Active control of flow boiling oscillation amplitude and frequency using a transverse jet in crossflow

Abstract

We demonstrate a technique to mitigate thermal oscillations in microchannel flow boiling and suppress the characteristic frequency associated with these oscillations. The method employs a transverse jet in crossflow that is fabricated along with the primary microchannel in a double-sided vinyl tape, using laser machining. Liquid at ambient temperature is injected into a flow boiling region at different momentum flux ratios to control the local temperature. A maximum reduction of 82% in temperature fluctuations was demonstrated and the dominant frequency of oscillations was completely suppressed within a particular range of momentum flux ratios. The observed phenomena are attributed to the replenishment of liquid into dryout regions, thereby preventing the large temperature rise and subsequent drop caused by dryout and rewetting, respectively.