非对称室内热环境的实现与控制

Asymmetric Thermal Environment in a Two-dimensional Rectangular Enclosure with Discrete Heat Sources

对含有非对称离散热源的二维矩形方腔的对流传热进行数值模拟,得出以下三种方式可以切断强热源对弱热源影响的结论,即在腔体中加入绝热隔板、设置冷空气幕和通入冷空气的冲击射流,因而能够实现室内的非对称热环境。文中通过强、弱热源的努谢尔特数(Nu)变化曲线图定性地分析了隔板对自然对流腔体内流体的流动和传热的影响,研究结果表明在控制参数瑞利数(Ra)的影响下控制绝热隔板的高度可以达到隔断的效果;并研究了采用混合对流方式(冷空气幕和冲击射流)对腔体内非对称热环境的控制,主要集中在分析雷诺数(Re)、格拉晓夫数(Gr)、热源间距以及浮升力比的影响,结果表明,流场的近似对称性对应着基本的隔热效果,并且流场的对称性会随Re、热源间距和浮升力比的增强而增强。

Heat convection in the two-dimensional rectangle enclosure with asymmetric discrete heat sources are investigated numerically, and drew the conclusions that there are three ways to break off the linkage between the strong and the weak heat source, which are adding adiabatic partition in the enclosure, setting the cold air curtain and adopting cold air impinging jet. In these ways, the asymmetric thermal environment can be achieved indoor. The effect of adiabatic partition in natural convection enclosure is investigated qualitatively according to the variations of Nusselt number of the strong and the weak heat source, and it demonstrates that the internal partition is valid; Control of the asymmetric thermal environment in enclosure using mixed convection （cold air curtain and impinging jet） is also investigated, which is aimed primary at the effect of the analysis of Re, Gr, the spacing of the heat sources and the buoyancy ratio, the result indicates that the approximately symmetry of flow field is matched with the effect of obstruction and the symmetry of flow field will be enhanced with the increase of Re, the spacing of the heat sources and the buoyancy ratio.