基于标准k-epsilon湍流模型的实验室微环境数值模拟

为了研究实验室微环境的气体污染物浓度分布问题,提出了基于标准k-epsilon湍流模型的数值模拟方法.建立"回"形和"一"形楼道二维简化模型,对其进行网格划分.以浓度为7.73ppm的NO_2作为研究对象,设置不同位置的气体污染物入口,对两种二维模型的风场和NO_2浓度场进行数值模拟和分析.结果表明,"回"形楼道不利于污染物的扩散,各区域都有污染物的分布,浓度最低区域降幅在87.6%~96.7%;"一"形楼道模型中,inlet10、inlet14和inlet19分别作为入口时,B区域NO_2浓度值很低,monitor5-9浓度接近0.模拟结果符合理论,可以为实验室设计选址提供一定参考,也可以为污染气体泄露应急预案和事故预报预警机制提供依据.

A Numerical Simulation Method Based on Standard K-epsilon Model in Laboratory Microenvironment

A numerical simulation method based on standard k-epsilon turbulence model is proposed to analyze the distribution of gas pollutants in laboratory micro environment. A homocentric square corridor 2D model and a I-shaped are established and divided into many meshes. An air-NO2 mixture contained 7.73 ppm of NO2 is employed and the different positions are set up as inlets of NO2 to investigate the wind field and concentration field in the two 2D models. According to the results, homocentric square corridor has poor effect in gas pollutant diffusion. Each area has the distribution of NO2 and the maximum concentration decline is 87.6%-96.7%. In the I-shaped corridor, when inlet10, inlet14 and inlet19 are set as NO2 inlet respectively, NO2 concentration in area B is low. NO2 concentrations on monitor 5-9 are close to 0. The simulation results and theoretical analyses fit well. The results can provide reference to laboratory design and site selection. The results can also provide evidences to emergency response plan and early warning system of gas pollutant leakage.