Experimental study on operating characteristics of a dual compensation chamber loop heat pipe in periodic acceleration fields

Systematic experiments were firstly designed and conducted to investigate the operating characteristics of a dual compensation chamber loop heat pipe (DCCLHP) under periodic acceleration conditions. A new acceleration test rig was built to generate acceleration magnitude up to 11 g. The heat load ranged from 150 W to 300 W. Three different periodic acceleration patterns, two loading modes and two acceleration directions were used to study their influence on the operating characteristics of the DCCLHP. The results demonstrated that the loop temperature could periodically oscillate with the periodic change of the acceleration. A large acceleration could lead to a high operating temperature. Configuration B could cause the lower operating temperature than configuration A for a fixed case. There were stable operating temperature difference and thermal resistance variation before and after the periodic acceleration acting for the loading mode 1. Temperature overshooting after unloading the periodic acceleration was also confirmed for the loading mode 2. Such phenomena could be explained by the change of the vapour-liquid distribution in the loop and the heat leak from the evaporator to the compensation chambers (CCs). The loop temperature oscillation with different frequency and amplitude might also occur during each periodic acceleration. For the cases of 150 W and configuration A, the acceleration effect could trigger the operating temperature exceeding 60 °C. Our work proves significant phenomena existing in the DCCLHP and presents detailed analysis, which would be of great importance for the development of new generation of loop heat pipe used in aircraft thermal management system.