Analysis of unsteady supersonic cavity flow employing an adaptive meshing algorithm

Some aspects of the numerical analysis of a supersonic cavity flow, including the effects of length scale, computational grid and time scale have been studied. A turbulent flow over a two-dimensional cavity has been analysed through solutions of the Reynolds-averaged Navier-Stokes equations. The effects of turbulence were modelled through a coupled solution of a k-ω turbulence model using compressibility corrections. A Riemann solver numerical scheme was employed. An adaptive mesh refinement technique has been used to capture the salient features of the transient fluid flow. Computational solutions have been obtained for cavities of length to depth ratios (L/D) of 1, 3, and 5, and freestream Mach numbers of 1.5 and 2.5; conditions corresponding to experimental data. It has been found that a single mode dominated oscillation existed at L/D = 1 and that multiple mode dominated flows in the longer cavities. Frequency staging was observed for the long cavities. When the oscillation was weak at L/D = 1, the predicted modes could be affected by the selection of the computational grid. The calculations were less sensitive to the grid characteristics for the longer cavities when the oscillation was strong. (