Search

This paper demonstrates the Scale-Adaptive Simulation approach for the computation of flows around transonic weapon bays idealised as rectangular cavities. Results are also compared with Detached-Eddy Simulations for the M219 cavity with and without doors. The Mach and Reynolds numbers (based on the cavity length) are 0.85 and 6.5\(\times 10^6\) respectively, with a grid size of 5.0 million for the cavity with doors-off and 5.5 million for the cavity with doors-on. Instantaneous Numerical schlieren contours made it possible to visualise the propagation of pressure waves in and around the cavities and also showed the high level of unsteadiness and breakdown of the shear layer for both doors on and doors off cases. Both cavities were seen to have similar acoustic signatures reaching maximum sound pressure levels of 170 dB. Spectral analyses revealed that the addition of the doors caused the second Rossiter mode to dominate along the length of the cavity. Scale-Adaptive Simulation results showed good agreement with experimental data for the M219 cavity at a tenth of the time required for Detached-Eddy Simulations.