Numerical study on the start-up characteristics and heat transfer performance of pulsating heat pipes with Tesla valve

Tesla valve, a type of check valve with no moving parts, is characterized by a significant disparity in pressure drop between forward and reverse flows. It is widely utilized in microfluidic applications and thermal control systems. This study aims to numerically analyze the effects of Tesla valve type, positional arrangement and loop number on the start-up characteristics and heat transfer performance of Tesla valve-type pulsating heat pipes (PHPs). The finding indicates that the Tesla valve is instrumental in enhancing the flow circulation of working fluid within the PHPs. Specifically, when positioned in the evaporation and adiabatic sections, the Tesla valve exhibits superior start-up characteristics compared to conventional PHPs. Furthermore, the arrangement of Tesla valve in these sections can lead to a reduction in thermal resistance by 10%~18%. The D-type Tesla valve PHP demonstrates more significant advantages over the TMW-type TVPHP, including shorter start-up times and lower thermal resistance. Additionally, the temperature fluctuations in the evaporation section are more stable during the flow circulation of working fluid. Under the same heating power conditions, the start-up time for the five-loop PHP is shorter and its thermal resistance is considerably lower than that of the three-loop PHP. This research provides valuable insights for the design and operation of PHPs that prioritize the compactness and high-efficiency heat transfer performance.