A study of drop generators in liquid droplet radiators for space applications

The paper reviews operational behavior of the drop generation system within the droplet radiator-cooler. It proposes a procedure for determining operational parameters of a drop generator (particle size and velocity, their angular divergence, etc.), which enable stable operation of the radiator-cooler while it performs its core function of providing the targeted mass-averaged temperature gradient in the droplet stream. It provides operational models for various types of drop generators. The models are based on generalized data from developmental testing various types of drop generators under microgravity, as well as on results of theoretical analysis of patterns in the behavior of various capillary phenomena associated with startup and shutdown of the droplet generator system. It identifies conditions for stable operation of various types of drop generators. It determines optimal operational parameters for drop generators with a flat spinnerette, as well as with a capillary nozzle.