Study On Transport Mechanisms Of Bio-aerosol Produced By Mouth In The Indoor Environment

The issue of indoor microbe contamination gradually draws widely and highly attentions of scholars all around the world. It has been proved by the results of enormous researches that the bio-particles containing virus and microbe, etc. can spread through air. Especially in the room or other sealed spaces which are crowded with people, the potential to contact with virus and then be infected is much higher. Thus the research on movement and transport of bio-particles indoor is critical and indispensable. Human body much as mouth, as the main source of indoor bio-aerosols, is discussed in this paper.The physics aerosol transport model as the basic analysis method is used combined with bio-aerosols character to build bio-particle transport mechanism. Basing on the Lagrangian equation, the Monte Carlo (MC) modeling method will be coupled into this simulation program to describe the bio-particle transport mechanism indoor. Many influent factors such as indoor airflow velocity,ventilation system model , the bio-aerosol generator velocity , particle diameter , and evaporation and death are considered synthetically in this paper. Consulting the normal aerosol outdoor dispersion model, the indoor bio-aerosol dispersion model is given. Compared with the experiment result, this bio-aerosol dispersion model is more accuracy.Meanwhile, a human emanation bio-aerosol simulation system is built in this paper. Under the experiment proved, the number of aerosol, the diameter distributing, and microbe content in the aerosol are same to the real condition. Though different location and different air condition experiment discussion, the transport result of bio-particle produced by mouth under different generator velocity, different indoor cleanness degree and different airflow velocity is given. As a result of each cough, the affected area extended as far as 2m, and the bio-particle produced by sneeze can transport farther distance.Using FLUENT to simulate bio-particle produced by human transport mechanism. First the simulation result and the experiment results are compared to prove the accuracy of the simulation. Then, more simulation cases are given to analysis different airflow condition, different ventilation system, different particle diameter'influence of indoor transport. Last, a new conception of indoor bio-aerosol life age is given to illustrate that the different particle size bio-aerosol's indoor survival time and influence ability are different. Building indoor environment regular and emergency control strategies and methods are developed.Additionally, reverse search source of bio-particle method is given using the VB program.