Covid 19 Airborne Risk Measuring in a Classroom

Covid 19 Airborne Risk Measuring in a Classroom, ANSYS Fluent CFD Simulation Training

This simulation is about covid 19 airborne risk measuring in a classroom via ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

Corona (COVID-19) is currently recognized as the most significant human challenge globally; Because this virus, in addition to being dangerous to human health, has a high transmission power between sick people and healthy people.

The breathing of a patient without a mask in a closed public environment transmits the virus to their neighbors. One of the doctors’ critical recommendations regarding preventing virus transmission is maintaining a proper social distance between people in such places.

For example, a short distance between a university student seat or a schoolboy in a classroom can increase the risk of transmitting COVID-19 disease from a patient to other people nearby.

This project simulates the breath of viral air from the mouth of sick coronavirus-carrier students in the classroom. This project aims to investigate the effectiveness of the ventilation system installed in the classroom in eliminating polluted air and cleaning the air.

In this project, a ventilation system has been used, with several vents for the entry of fresh air flow from the ceiling of the classroom and several panels for the exit of the old airflow at the bottom of the classroom’s sidewalls.

The geometry of the present model is drawn by Design Modeler software. This model includes a computational zone in the form of a classroom and chairs inside which a student is modeled on each of the chairs. For each student, a surface is defined as the mouth’s source for breathing and virus transmission.

The model is then meshed by ANSYS Meshing software. The model mesh is unstructured, and 2745511 cells have been created.

Covid 19 Method

For the present simulation, the discrete phase model (DPM) is used; Because this model allows us to study a mass of particles discretely in a continuous fluid (air). The discrete phase corresponding to the virus particles is defined in the steady-state solver.

After activating the discrete phase model, the injection process must be defined, determining the type and quality of discrete particles injected into the classroom.

In this model, the virus particles are defined as inert particles, and the injection type is surface and through the inner surface of the mouth of each student (mouth).

The discrete phase model’s boundary conditions are defined in the classroom with Escape mode, meaning that the particles pass through these boundaries. All the people and the body of the chairs and the classroom’s side walls have a Trap mode, which means that particles are trapped and accumulate in these borders.

Covid 19 Conclusion

After simulation, particle tracking of the virus particles is obtained based on the residence time of 60 s. Also, 2D and 3D contours related to temperature and air velocity inside the classroom have been obtained. The flow path lines are also obtained in 3D.

The results show that this ventilation system is inappropriate for the classroom and increases the risk of virus dispersion. This is because the virus particles spread completely in the classroom’s interior. In other words, the classroom ventilation system’s mechanism helps the virus survive in space.