Recent Advances in DNS and LES pp 431-442 | Cite as

# Large Eddy Simulations of Rectangular Jets in Crossflow: Effect of Hole Aspect Ratio

## Abstract

Large eddy simulations of rectangular jets in crossflow are performed to study the effect of hole geometry on the penetration and spread of the coolant jet. Three different holes of aspect ratio 0.5, 1.0 and 2.0 are studied. In the present study, the jet to crossflow blowing ratio is 0.5 and the jet Reynolds number is approximately 4,700.

It is observed that the dynamics of jets in crossflow are influenced significantly by the hole geometry for low jet to mainstream velocity ratios near the hole exit. The vertical penetration is greatest for the aspect ratio 2.0 and least for the aspect ratio 0.5. Dynamics of various steady as well as unsteady flow structures for different holes is markedly distinct at this Reynolds number. The separation between the leading and trailing edges of holes controls the evolution of the counter rotating vortex pair (CVP) near the jet exit. The relative strength of horseshoe vortex as compared to CVP changes with the hole geometry.

## Keywords

Wall Shear Stress Large Eddy Simulation Reynolds Stress Cross Flow Film Cool## Preview

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## References

- Ajersch, P., Zhou, J.M., Ketler, S., Salcudean, M. and Gartshore, I. A. (1995),
*Multiple jets in a crossflow: detailed measurements and numerical simulations*, ASME 95-GT-9Google Scholar - Andreopoulos, J. and Rodi, W. (1984),
*Experimental investigation of jets in a crossflow*. J. Fluid Mech., Vol. 138, pp. 93–127.ADSCrossRefGoogle Scholar - Andreopoulos, J. (1985),
*On the structure of jets in a crossflow*. J. Fluid Mech. Vol 157, pp. 163–197.ADSCrossRefGoogle Scholar - Bardina, J. Ferziger, J.H. and Reynolds, W.C. (1983),
*Improved turbulence models based on large eddy simulations of homogeneous, incompressible turbulent flows*. Report TF-19. Thermosciences Div., Eng., Dept. Mech. Stanford Univ.Google Scholar - Batchelor, G.K. ( 1953),
*Theory of homogeneous turbulence*, Cambridge University Press.Google Scholar - Chong, M.S., Soria, J., Perry. A.E., Chacin, J., Cantwell, B.J. and Na, Y. (1998),
*Turbulence structures of wall-bounded shear flows found using DNS data*. J. Fluid Mech., Vol. 357. pp. 225–247.MathSciNetADSzbMATHCrossRefGoogle Scholar - Chorin, A.J. (1967),
*A numerical method for solving incompressible viscous flow problems*, J. Comp. Phy., Vol. 2 pp. 12–26.ADSzbMATHCrossRefGoogle Scholar - Coelho, S.L.V. and Hunt, J.C.R. (1989),
*The dynamics of the near field of strong jets in crossflows*, J. Fluid Mech., Vol. 200 pp. 95–120.MathSciNetADSzbMATHCrossRefGoogle Scholar - Dubois, T., Jauberteau, F. and Temam, R. (1999),
*Dynamic multilevel methods and the numerical simulation of turbulence*, Cambridge University Press.Google Scholar - Fric, T.F. and Roshko, A. (1994),
*Vortical structure in the wake of a transverse jet*. J. Fluid Mech., Vol. 279, pp. 1–47.ADSCrossRefGoogle Scholar - Garg, V. K., and Gaugler R. E., (1995),
*Effect of velocity and temperature distribution at the hole exit on film cooling of turbine blades*, ASME paper 95-GT-2Google Scholar - Garg, V. K., and Gaugier R. E. (1994),
*Prediction of film cooling on gas turbine airfoils*, ASME paper 94-GT-2Google Scholar - Ghosal, S. (1999),
*Mathematical and physical constraints on large eddy simulation of turbulence*, AIAA Journal, Vol. 37, no. 4, pp.425–433.MathSciNetADSCrossRefGoogle Scholar - Ghosal, S. and Moin, P. (1995),
*The basic equations for the large eddy simulations of the turbulent flows in complex geometry*, J. Comp. Phy., Vol. 118, pp.24–37.MathSciNetADSzbMATHCrossRefGoogle Scholar - Haven, B.A. (1996),
*The effect of hole geometry on the near field character of crossflow jets*, PhD. thesis, University of Washington.Google Scholar - Haven, B.A. and Kurosaka, M. (1997),
*Kidney and anti-kidney vortices in crossflow jets*, J. Fluid Mech., Vol 352, pp.27–64.ADSCrossRefGoogle Scholar - Jones, W. P. and Wille, M. (1996),
*Large eddy simulation of a round jet in crossflow*, Engineering Turbulence Modeling and Experiments 3. Ed. Rodi, W. and Bergeles, G. pp.199–209Google Scholar - Jordan, S.A. (1994),
*Use of the large eddy simulation dynamic model for turbulent shear driven cavity flows*, ASME FED-Vol. 184 pp. 141–150.Google Scholar - Kelso, R.M., Delo, C. and Smits, A.J. (1993),
*Unsteady wake structures in transverse jets*, Fluid Dynamics Panel Symposium, UK, AGARD-CP-534.Google Scholar - Kelso, R.M., Lim, T.T. and Perry, A.E. (1996),
*An experimental study of round jets in crossflow*, J. Fluid Mech., Vol. 306, pp. 111–144.ADSCrossRefGoogle Scholar - Kim, S.W., and Benson, T.J. (1992),
*Calculation of a circular jet in crossflow with a multiple-time-scale turbulence model*, Int. J. Comp. Phys. Vol 59. pp. 308–315ADSCrossRefGoogle Scholar - Muldoon, F. and Acharya, S. (1999),
*Numerical investigation of the dynamical behavior of a row of square jets in crossflow over a surface*, (To be presented at ASME-IGTI99)Google Scholar - Patankar, S. V. Basu, D. K. and Alpay, S. A. (1977),
*Prediction of the three-dimensional velocity field of a deflected turbulent jet*, Trans. SME I: J. Fluids Engng 99, pp. 758–762CrossRefGoogle Scholar - Scotti, A., Meneveau, C. and Fatica, M. (1997),
*Dynamic Smagorinsky model for anisotropic grids*. Phys. Fluids. Vol. 9 pp. 1856–1858.MathSciNetADSzbMATHCrossRefGoogle Scholar - Speziale, C.G. (1985),
*Galilean Invariance of subgrid scale stress models in large eddy simulation of turbulence*, J. Fluid Mech. Vol. 156, pp. 55–62.ADSzbMATHCrossRefGoogle Scholar - Sykes, R. I., Lewellen, W. S. and Parker, S. F. (1986),
*On the vorticity dynamics of a turbulent jet in a crossflow*, J. Fluid Mech. vol. 80, pp. 49–80Google Scholar - Yuan L.L., and Street, R. L. (1996),
*Large Eddy Simulation of a Jet in Crossflow*, ASME Fluids Engineering Division Vol. 242, pp.253–260Google Scholar - Zang, Y., Street, R.L. and Koseff, J.R. (1993),
*A dynamic mixed subgrid scale model and its application to turbulent recirculating flows*, Phys. Fluids A Vol. 5 no. 12 pp. 3186–3196.ADSCrossRefGoogle Scholar - Zhou, Y., Vahala, G. and Hossain, M. (1989),
*A critical look at the use of filters in large eddy simulations*, Phys. lett. A Vol. 139 no. 7 pp. 330–332.ADSCrossRefGoogle Scholar