Exhaust Heat Characteristics of Single Liquid Droplet Stream for Liquid Droplet Radiator

摘要

In order to realize a liquid droplet radiator (LDR), which is an equipment used for waste heat rejection in large space structures, the exhaust heat characteristics of a single liquid droplet stream in vacuum are required. In this study, these characteristics were obtained by a combination of experiments and numerical analyses. Experiments were conducted for measuring the amount of waste heat coming from a single liquid droplet stream of silicone oil as the working fluid, using a radiant flux sensor (RFS). The emissivity of the RFS at low temperature was measured, using a black radiation ball with known emissivity at 26°C. Numerical analyses were also performed to separate the radiation from the background of the experimental apparatus included in the radiation measured by the RFS. It was determined that at approximately -180°C, the emissivity of the RFS falls from the catalog value of 0.8 to 0.5. Moreover, the emissivity of the liquid droplet was found to be approximately in the range 0.42-0.51 and the effective emissivity of the single droplet stream was approximately 0.10. The application of these results can improve the feasibility of LDRs.