会议室内飞沫气溶胶分布特征的数值模拟

Numerical Simulation of Droplet Aerosols in Conference Room

目的分析会议室内不同气流组织对人持续说话产生的飞沫气溶胶运动轨迹的影响,模拟飞沫气溶胶在会议室内的分布特征,确定最佳的气流组织方式.方法采用CFD数值模拟方法,选择RNG k-ε湍流模型计算空调房间的温度场和速度场,分析飞沫气溶胶颗粒的受力情况,采用拉格朗日法建立飞沫气溶胶颗粒运动的数学模型,模拟空调房间会议室内同侧上送上回、同侧上送下回、对侧上送下回3种混合通风和置换通风对飞沫气溶胶的运动轨迹.结果飞沫气溶胶运动轨迹显示飞沫气溶胶在置换通风停留时间和运动距离最短.3种混合通风气流组织相比,同侧上送上回的气流组织中飞沫气溶胶运动时间112 s和运动路程11.1 m最短,同侧上送下回次之,对侧上送下回最长.结论 3种混合通风中,同侧上送上回更容易避免飞沫气溶胶在室内传播,是最佳的混合通风气流组织方式.置换通风相比于混合通风更易减小人员之间受感染的可能性,是最佳的气流组织方式.

To analyze the influence of different air flow organization on trajectories and distribution characteristics of droplet aerosols released by speaking continually in conference room, the best air distribution pattern is proposed. CFD method with RNG k-8 turbulence model is introduced to sim- ulate temperature and velocity fields of the air conditioning room. Using Lagrange method, mathematical model of droplet aerosols movement is established through the analysis of the force on droplet aerosols. This paper studies the influence of mixing ventilation （ up-supply and the same side up-return;up-supply and the same side down-return;up-supply and the other side down-return） and displacement ventilation on trajectory of droplet aerosols in conference room. The trajectories show that residence time and movement distance of droplet aerosols are the shortest in dis- placement ventilation. Among the three kinds of mixing ventilation, in up-supply and the same side up-return the residence time and movement distance of droplet aerosols are the shortest, followed with up-supply and the same side down-return, in up-supply and the other side down-return are the longest. Conclusion is that displacement ventilation compared to mixing ventilation is the best ventilation airflow organization, which is easier to reduce possibility of infection among the staff. However, among the three kinds of mixing ventilation, up-supply and the same side up-return is the best mixing ventilation airflow organization, which is easier to avoid spreading droplet aerosols.