Effect of Surface Tension on the Thermal Performance of Pulsating Heat Pipe with and Without Surfactant

The development of electronic component cooling technology has enormous potential for a special kind of wickless structure called a pulsating heat pipe (PHP). In general, performance of PHP is significantly influenced by three parameters—geometric parameter, working fluid physical qualities, and operational parameter. Surface tension, one of the thermo-physical fluid properties, has an impact on PHP's hydrodynamics and reduces heat transfer, whereas surfactant increases nucleation sites, which lowers the energy required to form more and smaller bubbles, and more bubbles overall, increasing the heat transfer coefficient in the surfactant solution. A substance called a surfactant is used to lower surface tension and produce more stable fluid. Closed loop PHP uses a 5 turns of copper tube, 2 mm of an inner diameter, and 50% of a constant filling ratio. In order to study how PHP can improve heat transmission while reducing thermal resistance, the experiment uses water-based binary fluids in a 1:1 ratio, such as distilled water, ethanol, and acetone. The surfactant employed is sodium dodecyl sulfate. Along with bottom mode heating, the heat input is adjusted throughout steps of 10 W. When comparing the experimental results for pure and binary fluids with increasing heat rate, the surfactant mixture solution produced better results. In comparison to pure fluid with surfactant solution, water–acetone mixture has the highest efficiency and the lowest thermal resistance of any of these fluids, which is about 17%.