Application of the panel method to subsonic aerodynamic design

Abstract

Computational methods play an important part in aerodynamic development of modern flying vehicles. In order to improve the flying efficiency many assistant devices, such as leading/trailing flaps are applied. Although there exist many flow analysis methods useful in such aerodynamic configurations, the inverse methods can significantly improve the process of aerodynamic design and final aerodynamic efficiency. This paper presents a panel method which allows for design of 3-dimensional configurations with prescribed pressure distribution at various design angles of attack, including the effect of flap deflections. The high order panel method is applied to analyze the flow. The flap deflections are simulated by changing Neumann boundary conditions. The inverse problem is solved via optimization: the geometry which minimizes differences between design and actual pressure distributions is found iteratively using an optimization technique. The geometrical constrains and regularity conditions can be specified via penalty function concept. The idea of extending the range of applicability of the inverse panel method to transonic flow is also presented.