SMS Mevac UK Limited required a Computational Fluid Dynamics (CFD) analysis of a Fixed Fume Extraction Hood in order to understand the flow inside the hood, with a view to optimising its design.
Two CAD models of the fume extractor hood were supplied by SMS Mevac. The models had different sized slots in the horizontal and upper sections. The geometry was defeatured appropriately for CFD analysis and a fluid domain was derived for the inner portions of the hood. Some of the external/internal features of the hood which would not affect the flow were removed in order to mesh the model.
A boundary layer with an appropriate thickness was employed for the fluid domain walls to help capture the flow variations near the wall. In addition, a finer resolution mesh was placed on surfaces where there was a rapid change in fluid parameters or the geometric dimensions were relatively small.
A steady state, single fluid, non-buoyant, incompressible and isothermal CFD simulation was carried out in ANSYS CFX.
The boundary conditions applied to the two models were as follows:
The inlet was specified as an 'opening' boundary condition which allowed the fluid (in this case, air) to enter as well as leave the domain.
A volumetric suction flow rate of 50,000m3/h was applied at the main outlet of the hood.
Wall boundary conditions were given to all other surfaces through which there is no flow.