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Prediction of laminar, transitional and turbulent flow regimes, based on three-equation k-ω turbulence model

Published online by Cambridge University Press:  03 February 2016

R. Taghavi-Zenouz
Affiliation:
Department of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
M. Salari
Affiliation:
Department of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
M. Etemadi
Affiliation:
Department of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran

Abstract

A recently developed transitional model for boundary-layer flows has been examined on a flat plate and the well-known S809 wind turbine blade. Proposed numerical model tries to simulate streamwise fluctuations, induced by freestream turbulence, in pre-transitional boundary-layer flows by introducing an additional transport equation for laminar kinetic energy term. This new approach can be used for modeling of transitional flows which are exposed to both the freestream turbulence intensity and streamwise pressure gradient, which are known as the most dominant factors in occurrence of transition. Computational method of this model is based on the solution of the Reynolds averaged Navier-Stokes (RANS) equations and the eddy-viscosity concept. The model includes three transport equations of laminar kinetic energy, turbulent kinetic energy and dissipation rate frequency. The present model is capable of predicting either natural or bypass transitional mechanisms, which may occur in attached boundary-layer flows. In addition, the model can simulate transition in the separated free shear layers and the subsequent turbulent re-attachment to form a laminar separation bubble. Flat plate was exposed to different freestream turbulence intensities and streamwise pressure gradients. Wind turbine blade was examined under two different Reynolds numbers, with one of them suitable for the occurrence of laminar separation bubbles on its surfaces. To evaluate the performance of this new model in resolving transitional boundary-layer flows, final results have been compared to those obtained through application of conventional turbulence models. Comparison of final results for the flat plate and the S809 aerofoil with available experimental data show very close agreements.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2008 

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References

1. Wang, C. and Perot, B., Prediction of turbulent transition in boundary layers using the turbulent potential model, J Turbulence, 2002, 3, pp 115.Google Scholar
2. Suzen, Y.B. and Huang, P.G., Modeling of flow transition using an intermittency Transport equation, ASME J Fluids Eng, 2000, 122, pp 273284.Google Scholar
3. Mayle, R.E., The role of laminar-turbulent transition in gas turbine engines, ASME J Turbomachinery, 1991, 113, pp 509537.Google Scholar
4. Johnson, M.W. and Ercan, A.H., A Physical model for bypass transition, Int J Heat Fluid Flow, 1999, 20, pp 95104.Google Scholar
5. Arnal, D., Description and prediction of transition in two-dimensional incompressible flow, 1984, AGRAD report, No 709.Google Scholar
6. Savill, A.M., Some recent progress in the turbulence modeling of bypass transition, Near-Wall Turbulent Flows, 1993, pp 829848, So, R.M.C., Speziale, C.G. and Launder, B.E. (Eds), Science Publishers.Google Scholar
7. Savill, A.M., One-point closures applied to transition, Turbulence and Transition Modelling, 1996, pp 233268, Hallbäck, M., et al (Eds), Kluwer Publisher.Google Scholar
8. Suzen, Y.B., Huang, P.G., Hultgren, L.S. and Ashpis, D.E., Predictions of separated and transitional boundary layers under low-pressure turbine aerofoil conditions using an intermittency transport equation, J Turbomachinery, 2003, 125, (3), pp 455464.Google Scholar
9. Abu-Ghannam, B.J. and Shaw, R., Natural transition of boundary layers-the effects of turbulence, pressure gradient, and flow history, J Mech Eng Sci, 1980, 5, pp 213228.Google Scholar
10. Cutrone, L., De Palma, P., Pascazio, G. and Napolitano, M., An evaluation of bypass transition models for turbomachinery flows, Int J Heat and Fluid Flow, 2007, 28, pp 161177.Google Scholar
11. Mayle, R.E. and Schulz, A., The path to predicting bypass transition, ASME J Turbomachinery, 1997, 119, pp 405411.Google Scholar
12. Holloway, D., Walters, K. and Leylek, H., Prediction of unsteady, separated boundary layer over a blunt body for laminar, turbulent, and transitional flow, Int J Numerical Methods in Fluids, 2004, 45, pp 12911315.Google Scholar
13. Walters, D.K. and Leylek, J.H., A new model for boundary layer transition using a single-point RANS approach, ASME J Turbomachinery, 2004, 126, pp 193202.Google Scholar
14. Coupland, J., Ercoftac, Special Interest Group on Laminar to Turbulent Transition and Retransition, T3A, T3B and T3C test cases, 1990.Google Scholar
15. Matsubara, M. and Alfredsson, P.H., Disturbance growth in boundary layers subjected to free-stream turbulence, J Fluid Mech, 2001, 430, pp 149168.Google Scholar
16. Klebanoff, P.S., Effects of free-stream turbulence on a laminar boundary layer, Bull Am Phys Soc, 1971, 16.Google Scholar
17. Volino, R.J., A new model for free-stream turbulence effects on boundary layers, ASME J Turbomachinery, 1998, 120, pp 613620.Google Scholar
18. Bradshaw, P., Turbulence: the chief outstanding difficulty of our subject, Experiments in Fluids, 1994, 16, pp 203216.Google Scholar
19. Jacobs, R.G. and Durbin, P.A., Simulations of bypass transition, J Fluid Mech, 2001, 428, pp 185212.Google Scholar
20. Menter, F.R., Two-equation eddy-viscosity turbulence models for engineering applications, AIAA J, 2002, 40, (2), pp 254266.Google Scholar
21. Brodeur, R., Boundary Layer Transition Prediction for a Two Dimensional Reynolds Averaged Navier-Stokes Solver, MSc thesis, University of California, 1997.Google Scholar
22. Somers, D.M., Design and experimental results for the S809 airfoil, NREL/SR-440-6918, 1997, National Renewable Energy Laboratory, Golden, CO, USA.Google Scholar