A new hybrid large-eddy simulation/Reynolds-averaged Navier-Stokes simulation (LES/RANS) method is presented in this work. In this approach, the resolved turbulence kinetic energy, ensemble-averaged modeled turbulence kinetic energy and turbulence frequency and time-resolved turbulence frequency are used to form an estimate of an outer-layer turbulence length scale that is nearly Reynolds-number-independent. The ratio of this outer-layer scale with an inner-layer length scale (proportional to the wall distance) is used to construct a blending function that facilitates the shift between an unsteady RANS formulation near solid surfaces and a LES formulation away from the wall. The new model is tested through simulations of compressible flat-plate boundary layers over a wide range of Reynolds numbers and Mach 2.86 flow over a smooth compression ramp. The results show that the new model predicts mean and second-moment statistics that are in good agreement with experiment and are comparable with those obtained using an earlier model (Edwards, J. R., Choi, J-I., and Boles, J. A., "Hybrid Large-Eddy/ Reynolds-Averaged Navier-Stokes Simulation of a Mach-5 Compression Corner Interaction," AIAA Journal, Vol. 464, 2008, pp. 977-991.) which required a case-by-case calibration of a model constant.
Bibliographical noteFunding Information:
The work of D. Gieseking and J. Edwards is supported by the U.S. Army Research Office (W911NF-08-1-0430, monitored by Frederick Ferguson). The work of J.-I. Choi is supported by NASA under Cooperative Agreement NNX07AC27A-S01 and by the WCU (World Class University) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (R31-2008-000-10049-0). The work of H. A. Hassan is supported by the National Center for Hypersonic Combined-Cycle Propulsion. Computer resources have been provided by the High Performance Computing component of North Carolina State University’s Information Technologies Division and by the U.S. Department of Defense’s High Performance Computing system. We gratefully acknowledge Alexander Smits for providing J. Donovan’s thesis to us.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering