Photographic Pyrometry of Rocket Exhaust Jets: The Technique of Temperature Measurement and the Method of Reduction of Results

A photographic technique for determining temperatures in luminous rocket exhaust gases is reviewed, and some recent refinements in the reduction and analysis of the film records are described in detail. Some values of temperatures measured at the nozzle exit of a small rocket motor are compared with theoretical values based on measurements of the pressure in the chamber, the propellent mixture ratio, and the dimensions of the motor. The use of the method in studies of the expansion process in rocket nozzles is discussed.