Liquid droplet radiator (LDR) is characterized by the compact arrangement and the low mass per unit power. It is a promising cooling system for the high-power spacecraft. The characteristics of the droplet layer in LDR determine the performance of the heat dissipation. Thus, the study of the droplet radiation heat transfer mechanism is vitally important for the optimal design of the whole LDR system. In the present paper, the radiation heat transfer characteristics of a sparse LDR system are studied from the aspects of the single droplet. The results reveal that the smaller the droplet radius is, the higher the droplet radiation energy per unit mass is. The slower the initial emission speed is, the higher the radiation energy per unit mass is. The higher the initial temperature of the droplet, the higher energy of radiation power per unit mass of the droplet is. Meanwhile, the radiation heat transfer characteristics of different working mediums are also given. These conclusions can provide basis for the optimal design of the sparse droplet radiators and provide guidance for the subsequent research on LDR.
Keywords Liquid droplet radiator, thermal radiation, metal droplet, radiation power