Correlation of Theoretical Analysis With Experimental Data on The Performance of Charring Ablators

Abstract

Experimental data are obtained for surface recession, char depth, and temperatures in silica phenolic and carbon phenolic ablators from static test conducted on rocket nozzles. In an attempt to correlate the theoretical analysis with the experimental observations, it is found that the effective thermal conductivity of char is strongly dependent on the wall heat flux. An hypothesis is postulated that the char conductivity can best be correlated by cold wall heat flux treated as a generalized variable that includes the effects of other factors like temperature and chemical composition of the char. Exponential dependence of char conductivity on the cold wall heat flux is observed for both the ablators, and has offered excellent comparison between the theoretical and the experimental system response.