HIGH-TEMPERATURE SUPERSONIC COMBUSTION TESTING WITH OPTICAL DIAGNOSTICS

The development of supersonic combustion ramjet (SCRAMJET) engines req uires testing using new, nonintrusive, instrumentation methods in high -speed, high-enthalpy flow facilities. The stagnation temperatures for very high flight speeds (in excess of 3000 K) make the production of these flows impossible using conventional methods such as resistance h eaters or vitiated flows. Similarly, measurements of properties in the se flows is difficult since the measurement must be nonintrusive in na ture. This article describes a test series using a shock tunnel to pro duce Mach 3.0 flows with stagnation temperatures in excess of 3000 K a nd an optical diagnostic set specifically tailored for measurements in supersonic high temperature systems. The test facility includes a hyd rogen injection capability which makes combustion tests possible for t hese flows. This article describes the shock tunnel and its capabiliti es, provides an overview of the optical diagnostics used in the testin g, and discusses the results of both combusting and noncombusting test s.