Investigation on the fluid and heat transport characteristics of moderate and high-speed rotating heat pipes

A model was developed to characterize the effect of working fluid loading on the overall fluid and heat transport performance of moderate and high-speed rotating heat pipes. This model incorporated the liquid flow and heat transfer in the entire heat pipe. The natural convection in the liquid film induced by acceleration in the evaporator section was included in the current model. The predictions of the overall heat transfer performance were in good agreement with existing experimental results for high-speed rotating heat pipes up to 30,000 RPM. The predictions of the liquid flow and heat transfer characteristics were used to analyze the significant discrepancy between the high-speed rotating heat pipe experimental data and existing models.; Experiments were performed to examine the effect of fluid loading, rotational speed, and heat load on the overall performance of a cylindrical and a tapered heat pipe in the moderate-speed range. The heat transfer characteristics of the liquid flow in each section were further studied by measuring the axial temperature distribution along the pipe wall and along the pipe core. The present model predictions were in good agreement with the experimental results. A previous model that neglected the contribution of natural convection deviated significantly from the present measurements. The natural convection heat transfer may be the dominant heat transfer mechanism in the evaporator under high rotational speeds and large working fluid loadings.