Estimation of Tungsten Ablation Test Conditions Using 150 Kilowatt Arc Heater

Abstract

To investigate the tungsten ablation rate and secure the data needed to develop a numerical model on high-temperature environment supposed hypersonic flight condition, in which oxidation mainly causes the ablation, an ablation test of pure tungsten specimen was conducted in a 150 kW arc heater. Under three different flow conditions, the changes in shape of the specimen due to ablation were captured by a high-speed camera, from which the recession rate over time was calculated. A numerical simulation of the test conditions was performed on an axisymmetric nonequilibrium solver to calculate heat transfer rate and mass fraction, which could not be measured by the experiment because of the limitations of the arc-heated facility. In addition, the numerical simulation was used to investigate the effects of shape changes, particularly the position and radius of the specimen, on heat transfer rate during the test. The study confirmed that the change in shape of the specimen alone could reduce the stagnation-point heat transfer rate by approximately 35% during the test.