LARGE-EDDY SIMULATION OF A SPATIALLY EVOLVING SUPERSONIC TURBULENT BOUNDARY-LAYER FLOW

Several issues involving the large-eddy simulation of wall-bounded com pressible turbulent flows are investigated. A spatially evolving super sonic boundary layer is simulated using a high-order-accurate finite d ifference scheme and the dynamic subgrid-scale model. A parametric stu dy suggests that the finite difference scheme has a detrimental effect on the resolution of the smaller scales due to excessive numerical di ssipation from the spatial differencing. Also, because the dynamic mod el uses the smaller resolved-scale eddies to determine the model co ef ficients, the predicted coefficients do not have the appropriate value s. The use of higher-order schemes is found to better capture the smal ler resolved scales and to improve substantially the quality of the re sults. The effect of descretization errors on large-eddy simulation ne eds to be addressed further before proceeding with large-eddy simulati on of hows of engineering interest.