the heated water from the boiler to panel radiator. A pump circulates the water through the piping. To calibrate the setup the water heater was set to about 80C for the excess temperature of 50C and the system was waited for a while to achieve steady state conditions. The valve installed outside of the test room was then adjusted to get a temperature drop required. The steady state condition was achieved by monitoring both the temperature of reference air point 0.75m from the floor and desired excess temperature. Steady state operation was typically achieved in approximately three hours. The sample rate set to a thirty seconds interval for each test value. The first test was run for excess temperature of 50C, the second and the third ones were run for excess temperature of 60C and excess temperature of 30C, respectively. The test data was then collected from the software and compiled in Microsoft Excel in order to find the characteristic equation of the panel radiator. The difficulty of the experiment resulted

2

from the efforts to maintain the stability of measured values. In these measurements, the excess temperature was maintained within a 2.50C and the temperature of reference air point was maintained within a 0.50C when steady operating conditions existed. After accomplishment of test for the excess temperature of 50C, tests for the excess temperatures of 60C and 30C were performed, respectively. The water flow rate measured at the excess temperature of 50C was maintained in the remaining tests with the tolerance of 0.50 %. The average value of the test datas for each case are presented in Table 1.

CALCULATION OF EXPERIMENTAL HEAT OUTPUTS

The average values of experimental heat outputs of tested radiator can be determined from Equation 16 to be

exp, , , , , ,( )avg w avg pwi avg wi avg pwo avg wo avgm c T c T = (1)

The average values of experimental heat output calculated with respect to Equation (1) for all cases are given in Table 2.

Table.1: Mean experimental heat outputs of investigated radiator

The number of test points

Heat output of investigated radiator (W)

The excess temperature of 30C The excess temperature of 50C The excess temperature of 60C

413.23 821.59 1207.65

EN 442 heat outputs of tested radiator are presented also in Table.2.

Table.2. EN 442 heat outputs of tested radiator The number of test points Heat output of

investigated radiator (W) The excess temperature of 30C The excess temperature of 50C The excess temperature of 60C

415.41 878.37 1147.48

There is a small difference between the corrected experimental and EN 442 heat outputs of this panel radiator.

COMPUTATIONAL FLUID DYNAMICS CALCULATIONS OF PANEL RADIATORS

A three dimensional figure of the panel radiator whose dimensions were obtained from famous panel radiator manufacturer and test room specified by EN 442-2 were plotted appropriately by using CAD software. The three-dimensional view of panel radiator containing water volume is shown below. Turbulent typed air flow within a rectangular prism enclosure and water flow inside panel radiator will be simulated together. This study incorporates multi-region conjugate heat transfer, natural convection, forced convection and radiation heat

transfer. From Figure 4, it is clear that dark blue represents water volume, red represents solid panel radiator. To be able to model the natural convection, it was necessary to add a volume of air around the panel radiator. The three-dimensional view of panel radiator placed in a full-scale test room containing air volume is shown in Figure.3.

Figure.2: Perspective view of traditional panel radiator containing water volume

Figure.3: Perspective view of traditional panel radiator within a rectangular prism enclosure containing air

3

A three dimensional figure of the novel design panel radiator and test room specified by EN 442-2 were plotted appropriately by using CAD software. The three-dimensional view of the novel design panel radiator containing water volume is shown in Figure 6. Turbulent typed air flow within a rectangular prism enclosure and water flow inside panel radiator will be simulated together. This study incorporates multi-region conjugate heat transfer, natural convection, forced convection and radiation heat transfer.

Figure.4: Schematic representation of the problem and boundary conditions used for modeling air flow along panel radiator

To compare results of numerical modeling with experimental data the geometric dimensions and temperature conditions close to the conditions used in the experiment were defined. A three-dimensional panel radiator positioned inside a test room is shown in Figure 7.

Effects of thermal radiation are taken into account on the panel side of the radiator. Effects of thermal radiation are neglected on the fin side of the radiator. Panel surfaces have a mean surface temperature of approximately 70C and an emissivity of 0.92 at excess temperature of 50C. In case of other two excess temperatures panel surfaces are assumed to have an emissivity of 0.92 as well. The gravitational constant was chosen to act in the negative y-direction.

RESULTS AND DISCUSSIONS

CFD RESULTS FOR 50C EXCESS TEMPERATURE

The velocity contour plot through vertical channels and the temperature contour plot on the panel radiator are shown in Figure 13 and Figure 14, respectively.

From the contour plot in Figure.5, it can be seen that the velocity inside the panel radiator is relatively nonuniform due to the pressure loss in the radiator. When the water flows in a

Figure.5: Velocity contour plot inside panel radiator for first case

Figure.6: Surface temperature contour distribution on the panel radiator for first case

noncircular pipe, most part of the flow moves immediately towards the outlet, and therefore in the bottom right corner of the radiator, colder area arises.

