公共场所空间内气溶胶的扩散特性研究

通过数值仿真对局部触发的病毒气溶胶在公共室内环境中的传播规律进行预测. 采用常用的Realizable k-ε湍流模型研究公共空间内气溶胶瞬态扩散特性. 气溶胶颗粒在密闭空间中随时间向前上方向扩散，随室内环流存留在空气中. 当颗粒喷出后15 s内仅少数大颗粒落地，在60 s时部分颗粒附着于墙壁、人体，而70.86%(颗粒数目残留率)的颗粒存在于室内空气中. 提出3种通风方案:对侧通风、上送两侧通风、单侧通风-对侧/上侧回风. 通风条件破坏了原有的室内环流，颗粒随气流流出排风口. 结果发现:对侧通风方案中室内颗粒残留率为65.4%，上送两侧回风方案中残留率为63.22%，单侧通风-对侧/上侧回风方案中残留率为70.32%. 因此，上送两侧回风方案颗粒物传播距离较短，且颗粒残留率较低，是较理想的通风方案.

The Characteristics of Aerosol Diffusion in a Public Space

Numerical simulation was used to predict the spread of locally triggered virus aerosols in a public indoor environment. The common realizable k-ε turbulence model was used to study the transient diffusion characteristics of aerosols in a public space. Aerosol particles diffused forward and upward over time in a confined space and finally stayed in the air with the indoor circulation. After the particles were ejected, only a few large particles fall to the ground within 15 s, some particles adhered to the wall and the human body in 60 s, and 70.86%(particle number residual rate) of the particles were still in the indoor air. On this basis, a comparative study of three ventilation schemes was carried out, including opposite-side ventilation, upper-side ventilation, and single-side air ventilation of opposite- and upper-side return air. Ventilation conditions destroyed the original indoor circulation, and particles flew out of the exhaust vent along with the airflow. The results showed that the residual rate of indoor particles in the opposite ventilation scheme was 65.40%, that in the upper-side ventilation scheme was 63.22%, that in the single-side air ventilation scheme was 70.32%. Therefore, the upper-side ventilation scheme has a shorter particle transmission distance and a lower residual rate of indoor particles, which is an ideal ventilation scheme for reducing aerosols in a public spaces.