1. Description

Nozzles for solid rocket boosters require two types of material:

• a material that conducts heat in contact with the powder gases, enabling part of the thermal energy to be transferred while maintaining good mechanical strength;

• a thermal insulation material behind the conductive material, absorbing the transferred thermal energy and protecting the cold structural parts of the nozzle.

Studies [1] have shown that it is possible to use ablative materials in both cases, i.e. materials consumed by the combined action of a very hot gas stream and mechanical erosion. Indeed, the energy required to heat and then pyrolyze the material, added to the energy of reaction with the nozzle gases at the wall, enables a significant...