Abstract:

Motivated by attempts to reduce the spread of disease during the current pandemic, we investigate modifications to heating, ventilation, and air-conditioning (HVAC) systems. Our aim is to minimize airborne droplet transport, modelled as an advection-diffusion PDE, through optimization of ventilation and management of airflow patterns within the built environment. Thus, we consider the optimization of turbulent flows within enclosed environments using the direct-adjoint-looping (DAL) optimization. We use the incompressible Reynolds-averaged Navier-Stokes (RANS) equations, derive the corresponding adjoint equations and solve the resulting sensitivity equations with respect to boundary conditions. For validation, we solve an inverse-design problem, for which we recover known globally optimal solutions. We then solve the minimal mixing problem for a passive scalar in a region of interest, as representative of potentially infected droplet transfer between occupants. It is shown that the exposure time of occupants reduce drastically by optimizing merely the direction of the inlet velocity.