Skip to main content
Log in

Simulations of Turbulent Flow in a Plane Asymmetric Diffuser

  • Published:
Flow, Turbulence and Combustion Aims and scope Submit manuscript

Abstract

Large-eddy simulations (LES) of a planar, asymmetric diffuser flow have been performed. The diverging angle of the inclined wall of the diffuser is chosen as 8.5°, a case for which recent experimental data are available. Reasonable agreement between the LES and the experiments is obtained. The numerical method is further validated for diffuser flow with the diffuser wall inclined at a diverging angle of 10°, which has served as a test case for a number of experimental as well as numerical studies in the literature (LES, RANS). For the present results, the subgrid-scale stresses have been closed using the dynamic Smagorinsky model. A resolution study has been performed, highlighting the disparity of the relevant temporal and spatial scales and thus the sensitivity of the simulation results to the specific numerical grids used. The effect of different Reynolds numbers of the inflowing, fully turbulent channel flow has been studied, in particular, Re b  = 4,500, Re b  = 9,000 and Re b  = 20,000 with Re b being the Reynolds number based on the bulk velocity and channel half width. The results consistently show that by increasing the Reynolds number a clear trend towards a larger separated region is evident; at least for the studied, comparably low Reynolds-number regime. It is further shown that the small separated region occurring at the diffuser throat shows the opposite behaviour as the main separation region, i.e. the flow is separating less with higher Re b . Moreover, the influence of the Reynolds number on the internal layer occurring at the non-inclined wall described in a recent study has also been assessed. It can be concluded that this region close to the upper, straight wall, is more distinct for larger Re b . Additionally, the influence of temporal correlations arising from the commonly used periodic turbulent channel flow as inflow condition (similar to a precursor simulation) for the diffuser is assessed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Breuer, M., Jaffrézic, B., Peller, N., Manhart, M., Fröhlich, J., Hinterberger, C., Rodi, W., Deng, G., Chikhaoui, O., Šarić, S., Jakirlić, S.: A comparative study of the turbulent flow over a periodic arrangement of smoothly contoured hills. In: Lamballais, E., Friedrich, R., Geurts, B.J., Métais, O. (eds.) Direct and Large-Eddy Simulation VI, pp. 635–642. Springer, Dordrecht, The Netherlands (2006)

    Chapter  Google Scholar 

  2. Buice, C.U., Eaton, J.K.:Experimental investigation of flow through an asymmetric plane diffuser. CTR Annual Research Briefs, pp. 243–248 (1996)

  3. Buice, C.U., Eaton, J.K.: Experimental investigation of flow through an asymmetric plane diffuser. J. Fluids Eng. 122, 433–435 (2000)

    Article  Google Scholar 

  4. Fröhlich, J., Mellen, C.P., Rodi, W., Temmerman, L., Leschziner, M.A.: Highly resolved large-eddy simulation of separated flow in a channel with streamwise periodic constrictions. J. Fluid Mech. 526, 19–66 (2005)

    Article  MATH  ADS  Google Scholar 

  5. Germano, M., Piomelli, U., Moin, P., Cabot, W.H.: A dynamic subgrid-scale eddy viscosity model. Phys. Fluids A. 3(7), 1760–1765 (1991)

    Article  MATH  ADS  Google Scholar 

  6. Gravemeier, V.: Variational multiscale large eddy simulation of turbulent flow in a planar asymmetric diffuser. CTR Annual Research Briefs, pp. 257–268 (2005)

  7. Gullman-Strand, J., Törnblom, O., Lindgren, B., Amberg, G., Johansson, A.V.: Numerical and experimental study of separated flow in a plane asymmetric diffuser. Int. J. Heat Fluid Flow 25, 451–460 (2004)

    Article  Google Scholar 

  8. Iaccarino, G.: Prediction of a turbulent separated flow using commercial CFD codes. J. Fluids Eng. 123, 819–828 (2001)

    Article  Google Scholar 

  9. Kaltenbach, H.-J., Fatica, M., Mittal, R., Lund, T.S., Moin, P.: Study of flow in a planar asymmetric diffuser using large-eddy simulation. J. Fluid Mech. 390, 151–185 (1999)

    Article  MATH  ADS  Google Scholar 

  10. Leschziner, M.A.: Modelling turbulent separated flow in the context of aerodynamic applications. Fluid Dyn. Res. 38, 174–210 (2006)

