Nonaxisymmetric Body Supersonic, Aerodynamic Prediction
Abstract
A supersonic flow computational model was developed for flight vehicles with nonaxisymmetric bodies. The bodies may be pointed, with arbitrary initial cross, section, or blunted, with initially circular cross section; the remainder of the body may have an arbitrary cross-sectional variation. A vertical plane of symmetry is assumed except for fin deflections. The body is divided into piecewise continuous sections by planar discontinuities including inlets. All sections, except for the first one, may have fin sets. The fins, up to six per set, 1) are assumed to be aligned with a cylindrical coordinate ray, 2) depart only slightly from the midplane (thin fin approximation), 3) and are symmetric about the midplane. For the low Mach-number range, new research was developed for the inviscid flow regime. The computational model is based on a finite-difference, second-order, linear, potential solution. For pointed bodies, the computation is implicit up to the first planar body discontinuity and an explicit MacCormack scheme thereafter. Blunt body computations 1) assume an effective origin of disturbances and a modified Newtonian pressure distribution up to a matching or starting plane and 2) use an explicit solution thereafter. Local jump relations for discontinuities on the body, at fin roots, and fin edges are conservation relations obtained by applying the method of weak solutions to first-and second-order equations. For subsonic or lightly supersonic edges, adhoc heuristic assumptions are made. At high Mach numbers, where linear methods are not applicable, local pressure coefficient models were adapted for predicting the inviscid loading contributions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1987
- Accession Number
- ADA189338
Entities
People
- Leroy Devan
Organizations
- Naval Surface Warfare Center Dahlgren Division