Numerical Study Of Cavity Flow Field Based On Detached Eddy Simulation Method

With a higher engineering value, cavity flow is often encountered in aeronautical practicalengineering problems, such as the aircraft weapons bay, the landing gear compartment and so on. Theunsteady oscillation induced by the cavity flow is very unfavorable for aircraft flight safety. Thereforecavity flow has also become one of the most important research topics in the field of aircraft flightsafety.Based on the in-housed methods of unsteady Reynolds average N-S equations, detached eddysimulation (DES) is developed in this paper. Solver of RANS with S-A turbulence model is used inthe turbulent boundary layer, while Smagorinski’s LES model combining with S-A model isimplemented outer the turbulent boundary layer, which makes the improved model be used as S-Amodel and Smagorinski large eddy simulation model. To verify the effectiveness of the methoddeveloped, DES is applied to some typical flow field calculations including flow around the airfoiland cylinder, and then some comparisons between the calculated results and experimental results arealso made in the paper.After the ability of DES to simulate classical flow field is validated, flow field from cavity issimulated numerically in this paper. By studying the transonic flow field of two and three dimensionalcavity, pressure oscillation and sound pressure level from the bottom of cavity, the formation anddevelopment of vortices are investigated in the paper, in order to understand the performance of cavityflow field. Pressure curve, SPL and vortices at the specific position from the bottom of cavity are alsodisplayed in the paper. Some comparisons between the calculated result and one in the reference showthe effectiveness of DES developed in the paper. It is demonstrated that the magnitude of pressureoscillation at the bottom of cavity in3-D case is lower than that in2-D case due to the finite existingwidth of cavity, and the result from3-D case approaches the one in the reference. The3-D result ofsound pressure level is more similar to the existing conclusions.