An Experimental Investigation of the Heat Transfer Performance of an Oscillating Heat Pipe With Copper Oxide (CuO) Microstructure Layer on the Inner Surface

This paper presents an experimental investigation of whether heat transfer performance in an oscillating heat pipe (OHP) would improve if the inner surface of the heat pipe was coated with a layer of copper oxide (CuO). The OHP had six turns and three sections, i.e., evaporator, condenser, and adiabatic section with lengths of 40 mm, 64 mm, and 51 mm, respectively. The cleaned copper tubing was chemically treated with a chemical solution and heated in a furnace. A microstructure layer of CuO was formed in the inner surface of the OHP with K2S2O8 and KOH. The working fluid in this study was water with filling ratios ranging from 40% to 70%. The experimental results show that the CuO microstructure layer is superhydrophilic and can enhance the OHP heat transfer performance. The investigation results in a new way to enhance the heat transfer performance of an OHP.