Scaling analysis and experimental investigation of pulsating loop heat pipes

This paper focuses on performance analysis of pulsating heat pipe (PHP) with fluid having high boiling point like KOOLGARD (an engine coolant). Fluids like Ethanol and Methanol (E&M) mixture also have been used for checking of efficiency enhancement of PHP. Non-dimensional analysis has been carried out for PHP using Buckingham-Pi theorem. Using the obtained non-dimensional numbers, the range of heat flux for some common working fluid has been estimated. Approximate results are obtained before carrying out experimentation. KOOLGARD was found to sustain more than 200 W/m2 heat flux, although the thermal resistances offered are high. Flow visualisation has been carried out as well. Different instabilities are visualised in Ethanol and Methanol (E&M) mixture case while no disturbance is visible with KOOLGARD case.