A Study of Ice Particle Motion through a Shock Wave

Abstract

A high-speed body, such as a hypersonic aircraft or re-entry vehicle, travelling through weather may encounter a wide range of particle environments. The impact of these particles on the vehicle surface poses a significant erosion hazard to the vehicle’s thermal protection. However, interaction with the vehicle shock layer will alter the particle motion, mitigating the erosive impact. This thesis describes a study into the interaction of the high altitude ice particles with the shock layer surrounding a high-speed vehicle. A literature survey of the approaches and solution methods of previous researchers is presented. The evolution of these approaches suggested the development of a new numerical model. The development of this numerical model is described from the construction of a first order accurate Euler code and its extension to second order accuracy through to the inclusion of particle clouds and the physics required to determine their motion. The output of the model is then validated against numerical or exact results for a number of test cases, including a set of one dimensional Riemann problems and two dimensional flows. In addition, the thesis describes the results of a series of shock-tube experiments. These shock-tube experiments were undertaken to examine the motion of a cloud of inert test particles as it is swept up by a normal shock. Image and data processing tools developed to analyse output from the experiments are described. Experimental results are then compared with numerical predictions made using matching flow conditions, providing validation evidence for the model.