Mathematical Modeling and Experimental Validation of Oscillating Heat Pipes

This paper is intended to investigate the startup behavior of Oscillating Heat Pipes (OHPs). First, a mathematical model of OHPs is presented. The model is a one-dimensional slug flow model in which the movement of liquid slugs is governed by pressure differences between each vapor plug and pressure drops in the tubes. The positions of liquid slugs, pressure of the working fluid, temperature of the tube wall, and momentum of the liquid slugs are calculated at each time step. The model is experimentally validated by using a closed loop OHP with 16 turns. A comparison of the calculations and experimental results shows qualitative agreement. Finally, several conditions of initial liquid and vapor distributions are simulated to evaluate the effects on the startup of OHPs. The results show that initial conditions of the working fluid affect the startup behaviors of OHPs.