微尺度条件下近临界流体动力学与传热问题对新型微换热器、微混合器、微合成器以及微传感器等系统的设计、运行至关重要。本项目采用实验研究、热力学理论分析与数值模拟相结合的方法，研究单个微通道内近临界流体的流动、传热特性和机理；研究多尺度条件下微通道几何设计对近临界流体流动与传热的影响及作用机理；研究微尺度通道内近临界流体热边界层对流稳定性的演化与发展规律，探明微通道表面形貌、加热方式、温度、压力等条件对近临界流体动力学和传热稳定性的作用规律及内在机制；研究微通道内热-机械扰动及其在各种状态下的作用机理；研究微通道内近临界流体热混合机理并探讨相关松弛过程；搭建高精度激光干涉测量试验平台，定量获得近临界流场和温度场特性。通过本项目的研究将对微尺度条件下近临界流体流动的特征与热量传输在本质上有进一步深入的认识，为提高其在新型微换热器、微混合器、微合成器以及微传感器等系统上的应用水平打下坚实的基础。

Near-critical fluid flow and heat transfer in microscales have become one of the critical topics in the novel types of micro heat exchanger, micro mixer, micro synthesizer and micro sensor etc. In this project, experimental, numerical and thermodynamic methods are utilized to investigate basic microchannel near-critical flow and heat transfer characteristics and related mechanisms. This study aims at a deeper understanding of the multi-scale microchannel size effect and its influences on the flow and heat transfer behaviors. The stability characteristics of microchannel near-critical boundary thermal convection and the mainstream convective flow are planned to be studied, which also include different channel surface conditions, heating strategies, temperature, pressure and flow control conditions, etc. The near-critical thermal-mechanical effects on various flow situations of microchannel flow and heat transfer will be focused. In addition, the design and construction of high-precision interferometer measurement system will be made, in order to quantitatively obtain the flow and temperature field of the near-critical microscale flow information. It is hoped that this project will introduce deeper understandings of micro-scale near-critical fluid flow and related thermal transport phenomena, making a strong basis for further application of novel micro heat exchanger, micro mixer, micro synthesizer and micro sensor etc.