The transient response of wicked heat pipes with non-condensable gas

Experiments were performed to evaluate the effect of non-condensable gases and axial conduction on the transient performance of copper-water wicked heat pipes. An existing transient network model for wicked heat pipes was extended to incorporate the effects of axial conduction and non-condensable gas. The different components were modeled by a larger number of smaller elements in both axial and radial directions. The model predictions of the steady and transient response of the vapour and wall temperature of the heat pipes were in good agreement with the experimental results. The non-condensable gases and axial conduction did not significantly affect the transient response during the heat-up phase; however, it significantly slows down the cool-down phase. ► A transient network model was developed for heat pipes with non-condensable gases. ► Model predictions for the steady and transient performance were in good agreement with experimental results. ► The non-condensable gases did not significantly affect the transient response during the heat-up phase. ► The non-condensable gases significantly slowed down the cool-down phase.