Improving Engine Performance and Efficiency by Minimisation of Knock Probability Project nº...

Improving Engine Performance and Efficiency by Minimisation of Knock Probability

Project nº ENK6-CT-2003-00643

Edgar C. FernandesIlídio GuerreiroNuno RoloLaboratory of Thermofluids, Combustion and Environmental SystemsInstituto Superior Técnico -Technical University of Lisbon, Portugalhttp://in3.dem.ist.utl.pt

MinKnock

WP2 : Advanced experimental analysis of auto ignitionTask 2.1 Fundamental Experiments

Stuttgart, 2nd of December of 2005

• Main Objective

• Experimental Setup• Combustion chamber• Techniques• Working conditions

• OutputResultsSoftware development(Matlab-interactive soft)Deliverables, ReportsAcademic formation

-MSc-Final year project-

GraduationTwo planned papers

Presentation Outline

Flow topology

nUnWSd

)(

)(

nS

UUnnK

d

KLSS ald

wall

Flame boundary

n

UW

Sd

burned

unburned ?

Flow topology characterization

WALL

Flame

WALL

Flame

Experimental Setup

TechniquesAcquisition area

Perturbation object

IgnitionTop wall

Acquisition area

Perturbation object

IgnitionTop wall

Perturbation object

IgnitionTop wall

Kodak CCD High speed camera-512 x 512Spectra Physics Ar-Ion Laser-5WTypical data: 1000fps ; 1/2000-1/5000sSpatial resolution for flame front displacement: 0.5mmSpatial resolution for velocity vectors: 21vectors/45mm=1vector/2mm

Lean & Rich flames

Premixed propane-air =0.7 ; 1.3

Symmetric flame

Non-Symmetric flame

Pla

ne w

all

Inclin

ed

wall

Forc

ed

/Natu

ral

dis

turb

an

ces

Cases Studied

Mixture preparation

x (mm)

y(m

m)

20 40 60 80

10

20

30

40

50

60

70

80

vort: -0.02 -0.01 -0.01 -0.00 0.01 0.01 0.02

Frame 001 04 Aug 2004 Frame 001 04 Aug 2004

x (mm)

y(m

m)

20 40 60 80

10

20

30

40

50

60

70

80


x (mm)

y(m

m)

20 40 60 80

10

20

30

40

50

60

70

80


x (mm)

y(m

m)

20 40 60 80

10

20

30

40

50

60

70

80


0 14 19 t [s]

Clockwise vortex

Counter-Clockwise

vortex V U 0.05 m/sV U 0.05 m/s

“Low turbulence” field

V U 0.0050.005 m/s

30

Data post-processing

wall

n

UW

Sd

PIV

burned

unburned

FlameFront

wall

n

UW

Sd

PIV

burned

unburned

FlameFront

(PIV)

1 m/s

1mm

Software – Main

Selection of images

Framerate

Scale factor

Selection of region

Determination of flamefront and displacement velocities

Determination of flow velocities

Crossing results

Plotting

Export and closeSave continue to another

Software - MatPIVSelection of images (predefined in main)

Filtering procedures

Masking

Determination of scale factor (perdefined in main)

PIV conditions

Software – flamefront calculation

Images / preview of determined flamefrons

Filtering procedures

Reflex reduction

h/D

r/D

WallWall

-0.36

0.6

0.31

h/D

r/D

WallWall

-0.36

0.6

0.31

h/D

WallWall

0.36

0.6

0.31

h/D

r/D

WallWall

0.6

Plane-wall / Symmetric Flame “undisturbed flame”

Wallf = 0,7

Plane-wall / Symmetric Flame

A typical result for a disturbed rich A typical result for a disturbed rich flame

WallWall

0.6

WallWall

r/D0.36 0.31

h/D

r/D

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4r/D

h/D

Plane-wall / Symmetric FlameUnburned gas velocity, PIVUnburned gas velocity, PIV

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28

Frame 001 11 Jul 2005 Jacto | Jacto | Jacto | Jacto | Jacto | JactoFrame 001 11 Jul 2005 Jacto | Jacto | Jacto | Jacto | Jacto | Jacto

14 ms

r/Dh

/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


24 ms

r/Dh

/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


24 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


34 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


34 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


44 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


44 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


54 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


54 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


64 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


64 ms

r/D

h/D

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.04 0.08 0.12 0.16 0.2 0.24 0.28


