Abstract: In order to meet the development requirements of the blended wing body (BWB) configuration for N+2 generation civil transport aircraft in 2020, this paper establishes a goal of reducing the wave drag, and uses a shock control bump to weaken the shock and hence reduce the wave drag by a computational fluid dynamics(CFD) method. Bump control principles besed on strong disturbance created by the λ shock structure and weak disturbance created by infinitely quasi-isentropic shocks are put forward; the geometric design method and engineering feasibility analysis of the two different bumps are studied. The results show that the bump based on a λ shock structure can be easily realized in engineering applications. The parameters of the length, height and location of the bump which produces a λ shock structure are investigated in detail so as to find their impact on wave drag reduction and yield the principles for parameter selection. It can be concluded that the best matching of these parameters with regard to such flow conditions as shock strength and its location can realize obvious drag reduction, the results show that the maximal drag reduction can reach 21% for RAE2822 and 12% for NACA0012.

Key words: bump, airfoil, shock waves, drag reduction, flow control