On the estimation of aerodynamic blocking in heat-transfer studies of char-forming ablators

Simpler relationships for predicting aerodynamic blocking effects on heat transfer by char-forming ablators are sought, in order to reduce computing time. Results of the Norair heat-transfer program can be simulated for re-entry from circular orbits by relying on linear ablation theory with a constant transpiration factor. A simple method of estimating the amount of heat conducted into the material, useful in some engineering applications, is devised on the basis of an experimental correlation of vapor injection rates.