Effect of Filling Ratio on Thermal Characteristics and Performance of a Pulsating Heat Pipe

Abstract

Pulsating heat pipes are complex devices for heat transfer and their optimal thermal performance depends mainly on different parameters. This work is about the thermal efficiency of a closed-loop oscillating heat pipe with a diameter of 2.0 mm and 3.0 copper tube inner and outer. For all experiments, the filling ratio (FR) was used 40%, 50 %,70%,80% and heat inputs of 20W, 40W, 60W, and 80W was provided to PHP. The position of the PHP was vertical bottom heat type. The length of evaporator, adiabatic and condenser section was maintained 52 mm,170mm,60mm. Water and benzene were selected as working fluids. From the available literature it is observed that working fluid and filling ratio are key factors in PHP's performance. The results show that the thermal resistance decreases rapidly with the increase in the heat input to 20 to 40 W., while it decreases gradually over 40 to 80W.Simulation is done in CFD and experimental data were equated to the results.