The surface temperature contour plot illustrates that nonhomogeneous temperature distribution on the panel radiator exists due to nonhomogeneous water flow inside vertical channels. There is very little movement (average velocity of approximately 0.0m/s) in the last three vertical channels compared to the first five. A streamlines displayer to show the flow path of the air particles inside the test room is shown in

4

Figure.6. Figure.6 shows the result with radiation and natural convection included.

In Figure.8, it can be seen that the mass flow rate is highest

Figure.7: Streamline velocity contour distribution inside the test room

Figure.8: Mass flow rate distribution through all vertical ducts at the radiator inlet and decrease gradually to about zero in the flow direction. As water flows through the horizontal non-circular pipe, the mass flow rate distribution is nonhomogeneous due to the pressure drop. In the region from the pipe inlet, the mass flow rate is greater than exact flow. The region beyond the seventh duct the mass flow rate is smaller than exact flow.

The results obtained numerically in the current study are compared with the experimental results. Comparison of results are presented in Table.1.

CFD RESULTS FOR NOVEL DESIGN PANEL RADIATOR

Figure.9: Velocity contour plot inside novel design panel radiator for excess temperature of 50C

Figure.10: Surface temperature contour distribution on the novel design panel radiator The velocity contour plot through vertical channels on the novel design panel radiator and the temperature contour plot on the novel design panel radiator are shown in Figure.9 and Figure.10. From the contour plot in Figure.9, it can be seen that the velocity inside the panel radiator is about uniform. When the water flows through a noncircular pipe, it enters each vertical channel almost equally.

5

The surface temperature contour plot illustrates that homogeneous temperature distribution on the panel radiator

Table.1: Mean test values during tests

Mean test values The excess temperature

of 30C

The excess temperature

of 50C

The excess temperature of

60C Temperature at 0.05 m from the floor

Temperature at 0.75 m from the floor

Temperature at 1.50 m from the floor

Temperature at 0.05 m from the ceiling

Floor temperature

Ceiling temperature

Right wall temperature

Opposite wall temperature

Left wall temperature

Water inlet temperature

Water outlet temperature

Excess temperature

19.4

20.0

20.5

21.6

18.5

19.5

19.0

19.0

19.5

52.3

46.5

29.4

18.0

19.5

20.1

22.4

16.5

18.5

17.4

17.2

19.0

75.5

63.6

50.1

18.5

19.9

20.8

23.4

16.5

18.8

17.4

17.5

19.4

88.0

70.6

59.4

Table.2: Comparison of computational and experimental results for excess temperature of 50C Results Computational Experimental % Difference

Air temperature at 0.05 m from the floor

Air temperature at 0.75 m from the floor

Air temperature at 1.50 m from the floor

Air temperature at 2.95 m from the floor

Outlet water temperature (C)

Excess temperature (C)

Convection heat transfer (W)

Radiation heat transfer (W)

Total amount of heat transfer rate (W)

Heat transfer rate of the panel portion

Heat transfer rate of the convector portion

17.7

19.99

21.5

24.55

62.4

48.96

759.91

133.37

893.28

376.08

517.58

18

19.5

20.1

22.4

63.6

50.1

-

-

878.37

-

-

1.67

2.51

6.96

9.6

1.89

2.27

-

-

1.7

-

-

Table.3: Comparison of results for excess temperature of 50C

Results Traditional panel

radiator

Novel panel

radiator % Difference

Air temperature at 0.05 m from the floor

Air temperature at 0.75 m from the floor

17.75

19.94

17.75

20.28

1.67

2.51

6

Air temperature at 1.50 m from the floor

Air temperature at 2.95 m from the floor

Outlet water temperature (C)

Excess temperature (C)

Convection heat transfer (W)

Radiation heat transfer (W)

Total heat transfer (W)

Heat transfer from finned surfaces

Heat transfer from panel surfaces

Surface area of finned surfaces (m2)

Surface area of panel surfaces (m2)

Total mass (gr)

21.73

25.64

62.4

48.96

760.34

133.31

893.65

517.58

376.08

3.39

2.49

18536.54

22.02

26.02

61.36

48.15

802.40

161.29

963.69

564.36

399.34

3.69

1.99

15336.66

6.96

9.6

1.89

2.27

5.53

20.99

7.88

9.04

6.18

8.85

20.08

17.26

exists due to a homogeneous water flow inside vertical channels.

Mass flow rate distribution through 20 vertical ducts is given below.

Figure.11: Mass flow rate distribution through all vertical ducts

In Figure 11, it can be observed that mass flow rate distribution is almost the same relative to exact flow at the all vertical ducts. Homogenous mass flow rate distribution was formed thanks to new configuration. The results obtained numerically in the current study are compared with the traditional panel radiator results. Comparison of results are presented in Table.3.

