The Effect of the Time Dependent Pressure Difference on Bubble Dynamics in Microchannels

Abstract

The physical processes responsible for bubble formation in microchannels are not well understood and lack fundamental understanding. Experimental results are not exactly in agreement with each other and there are no definite theories to explain the possible effects of different parameters. Among different parameters the microchannel hydraulic diameter can affect the bubble formation mechanism in microchannels strongly. In this paper the effect of the time dependent pressure difference between inside and outside of the bubble on bubble dynamics in microchannels have been investigated. The source of this time dependency can be the emergence of bubble embryos which produces a density perturbation in liquid. Results show that bubble growth rate and maximum bubble diameter in microchannels are smaller than them in ordinary size channels. These results are in good agreement with some researchers’ observations, sometimes called fictitious boiling and bubble-extinction, in microchannels.