大功率激光器高热流密度散热的电场强化闪蒸喷雾冷却机理研究

伴随着半导体激光器高功率化和低操作温度的发展趋势，低温、高热流密度散热已成为制约其发展的主要瓶颈之一。制冷剂闪蒸喷雾冷却可满足其低温散热需求，但存在冷却不均匀和冷却能力不足的问题。受静电喷雾技术启发，本项目通过引入静电场在改善冷却均匀性的同时提高冷却能力，从而发展电场强化闪蒸喷雾冷却技术。采用高速摄像机、PDPA等研究电场作用下闪蒸喷雾热力学与动力学特性，揭示电场对喷雾特性的调控机制；使用显微可视化手段研究电场作用下流动液膜内气泡动力学行为规律，揭示电场强化核态沸腾换热机制；考虑电场对流动液膜的作用力并发展电场强化核态沸腾换热模型，构建电场作用下热沉表面相变传热总体理论模型，揭示喷雾特性对表面传热的影响机理，进而优化冷却性能。本项目可为电场强化闪蒸喷雾冷却技术在高功率激光器散热领域的应用提供理论基础和科学指导，具有显著的学术价值与应用前景。

Thermal dissipation with low temperature and high heat flux has been one of the main bottlenecks restricting the development of semiconductor lasers due to its increasing power density and decreasing operating temperature. Cryogen spray cooling (CSC) is promising to meet the requirement of low-temperature thermal dissipation for high-power lasers, whereas the problems of the cooling non-uniformity and insufficient cooling capacity are needed to be solved. Inspired by the electrostatic spray, the electric field is introduced to decrease the cooling non-uniformity and enhance cooling capacity to develop the novel technique of electric-field enhanced flash evaporation spray cooling. The thermodynamic and kinetic spray characteristics, as well as its regulatory mechanism under electric field are investigated by high-speed camera and phase Doppler particle analyzer (PDPA). The bubble dynamics behavior in liquid film under electric field is studied by microscopic visualization to understand the mechanism of nucleate boiling heat transfer enhanced by electric field. The complete phase change heat transfer model on heating surface is established by considering the electric force on thin film and developing the electric-field enhanced nucleate boiling heat transfer model to reveal the affecting mechanism of spray characteristics on surface heat transfer and optimize the cooling performance. This project provides the theoretical foundation and guiding for the application of electric-field enhanced flash evaporation spray cooling in the thermal dissipation of high-power semiconductor lasers with prominent academic significance and practical prospect.