Time domain simulations of a flexible wing in subsonic, compressibleflow

Abstract

As computational costs decrease and manpower costs increase, alternate approaches for aeroelastic systems modelling should be investigated. A new unsteady aerodynamic method is used to simulate the aeroelastic response of a flexible wing with an aileron control surface. The unique aspect of this aeroelastic simulation is the unsteady aerodynamic simulation method. the recently developed Time Domain Panel (TDP) m e t h ~ d ' ~ ~ ~ ~ ~ ~ . This is a time stepping linear aerodynamic algorithm. In the example given here, the TDP algorithm is incorporated into a time stepping linear aeroelastic algorithm. The aeroelastic attributes addressed here include structural dynamics and linear, unsteady, subsonic, compressible aerodynamics. In this paper, emphasis is placed on generating minimal order aeroelastic transfer functions which relate control surface motion to sensor motion. These transfer functions have application to the design of control systems where unsteady aerodynamics is important. The approach taken here is not exclusive and other procedures for using the TDP method are discussed within the context of the current state of the art for modelling aeroelastic systems. All the simulation studies presented here were performed on a 2 7 MIP computer workstation (V.4Xstation 3). method results in a time stepping algorithm for modelling the transient aerodynamic response for thin wings. This paper suggests several useful follow-on applications of the TDP method which was first presented in reference 3. The most obvious (and easiest to program) application is the direct incorporation of the TDP algorithm into the aeroelastic equations of motion. An example of this direct application of the TDP method is presented. This example involves a numerical scheme for the time integration of the aeroelastic equations of motion for a flexible wing. The main text of this paper is divided into seven sections. The Background section gives a brief review of the current approaches taken for computing aeroelastic transfer functions. The following two sections review the TDP Method and describe the aeroelastic simulation procedure. The example case is then described and results are given. The final two sections present a discussion of the TDP method and some conclusions are drawn.