Computational Transonic Inverse Procedure for Wing Design

A computational transonic inverse procedure for three-dimensional wings in which shapes are determined supporting prescribed pressures is presented. The method is based on modified small disturbance (MSD) theory and can handle wing design in the presence of a fuselage. A consistent analysis-inverse differencing is implemented at the wing slit grid points to ensure recovery of specified pressures in the analysis mode. Formation of an open or a fishtail trailing edge is avoided by a systematic alteration of the velocity potential in front of the leading edge of span stations under inverse mode, until closure is achieved. To lend support to the numerical procedure, an analogous incompressible two-dimensional problem is studied analytically. As an illustration of the usefulness and versatility of the method, the development of a laminar flow control (LFC) wing from a given base wing geometry is presented along with the analysis verification.