Ground Testing Facility for Modeling Real Projectile Flight Heating in Earth Atmosphere

Abstract

An analytical method for obtaining the heating of a hypersonic projectile with a conical forebody and data obtained from a special ballistic range to validate the method are presented. The method is a classical boundary-layer technique for turbulent flow. It involves a coordinate transformation that enables flat plate solutions to be adapted to the conical coordinates. The heating to the projectile nose cone was then obtained analytically with a semi-infinite slab, according to the given boundary conditions for flow velocity and gas temperature. The use of a transformation technique enables scaling of high-pressure conditions in the ballistic range, the so-called aerothermoballistic high-pressure test range, to actual atmospheric flight conditions. This facility allows duplication of the heating scenario during some seconds of atmosphere flight, with a flight in compressed gas resulting in the same heat flux for a flight time of some milliseconds. The transformation was validated using data from the range, obtained from the infrared surface emission at two wavelengths. Herewith the cone surface temperature is measured by detecting the intensity of the infrared emission coming from the cone surface