Study on heat transfer of a rotating heat pipe cooling system in dry abrasive-milling

A vertical rotating heat pipe was incorporated in the abrasive-milling tool to help dissipate heat during the machining process and realize green machining of difficult-to-machine materials. In this study, a simulation is performed to investigate the heat transfer mechanism in the evaporator and condenser section of the rotating heat pipe abrasive-milling tool (RHPAMT) at a rotational speed of 1600 rpm. The results indicate that natural convection boiling heat transfer occurs in the evaporator. Film condensation is the heat transfer regime in the condenser section. The heat transfer performance of the RHPAMT is investigated in dry abrasive-milling of Ti-6Al-4V with different cooling conditions, filling ratio and feed speed. Dry machining without rotating heat pipe is also performed and compared with RHPAMT. The optimal heat transfer performance can be obtained with a cooling pressure of 0.36 MPa and a filling ratio of 16.4%. The temperature in the evaporator section can be lowered by approximately 65.7% compared to the same machining process without heat pipe.