Heat Transfer to a Composite Material Under Ice Particle Impacts

Abstract

This paper examines what would happen if a supersonic vehicle Dies through an atmosphere laden with ice particles. In previous research of the present authors, an experiment was performed to determine the characteristics of ice-particle impact phenomenon. Therein, the mass loss from the vehicle's surface material by the impacts was measured and the fragments' behavior was studied. In the present work, the trajectories of fragments from the stagnation region were calculated at the experimental conditions. It was surmised that the flow in the stagnation region is turbulent. Turbulent flow increases the heat transfer rate to the surface, and consequently the mass loss increases. To determine the extent of heat transfer rate increase, the new turbulence model, tentatively named crater-induced turbulence model, was proposed. Therein, an assumption was introduced that the turbulent mixing length is proportional to the depth of the impact craters. The constant of proportionality was determined from the existing experimental data taken in wind-tunnel tests. It is shown that heat transfer rate may increase up to 14 times that without ice-particle impacts.