Numerical investigation into influence of heating obstacle on airflow distribution inside fume hoods

Using CFD method simulates airflow distribution inside fume hoods for the empty hood, the hood with an obstacle and the hood with a heating obstacle, respectively. The results show that a heating obstacle has a significant effect on the airflow distribution inside the fume hood. For the situation that the heating obstacle is placed in the middle of operating floor of the fume hood, the blocking effect to the incoming airflow produces symmetrically distributed eddies at the two sides and leeward side around the heating obstacle, and the eddies on the top, which is not beneficial to exhaust the contaminants; but the buoyancy generated by the heating obstacle is helpful to drive the airflow up to the outlet, especially for the airflow near the front wall of the fume hood, however, the improvement to the airflow distribution is associated with heat load of the heating obstacle; when the heating obstacle is close to the opening or the rear wall of the fume hood, the airflow pattern is less effective to exhaust the contaminants.