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Cavitation Models : Performance and Limitations
R. Bannari, P. Proulx
Cavitation Models : Performance and Limitations
S. Cupillard, M. Page,A-M. Giroux
OutlinesOutlines
Introduction
Cavitation Models
Test Cases
Results
Conclusion and future work
Introduction
Cavitation Models
Test Cases
Results
Conclusion and future work
Introduction
Introduction
Consequences
Objectives
Increase the efficiency of turbo machinery.
Better understanding of the complex relationship betweenthe cavitation and the associated drop in performance.
The accurate prediction of thisphenomenon is essential for:
Increase the efficiency of turbo machinery.
Better understanding of the complex relationship betweenthe cavitation and the associated drop in performance.
The accurate prediction of thisphenomenon is essential for:
CavitationCavitation ModelsModels
Sauer Singhal Kunz Zwart
1e 7 / 1e 8
CavitationCavitation ModelsModels
SinghalSauer Singhal Kunz Zwart
CavitationCavitation ModelsModels
SinghalSauer Kunz Zwart
Cprod= 100Cdes=100
Cprod= 0.2Cdes=0.2
Cprod= 1e 7
Cdes=1
CavitationCavitation ModelsModels
Sauer Singhal
Convergence problem (OF) when RB> 1.e-4
Mass transfer calcultated by UDF ≠ mass transfer
calculated by the same integrated model
ZwartKunz
rnuc= 5.e-4
Fvap =50Fcond =0.01RB= 1.e-6
Convergence problem (OF) when RB> 1.e-4
Mass transfer calcultated by UDF ≠ mass transfer
calculated by the same integrated model
CavitationCavitation ModelsModels
Sauer Singhal
*
Mass transfer calcultated by UDF ≈ mass
transfer calculated by the same integratedmodel
ZwartKunz
rnuc= 5.e-4
Fvap =50Fcond =0.01RB= 1.e-6
Mass transfer calcultated by UDF ≈ mass
transfer calculated by the same integratedmodel
Test Cases: Naca0015Test Cases: Naca0015Test Cases: Naca0015Test Cases: Naca0015
Experimental Kunz model Sauer model
Test Cases: Naca0015Test Cases: Naca0015
Experimental Kunz model Sauer model
Test Cases: Naca0015Test Cases: Naca0015
IntroductionIntroduction
Sauer
Zwart
Test Cases: Naca0015Test Cases: Naca0015
Kunz
Test Cases: Naca0015Test Cases: Naca0015
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
P_out (pa) 13128.5
0.2
Re=13600
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
18113.5 28083.5
0.3 0.5
Re=13600
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Coarse Grid10675 cell
Fine Grid69406 cell
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Medium Grid47487 cell
Fine Grid69406 cell
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Effect of Grid σ=0.2Surface pressure of measured and predicted
distribution at σ=0.2
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Effect of Grid σ=0.2Surface pressure of measured and predicted
distribution at σ=0.2
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Surface pressure of measured and predicted distribution at σ=0.2 .Comparison between 2 comercials code and OF (zwart modified and
original )
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Surface pressure of measured and predicted distribution at σ=0.2 .Comparison between 2 comercials code and OF (zwart modified and
original )
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Surface pressure of measured and predicted distribution at σ=0.2 .Comparison between k-ε and k-ω sst model using modified zwart model
(left Coarse grid, left medium grid )
K-ω SST is more appropriate than k-ε
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Surface pressure of measured and predicted distribution at σ=0.2 .Comparison between k-ε and k-ω sst model using modified zwart model
(left Coarse grid, left medium grid )
K-ω SST is more appropriate than k-ε
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
σ=0.2
Surface pressure of measured and predicted distribution.
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
σ=0.5
Surface pressure of measured and predicted distribution.
The modified Zwart model and Kunzmodel are in a good agreement with theexperimental data
The k-ω SST is more appropriate than k-εmodel.
