Numerical study on heat transfer enhancement of closed loop oscillating heat pipe through active incentive method

Abstract

In this paper, a mathematic model of a closed loop OHP with two branches was established to reveal the motion law of internal working fluid and the mechanism of heat transfer enhancement excited by different heat source modes, that is, uneven pulsing heat source mode (UP-mode), the even pulsing heat source mode (EP-mode) and the alternate heat source mode (A-mode). The simulation result shows that the vapor plug pressure and the liquid slug displacement both present the characteristic of variable amplitude fluctuation under the three heating modes. The amplitude generally changes periodically which is different from that of the continuous external heat source mode, which make the parameters above show additional fluctuation characteristics on the original oscillation law. The specific variation law is affected by the factors such as the heating period and heating interval. The three heat source modes introduced can enhance the transfer heat capability of the OHP under appropriate condition. But if the configuration condition is not suitable, the three modes above will weak the transfer heat ability, even result in that work stability of OHP deteriorates and stops.