Thermal performance analysis of a trapezoid-shape grooved heat pipe with different working fluids for zero gravity applications

Abstract

Grooved heat pipes can work well in no gravity conditions such as aerospace applications. This study deals with the numerical simulation of nanofluid flow and heat transfer in a capillary-grooved heat pipe. We solve numerically the governing equations in three-dimensional form applying finite volume approach, and track the fluid–solid interface using volume of fluid method. Also, we perform some experimental measurements of temperature on a sample fabricated grooved heat pipe. The numerical results are compared with the measurements in case of acetone-fluid aluminum-wall heat pipe, and the difference is averagely 12%, which is acceptable for the problems deal with phase change processes. Moreover, we investigate the effect of working fluids, consisting of acetone, water, and water-CuO nanofluid with different volume fraction of nanoparticles. The results indicate that a grooved heat pipe has better thermal performance with water than with acetone, though the working temperature is higher in case of water working fluid. It was found that using nanofluid with 1% volume fraction significantly reduces the wall temperature, and the temperature difference between evaporator and condenser, which results in improvement in thermal performance of the heat pipe, with 18% reduction in its thermal resistance, and 21% enhancement in its effective thermal conductivity. We also observe that further enhancement in nanofluid concentration has no considerable effect on the performance of the heat pipe. © 2023 Elsevier Ltd