阁楼空间内的流动和传热机理

The design of an attic is crucial in building energy conservation, which is one of strategies of Chinese energy conservation. This project is aimed to investigate the mechnism of natural convection flows and heat transfer in a triangular cavity, a prototype of the attic, through theoretical analyses and numerical simulations as well as experiments. This project involves: analyzing main regimes of natural convection flows and heat transfer in the cavity; observing the transition from a laminar to a turbulant flow in the cavity for different conditions and presenting the diagram of the transition in the dimensionless parameter space of the Rayleigh number, the Prandtl number and the aspect ratio; investigating the dependence of heat transfer on dimensionless parameters under different regimes, and obtaining fundamental data and optism parameters for building energy conservation. The outcomes from this project may increase fundamental knowledge in fluid mechanics and heat transfer, and provide the design of building energy conservation with new ideas.

建筑节能是国家节能减排规划中的重要方面，而建筑顶部三角阁楼的合理设计是建筑节能的一项关键技术。本项申请拟利用理论分析、数值模拟和模型实验等方法研究以建筑阁楼为原型的三角腔内流动和传热的机理。主要内容包括：分析阁楼形三角腔内流动的主要动力和传热控制机制；观察不同热边界条件以及不同控制参数下三维流动结构和流态间的演化，获得流动间演化的临界无量纲参数，给出流动演化规律在无量纲控制参数空间内的图谱；研究传热对不同流态流动的定量依赖规律，获得适用于建筑阁楼节能设计的基础性数据和潜在的优化控制参数。本项研究计划的成果可补充及扩展现有流体力学和传热学方面的基础知识，并为建筑节能设计提供新的思路。