Abstract: The range of validity of the correlation for the
effective char thermal conductivity of charring ablators (as a function of
cold-wall heat flux) proposed previously by the author has been extended. The
extension of maximum cold-wall heat flux from to for carbon
phenolic ablator is based on static test data on a full scale rocket nozzle,
while the original correlation was based on a 2/3
scale-model nozzle data. The wider range of applicability of the correlation
lends further support to the original hypothesis that the effective thermal
conductivity of charring ablators can be correlated via cold-wall heat flux
treated as a generalized variable incorporating the effects of temperature, char
porosity, thermal radiation, and chemical composition of the char.
