室内气流大涡模拟的基础性问题研究

室内气流流动是暖通空调工程中的一个重要问题,大空间内的空气分布尤其如此.由于湍流结构的极端复杂性,用解析法对它求解目前是不可能的.大涡模拟作为一种最新发展起来的湍流模拟方法,不但计算工作量较直接模拟小而且在许多情况下具有很高的精度.然而,在把它用于大空间室内气流数值模拟前必须解决一些基本的问题.以高大空间强迫对流为例,研究了大涡模拟中诸如边界条件设定、空间差分和时间差分及时间步取值等重要问题,为大涡模拟在室内气流数值仿真中的应用打下了基础.

Some Basic Problems of Large Eddy Simulation of Indoor Air Flow

The status of indoor airflow, especially the air distribution of great space, is an important issue in heating, ventilating, and air conditioning engineering. Due to the extreme complexity of turbulent structure, there is no way to solve the problem theoretically. Large eddy simulation (LES),as a newly developed method for turbulent airflow simulation, has not only the advantage of smaller calculation effort but also achieve very high accuracy in most cases. Some basic problems, however, should be studied before applying the method into indoor airflow simulation of great space. With a forced ventilation system of a large workshop as an example research was made on some important LES factors of indoor air flow such as boundary conditions, spatial difference schemeand time advancing scheme, time step etc., which create the basis for the LES application to indoor forced airflow simulation.