Propulsor Hydrodynamics and Hydroacousticsonlinepubs.trb.org/onlinepubs/nec/093009Kim.pdf · design...
Transcript of Propulsor Hydrodynamics and Hydroacousticsonlinepubs.trb.org/onlinepubs/nec/093009Kim.pdf · design...
Propulsor Hydrodynamics andHydroacoustics
Presented
To
Committee on Naval Engineering in the 21st Century
Dr. Ki-Han Kim
30 September 2009
Distribution Statement A: Distribution Unlimited
Research Sub-Area Breakdown
Advanced Sea PlatformHydromechanics
Propulsor Hydrodynamics and Hydroacoustics
Cavitation & Highly Unsteady Flow
Flow Noise &Propulsor Noise
Evolution of Naval Propeller Concepts
Conventional Propeller Highly-Skewed Prop
(1970’s)Ducted Prop: USS
Glover (1965)
Azimuthing Podded Prop(late 1980’s)
Advanced Blade Section:DDG-51 (1980’s)
Advanced Waterjet(2000’s)
Future?Podded Prop(2000’s)
Strategic Long-Term Vision
•
Develop knowledgebase of the governing physics (6.1)
•
Develop accurate, reliable and robust predictive/simulation tools and methods for design and behavior of propulsors (6.1, 6.2)
•
Explore and demonstrate at lab-scale novel propulsor concepts (6.2)
Provide the ship and submarine communities with quiet, efficient and affordable propulsor concepts
(options) and capabilities (knowledgebase and computational tools and methods) that would meet
the emerging mission requirements.
Research Sub-Area Breakdown
Advanced Sea PlatformHydromechanics
Propulsor Hydrodynamics and Hydroacoustics
Cavitation & Highly Unsteady Flow
PIs:
S. Ceccio
(U. Michigan) J. Katz (Johns Hopkins)K. Mahesh (U. Minnesota)S. Apte
(Oregon State U.)G. Chahine
(Dynaflow, Inc.)S. Kinnas
(UT, Austin)E. Paterson (ARL/PSU)J. Kerwin
(Alion/MIT)S. Jessup (NSWCCD)S. Kim (NSWCCD)P. Chang (NSWCCD)J-P Franc (Grenoble)
Flow Noise &Propulsor Noise
Cavitation of Naval Interest
Sheet Cavitation
Cloud Cavitation
Tip Vortex CavitationTip Leakage Vortex Cavitation
Significant source of noise for ships and submarines
Erosion damage on materials
Source of performance degradation
Hull vibration
Efficiency loss – thrust breakdown
Motivation for Cavitation Research
Pump Impeller
DDG51 Rudder
CVN 76 Propeller
Critical Technical Issues
Cavitation Inception
Inception is critical to submarine propeller
Physics of inception poorly understood
Thrust Breakdown
Important to surface ship propellers, particularly waterjets
Material Erosion due to Cavitation
Important to surface ship propellers, particularly waterjets
& composite propellers
Scaling
Scaling of inception not well understood
Scaling of erosion poorly understood
Modeling of Cavitation
Multiphase physics modeling–
Discrete Bubble Model (cavitation
inception)•
Bubble dynamics –
Lagrangian
particle tracking approach using Rayleigh-Plasset
equation•
Carrier flow -
highly turbulent flows (experiments or computations using RANS/LES
–
Continuum Mixture Model •
For different types of “developed”
cavitation
(sheet, vortex, and cloud cavitation)
•
Mass transfer model based bubble dynamics
Turbulence modeling for multi-phase flows–
Modern RANS turbulence model for steady & quasi-steady state flows
–
Large Eddy Simulation (LES) and URANS/LES hybrid approach for higher spatio-temporal resolution
Bubble-Tip Vortex Interaction
•
Developed computational model to predict multiple bubbles interacting with propeller vortical flow
•
Bubble dynamics modeled by Rayleigh- Plasset equation, surrounding vortical flow by experiments or computations (RANS, LES)
•
Current capabilities includeSingle bubble: spherical, non-spherical (2D),
and 3-D shapesMultiple bubbles with size distribution
interacting with surrounding flow (tracking up to 200,000 individual bubbles so far)Bubble deformation: elongation, splitting
and cavitation inception criteriaBubble trajectory in the vortical flowAcoustic pressure resulting from bubble-
vortical flow interaction•
Future PlansDevelop bubble coalescence model
Nuclei Distribution
2 2 ( )s ig n a l a cq u is itio n tim e
l U r tt
NACA-0015 Hydrofoil
= 8°, Re = 3 x105
Courtesy: Prof. Roger ArndtSt. Anthony Falls Laboratory
U. of Minnesota
URANS ComputationS.E. Kim (2008 )
27th Symp. On Naval Hydrodynamics
(
= 1.08) (
= 1.2)
Sheet-to-Cloud Cavitation
Summary of Cavitation and Erosion Predictive Capability
Inception Extent Scaling Control
Sheet Cavitation
Tip Leakage Vortex Cavitation
Tip Vortex Cavitation
Thrust Breakdown N/A
Cloud Cavitation
Cavitation Erosion
: Reasonably well understood. Some well-documented validation case available.
