Design considerations when using edge-mounted heat pipes in space radiators

An effort to create a design tool for the evaluation of potential heat-pipe fin designs, specifically for flat-plate heat-pipe fins used as space radiators, has been carried out. The axial temperature distribution along the fin was derived using an energy balance. The solution to the differential equation for the temperature distribution was found using the finite difference method. From this solution, the heat transfer from the fin was found, and the efficiency of the fin was calculated. The resulting efficiencies were then plotted as design charts based on the critical parameters. When compared to experimental results of four different tests from the literature, the model yielded good results. The fin model was also used to consider improvements to existing satellites. The Viking 1 and 2 orbiters, each with a SNAP-19 radioisotope thermal generator, were studied.