基于Vreman亚格子模型的有限开口空间内热驱动流数值模拟

Numerical simulation of thermal fluid in partially open enclosures based on Vreman subgrid-scale model

利用基于Vreman亚格子模型的大涡模拟技术对有开口的单室和双室房间内热驱动流进行了数值模拟,利用函数分析法定量分析了模拟结果的准确性,并与Smagorinsky亚格子模型的模拟结果进行了比较。结果表明,Vreman和Smagorinsky亚格子模型的计算结果均能够满足工程的需求,但Vreman亚格子模型在开口附近区域的温度和U速度计算结果在整体上比Smagorinsky亚格子模型更接近实验值;Vreman亚格子模型未像Sma-gorinsky亚格子模型那样过高地估算壁面附近高温区域的粘性耗散;对于单室房间内热烟气层高度的预测,采用Vreman模型得到的计算结果准确性比Smagorinsky亚格子模型提高近50%。

Numerical simulations on thermal flow field in a room and two adjoining rooms are carried out by means of the large eddy simulation based on Vreman subgrid-scale model. Results of simulation are evaluated by functional analysis. And results given by Vreman subgrid-scale model are compared with results given by Smagorinsky subgrid-scale mode. It is indicated that two models both give acceptable results in engineering. However, temperature and U velocity calculation results obtained by Vreman subgrid-scale model are closer to experimental values than obtained by Smagorinsky subgrid-scale model in regions near the opening. Vreman subgrid-scale model do not overestimate the coefficient of viscosity for hot gases zone near the wall as Smagorinsky subgrid-scale model do. The accuracy of computation result obtained by Vreman subgrid-scale model is 50% higher than that of Smagorinsky subgrid-scale model for hot smoke layer in a compartment with partially opening.