It can be seen that, compared to an unmodified panel radiator, the total heat output from the radiator was increased by 7.88% by the use of a black saw-tooth surface type. This is due to, water passes through all vertical ducts uniformly. Mass of the

panel radiator was also decreased by 17.26%. Novel design panel radiator can be justified economically, and thus it should offer a good compromise between heat transfer performance and the panel radiator size.

CONCLUSIONS

A study of combined fluid flow and heat transfer including forced and natural convection, thermal radiation and conduction through solidfluid interfaces has been performed. The contact interface type is used to join together to permit conjugate heat transfer between a fluid and solid regions. The aim of this study is to enhance thermal output and reduce the cost of the panel radiator by the help of a commercial CFD code of STAR-CCM+. Before the structural changes, CFD solutions need experimental validation. Thus, EN 442 part 2 standard will be used in the determination of heat output of panel radiator. The results obtained from computational methods will be compared with experimental results and results of characteristic equations derived in accordance to EN 442 part 2 standard. In this study, the low-Reynolds number k-epsilon model is employed to study turbulent buoyant flow to overcome the shortcoming of the standard k-epsilon model. The low Reynolds extension of the k-epsilon model results were in good agreement with experimental results.

From the steady state analysis performed for the tested radiator, relatively closer results are obtained for the panel radiator model. The numerical scheme yields good agreement with experimental results when the experimentally measured mass flow rate of water, wall and water inlet temperatures are implemented as boundary conditions in the program. The difference between experimental and computational heat transfer rates is 1.70% for the panel radiator model investigated

7

in this study in case of the excess temperatures of 50 C. Quite good results are obtained for the excess temperature of 50 C.

Non-uniform temperature distribution on the front surface

of tested radiators was observed in the experimental study. Similar temperature distributions were also seen at the end of the computational study. It is considered that the uniform cross sections of vertical channels, top distribution duct and bottom collecting duct in the radiator should be reassessed in the design of new radiators. Therefore, novel panel radiator was created in order to distribute mass flow rate uniformly. The difference between experimental and computational heat output in percentage fluctuate between 1.7 and 10.03 for the panel radiator model investigated in this study. The computational heat output at the excess temperature of 50C for the novel panel radiator model is 7.88% above the computational value of the panel radiator model investigated in this study. The mass of the panel radiator was decreased by 17.22 g by the use of a novel panel type.

REFERENCES

[1] Peach, J.: Radiators and other convectors, J.I.H.V.E.

(39) (1972) 239-253. [2] Beck, S. M. B.; Grinsted S. C.; Blakey S. G.; Worden

K.: A novel design for panel radiators, Applied Thermal Engineering 24 (2004) 1291-1300

[3] Lu, W.; Howarth A. T.; Jeary A. P.: Prediction of airflow and temperature field in a room with convective heat source, Building and Environment 32 (6) (1997) 541-550

[4] Weathers J.W.; Spitler J.D.: A comparative study of room airflow: numerical prediction using computational fluid Dynamics and full-scale experimental measurements, ASHRAE Transactions 99 (1993) 144-157.

[5] Rundle, C.A.; Lightstone, M.F.: Validation of turbulent natural convection in a square cavity for application of CFD modeling to heat transfer and fluid flow in atria geometries; 2nd Canadian Solar Buildings Conference, Calgary, Canada, June (2007) 1014;

[6] Myhren, J.A.; Holmberg, S.: Design considerations with ventilation-radiators: Comparisons to traditional two-panel radiators Energy and Buildings 41 (2009) 92100

[7] Beck, S. B. M.; Blakey, S. G.; Chung M. C.: The effect of wall emissivity on radiator heat output, Building Services Engineering Research & Technology 12 (3) (2001) 185-194

[8] Gritzki, R.; Perschk, A.; Rsler, M.; Richter, W.: 2007. Modelling of Heating Systems and Radiator in Combined Simulations. Proceedinngs of Clima 2007 WellBeing Indoors, Helsinki, Finland, June, (2007) 10-14

[9] Chang Y.P.; Tsai R.: Natural Convection in a Square Enclosure with a Cold Surface, International Communications Heat and Mass Transfer. 24 (7) (1997) 1019-1027

[10] Tian Y.S.; Karayiannis T.G.: Low turbulence natural convection in an air filled square cavity Part I: the thermal and

fluid flow fields, International Journal of Heat and Mass Transfer 43 (2000) 849-866. 143

[11] Zitzmann, Y.; Cook, M.; Pfrommer, P.; Rees, S.; Marjanovic, L.: Simulation of steady state natural convection using CFD, Ninth International IBPSA Conference, Montreal, Canada, August, (2005) 15-18

[12] Ben-Nakhi, A.; Chamkha, A.J.: Conjugate natural convection in a square enclosure with inclined thin fin of arbitrary length International Journal of Thermal Sciences 46 (2007) 467478

[13] Fomichev A. I.: Comparison of the results of modeling convective heat transfer in turbulent flows with experimental data, Journal of Engineering Physics and Thermophysics 83 (2010) 3849-3860.

