Large-eddy simulation/Reynolds-averaged Navier-Stokes (LES/RANS) hybrid methodology is applied to a high-Reynolds-number supersonic axisymmetric base flow. Accurate predictions of the base flowfield and base pressure are successfully achieved by using the LES/RANS hybrid methodology with less computational cost than that of pure LES and monotone integrated large-eddy simulation (MILES) approaches. Both the efficiency and reliability of the present LES/RANS hybrid methodology for the prediction of massively separated high-Reynolds-number flows an identified by comparison with the results obtained by LES, MILES, RANS, and the experiments in detail. The LES/RANS hybrid simulation accurately resolves the physics of unsteady turbulent motions, such as shear-layer rollup, large-eddy motions in the downstream region, small-eddy motions inside the recirculating region, and formation of large mushroom-shaped patterns in the end view. Comparison of the results shows that it is necessary to resolve approaching boundary layers and free shear-layer velocity profiles from the base edge correctly for the accurate prediction of base flows. Given the required mesh resolution near solid surfaces for pure LES and MILES at high-Reynolds-number flows, reduction of the computational cost is considerable when using the LES/RANS hybrid methodology. The consideration of a Smagorinsky constant for a compressible flow analysis may suggest that the optimal value of Smagorinsky constant may be larger in the flows with strong compressibility than in incompressible flows.
Computational study of supersonic base flow using hybrid turbulence methodology
Numerische Simulation der Überschallströmung hinter einem rotationssymmetrischen Körper unter Verwendung eines hybriden Turbulenzmodells
AIAA Journal ; 43 , 6 ; 1265-1275
2005
11 Seiten, 21 Bilder, 1 Tabelle, 40 Quellen
Article (Journal)
English
Geschwindigkeitsprofil , Hybridtechnik , mathematisches Modell , Methodenvergleich , Nachlaufströmung , numerische Strömungssimulation , numerisches Verfahren , Rezirkulation , scheinbare Viskosität , Strömung an Rotationskörpern , Strömungsabriss , Theorie-Experiment-Vergleich , Turbulenz , Überschallströmung , Wirbelströmung
FLUID DYNAMICS - Computational Study of Supersonic Base Flow Using Hybrid Turbulence Methodology
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