Characterization of Particle-Surface Impacts on a Sphere-Cone at Hypersonic Flight Conditions

This study utilizes in-situ data of stratospheric particle size distributions to understand particle-surface impacts at hypersonic flight conditions. Particle diameters range from 0.2 to 10 μm. Simulations are performed to track Lagrangian particles through the flowfield and statistically gather the characteristics of particles that impact the surface. Probability density functions in terms of surface-impact locations, particle sizes, velocities, incident angles, and kinetic energies are presented. The results indicate that sub-micrometer-diameter particles most frequently impact the nosetip of the vehicle at a range of velocities that tend toward the freestream velocity at higher altitudes. However, it does not appear that sub-micrometer particles significantly contribute to the net surface-impact kinetic energy. It is shown that larger particles between 6 and 8 μm are responsible for the majority of net surface-impact kinetic energy, despite these surface-impact events being infrequent.