The Annals of Occupational Hygiene · 1977 · 28 citations · 0 references
EngineeringMechanical EngineeringAerodynamicsFluid DynamicsGeometric ModelingAspect RatioExperimental AerodynamicsAspect Ratio DesignAspect Ratio EffectsExhaust Hood GeometrySlot Hood DesignVariable Aspect Ratio
Measurements of centreline velocities in front of rectangular unflanged exhaust hoods, with areas between 25 and 900 cm2 and aspect ratios (ratio of slot length to its width) between 1: 1 and 16: 1 have shown that for a given face area and volume flow the velocity at a fixed point decreases as the aspect ratio increases. The present experiments show that design formulae previously used to predict these velocities are not valid over the range of aspect ratios usually claimed for them, and a new non-dimensionalized formula which takes account of aspect ratio is proposed.