Numerical approach to ablation measurements using a new plasma pre-heating technique

Abstract

Abstract A new technique for preheating axisymmetric samples of heat shield materials has been applied to graphite sample ablation through this work. A 50 mm diameter graphite disc was heated from the downstream side with a plasma to approximately 2500 K, and then exposed to a cold Mach 4.5 flow. The experimental probe was very similar to the European standard probe, normal to the flow. This work presents the simulation results, which will be used to explain how well the experimental results are able to be duplicated by simulation. The simulation results have been used to calculate a mass loss rate of 0.023 g/s during the flow period of the heated-with-flow runs. This calculation was achieved by using the simulations' mass flow rates and applying ratios of atomic weights to calculate the carbon leaving in the gaseous flow. The results show that thickness reduction at the stagnation point was 0.123 mm while the edges reduced by 0.020 mm over the 8.64 s of the total flow time of the final experiments. Thus, leading to the general conclusion that higher temperatures produce more chemical reactions and material losses. The surface reactions were simulated using Ansys Fluent CFD, modelled in a 2D axisymmetric mode. The mass of carbon contained in the reaction products calculated by the simulations was used to calculate the recession rate.