Multi-objective-oriented removal of airborne pollutants from a slot-ventilated enclosure subjected to mechanical and multi component buoyancy flows

Abstract

• Enclosure flows subjected to mechanical and buoyancy forces simultaneously. • Removal of airborne pollutants is optimized by an inverse convection problem. • Single and multi objective optimizations are implemented separately for many cases. • Optimal values of spatial average concentration and mean radius of diffusion are determined. Slot-ventilated enclosure flows, jointly driven by two component buoyancy forces and forced ventilation, extensively exist in the industrial and civil environment. Inverse fluid flow solutions of the multi-objective oriented removal of airborne pollutants from the slot ventilated enclosure, simultaneously subjected to mechanical forces and multi-component buoyancy forces, are conducted in the present work. A simplified conjugate gradient methodology has been implemented to provide effective convection removal of contaminants, under different flow regimes. In particular, direct and inverse convection problems are subsequently solved in detail. For the direct convection problem, aiding and opposing multi-component buoyancy effects are included to study the convective heat and species transport mechanism. For the inverse optimization problem, a single-objective optimization is firstly implemented, which also provides input parameters for the multi-objective optimization. Following that, a multi-objective function is set up by combining the two single objectives involving the spatial average concentration and the mean radius of diffusion. Multi-objective optimization is then implemented depending on the conjugate gradient procedures. Both the single and multi-objectives could be achieved reasonably through positioning of local heating sources and the free vent outlet. Our solution methodology will be useful for improving room pollutant removal and developing efficient ventilation strategies.