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
The modified Zwart model and Kunzmodel are in a good agreement with theexperimental data
The k-ω SST is more appropriate than k-εmodel.
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Surface pressure of measured and predicted surface pressure distribution atσ=0.2 . Modified zwart model using the two phase Euler Model
The E-E model need more calibration using the differentinterphase change forces [Bannari et al., 2008; 2009].
The vof mixture model is in a good agreement than theE-E two phase model.
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
Surface pressure of measured and predicted surface pressure distribution atσ=0.2 . Modified zwart model using the two phase Euler Model
The E-E model need more calibration using the differentinterphase change forces [Bannari et al., 2008; 2009].
The vof mixture model is in a good agreement than theE-E two phase model.
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
The amelioration of the models (in progress)
[Bannari et al., 2008; 2009- Selma et al., 2010].
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
The amelioration of the models (in progress)
[Bannari et al., 2008; 2009- Selma et al., 2010].
Used model
(Luo & Svendsen 1996)
échelle deKolmogorov
avec énergie E
breakup
d1
d2
coalescence
Used model
(Luo & Svendsen 1996)
énergie de surface
grande (uniforme)
breakup
h0 hC
d12
énergie de
surface petite
(non-uniforme)
coalescence
d12
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
[Bannari et al., 2008; 2009- Selma et al., 2010].
Test Cases:Test Cases: HemisphericalHemispherical Body (Body (RouseRouse andand McNownMcNown))
[Bannari et al., 2008; 2009- Selma et al., 2010].
Sauter mean diameter
[1] Brahim Selma, Rachid Bannari and Pierre. Proulx. "Simulation of bubbly flows: Comparison between the Direct Quadrature Method ofMoments and The Method of Classes", Chemical Engineering Science, accepted manuscript (2009), CES-D-09-00340.
Sauter mean diameter
[1] Brahim Selma, Rachid Bannari and Pierre. Proulx. "Simulation of bubbly flows: Comparison between the Direct Quadrature Method ofMoments and The Method of Classes", Chemical Engineering Science, accepted manuscript (2009), CES-D-09-00340.
[1] Brahim Selma, Rachid Bannari and Pierre. Proulx. "Simulation of bubbly flows: Comparison between the Direct Quadrature Method ofMoments and The Method of Classes", Chemical Engineering Science, accepted manuscript (2009), CES-D-09-00340.
Diamètre deSauter [m]
CM 25 DQMOM[1] Brahim Selma, Rachid Bannari and Pierre. Proulx. "Simulation of bubbly flows: Comparison between the Direct Quadrature Method ofMoments and The Method of Classes", Chemical Engineering Science, accepted manuscript (2009), CES-D-09-00340.
- Nurick (1976)
CFD
Comparaison of cavitation model predisctions with Nurick’s correlation
Test Cases:Test Cases: CircularCircular orificeorifice
Comparaison of cavitation model predisctions with Nurick’s correlation
Test Cases:Test Cases: CircularCircular orificeorifice
Conclusion and future work
The E-E model needs more calibration using thedifferent interphase change forces [Bannari et al.,2008; 2009].
Use of other test cases.
Ameliorations of existent models.
Use of the cavitation model on hydraulic turbine,and the effect on the efficiency.
Other model of turbulence and other wall function
Conclusion and future work
The E-E model needs more calibration using thedifferent interphase change forces [Bannari et al.,2008; 2009].
Use of other test cases.
Ameliorations of existent models.
Use of the cavitation model on hydraulic turbine,and the effect on the efficiency.
Other model of turbulence and other wall function
Thanks
The author wish to acknowledge the financial support ofthe FQRNT and IREQ.
The authors also wish to thank the developers of the OpenFOAMpackage for their hard work and gracious collaboration.
The author wish to acknowledge the financial support ofthe FQRNT and IREQ.
The authors also wish to thank the developers of the OpenFOAMpackage for their hard work and gracious collaboration.
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