Numerical Investigation on the Thermal Performance of Three Advanced Micro Heat Pipes

Three micro heat pipes belonging to different types are selected as the research objects due to their lowest thermal resistance and the steadiest operation according to published literatures. They are the pulsating heat pipe with corrugated configuration (CPHP), the flat-plate heat pipe with eight microchannels (FPMHP) and the radial pulsating heat pipe (RPHP). A mathematical model common to the three micro heat pipes is built, and the maximum deviation between simulation and actual results is 16.1%. It is found that CPHP has the best heat transfer performance with the minimum thermal resistance of 1.14 K center dot W-1. Its average wall temperature and center-line velocity regularly oscillate after the startup point. There is a pause phenomenon of motion for CPHP, and the pause period of motion decreases from 8.93 s to 7.25 s with the increasing input heat flux. RPHP possesses the most excellent temperature uniformity with the maximum axial temperature difference of 5.24 K. Furthermore, FPMHP is suitable for cooling temperature-resistant devices because its average wall temperature of evaporation section is the highest.