Microchannel flow boiling instability: Mechanisms, key factors, stabilization, and future directions

Microchannel flow boiling is a typical thermal management technique widely used in fields such as electronic device cooling, micro heat exchangers, and automotive cooling systems. With the development of electronic devices toward high power and high density, microchannel flow boiling has become an ideal thermal management method due to its efficient heat transfer performance. However, in practical applications, microchannel flow boiling faces many challenges, among which the most critical is its boiling instability. Boiling instability can cause severe fluctuations in thermal performance, affect cooling effectiveness, and may even cause equipment overheating or malfunction. The instability of flow boiling in microchannels is mainly manifested by nonlinear changes in fluid dynamics and heat transfer processes, and its occurrence mechanism is complex, influenced by various factors such as flow characteristics, liquid properties, and heating surface conditions. The interaction of these factors can lead to severe fluctuations in gas–liquid two-phase flow, making the boiling process unpredictable and unstable. Therefore, studying the instability of microchannel flow boiling and its stabilization methods plays an important role in improving the performance of microchannel thermal management systems. This article explores the theory of flow boiling instability in microchannels and analyzes the key factors of microchannel instability, including geometric structure, thermodynamic properties, fluid dynamic characteristics, boiling utilization efficiency, etc. On this basis, strategies to suppress flow boiling instability were proposed to provide some reference for related research.