Piston cooling with shaking-up heat pipes (SUHP) and thermal analysis of the cooling system

An engine piston cooling method incorporating shaking-up heat pipes (SUHPs) is described. In shaking-up heat pipes, the liquid return from the condenser to the evaporator section is achieved by a high-frequency shaking-up action. In addition, the liquid splash and impingement on the inner surface facilitate temperature uniformity along the heat pipe. The concept of the SUHP is verified by experimental observation of a transparent heat pipe and thermal testing of a copper/water SUHP. A comparative thermal analysis on the SUHP and gallery cooling systems is performed. The approximate analytical results show that the piston ring groove temperature can be significantly reduced using the heat pipe cooling technology, which may contribute to an increase in engine thermal efficiency and a reduction in environmental pollution.