Calculation of transonic flows over bodies of varying complexity using slender body theory

Abstract

Transonic flows over several bodies of varying complexity, including a simple wing-body combination and the Shuttle Orbiter, have been modeled with the use of slender body theory. In the theory, the original three-dimensional problem is divided into two simpler component problems, the near field and the far field. The near field problem represents a crossflow that is almost incompressible and is defined by Laplace's equation with a flow tangency boundary condition on the body. A nonlinear transonic small disturbance approximation is the basis for the far-field problem and describes the flow over a body of revolution having the same longitudinal area distribution as the asymmetric body. Both the nearand far-field problems are two-dimensional boundary value problems. A boundary-element method is used to solve the near-field problem. The solution for the axisymmetric far-field problem is obtained by a successive line overrelaxation method. The two component solutions are combined to obtain the complete solution. Flows with various angles of attack and zero sideslip have been considered. Also, some off-body flow calculations were conducted. For attached flows, the calculations predicted the pressure results with good accuracy.