Technique and Measurement of Heat Flux and Flame Temperature in Rocket Plume Exposures

Abstract

Abstract : An investigation was performed using model rocket static test engines simulating full scale rocket engine firings with instrumented live animals, heat flux transducers and thermocouples for burn injury assessments. Available data on rocket engine flame temperatures was either extrapolated or computed from chemical compositions and because of the unique 'dirty' characteristics of the flame, it was necessary to devise special instrumentation for direct measurements. A heat flux transducer was fabricated to measure the energy impingent upon the skin surface at various distances from the rocket engine. The transducer was calibrated against a graphite imaging furnace capable of producing 15 cal/sq cm sec, in conjunction with a standard radiation source and radiometer. Radiometric observations were used also to describe precisely the pulse shape of the rocket engine plume. External and intradermal thermocouples measured the actual temperatures experienced in producing a white burn in the rat (equivalent to a second degree burn in the human) and for monitoring each test and correlating one exposure with another. This paper describes the techniques and measurements used, the generation of a time-temperature profile for producing the standard burn effect and provides a temperature history at the level of the burn site.