Effect of number of mesh layers and fluid loading on the performance of screen mesh wicked heat pipes

An experimental study has been performed to determine the effect of the number of mesh layers and amount of working fluid on the heat transfer performance of copper–water heat pipes with screen mesh wicks. It was found that the effective thermal resistance decreases with an increase in heat flux, and approaches an approximately constant value at higher heat fluxes. This non-linearity in the thermal resistance is larger for wicks with fewer mesh layers. There is a small increase in thermal resistance of the heat pipe when the thickness of the wick is increased, but this is significantly smaller than that predicted by models based on conduction heat transfer across the wick. For all orientations, the maximum heat transfer through the heat pipe increased as the number of mesh layers of the wick was increased, as expected. The heat pipes with amounts of working fluid close to that required to fully saturate the wick performed similarly. Heat pipes with significantly less working fluid had somewhat lower effective thermal resistances, but the maximum heat transfer rate was significantly reduced.