Plane-wall / Symmetric Flame K, KK, Kcc, K, Kss and S and Sdd along a along a flame frontflame front

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4

r/D

h/D

-16000

-14000

-12000

-10000

-8000

-6000

-4000

-2000

0

2000

k [

s-1

]

Flame front

K

24 ms

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4

r/D

h/D

-16000

-14000

-12000

-10000

-8000

-6000

-4000

-2000

0

2000

k [

s-1

]

Flame front

Ks

Kc

Plane-wall / Symmetric Flame K, Kc, Ks and Sd along a flame front

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4

r/D

h/D

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

k [

s-1

]

Flame front

Sd

Plane-wall / Non-Symmetric Flame

A typical result for a lean flame with a “non-symmetric” perturbation

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.3 -0.2 -0.1 0 0.1 0.2 0.3

r/D

h/D

h/D

0.5

0

-0.19 0.310 r/D

WallWall

h/D

0.5

0

-0.19 0.310 r/D

WallWall


Frame 001 20 Jan 2005 Jacto | JactoFrame 001 20 Jan 2005 Jacto | Jacto

Unburned gas velocity, PIVUnburned gas velocity, PIV

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56

Frame 001 13 Jul 2005 Jacto | Jacto | Jacto | JactoFrame 001 13 Jul 2005 Jacto | Jacto | Jacto | Jacto

8 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


8 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


18 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


18 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


26 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


26 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


36 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56


36 ms

r/D

h/D

-0.2 -0.1 0 0.1-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

| V |: 0 0.08 0.16 0.24 0.32 0.4 0.48 0.56



K, KK, Kcc, K, Kss and S and Sdd along a along a flame front

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.3 -0.2 -0.1 0 0.1 0.2 0.3r/D

h/D

-2000

-1500

-1000

-500

0

500

1000

1500

K [

s-1

]

Flame front

K

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.3 -0.2 -0.1 0 0.1 0.2 0.3r/D

h/D

-2000

-1500

-1000

-500

0

500

1000

1500

K [

s-1

]

Flame front

Ks

Kc


Sd along a flame front

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

-0.3 -0.2 -0.1 0 0.1 0.2 0.3r/D

h/D

0

0.2

0.4

0.6

0.8

1

1.2

Sd [

ms-1

]

Flame front

Sd

Flow topology-Plane wall

Stagnation points

wall

flame

U

wall

-modulus of k and Sd decreases as the flame approaches the wall- Kc >> Ks-Flame survives after passing the critical “quenching” distance of about 1mm-The propagation of a symmetric flame generates lower U velocity, close to the wall, when compared withasymmetric flame propagation

This SP moves upwards toward the wall,during flame propagation

wall wall

Inclined-wall / Non-Symmetric Flame

A typical result for a lean flame with a “non-symmetric” perturbation


Flame front detection and flame front displacement velocity (W)

Wal

l

Inclined-wall / Non-Symmetric Flame a) 0ms b) 10ms

c) 16ms d) 20ms

|V|wall

e) 29ms f) 32ms

Stagnation points

Stagnation points

Stagnation point

Flamefront

a) 0ms b) 10ms

c) 16ms d) 20ms

|V|wall

e) 29ms f) 32ms

Stagnation points

Stagnation points

Stagnation point

Flamefront


K, KK, Kcc, K, Kss and S and Sdd along a along a flame frontflame front

Sd v.s. K

KLCSS ald

-15000 -10000 -5000 0 5000 10000K(1/s)

0.01

0.1

1

10

Sd

(m/s

)

R ich flame

Sd = -9.007651558E-005 * k + 0.2872359482 R-squared = 0.606857

-20000 -15000 -10000 -5000 0 5000K(1/s)

0.01

0.1

1

10

Sd

(m/s

)

Lean Flame

Sd = -5.889812277E-005 * k + 0.3782254965R-squared = 0.525042

n

UW

Sd

Sd v.s. K

Lean (0.7)

Rich (1.4)

Data presentation

Flame speed variation

Lean (0.7)

Rich (1.4)

Stretch DistributionLean Rich

d) 20ms

Stagnation points

d) 20ms

Stagnation points

Flamefront orientation

Lean Rich

02 0lim mmd

wall nwall nflame

d wallwall wallwall

Resume

wall

flame

U

wall

This SP moves upwards toward the wall,during flame propagation

wall wall

wallwall wallwall

Ks

Kc

constSd

Improving Engine Performance and Efficiency by Minimisation of Knock Probability Project nº...

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