    Article  MATH  ADS  Google Scholar 

  11. Lesieur, M., Métais, O.: New trends in large-eddy simulations of turbulence. Annu. Rev. Fluid Mech. 28, 45–82 (1996)

    Article  ADS  Google Scholar 

  12. Lilly, D.K.: A proposed modification of the Germano subgrid-scale closure method. Phys. Fluids A. 4(3), 633–635 (1992)

    Article  ADS  Google Scholar 

  13. Meneveau, C., Katz, J.: Scale-invariance and turbulence models for large-eddy simulation. Annu. Rev. Fluid Mech. 32, 1–32 (2000)

    Article  ADS  Google Scholar 

  14. Moin, P., Kim, J.: Numerical investigation of turbulent channel flow. J. Fluid Mech. 118, 341–377 (1982)

    Article  MATH  ADS  Google Scholar 

  15. Na, Y., Moin, P.: Direct numerical simulation of a separated turbulent boundary layer. J. Fluid Mech. 374, 379–405 (1998)

    Article  MATH  ADS  Google Scholar 

  16. Obi, S., Aoki, K., Masuda, S.: Experimental and computational study of turbulent separating flow in an asymmetric diffuser. In: Proceedings of the Ninth Symposium on Turbulent Shear Flows, pp. P305.1–P305.4. Kyoto, Japan (1993)

  17. Obi, S., Nikaido, H., Masuda, S.: Reynolds number effect on the turbulent separating flow in an asymmetric plane diffuser. In: ASME/JSMR Fluids Engineering Division Summer Meeting 1999, FEDSM 99-6976, ASME (1999)

  18. Ohta, T., Kajishima, T., Fujii, S., Nakagawa, S.: Direct numerical simulation of turbulent separating flow in an asymmetric plane diffuser. In: Hanjalić, K., Nagano, Y., Tummers, M. (eds.) Turbulence, Heat and Mass Transfer 4, pp. 441–448. Begell House, Redding, UK (2003)

    Google Scholar 

  19. Piomelli, U.: High Reynolds number calculations using the dynamic subgrid-scale stress model. Phys. Fluids A. 5(6), 1766–1771 (1993)

    Article  Google Scholar 

  20. Piomelli, U., Balaras, E.: Wall-layer models for large-eddy simulations. Annu. Rev. Fluid Mech. 34, 349–374 (2002)

    Article  ADS  Google Scholar 

  21. Sagaut, P.: Large Eddy Simulation for Incompressible Flows, 3rd edn. Springer, Berlin, Germany (2005)

    Google Scholar 

  22. Schlatter, P., Stolz, S., Kleiser, L.: Evaluation of high-pass filtered eddy-viscosity models for large-eddy simulation of turbulent flows. J. Turbul. 6(5), (2005)

  23. Schlüter, J.U., Wu, X., Pitsch, H.: Large-eddy simulation of a separated plane diffuser. AIAA Paper 2005-0672, (2005)

  24. Simpson, R.L.: Aspects of turbulent boundary-layer separation. Prog. Aerospace Sci. 32, 457–521 (1996)

    Article  ADS  Google Scholar 

  25. Skote, M., Henningson, D.S.: Direct numerical simulation of a separated turbulent boundary layer. J. Fluid Mech. 471, 107–136 (2002)

    Article  MATH  ADS  Google Scholar 

  26. Smagorinsky, J.: General circulation experiments with the primitive equations. Mon. Weather Rev. 91(3), 99–164 (1963)

    Article  Google Scholar 

  27. Törnblom, O.: Experimental study of the turbulent flow in a plane asymmetric diffuser. KTH Stockholm, Sweden (2003)

    Google Scholar 

  28. Townsend, A.A.: Self-preserving flow inside a turbulent boundary layer. J. Fluid Mech. 22, 773–797 (1965)

    Article  MATH  ADS  Google Scholar 

  29. Wu, X., Schlüter, J., Moin, P., Pitsch, H., Iaccarino, G., Ham, F.: Computational study on the internal layer in a diffuser. J. Fluid Mech. 550, 391–412 (2006)

    Article  MATH  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to P. Schlatter.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Herbst, A.H., Schlatter, P. & Henningson, D.S. Simulations of Turbulent Flow in a Plane Asymmetric Diffuser. Flow Turbulence Combust 79, 275–306 (2007). https://doi.org/10.1007/s10494-007-9091-5

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10494-007-9091-5

Keywords

Navigation