[14] Fedorov A. G.; Viskanta R.: Turbulent natural convection heat transfer in an asymmetrically heated, vertical parallel-plate channel, Int. J. Heat Mass Transfer 40 (1997) 3849-3860.

[15] Incropera, F. P. and DeWitt, D. P.: Fundamentals of Heat and Mass Transfer, 4th edition, Wiley, New York, USA, (1996)

[16] Godaux, R. and Gebhart, B.: An experimental study of the transition of natural convection flow adjacent to a vertical surface Int. J. Heat and Mass Transfer, (17) (1974) 93-107

[17] Launder, B. E. and Spalding, D. B.: The numerical computation of turbulent flows, Computer Method in Applied Mechanics and Engineering 3, (1974) 269-89.

[18] Rodi, W.: Turbulence models and their application in hydraulics, a state of the art review, Int. Ass. For Hydraulic Research, Delft, The Netherlands (1980).

[19] Fraikin M. P.; Portier J. J. and Fraikin C. J.: Application of a k- turbulence model to an enclosed buoyancy driven recirculating flow, Chem. Eng. Commun. (13) (1982) 289-314 144

[20] Ince N. Z. and Launder B. E.: Computation of turbulent natural convection in closed rectangular cavities. 2nd U.K. Natn. Conf. on Heat Transfer, Glasgow (1988) 1389-1400.

[21] EN 442-2.: Radiators and convectors-Part 2: Test methods and rating, European Standard (1997)

[22] STAR-CCM+. User manual, version 8.06.006. CD Adapco, 2014.Put references here.

8

CONFERENCE ON ADVANCES IN MECHANICAL ENGINEERING ISTANBUL 2016 ICAME2016 11-13 May 2016, Yildiz Technical University, Istanbul, Turkey

VASCULAR STRUCTURES FOR SMART FEATURES: SELF-COOLING AND SELF-HEALING

Erdal etkin* Izmir Institute of Technology, Department of Mechanical

Engineering Urla, Izmir, Turkey

Keywords: Constructal; Vascular; Smart features; Self-cooling; Self-healing * Corresponding author: Erdal etkin, Phone: +90(232)750-6713, Fax: +90(232)750-6701

E-mail address: erdalcetkin@iyte.edu.tr

ABSTRACT Here we show how smart features of self-cooling and self-

healing can be gained to mechanical systems with embedded vascular structures. Vascular structures mimic the circulatory system of animals. Similar to blood distribution from heart to the animal body, vascular channels provide the distribution of coolant and/or healing agent from a point to the entire body of a mechanic system. Thus the mechanic system becomes capable of cooling itself under unpredictable heat attacks and capable of healing itself as cracks occur due to applied mechanical loads. These smart features are necessary for advanced devices, equipment and vehicles. The essential design parameter is vascularization in order to provide smart features. There are distinct configurations for vascularization such as radial, tree-shaped, grid and hybrids of these designs. In addition, several theories are available for the shape optimization of vascular structures such as fractal theory and constructal theory. Unlike fractal theory, constructal theory does not include constraints based on generic algorithms and dictated assumptions. Therefore, constructal theory approach is discussed in this paper. This paper shows how smart features can be gained to a mechanical system while its weight decreases and its mechanical strength increases simultaneously.

INTRODUCTION Uncovering the design with the smallest resistance to the

flow of heat, fluid and stresses is the fundamental of technological improvement. The reason of this is that the flow of heat, fluid and stresses are functions of the design. Using higher-conductivity material increases the heat transfer rate from a heat exchanger but the challenge is finding the best shape for minimizing thermal resistances by using a given

material with fixed volume. The same challenge is also valid for minimization of resistances to the flow of fluids and stresses. Uncovering the best performing design ensures the usage of scarce materials and energy wisely, i.e. where they are necessary.

There are two well-known theories in the literature for design optimization: constructal theory [1-4] and fractal theory [5-6]. Fractal theory discusses that the design should repeat a pattern that displays at every scale, i.e. the shape of a tree should be the same for every regions of the tree: from trunk to the branches [5-6]. However, the designs in nature do not confirm this theory. In addition, Bejan and Lorente [2] showed that the fractal designs do not provide the smallest resistance to the fluid flow in tree-shaped architectures but constructal designs do.

