The numerical modelling of a two-dimensional local exhaust system associated with an inclined jet flow

Previous mathematical models employed by the authors have been further developed in order to consider the effect of an inclined jet on the air flow of a two-dimensional bench-slot Aaberg exhaust system. The air flow in this local exhaust ventilation system is solved using two approaches, namely, (i) a simple potential-flow model and seeking the solution of the resulting Laplace equation by means of a boundary-integral technique, and (ii) a turbulent model using the k-ε formulation and solving the resulting turbulent Navier-Stokes equations by means of a control-volume method and the SIMPLE algorithm. The effect of the angle α that the jet makes with the direction of the surface of the workbench and the momentum ratio on the air flow in the exhaust system are investigated. It is found that, by inclining the jet, the system can become more energy efficient and the region of capture of the contaminant from close to the bench can be increased.