Thermal Control in Solids With Rapid Relaxation

Abstract

Feedback control of temperature in solids with a finite speed of heat propagation is investigated in this work. The emphases are placed on the effect of rapid thermal relaxation in high-rate heating and the possible delay during the short-time operations. Fundamental characteristics and dominating parameters are identified for effective feedback control in proportional heating. Transient instability, including the intrinsic transition from the desirable stability, neutral stability, to the ultimate unstable response are investigated in a wide spectrum of heating rates. Delayed heating is found to have a destabilizing effect during the short-time transient.