Experimental study on the operation of a dual compensation chamber loop heat pipe under the effect of vibration

Loop heat pipe (LHP) technology has been identified as an efficient two-phase heat transfer solution with significant potential for aircraft applications. However, the practical application of LHP technology in aircraft has been hindered by several unclear issues, with the ability to withstand vibration being a particular concern. In this paper, the effect of vibration on the operation of a dual compensation chamber loop heat pipe (DCCLHP) was systematically investigated by experiment. Three typical vibration directions were considered, with frequencies ranging from 5 Hz to 100 Hz and peak accelerations of 1 g, 3 g, and 4.5 g. The test results showed that when the DCCLHP operated at high heat loads (800–1000 W in this study), the impact of vibration was negligible. At low heat load (200 W in this study), however, low-frequency vibrations tended to cause temperature rises, particularly in the direction parallel to the evaporator axis, and a maximum vapor temperature rise of 8.8 °C could be observed within the test parameters, while high-frequency vibrations could lead to slight temperature drops. The influence of peak acceleration was non-monotonic and associated with uncertainty, but within the parameter ranges tested, the induced effects were not statistically significant, with temperature variations remaining below 3.5 °C. Besides, temperature oscillations could be observed under low-frequency vibrations. Two mechanisms were identified as the primary factors responsible for the observed performance changes: alterations in heat leak resulting from shifts in liquid distribution, and the enhancement of internal heat exchange within the evaporator core and compensation chambers. The findings of this research could deepen the understanding of LHP theory in a vibration environment and promote the application of LHP technology in aircraft.