Constructal theory was stated by Adrian Bejan in 1996 as For a finite-size system to persist in time (to live), it must evolve in such a way that it provides easier access to the imposed currents that flow through it [1]. This theory actually uncovers that there is no optimum design but best performing designs for a known time, constraints and conditions. As these time, constraints and conditions change, the design should also be morphed in order to survive. For example, some bacteria colonies such as living in lassen volcanic national park (California, USA) are capable of living in highly acidic regions. Even though these bacteria live in very harsh conditions (in terms of pH), they cannot be called the optimum or best bacteria kinds because they have evolved to live in these conditions. In technology, this trend of shape change in time (evolution) is also necessary and valid. For example, Walkman was revolutionary because of gaining mobility to music players. However, mobile music players have evolved from Walkman to

9

mp3 players and then to the applications in smart phones. The brand of Walkman has forgotten because it have not evolved as fast as technology does. There are many similar examples in biology, geophysics, physics, chemistry and engineering. This shows that constructal theory is a unifying theory of animate and inanimate as discussed in the literature [7-8]. Constructal theory has been used in distinct fields such as biology, chemistry, physics, geophysics and engineering in order to show how design affects the performance in lungs, bacteria colonies, river-deltas, Eiffel tower, lightning bolts, snow flakes and so on [1-4, 7-8].

In summary, constructal theory unifies and connects distinct fields, and it is valid for animate and inanimate. The best performing design for given conditions and constraints is the constructal design, and this constructal design changes as conditions and constraints change, i.e. the design is dynamic. Furthermore, the design is not restricted by generic algorithms and dictated design assumptions in constructal theory, i.e. the design is morphed freely in order to minimize resistances.

RESULTS AND DISCUSSION Self-healing and self-cooling applications in engineered

systems are biologically inspired. Similar to distribution of blood in the human body for keeping its temperature uniform and providing healing when a cut occurs on the body, distributing coolant and/or healing agent to the entire volume of a mechanical system provides self-cooling and/or self-healing capability to it. There are two main methods for self-healing: vascularization and microcapsules. White et al. showed that a damaged structure can be healed with embedded microcapsules which are filled with healing agents [9]. As cracks damages the microcapsules, microcapsules crack and the healing agent inside fills the gaps and polymerizes. Therefore, this healing method can be used on time for the lifetime of the mechanical system. In addition, literature shows that the mechanical strength of a structure drops after healing occurs [10-11]. Moreover, literature also shows that after the structure is damaged the applied mechanical force is unloaded for structure to be healed during experiments [12-13]. In addition, literature shows that the conductivity of a self-healing structure can be restored [14-15].

Unlike embedding microcapsules filled with healing agents, embedding a vascular structure in which healing agent flows in engineered structure enables the structure of healing countless time [16-18]. This embedded structure is similar to the blood veins in circulatory system of warm blooded animals. There are different kinds of vascular architectures in the literature such as: radial, grid, hybrid and tree-shaped designs. Each architecture has its positives and negatives. Radial and tree-shaped designs provide the smallest pressure drop in comparison with grid and hybrid structures [19-22]. However, grid and hybrid structures bathe the entire volume more uniformly in comparison with radial and tree-shaped designs [19-22]. In self-healing and self-cooling, it is essential to bathe the entire volume with coolant and/or healing agent due to random and unpredictable

characteristics of heating and mechanical loads. The pressure drop of hybrid of grid and tree-shaped designs is smaller than grid designs and greater than tree-shaped architectures. In addition, this hybrid architecture bathes the entire volume almost as good as grid designs [22]. Therefore, hybrid of grid and tree-shaped designs became the best option for smart features.

Literature also shows that the vascularization gains self-cooling capability to a structure [16-25]. Similar to healing agent flow inside the vascular channels, a coolant flows through the embedded vascular channels. The cooling performance of the vascularized structure is affected by the volume fraction, the complexity of the design, the pressure difference which governs the flow and the flow direction [19-22]. For a given set of conditions (such as boundary conditions) and constraints (such as volume fraction), there is an optimal design which provides the smallest peak temperature. This optimal design should be morphed to the new optimal design as conditions and constraints change. This dynamic behavior of design is in accord with constructal theory. Therefore, the optimal design for a given set of conditions and constraints can be called the constructal design. As time passes, the structure should be morphed into the next constructal design if not it cannot survive. This trend is valid for animate and inanimate (natural or engineered).

Furthermore, the cooling requirements can be deterministic and random. The deterministic cooling requirements are due to heat sources which are known and steady, and random ones are unsteady and diverse. A structure is protected from random and deterministic heat sources via embedded vascular cooling channels [20]. Random cooling requirements are responsible of damaging the structure which is designed to work in steady state due to their unpredictable nature.

In addition of gaining smart features to a structure, vascularization provides mechanical strength with light weight which are essential for advanced vehicles [19-22, 26-27]. The strength of a structure decreases due to removal of the material in order to create vascular channels. However, if the material volume is fixed, the removed material is placed outside of the structure [19, 28]. It is also known from the strength of materials that the centerline of a structure is not stressed under bending. Therefore, removing the material from center and placing it around the vascular channels increase mechanical strength of the structure, i.e. the material is put where it is loaded the most. Therefore, the strength of the structure increases with vascularization. Furthermore, if the structure is heated then the effect of thermal stresses cannot be neglected. Cetkin et al. shows when the effect of thermal stresses can and cannot be neglected [28]. Coolant flow in the vascular channels decreases the peak temperature and creates a more uniform temperature distribution in the solid domain; so, thermal stresses decrease greatly. Therefore, self-cooling structures have greater mechanical strength than non-vascularized structures under great heat fluxes.

