Numerical simulation of oscillatory flow and heat transfer in pulsating heat pipes with multi-turns using OpenFOAM

The oscillatory flow and the heat transfer in two-dimensional pulsating heat pipes (PHPs) with multi-turns were simulated using OpenFOAM. The volume of fluid method was used for the phase change, and the behavior of the working fluid was achieved by considering the mass transfer balance between the evaporation and the condensation. Ethanol was used as the working fluid, and the liquid phase and the vapor phase were assumed to be incompressible. The result revealed that the temperature variation curves did not converge to one pattern according to the number of grids in the symmetric shape of the PHP because the starting time of the working fluid circulation was different. In the PHP with the asymmetric shape, the circulation started earlier than in the PHP with symmetric shape. When the bond number was 0, which means being in zero gravity, the working fluid dried out in the evaporator section of the PHPs with 5 and 10 turns. However, the working fluid still remained in the PHPs with 15 and 20 turns. The numerical analysis performed in this article is expected to help to simulate the flow phenomenon in PHP.