ABSTRACT
Ablation is a heat transfer process consisting of a phase change in the material on the surface of a body subject to a thermal flux, with the immediate removal of the new phase, when produced. Chemical reactions occur between the surface of the aircraft and the surrounding liquid and gaseous substances at high temperature; mechanical erosion is present, and the phase transition on the boundary surface of the shield is accompanied by an injection of the ablation products. Ablation assumes a particular relevance in the study of the behavior of thermal shields of spacecraft entering the atmosphere. The problem of ablation in a semi-infinite body subject to a heat flux depending on time has been analyzed with the application of a modification of the heat balance integral method. The exact solution of ablation, however, is extremely difficult and requires numerical methods even when simplifying hypotheses are adopted.
