Detached-Eddy Simulations Past a Circular Cylinder

The flow is calculated with laminar separation (LS) at Reynolds numbers 50,000 and 140,000, and with turbulent separation (TS) at140,000 and 3 × 106. The TS cases are effectively tripped, but compared with untripped experiments at very high Reynolds numbers. The finest grid has about 18,000 points in each of 56 grid planes spanwise; the resolution is far removed from Direct Numerical Simulations, and the turbulence model controls the separation if turbulent. The agreement is quite good for drag, shedding frequency, pressure, and skin friction. However the comparison is obscured by large modulations of the vortex shedding and drag which are very similar to those seen in experiments but also, curiously, durably different between cases especially of the LS type. The longest simulations reach only about 50 shedding cycles. Disagreement with experimental Reynolds stresses reaches about 30%, and the length of the recirculation bubble is about double that measured. The discrepancies are discussed, as are the effects of grid refinement, Reynolds number, and a turbulence-model curvature correction. The finest grid does not give the very best agreement with experiment. The results add to the validation base of the Detached-Eddy Simulation (DES) technique for smooth-surface separation. Unsteady Reynolds-averaged simulations are much less accurate than DES for LS cases, but very close for TS cases. Cases with a more intricate relationship between transition and separation are left for future study.

[1]  J. Humphreys.  On a circular cylinder in a steady wind at transition Reynolds numbers , 1960, Journal of Fluid Mechanics.

[2]  Surya Pratap Vanka,et al.  Effects of intrinsic three-dimensionality on the drag characteristics of a normal flat plate , 1995 .

[3]  E. Széchényi.  Supercritical Reynolds number simulation for two-dimensional flow over circular cylinders , 1975, Journal of Fluid Mechanics.

[4]  S. Szepessy,et al.  On the spanwise correlation of vortex shedding from a circular cylinder at high subcritical Reynolds number , 1994 .

[5]  V. E. Kozlov,et al.  A universal one-equation model for turbulent viscosity , 1993 .

[6]  P. Moin,et al.  Numerical studies of flow over a circular cylinder at ReD=3900 , 2000 .

[7]  S. Balachandar,et al.  Low-frequency unsteadiness in the wake of a normal flat plate , 1997, Journal of Fluid Mechanics.

[8]  B. Cantwell,et al.  An experimental study of entrainment and transport in the turbulent near wake of a circular cylinder , 1983, Journal of Fluid Mechanics.

[9]  P. Spalart.  A One-Equation Turbulence Model for Aerodynamic Flows , 1992 .

[10]  Philippe R. Spalart,et al.  Navier-Stokes simulation of shedding turbulent flow past a circular cylinder and a cylinder with backward splitter plate , 1996 .

[11]  P. Spalart.  Comments on the feasibility of LES for wings, and on a hybrid RANS/LES approach , 1997 .

[12]  K. Squires,et al.  LES and DES investigations of turbulent flow over a sphere , 2000 .

[13]  A. Roshko.  Experiments on the flow past a circular cylinder at very high Reynolds number , 1961, Journal of Fluid Mechanics.

[14]  G. Schewe.  On the force fluctuations acting on a circular cylinder in crossflow from subcritical up to transcritical Reynolds numbers , 1983, Journal of Fluid Mechanics.

[15]  Wolfgang Rodi,et al.  Large-Eddy Simulations of the Flow past Bluff Bodies: State-of-the Art. , 1998 .

[16]  Philippe R. Spalart,et al.  Mechanisms of transition and heat transfer in a separation bubble , 2000, Journal of Fluid Mechanics.

[17]  M. Breuer.  A CHALLENGING TEST CASE FOR LARGE EDDY SIMULATION: HIGH REYNOLDS NUMBER CIRCULAR CYLINDER FLOW , 2000, Proceeding of First Symposium on Turbulence and Shear Flow Phenomena.

[18]  S. Balachandar,et al.  Effect of three‐dimensionality on the lift and drag of nominally two‐dimensional cylinders , 1995 .

[19]  C. Norberg.  An experimental investigation of the flow around a circular cylinder: influence of aspect ratio , 1994, Journal of Fluid Mechanics.

[20]  Strategies for turbulence modelling and simulations , 2000 .

[21]  E. Achenbach,et al.  Distribution of local pressure and skin friction around a circular cylinder in cross-flow up to Re = 5 × 106 , 1968, Journal of Fluid Mechanics.

[22]  P. Moin,et al.  Turbulence statistics in fully developed channel flow at low Reynolds number , 1987, Journal of Fluid Mechanics.

[23]  S. Ragab,et al.  A Large-Eddy Simulation of the Near Wake of a Circular Cylinder , 1998 .

[24]  Philippe R. Spalart,et al.  Detached-eddy simulation of an airfoil at high angle of attack , 1999 .

[25]  P. Spalart,et al.  On the sensitization of turbulence models to rotation and curvature , 1997 .

[26]  C. Norberg,et al.  Pressure Forces on a Circular Cylinder in Cross Flow , 1993 .

[27]  M. Breuer.  LARGE EDDY SIMULATION OF THE SUBCRITICAL FLOW PAST A CIRCULAR CYLINDER: NUMERICAL AND MODELING ASPECTS , 1998 .

[28]  M. S. Chong,et al.  A Description of Eddying Motions and Flow Patterns Using Critical-Point Concepts , 1987 .

[29]  J. W. G. van Nunen.  Pressures and Forces on a Circular Cylinder in a Cross Flow at High Reynolds Numbers , 1974 .

[30]  M. Breuer.  Large eddy simulation of high reynolds number circular cylinder flow , 1999 .