Subsonic/supersonic linear unsteady analysis

Abstract

Using an expansion in powers of reduced frequency, a linearized unsteady panel formulation is developed which is valid for both subsonic and supersonic Mach numbers. With this formulation a numerical pilot code was developed, using chord plane singularities, to analyze relatively general three-dimensional geometries for a wide range of oscillation frequencies. A constant value of unsteady ACp across each panel eliminates the problem of singularities associated with control points near Mach cones emanating from panel corners, and from singularities associated with panels having sonic edges. computations indicate good agreement with a doublet lattice analysis at subsonic Mach numbers, for a nonplanar oblique wing configuration. and with an exact solution at supersonic speeds for a 60 degree delta wing. exactly in closed form and the technique may be expanded to more general panels of the Pan-Air type. Results from the