Controlling Strategies for Flow Boiling Instability in Microchannels

Microscale flow-boiling instability is an intriguing phenomenon in heat-transfer microchannels. The instable flow and heat transfer induces harmful vibration to the thermal equipment, and shifts the thermal dynamic process, resulting in inefficient heat transfer and non-uniform thermal stress, creating fatigue damage to the equipment. It is thus important to suppress such instability and improve the efficiency of phase change heat transfer. In this article, the control strategies for flow boiling instability in microchannel are summarized. These strategies can be divided into two categories: active and passive schemes. The active-controlling methods include seed bubble technology, air bubble injection, nanofluids. The passive-controlling methods involve introducing inlet throttling device, fabrication of nucleation cavity, using expanding channels etc. This paper describes the principle, technical routes and performance of each kind of the methods. The advantages and disadvantages of the proposed approaches are compared and discussed. Future research directions are additional targeted. The result of this study provides guidance of the design, control and operation of micro-heat transfer system.