Designing a Shock Control Bump Array for a Transonic Wing–Body Model

Abstract

Research on three-dimensional shock control bumps has paid little attention to design methods for arrays on aircraft. This paper takes a first step, examining whether design rules for maximizing the on-design performance of swept infinite-wing bumps can be successfully used to build a finite array. A computational study using infinite-wing and aircraft models creates a design method tailoring bump location, ramp angle, and rotation to local flow conditions on the aircraft wing. Rules for rotation and ramp angle produce comparable performance trends on both models. The former correctly predicts the best rotation as a few degrees from the average local flow direction, whereas the optimal ramp angles were 0.625 times that of the initial distribution because the beneficial influence on lift of shorter arrays was stronger than that provided by infinite-wing shock control bumps. This final array performance was in good agreement with a ballpark prediction for its impact on local wave drag. However, the total aircraft drag change was larger than the local impact, due to an influence away from the immediate vicinity of the array, and the impact on lift. Consequently, when choosing preferred array designs, it is essential to consider the impact on the entire aircraft model at fixed-lift conditions.