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Similar to how advanced capabilities of self-healing and self-cooling require vascularization in order to bathe the entire volume with coolant fluid and/or healing agent, vascularization is also essential in order to decrease the resistances of the distribution of energy, goods and water [1-4, 29]. A factory distributes all its products to the cities located around the world and collects raw materials around the world similar to distribution and collection of coolant and/or healing agent in advanced materials. These distribution and collection kinds of flows are examples of flows from a point to an area (or volume). Vascularized structures with uniform and non-uniform heating

A structure can be bathed by coolant and/or healing agent with embedded vascular channels while its mechanical strength increases and its weight decreases. Discussion of some vascular channel configurations with uniform and non-uniform heating is required in order to uncover how the coolant and/or healing agent is distributed throughout the structure with random (non-uniform heating) and prescribed (uniform heating) boundary conditions. The objective is to find the design with the best cooling performance (i.e. uncovering the design which bathes the entire volume with coolant and/or healing agent).

Here we show that the mechanical strength and thermal performance of a heated and mechanically loaded circular plate can be increased with embedded radial and tree-shaped vascular structures in it. The diameter and thickness of the circular plate are D and H, and their ratio is D/H = 10 which is fixed, Fig. 1a [19]. The solid volume is fixed, so is the volume of the vascular channel network. The plate is subjected to uniformly distributed force and uniform heat flux, both acting from below, Fig. 1a.

Figure 1. (a) Radial channel configuration embedded in the circular plate. (b) The effect of the number of cooling ducts on the dimensionless peak temperature and the dimensionless peak stress, Ref. [19].

The dimensionless governing equations (the conservation

of the mass, the conservation of the momentum for the fluid domain, the energy equations for fluid and solid domains, the generalized Hookes law and the conservation of momentum

equations for solid domain) were solved in a finite element software [30]. Mesh test was also performed to confirm mesh independency of the results.

The heat flux and the mechanical load are applied on the bottom surface of the plate as shown in Fig. 1a. The pressure difference between inlet and outlet is non-dimensionalized as Bejan number [31, 32].

)DP(PP~2

refinmax

= (1)

where and are dynamic viscosity and thermal diffusivity of the fluid. The value of represents the dimensionless overall pressure difference between the coolant inlet and outlet. The flow is laminar in all the channel configurations, Re < 2000.

The peak temperature and the peak stress is affected by the design. Therefore, the design corresponding the smallest resistance to the flow of heat, fluid and stress can be uncovered by freely morphing the design. Figure 1b shows the relation between the temperature, stress and number of ducts when is 107 and 108. The maximum stress decreases when the number of the cooling channels increases from 6 to 8, and it increases when the number of the cooling ducts increases from 8 to 32. The reason of this behavior is that the maximum stress increases in the vicinity of the junctions of the cooling ducts. Even though the peak stress is the minimum when the number of the channels is 8, neighboring designs (6 cooling channels when = 107 and 12 cooling channels when = 108) offer minimum peak temperatures. In summary, when the pressure drop is prescribed, it is possible to identify one design (or a group of designs) that provides the minimum peak stress and peak temperature, or vice versa. However, there is no optimal design for all the constraints and conditions.

Next consider a square plate with length L and thickness H = 0.1L with embedded vascular channels, Fig. 2a [22]. The plate is subjected to a uniformly distributed load and uniform heat flux both acting from below. The volume of the solid and the fluid are fixed. Lg is the length scale of the square area in which the grid cooling channels are embedded as shown in Fig. 2a.

Figure 2. (a) Grid structure connected to the perimeter with radial channels, i.e. hybrid configuration of grids and trees of a square slab. (b) Minimum peak temperatures relative to their peak stresses as Lg/L varies, Ref. [22].

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The grid channels are connected to the periphery with radial channels. Coolant enters or exits from the center of the grid, and it is driven by the pressure difference maintained between the inlet and outlet boundaries. The results were obtained by solving the governing equations numerically.

Figure 2b shows that the minimum peak temperatures plotted against the peak stresses as Lg/L varies. The effect of the flow direction on the peak temperature and stress is weak. Tpeak and decreases when Lg/L < 0.25, and the peak temperature increases as Lg/L increases even though the peak stress decreases and increases. The peak stress is the minimum when the design is a hybrid of grid and trees. However, the peak temperature is the minimum with radial channels.

Consider that the heating is concentrated in a small region on the vascularized solid domain. The area of the heated spot is 1/16 of the square area of length scale Lg, Fig. 2 [22]. The total heating rate of the concentrated heat generation is fixed, i.e. volumetric heating rate increases as the heat generating region size decreases in order to conform fixed heating rate.

