EXPERIMENTAL STUDY OF THREADED AND GROOVED RADIATING PIN FIN

摘要

An experimental study was performed to provide information on the heat radiated to the space from grooved pin fin radiator of three different geometries. Since mass is at a premium on spacecraft, the space radiator used in its temperature control system needs to be optimized with respect to mass. A literature review shows that much of work on radiating fins has been carried out analytically and numerically. Presently, a radiating pin fin with threads and grooves on its outside surface is investigated experimentally. A test facility with a vacuum chamber and instrumentation is fabricated. The heat input to the fin is varied such that the base temperature is maintained constant under steady state. Based on a study of effect of vacuum, using available resources, the chamber is designed for a vacuum of 680 mm Hg such that the contribution of convection to the total heat transfer could be ignored. The study shows that there exists optimum thread per inch(TPI), angle of threads and depth of grooves for which the heat loss per unit mass is a maximum. The threaded and grooved radiating fin loses 1.2 to 1.34 times greater heat per unit mass, respectively, compared to the bare pin fin.