Generation of a Shock Control Bump by Pressurized Chambers

Abstract

In the design of a new generation of eco-efficient aircrafts, fuel reduction is the number one objective. To increase the efficiency of the next generation aircraft, disruptive technologies are under investigation to achieve a significant benefit and advantage in the market. Such technologies often mentioned as game changer technologies like for example laminar flows are under investigation since decades and have not yet reached a technology readiness level suitable for serial production of large passenger aircraft. Besides laminar flow and other game-changer technologies, there are technologies like for example variable camber and shock control, which offer less improvement in efficiency compared for example to laminar flow, but which are easier to get developed to the needed technology readiness level since only small changes in system architecture and/or the structural layout are necessary. Therefore in this paper a structural concept for an adaptive spoiler shock control bump is presented. The objective of the shock control bump is to spread a single transonic shock which causes a significant drag increase into several smaller shocks with less drag penalty. Since the shock bump performance depends on various parameters and flow conditions like height, density, temperature, flow velocity, etc. the optimal shock position and height is changing during flight. Therefore, a shock control bump concept which is able to adapt the bump to the varying flight conditions is presented. A simplified analytical model for the structure is used in the framework of an optimization module to investigate the interdependencies of structural parameters and actuation parameters for the accurate approximation of given aerodynamic target shapes. An outlook is given on the design issues for a 3D design of the pressure actuated adaptive bump spoiler concept.