Figure 3a shows how the peak temperature changes as Lg/L increases. When the concentrated heating is located in the center of the slab, Tpeak decreases as Lg/L. When the concentrated heating is located in the corner of the grid, Tpeak increases as Lg/L increases. Tpeak is the lowest when Lg/L = 0.25 with the concentrated heating is in the corner, and when Lg/L = 0.625 with the concentrated heating is in the center. In addition, when Lg/L = 0.375 the peak temperature becomes almost as low as the lowest peak temperature obtained when the concentrated heating is located in the center or in the corner. Figure 3b shows the temperature distribution in the mid-plane of square domain when the heat generation is concentrated in the center of the slab and in the corner of the grid for Lg/L = 0.25 and 0.5. The effect of flow direction on the temperature distribution is also shown in Fig. 3b.

(b)

(a)

Figure 3. (a) Peak temperature relative to Lg/L when the flow direction and the concentrated heat generation location change. (b) The temperature distribution in the mid-plane of the slab,Ref. [22].

Consider a square plate of length scale L, and thickness of H = 0.1L as shown in Fig. 4 [20]. A vascular channel network is embedded in the plate in order to keep it under an allowable temperature ceiling while the plate is heated with a concentrated and moving heat flux. The length scale of the square footprint of the heating spot is 0.1L and it moves with the constant speed of W from one edge of the plate to another. Four possible beam paths are discussed as shown in Fig. 4. The volume of the solid is fixed, so is the volume of the fluid. Coolant enters or exits from the center of the slab while the pressure difference between the inlet and exit boundaries is constant. The flow is incompressible with constant properties, and the dimensionless governing equations are time dependent, the dimensionless equations can be found in Ref. [20].

Figure 4. The average peak temperatures of four competing designs with vascular channels and the peak temperature of solid plate (without vascular channels), Ref. [20].

Figure 4 shows the average peak temperature of a solid structure (without embedded vascular channels) and the average peak temperature in four competing designs with embedded vascular channel configurations. The error bars indicate the maximum and minimum peak temperatures when the dimensionless time is greater than 0.1, i.e. after the entire concentrated heat flux enters the plate surface. Figure 4 also shows that a plate heated by a moving beam with an unpredictable path can be cooled by embedding vascular cooling channels in the plate. The effect of changing from no cooling to vascular cooling is dramatic with random cooling requirements similar to with prescribed cooling requirements.

Next, consider the plate with uniform heating load applied on its surface has embedded channels configured as radial, tree-shaped and their hybrid, Ref [33]. Figure 5 shows how the temperature distribution changes as the design and pressure drop (the difference between the inlet and outlet pressures) are altered. The resistance to the fluid flow is smaller in tree-shaped designs in comparison with the radial designs (for instance mass flow rate is 9 to 19% greater for the same pressure drop and volume fraction with tree-shaped design in comparison to the radial design Ref [33]). However, Figure 5 also shows that the thermal resistances in tree-shaped designs are greater than the radial designs, therefore, the peak temperature value is greater in tree-shaped designs when the pressure drop increases, for

12

example the comparison of radial and tree-shaped designs with 290 Pa pressure drop value. Overall, the tree-shaped and radial designs promise to minimum resistances to the fluid flow and heat flow, respectively. The novel idea is to combining these two in one design, i.e. the hybrid design as shown in Fig. 5. Hybrid design performs almost as good as radial design and tree-shaped designs in terms of resistances to the heat and fluid flow. Both resistances are slightly greater (several per cent) than the corresponding minimum value of the best performing design.

Figure 5. Temperature distribution of radial design for (a) 30 Pa, (b) 290 Pa, tree-shaped design for (c) 30 Pa, (d) 290 Pa, and hybrid design for (e) 30 Pa, (f) 290 Pa, Ref. [33].

The result of Figure 5 uncovers that in some cases the conductive resistances are in great importance. In order to increase the overall thermal conductance of a solid material high-conductivity inserts can be placed. Figure 6 shows how the locations of this high-conductivity inserts affect the thermal conductance by minimizing the peak temperature for fixed boundary conditions, Ref. [34].

Figure 6. The effect of the location of the second level of high-conductivity inserts on maximum temperature when the location of the first level of insert is fixed, Ref. [34].

Figure 6 shows that high-conductivity inserts should be embedded non-equidistantly in order to minimize thermal

resistances. However, Figure 6 shows that there are family of best options, i.e. similar performing designs. For instance, if the first insert is fixed at 0.2 position, then second insert should be located at 0.8. However, the same performance can be achieved with placing inserts at locations 0.4 and 0.75.

