Plume Temperature Measurements of a Spin-Stabilized Rocket

Rocket plume temperature distribution plays an important role on the heat transfer analysis of launch carriers. Thus, a non-intrusive IR scanner is used in this paper to analyze the influence of spin motion on plume centerline temperature measurements of spinning solid-propellant rockets. Results show that the average error of temperature measurement is below 3.5% even with a 10% error of estimated emittance value. At the early burning stage under no-spin condition, the rocket plume contains a high-percentage of flammable gas and is cooled by the vortex of ambient air, which is induced by the transient plume jet of the rocket. Hence, the plume at the nozzle exit has a low temperature during the early burning stage. After a short period, high-temperature particles apparently are ejected and emit high-intensity IR that causes the increase of plume temperature at the nozzle exit. Regardless of plume temperature level at the nozzle exit and the existence of rocket spin, the plume temperature for secondary combustion of flammable gas is consistent, and the average temperature error is less than 6 percent. This study also offers an economical and practical method for the study of plume temperature distribution of a spin-stabilized rocket. Introduction The radiation property of rocket plumes is an important parameter for the analysis of radiation heat transfer in the rocket motor burn phase, because the radiation is the main heat transfer mode in space. Hence, in the development process of spinning solid-propellant rockets, rocket plume temperature measurement 28,37 and radiation property studies are important 3,6,9,15,19,20 . They are also helpful in increasing the ability of infrared (IR) detection and launch system development. Research on heat insulation of launch carriers, such as the space shuttle and satellites, are very important because the thermal radiation emitted from the rocket plume causes electronic equipment in the carrier or satellite become risky during rocket motor burn phase. Furthermore, the radiation property study of rocket plumes also plays an important role in the R&D of insulators and in the heat transfer analysis of the nozzle surface 30 . Nevertheless, for the analysis of radiation characteristics, the rocket plume temperature must be measured. These motivations have inspired R&D on intrusive and nonintrusive technology of flame and/or combustion gas temperature measurement in recent years. 1 Fooyin University School of Enviromental and Life Science, Kaohsiung, Taiwan. R.O.C. Cheng-Shiu Institute of Technology Department of Industry and Management Kaohsiung, Taiwan, R.O.C