Abstract

Thermal performance of water-stainless steel screen mesh wick heat pipes was investigated in this study. Three screen mesh wick heat pipes were fabricated and tested all different inclinations, and their thermal conductance in different modes were compared (experimental, calculated and numerical). The different mesh numbers can bring different meanings in terms of both liquid flow resistance and capillary pumping. The aim was to analyze the thermal behavior in the permanent and transient regime for each power when operated with the power step in mid-level temperature, for use in several industrial and aerospace applications when those levels of temperature are required. The calculated thermal conductances based on the thermal resistance analysis were used to be compared with the obtained experimental thermal conductances. An adjustment factor was calculated with the objective of being used in the results of the calculated thermal conductances to bring them closer to the actual results that were obtained experimentally with the water-stainless heat pipes. The numerical approaches undertaken in analysing the transient thermal performance was used the multifluid model where two different fluid zone were created to represent vapour flow in the middle and liquid flow in the porous wick. The predicted surface temperatures with varying heat inputs (25 W - 125 W) from the numerical model and experimental tests were used for thermal conductance (numerical and experimental) were compared with calculated thermal conductance.