Ablation/Erosion Facility Employing Multi-Component Flow Concepts

Abstract

Theme A has arisen in recent years for testing of re-entry vehicle heat shield materials in combined ablation and erosion environments. Such testing can be accomplished for very short time intervals (0.05 sec) in ballistics range facilities. For longer times measured in seconds, however, ablation and erosion tests currently can only be accomplished separately in different wind tunnel facilities. In state-of-the-art ablation facilities, the expansion nozzles are so short that direct drag acceleration of particles in the flow is relatively ineffective. Conversely, in wind tunnel facilities designed for maximum drag acceleration of particles by use of very long nozzles, the Mach number increases to such a degree that stagnation point heating rates are well below the range of interest for ablation testing. An analytical study has been made for a facility configured to produce ablation and erosion environments simultaneously. The proposed approach utilizes a conventional arc-heated ablation facility and a separate light-gas particle acceleration nozzle for generation of the erosion flux. These two components are combined by means of an inertial transfer of particles across a mixing layer formed between the two flows, similar to the process proposed as part of the RHEA (Re-entry Heating Energies Analyzer) facility concept.