Heat transfer and temperature characteristics of single-loop oscillating heat pipe under axial-rotation conditions

Thermal management is important for rotating machinery, such as spindles, grinding wheels or drillers, etc. If the heat cannot be dissipated in time, high temperatures will be generated, and abnormal operations or even destruction of the machinery may occur. Oscillating heat pipes (OHP) have attracted attention in thermal management and also have a demonstrated potential to transfer heat under rotation conditions. Research on OHPs under rotation is still insufficient: For example, the heat transport capacity and the temperature characterization of OHP under axial-rotation are not investigated, and also the motion of the working fluid is not yet recorded and analyzed. The thermal performance of a single-loop OHP under axial-rotations is here experimentally investigated. The temperature characteristics of the evaporator and condenser are analyzed. The inside flow is also visualized to better understand the heat transfer process. The results show that the heat transfer capacity of OHPs filled with acetone and methanol improves with the increase of centrifugal acceleration; while the thermal performance of an OHP filled with water peaks at rotation centrifugal acceleration of 30 m/s2. The centrifugal acceleration promotes movements of the working fluid and improves the heat transport capacity. Besides, the OHP shows a chaotic state under the axial-rotation based on nonlinear dynamic analysis.