  The education sector has suffered a catastrophic setback due to ongoing
COVID-pandemic, with classrooms being closed indefinitely. The current study
aims to solve the existing dilemma by examining COVID transmission inside a
classroom and providing long-term sustainable solutions. In this work, a
standard 5m x 3m x 5m classroom is considered where 24 students are seated,
accompanied by a teacher. A computational fluid dynamics simulation based on
OpenFOAM is performed using a Eulerian-Lagrangian framework. Based on the
stochastic dose response framework, we have evaluated the infection risk in the
classroom for two distinct cases: (i) certain students are infected (ii) the
teacher is infected. If the teacher is infected, the probability of infection
could reach 100% for certain students. When certain students are infected, the
maximum infection risk for a susceptible person reaches 30%. The commonly used
cloth mask proves to be ineffective in providing protection against infection
transmission reducing the maximum infection probability by approximately 26%
only. Another commonly used solution in the form of shields installed on desks
have also failed to provide adequate protection against infection reducing the
infection risk only by 50%. Furthermore, the shields serves as a source of
fomite mode of infection. Screens suspended from the ceiling, which entrap
droplets, have been proposed as a novel solution that reduces the infection
risk by 90% and 95% compared to the no screen scenario besides being completely
devoid of fomite infection mode. As a result of the screens, the class-time can
be extended by 55 minutes.
