Stagnation Point Heat Transfer Testing in Non-Equilibrium Flow Produced by the HEG

Abstract

One simple model that provides a wealth of knowledge into the flow dynamics of non-equilibrium chemistry is the sphere, e.g. Wen (1994). In the HEG, tests on spheres ranging in diameter from 20 to 160 mm, mounted on a sphere rake, at two of the standard operating conditions, I and III, for air as test gas, were recently performed. Of particular interest in the course of the presented study was the detection, if present, of effects of surface catalysis. While the previous attempted studies of catalytic effects of surface materials were performed on complex and difficult to interpret models, it was thought that with the spheres, due to the simple geometry, there was a perfect opportunity to investigate surface catalysis. The spheres had various coatings deposited onto their surfacess and the coated spheres were test at conditions I & III (p/0 &#61 50 MPa, h/0 &#61 20 and 12 MJ/kg), in air.