空气中传染性飞沫传播过程的数值模拟

发布时间：2018-01-03 10:40

本文关键词：空气中传染性飞沫传播过程的数值模拟　出处：《内蒙古科技大学》2011年硕士论文　论文类型：学位论文

【摘要】：非典型肺炎（俗称SARS）的爆发、禽流感疫情的出现和甲型H1N1流感病毒的流行，使得空气中有关微生物污染方面的研究引起了世界各国的广泛关注，并得到广大学者广泛而高度的重视。随着公共卫生事件的一次次发生，人们对通过飞沫进行传播的疾病的研究也越来越深入，大量的相关资料及研究成果，都已经表明含有病毒等微生物的微粒可以通过空气进行传播，在空气流动比较差的地方或人员相当密集的封闭空间人们更容易接触和感染病菌，因此有必要对生物颗粒物在空气中的运动和传播规律进行研究。患病人体在呼吸、咳嗽或打喷嚏时，都会释放含有病毒或细菌的飞沫，本文将对这三个生理过程所产生飞沫的运动现象进行分析。首先，运用流体力学计算软件，分别取0.3m/s,10m/s和40m/s三个呼出气流速度对应正常呼吸、咳嗽（咳嗽一次和连续咳嗽）和打喷嚏三个过程，分析不同工况下产生的飞沫在空气中的运动和传播规律。结果表明：人体在呼吸过程中，产生的飞沫在沿呼出气流直线方向上，可以传播至4m；咳嗽一次产生的飞沫，在5s内可以传播3m，连续咳嗽产生的飞沫，在5s内可以传播4.5m；打喷嚏一次产生的飞沫，在1s内也可以传播至4.5m。然后，将连续咳嗽过程的模拟结果与天津大学的学者关于“室内生物颗粒物运动和传播的实验研究”中的实验结果进行对比发现，在飞沫发生方向上的传播过程，无论是在飞沫的传播距离上还是浓度分布上，，二者完全吻合；在传播方向的两侧各1.5m处，沿与传播方向平行的方向上，模拟结果与实验结果也基本吻合，并且模拟结果更直观地解释了实验研究与理论研究之间产生的偏差。此外，本文还对环境温度的变化对飞沫的传播过程的影响进行分析，选取环境温度为280K和298K两种工况进行计算，模拟结果表明：环境温度为280K时，呼出气流在周围空气中形成的影响范围较大，沿发生方向的传播距离相对较远。
[Abstract]:Atypical pneumonia (commonly known as SARS) the outbreak of avian flu and influenza a H1N1 influenza virus epidemic, which makes the research on air pollution of microorganism has attracted extensive attention all over the world, and the majority of scholars widely and highly attention. With a time of public health events, people study of disease spread through droplets is also more and more deeply, a lot of relevant data and research results, have shown that particles containing viruses and other microorganisms can be spread through the air, the air flow in the closed space of people with poor local or personnel intensive easier contact and infection of pathogenic bacteria, so it is necessary to study the bio particles in the air movement and propagation.
The prevalence of human breathing, coughing or sneezing, will release a virus or bacteria containing droplets, the phenomenon of movement of the three physiological process generated droplets were analyzed. Firstly, by using fluid mechanics calculation software, respectively 0.3m/s, 10m/s and 40m/s three exhaled air flow rate corresponding to the normal breathing, cough (a cough and continuous cough and sneezing) three processes, analysis under different conditions of the droplets in the air movement and propagation. The results show that the human body in the process of respiration, the droplets produced in a straight line along the direction of exhaled air, can spread to the 4m; a cough droplets produced in 5S. Can the spread of 3M, continuous cough droplets can spread in 5S 4.5m; a sneeze droplets produced in 1s, also spread to 4.5m.
Then, comparing the simulation results of continuous cough process and Tianjin University scholars "Studies" movement and transport of indoor bio particles in the experimental results were found during the transmission direction of the droplets, both in droplets spread distance or concentration distribution, two identical on both sides of communication; the direction of the 1.5m, along with the direction of propagation parallel to the direction, the simulation results and the experimental results are consistent, and the simulation results intuitively explain the deviation between the experimental and theoretical studies.
In addition, this paper also analyzed the impact of propagation to the environment temperature of droplets, selection of environmental temperature of 280K and 298K in two different conditions were calculated. The simulation results show that the environmental temperature is 280K, the influence range of exhaled air is formed in the air around the larger, along the direction of propagation occurred in a relatively far distance.

【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R311

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