Heat Transport Characteristics of an Oscillating Heat Pipe With Al₂O₃ Nano-Fluid

Experimental investigation was conducted to exam the heat transport characteristics of an oscillating heat pipe (OHP) by using Al₂O₃ nano-fluid and pure water as working fluid. The test pipe consists of a copper tube with external diameter of 2.5 mm, inner diameter of 1.3 mm, and is welded into a four-turn oscillating heat pipe. The heat transport characteristics of the OHP have been studied under different liquid filling rates, different heat loads and different inclination angles (0° and 90°) when using water as working fluid. The results show that when heat load increases to a certain magnitude, the thermal resistance almost has little difference regardless of vertical bottom heat mode or horizontal heat mode. Comparing with pure water, Al₂O₃ nano-fluid as working fluid can enhance its heat-transport capability. When using vertical bottom heat mode and horizontal heat mode, the best concentration of Al₂O₃ nano-fluid is 0.5wt% and 0.1wt%, respectively.