Control-oriented analysis of thermal gradients for a hypersonic vehicle

Structural damage resulting from the tremondous heating incurred during hypersonic flight is mitigated by a thermal protection system; however, such mitigation is accompanied by an increase in weight that can be prohibitive. The actual design of a thermal protection system can be chosen to vary the level of heating reduction, and associated weight, across the structure. This paper considers how such designs and resulting thermal gradients influence the ability to achieve closed-loop performance. A control architecture is used that damps any thermal effects for a range of temperature profiles. Various designs are considered for a representative model to show the large variation in flight dynamics. The resulting closed-loop performance is characterized as a function of the induced thermal gradients to indicate the optimality of the designs.