Efficacy of face coverings in reducing transmission of COVID-19: Calculations based on models of droplet capture

In the COVID--19 pandemic, among more controversial issues is use of masks and face coverings. Much concern boils down to question -- just how effective are coverings? One means address this review our understanding physical mechanisms by which coverings operate steric interception, inertial impaction, diffusion electrostatic capture. We enquire as what extent these can be used predict efficacy combine predictions models exist in filtration literature compare with recent experiments lattice Boltzmann simulations, find reasonable agreement former good latter. Building on results, we explore parameter space for woven cotton fabrics show that three-layered cloth constructed comparable performance surgical under ideal conditions. Reusable thus present an environmentally friendly alternative so long seal adequate enough minimise leakage.