Temperature Compensation Techniques and Technologies-An Overview

Most current propulsion concepts are designed to operate below optimum performance levels solely because of the need to compensate for temperature sensitivity. Performance at ambient temperature is restricted such that firing under temperature extremes will not exceed system safety limits for pressure. This allows a propulsion concept to perform worldwide in environments ranging from desert to arctic. If a system were available which had little or no temperature sensitivity in practical operating environments (-45 degrees C to 63 degrees C) propulsion concepts could be designed to operate at peak pressure levels through all temperatures. Such system optimization through temperature compensation could achieve significant performance gains. Various concepts have been proposed, suggested, or in a few cases experimentally demonstrated which attempt to achieve temperature compensation. This paper surveys available literature on such concepts and assesses the practicality and performance benefits of each. Concepts addressed include chemical techniques (propellant formulation and use of additives), propellant surface area control, and relatively new volume compensation techniques.