: Poorly understood. No documented validation case available. Significant investment required.
: Currently invested with some promising results. : Currently invested. No significant results yet.
Highly Unsteady Flow: Crashback
Crashback generates side forces
that could produce highly undesirable maneuvering
forces and moments.
High amplitude pressure fluctuations on blades may cause high stress and bending moments
–
potential cause of blade failure.
Large eddy simulations (LES) may be the optimal method for computing the highly separated and turbulent flows that occur during crashback.
Approach
Develop predictive capability: Energy conserving, unstructured LES code (U. of Minnesota)
Validation experiments (NSWCCD)
Water Tunnel
Test
LCC Test
(With Fully Appended Model Hull)
Towing Tank Test
Large Eddy Simulatioin
(LES)
LES Computational Grid
Instantaneous Velocity Vectors and Pressure
Dynamic Blade Loading during High Amplitude Event in Crashback: J=-0.5
Crachback Code Validation
LES predictions show good agreement with experimental results of Jessup et al., (2004).
10−2
10−1
100
101
10−8
10−7
10−6
10−5
10−4
10−3
10−2
10−1
frequency [rev−1]
KT p
ower
spe
ctra
l den
sity
[1/r
ev−
1 ]
LES
Exp (Jessup)
THRUST(J=-0.5)
0.0160.0110.057Experimental Data36in WT
0.0140.0100.056LES Predicted
KFMAGKQKT
0.0160.0110.057Experimental Data36in WT
0.0140.0100.056LES Predicted
KFMAGKQKTStandard Deviation
J
KT
-1.2 -1 -0.8 -0.6 -0.4 -0.2 0-1
-0.8
-0.6
-0.4
-0.2
0
Open WaterVPWTMpcugles
J
10K
Q
-1.2 -1 -0.8 -0.6 -0.4 -0.2 0-1.4
-1.2
-1
-0.8
-0.6
-0.4
Open WaterVPWTMpcugles
Mean KT
& KQ
Fluid-Structure Interaction for Crashback: Coupling with FEM: J=-0.5
Ducted Propulsor Crashback
Grid Instantaneous Axial Velocity and Pressure
Model in the Water Tunnel
Iso
Contour p = -0.29
Research Sub-Area Breakdown
Advanced Sea PlatformHydromechanics
Propulsor Hydrodynamics and Hydroacoustics
Cavitation & Highly Unsteady Flow
PIs:
M. Wang (U. Notre Dame) W. Devenport
(VPI)R. Simpson (VPI)S. Glegg
(FAU)S. Morris (U. Notre Dame)W. Blake (NTI)R. Martinez (Alion)D. Noll (NSWCCD)J. Anderson (NSWCCD)I. Zawadski
(NSWCCD)
Flow Noise &Propulsor Noise
Flow Noise Sources
Hull TBL (smooth surface)
Sail/Control Surface
Cavity Flow
Roughness: current focus of Hydroacoustics
program
Step Flow
Gap FlowSurface
Discontinuities
Roughness Noise Mechanisms
IncidentTurbulence
(Likely more significantfor larger roughness size)
Rayleigh-LikeTurbulence Scattering
(Likely more significantfor smaller roughness size)
Shed Vorticity(Likely more significant
for larger roughness size)
Surface roughness drastically enhances TBL noise–
Diffraction of hydrodynamic pressure–
Distortion of incoming turbulence–
Turbulence generation (vortex shedding, horseshoe vortices …)
Source mechanisms are difficult to separate–
Strong nonlinear interactions
EXPERIMENTAL
Predictive Model Development
x*
rs
φs
ars
x*
rs
φs
ars
Frequency
SP
L (d
B) Other
Sources
Roughness
Overall
COMPUTATIONAL
ANALYTICAL
Radiated SoundPrediction Tool
INTEGRATED EXPERIMENTAL
AND COMPUTATIONAL EFFORTS IN CONCERT WITH THEORETICAL ANALYSES SUPPORT
COMPREHENSIVE, ROBUST MODEL DEVELOPMENT
VPI Wind Tunnel NSWCCD AFFDevenport, Simpson (VPI) Anderson, Blake (NSWCCD)
Wang (U. Notre Dame)
Martinez (Alion) Glegg
(Florida Atlantic U.)
