Numerical investigation on the heat transfer performance inside sublimator driven coldplate for aerospace applications

Sublimator offers effective heat rejection for the spacecraft, which work in warm environments or with peak heat loads, by evaporating or sublimating water into the vacuum. The sublimator type studied in this paper is sublimator driven coldplate, which is proposed in recent years and is currently under research. Many conclusions have yet to be revealed. In this research, two common feed water gaps first were established. Based on the above, the structural characteristics of aluminum foam were studied emphatically. In particular, a novel method to calculate the effective thermal conductivity of aluminum foam and water was proposed. It turned out that the results obtained by this method are very consistent with experiments. Finally, the effect of porous tube, the layout of heat sources and the emissivity of mounting surface for sublimator were investigated successively. The results show that the reasonable pore diameter and porosity of porous tube are 6 μm and 0.15, respectively. The opened-cell porosity of aluminum foam should be more than 0.2. In addition, the formula for calculating the thermal conductivity of aluminum foam in this paper can be applied to the numerical simulation of water sublimator. Importantly, the works done in this paper provide an important reference for the rare numerical simulation of sublimator.