Physics Based Modeling of Hydrometeor/ Aerodynamic Interactions due to Ballistic Missiles Radomes

Hydrometeor impact/erosion qualification evaluations of aerospace vehicle components have to relate testing carried out in ground test facilities to what the components experience in the flight environment. The size distribution and condition of the hydrometeors that impact the surface of a radome can differ substantially from what they are in the natural environment before encountering a missile’s bow shock. The resulting transformed conditions of the hydrometeors have a strong influence on the magnitude and extent of any damage that results from their collision with a radome’s surface. Previous analyses have concentrated on spherical raindrops, however falling raindrops greater that 1 mm are not spherical but develop a flattened shape that becomes more severe with increasing diameter. Rain is present up to roughly 5 km and can be anywhere from a small to moderate fraction of the hydrometeor population in the prevailing adverse weather. Other types of hydrometeors comprising adverse weather are present at higher altitudes where the missile’s velocity is increasing. Methods will be developed to calculate what happens to the falling raindrop geometries, the prevalent geometries of irregular shaped ice particles, and additional hydrometeor types when they pass through the missile’s bow shock to impact the radome.