TY - JOUR
T1 - Hybrid turbulence model simulations of hemisphere-cylinder geometry
AU - Gross, A.
AU - Fasel, H. F.
N1 - Funding Information:
This work was funded by the Office of Naval Research (ONR) under Grant No. N00014-10-1-0404 with Dr. R. Joslin serving as program manager. Compute time was made available through a Department of Defense (DoD) High Performance Computing (HPC) Modernization Program challenge grant.
Publisher Copyright:
© 2015.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - When low aspect ratio geometries such as submarines, torpedoes, or missiles are operated at large angles of attack three-dimensional separation will occur on the leeward side. Separation incurs losses and can result in undesirable unsteady forces. An improved understanding of three-dimensional separation is desirable as it may open the door to new methods for the control or prevention of separation. Numerical simulations of three-dimensional separation can provide detailed insight into instability mechanisms and the resultant flow structures. For most technical applications the Reynolds numbers are too high for direct numerical simulations and lower-fidelity approaches such as hybrid turbulence models become attractive. In this paper a hybrid turbulence model blending strategy is employed that adjusts the model contribution according to the local grid resolution. The strategy is validated for two-dimensional plane channel flow at Reτ=395 and 2000. The model is then employed for simulations of a hemisphere-cylinder geometry at 10° and 30° angle of attack. The simulations demonstrate satisfactory model performance over a wide range of Reynolds numbers (5×104<ReD<5×105). A nose separation bubble is captured for the lower Reynolds numbers and leeward vortices are observed for 30° angle of attack regardless of Reynolds number.
AB - When low aspect ratio geometries such as submarines, torpedoes, or missiles are operated at large angles of attack three-dimensional separation will occur on the leeward side. Separation incurs losses and can result in undesirable unsteady forces. An improved understanding of three-dimensional separation is desirable as it may open the door to new methods for the control or prevention of separation. Numerical simulations of three-dimensional separation can provide detailed insight into instability mechanisms and the resultant flow structures. For most technical applications the Reynolds numbers are too high for direct numerical simulations and lower-fidelity approaches such as hybrid turbulence models become attractive. In this paper a hybrid turbulence model blending strategy is employed that adjusts the model contribution according to the local grid resolution. The strategy is validated for two-dimensional plane channel flow at Reτ=395 and 2000. The model is then employed for simulations of a hemisphere-cylinder geometry at 10° and 30° angle of attack. The simulations demonstrate satisfactory model performance over a wide range of Reynolds numbers (5×104<ReD<5×105). A nose separation bubble is captured for the lower Reynolds numbers and leeward vortices are observed for 30° angle of attack regardless of Reynolds number.
KW - Computational fluid dynamics
KW - Hybrid turbulence model
KW - Leeward vortices
KW - Reynolds number scaling
KW - Three-dimensional separation
UR - http://www.scopus.com/inward/record.url?scp=84929321094&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84929321094&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatfluidflow.2015.04.007
DO - 10.1016/j.ijheatfluidflow.2015.04.007
M3 - Article
AN - SCOPUS:84929321094
SN - 0142-727X
VL - 54
SP - 28
EP - 38
JO - International Journal of Heat and Fluid Flow
JF - International Journal of Heat and Fluid Flow
ER -