New Particle Diagnostic Methods in Arc-Heated Ablation/Erosion Facilities

摘要

Arc-heated flow facilities with injected particles are used at the Arnold Engineering Development Center (AEDC) to simulate the erosive and ablative/erosive environments encountered by spacecraft reentry through fog, clouds, thermonuclear explosions, etc. Newly developed electro-optical particle diagnostic techniques used to calibrate these facilities are discussed. Each of these techniques acquires data by optically probing the in-flight particle field. One technique measures particle velocity and is based on the detection of thermal radiation and/or chemiluminescence from the hot seed particles in a model ablation/erosion facility. A second technique measures a localized rate per unit area or mass flux of particles in a dust erosion tunnel (DET) facility; this technique is based on the photodetection of singular events caused by particles intercepting a laser beam. The third technique, similar to the latter, employs a multilaser beam arrangement to measure the velocity, two orthogonal dimensions of size, and the relative contribution of rate per unit area of individual, in-flight particles in the DET facility. (Author)