Investigation of shock control bump for blended wing body configuration

In response to the ever-increasing economic and environmental requirements of future aviation,the current research takes reducing wave drag of Blended Wing Body (BWB)configuration as the goal and uses the Computational Fluid Dynamics (CFD)method to investigate the flow control technology based on the shock control bump.Aerodynamic characteristics of the BWB are analyzed and then the bump should be arranged in the thick center-body and the blending area which is easy to generate the shock induced separation.The asymmetrical bump based on the principle of isentropic compression is used to weaken the shock waves,and the bump construction method is presented.Three asymmetrical bumps based on the three different kinds of flow states are designed.The CFD simulations show that drag reduction of the three bumps in their design points are 7.1counts, 10.4 counts and 16.6counts,respectively.The bump can eliminate weak separation induced by shock wave,but it has limitation in controlling the strong separation.The off-design behavior shows that bumps are robust in reducing drag at a certain Mach number (Ma:0.8-0.85,CL=0.286)and lift range (CL:0.14-0.5,Ma=0.82;CL:0.12-0.5, Ma=0.83;CL:0.05-0.5,Ma=0.85).