Experimental study of vapor bubbles in small-sized channels

This paper investigates the effect of evaporation on the shape of liquid/vapor interfaces in small-scale systems. Vapor bubbles are generated due to localized heating in a small-sized channel (with an inner dimension of 3×3×200 mm3×3×200 mm) filled with pentane, for which heat fluxes and temperature distributions are simultaneously measured. The length of the resulting vapor bubble is studied as a function of the power input and heater temperature, and is found to be not only repeatable but nonhysteretic. The bubble length depends nearly linearly on the power input, in qualitative agreement with an approximate theory of Ajaev and Homsy [V.S. Ajaev, G.M. Homsy, J. Colloid Interface Sci. 244 (2001) 180]. In addition, it is found that vapor bubbles oscillate very slowly due to the effect of thermal relaxation.

The length of the vapor bubble depends nearly linearly on the power input, in qualitative agreement with an approximate theory of Ajaev and Homsy [V.S. Ajaev, G.M. Homsy, J. Colloid Interface Sci. 244 (2001) 180].Figure optionsDownload as PowerPoint slide