Numerical Simulations of Pulsating Heat Pipes, Part 2: Comparison to Experimental Data

Abstract

Due to the local pulsating/transient nature and complex thermal-hydraulic coupling of a closed loop pulsating heat pipe (CLPHP), there is a need to develop an effective simulation code capable to design and predict the local and overall thermal performances of these units. In particular, CLPHPs are complex, with many design and dimensional choices, and this makes the modelling extremely challenging. In part 1 of this paper, a pragmatic 1-D simulation code was presented to predict the thermal-hydraulic performance of CLPHPs, providing relatively low computational times. Here, in part 2, the predictive capabilities of the simulation code are compared, in terms of thermal performance, against an independent experimental database collected by an external academic source. The present database includes experimental results for heat loads ranging from 2 W to 82 W, different orientation angles of 0 (horizontal), 30, 60 and 90, a filling ratio of 50%, and ethanol as the working fluid. Furthermore, the experiments were performed on a CLPHP made in a silicon substrate with a pyrex cover plate. The results presented in this study demonstrated a good agreement between experimental and simulation results. Hence, the proposed simulation code is shown to be quite accurate and reliable for thermal design of CLPHPs over the current wide range of operating conditions.