CONCLUSION

This paper shows how the smart features of self-cooling and self-healing can be gained to an engineered structure. Vascularization is essential in order to bathe the entire volume of the system with coolant and/or healing agent. The best performing vascular channel networks for circular and rectangular plates with uniform and non-uniform loads are documented. Novel hybrid designs of radial and tree-shaped designs are documented. In addition, the increase in the overall thermal performance for self-cooling with embedded high-conductivity materials is uncovered.

This paper also shows that the hybrid designs combine the best features of each design that they were constructed from. Furthermore, this paper uncovers that there is no best design but family of best designs. This idea is in accord with the constructal law and the tendency in the nature. For instance, even the tree-shaped designs minimizes the resistances to the fluid flow for point to area (or volume) flows which explains why the tree roots and branches are similar to the animal lungs, none of the trees and animal lungs are identical and they vary from plant to plant and animal to animal (even for the same species).

ACKNOWLEDGMENTS This work was supported by the Scientific and

Technological Research Council of Turkey (TUBITAK) under Grant No. 114M592.

NOMENCLATURE

d diameter of cooling channels, m H plate thickness, m k thermal conductivity, W m1 K1 L rectangular plate length scale, m Lg length scale of the grid region, m P pressure, N m2 Pst mechanical load, N m2 Pin inlet pressure, N m2 R circular plate radius, m q'' imposed heat flux, W m2 T temperature, K x horizontal direction, m Greek symbols thermal expansion coefficient, K1 dynamic viscosity, kg m1 s1 normal stress, N m2 Subscripts in inlet st mechanical

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max maximum ref reference Superscript ~ dimensionless

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[16] Lee, J., Kim, Y., Lorente, S. and Bejan A., Constructaldesign of a comb-like channel network for self-healingand self-cooling, Int. J. Heat Mass Transfer, 2013, 66,pp. 898905.

[17] Lorente, S. and Bejan, A., Vascularized smartmaterials: designed porous media for self-healing andself-cooling, J. Porous Media, 2009, 12(1), pp. 118.

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http://www.comsol.com/

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CONFERENCE ON ADVANCES IN MECHANICAL ENGINEERING ISTANBUL 2016 ICAME2016 10-13 May 2016, Yildiz Technical University, Istanbul, Turkey

PERFORMANCE OF HUMIDIFICATIONDEHUMIDIFICATION DESALINATION UNIT USING A DESICCANT WHEEL

El-Sayed Abd El-Azim El-Agouz Tanta University

Tanta, Egypt

Keywords: Solar desalination; Humidificationdehumidification; Desiccant wheel; Theoretical * Corresponding author: +20506810503; +201093243110; Fax: +2040 3315861

E-mail address: elagouz2011@yahoo.com, el-sayed.abdelazim@f-eng.tanta.edu.eg

ABSTRACT In the present work, theoretical performance of

humidificationdehumidification desalination unit using a desiccant wheel or heat exchanger in order to increase the thermal performance of the system is investigated. The sensitivity of each parameter including the inlet water and air flow rates ratio, inlet hot water temperature, inlet cooling water temperature, inlet air humidity and regeneration temperature on the fresh water production, Gain output ratio, specific thermal energy, and recovery ratio is studied. Also, the optimum condition of different parameters of desalination units is presented. The results show that, the desalination unit with desiccant wheel is more efficient than the base humidificationdehumidification or use a heat exchanger to provide distillate water. The inlet cooling water temperature and inlet air humidity has a tiny effect on Gain output ratio and specific thermal energy while inlet water and air flow rates ratio, inlet hot water temperature, and regeneration temperature has measurable effect on Gain output ratio and specific thermal energy. The maximum fresh water production is about 0.4603 kgw /kga, Gain output ratio is about 4.515, recovery ratio is about 46.03% and minimum specific thermal energy is about 0.149 kWh/kg.

INTRODUCTION Humidification-dehumidification (HDH) desalination unit

was developed while trying to solve the major problem of solar stills that is the energy loss in the form of latent heat of condensation. Therefore, the latent heat of condensation is used for preheating the saline feed water. In this process, air is heated and humidified by the hot water received from a solar collector. The simplicity, flexibility in capacity, moderate installation, operating costs, and possibility of using low-grade thermal energy are several advantages of HDH. When air passes through the desiccant wheel, it becomes dryer and

warmer. Therefore, the desiccant wheel behavior improves the fresh water production from the HDH and it can produce water from the outlet humid air of the desiccant wheel by adding HDH.

In literature, various designs of solar HDH with different shapes, dimensions and adding air and water solar collectors were theoretically and experimentally studied. Nafey et al. [1] presented a numerical investigation of the HDH desalination process in which the air was heated using a flat-plate solar air heater and water was heated using a solar concentrator. The results showed that the productivity of the unit was strongly influenced by the cooling water flow rate, airflow rate, and total solar energy incident through the day. Zhani et al. [2] presented the modeling and the experimental validation of HDH solar desalination unit using air and water solar collectors. The proposed mathematical models can be used to size and test the be