Manned Spacecraft Design Principles

Chapter 9

Thermal Protection Systems

Abstract

The primary determinant of thermal protection is the stagnation point heat transfer, and attention is paid to the most useful correlations. The high temperatures ensure dissociation and ionization of air molecules, so approximations are developed for the treatment of air chemistry. Heat transfer on a blunt hemispherical body and a spherically capped cone is addressed to highlight the different mechanisms at work. The analyses developed are extended to the design of heat shields for entry vehicles. Heat sink, melting ablator, and charring ablator heat shields are analyzed, as are active systems involving surface injection of coolants. The similarity parameters crucial to heat transfer effects are reviewed. ...