Interaction of Spalled Particles with Shock Layer Flow

Abstract

The influence of the solid particles injected into the shock layer by the spaliation of a carbonaceous ablating heatshield on the shock layer flow is investigated theoretically. The equation of motion of a solid particle is integrated using a polynomial expansion. Assuming a Gaussian distribution for the initial masses and velocities of the particles, the rates of production of CO, CN, C 3 , and turbulence energy are calculated by integrating those production rates for one particle over the mass and velocity distributions. The results for the environment of Stardust Earth reentry show that these production rates decay approximately exponentially in the normal direction from the ablating wall. Correlation formulas for the magnitudes and slopes of this decay pattern are derived. The lower limits of particle size and initial velocity are estimated for a carbon-phenolic material from a spectroscopic result obtained in an arcjet wind-tunnel test