DESIGN AND EVALUATION OF ACTUATION SYSTEMS FOR POSITION VARIABLE SHOCK CONTROL BUMPS

Abstract

A shock control bump (SCB) on the wing of a transonic airfoil can reduce the drag coefficient. However, a permanently active bump can also have negative effects and thus cannot be active over the entire flight envelope. Therefore, an adaptive SCB is required to take advantage in certain flight phases without having a negative effect on the flight in other phases. A position variable SCB can cover a larger flight range than a position fixed SCB. The system design process for a position variable SCB is strongly driven by interdisciplinary considerations, as both aerodynamic and structural boundary conditions have to be addressed. This paper describes the conceptual design process of such an SCB system, with the design of the actuating system and the analysis of the available installation space being the main focus of this work. The process starts with a preliminary design of the kinematic points of the actuation system. From the kinematic design and the provided aerodynamic loads, initial performance requirements for the actuator are derived. In the next step, three-dimensional models of different actuator technologies are automatically generated based on the performance requirements. Within the model environment, an installation space analysis can then be carried out in greater detail to further determine the integrability of the system. To investigate different concepts and apply the process to different wings, many steps of the process are automated or semi-automated. Based on the system design and the inclusion of aspects from aerodynamics and structure, a concept for a position variable SCB system was defined. Finally, the design was evaluated at aircraft level based on a flight mission.