Effect of nanoparticle deposition on capillary wicking that influences the critical heat flux in nanofluids

When nanofluids are boiled, nanoparticles are deposited on the heater surface, causing a significant critical heat flux (CHF) enhancement. The authors examined the effect of the surface wettability and the capillarity of the nanoparticle deposition layer on CHF. It is well known that the deposition of nanoparticles changes the surface wettability, but it also causes capillary wicking on a porous surface, whereby the supplied liquid effectively delays the irreversible growth of a dry patch. This study demonstrates that the outstanding CHF enhancement in nanofluids is the consequence of both the improved surface wettability and the capillarity of the nanoparticle deposition layer.