LES Computations
Enabled by collaboration among computational and experimental performers
y/δ
x/δ
Instantaneous Streamwise Velocity (U)
PI: M. Wang (U. of Notre Dame)
Rough-Wall TBL: Large-eddy simulation (LES)
Far field: Lighthill’s theory with appropriate Green’s function
LES
Lighthill’stheory
U
= 27.5 m/shg
= 1.4 mm (0.036)h+
= 95
= 39.3 mm
= 3.82 mmRn
() = 7500X=1.35D downstream
2 Hemispheres: Acoustic Spectra
Spectral levels are amplified at all frequenciesBroad peak in streamwise
dipole sound from 2nd hemisphere
(x, y, z) / = (50, 50, 0) (x, y, z) / = (0, 50, 50)
1st hemisphere
2nd hemisphere
both hemispheres
1st hemisphere
2nd hemisphere
both hemispheres
pa
M 2 U2 2 U
f U f U
Streamwise
Velocity Vorticity
Distributed Roughness Elements
Simulation set-up based on experiment at NSWC/CD (Goody et al.)
Roughness parameters: h = 0.127 delta, L=5.88h, (Re)h=3898
In wall units: (h)+ = 162
4L in wall normal direction y
L
0.34L
3L
9L 4L
4L
4L
4L
TurbulentInflow
Instantaneous Vorticity
(Coarse Mesh: Preliminary Results)
Propulsor Hydroacoustics
Trailing-Edge Noise
–
Direct radiation (focus of previous initiatives)
Tonal and BB
noise from propulsor/inflow interaction
–
Superposition time mean and homogeneous turbulence
Ingestion of locally quasi-
deterministic but globally turbulent structures into propulsor
and their role in the generation of tonal and BB
noise
Global viscous response of blade to large-scales
Current Design Practice(Knowledge Gaps Exist)
New direction in space-time large- scale nonhomogeneous turbulence
International Collaborations
Global Optimization using Variable Fidelity / Variable Physics Approach–
Italian Ship Model Basin (INSEAN), Italy
–
National Maritime Research Institute (NMRI), Japan–
Iowa Institute of Hydraulic Research (IIHR), U.S.
Modeling of Cavitation Erosion–
Grenoble Institute of Technology, France
–
Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
–
Dynaflow, Inc., U.S.
•
Presidential Early Career Award for Scientists & Engineers (PECASE): J. Dabiri
(Caltech)•
Popular Science Magazine “Brilliant 10” Scientists: J. Dabiri
(Caltech)•
Clair-elect, American Assoc. of Engineering Society & AIAA Past President: R. Simpson (VPI)•
Associate Vice President for Research: S. Ceccil
(U. Michigan)•
Technical Editor (1), J. of Fluids Eng., ASME: J. Katz (Johns Hopkins)•
Associate Editor (2), J. of Fluids Eng., ASME: S. Ceccio
(U. Michigan), M. Wang (U. Notre Dame)•
Editorial Board, J. of Sound and Vibration, AIAA: S. Glegg
(FAU)•
Editorial Board, J. of Aeroacoustics, AIAA: S. Glegg
(FAU)•
Deputy Editor, J. of Marine Science & Technology: Y. Tahara
(NMRI, Japan)•
Editorial Board, J. of Marine Science & Technology (2): F. Stern (U. Iowa), E. Campana
(INSEAN) •
Editorial Board, J. of Boundary Element Method (S. Kinnas, U. Texas, Austin)•
Editorial Board, Theoretical and Computational Fluid Dynamics: J. Dabiri
(Caltech)•
Editorial Committee (2), J. of Ship Research: S. Kinnas
(UT, Austin), F. Stern (U. Iowa)•
Corresponding Editor: Computational Modeling in Engineering & Science: S. Lee (U. MD)•
Associate Fellow (2), AIAA: W. Devenport
(VPI), S. Glegg
(FAU)•
Chair, Award Committee, AIAA Aeroacoustics: S. Glegg
(FAU)•
Plenary Speaker, APS 2009: S. Ceccio
(U. Michigan)•
Executive Organizing Committee for G2010 Workshop, SIMMAN2 Workshop: F. Stern (U. Iowa)
Accomplishments (FY2009)
27
Refereed
Journals
published47
Conference papers
presented18
Graduate students supported
Honors & Awards
4
Post-docs supported4
PhDs graduated3
Masters graduated