Assessment of velocity fields in the vicinity of rectangular exhaust hood openings.

Presents new empirical formulae for the prediction of the air velocity in front of rectangular (slot) openings. Infers the equations from an experimental study of a common type of local exhaust opening. The formulae describe the three-dimensional velocity field near a rectangular exhaust hood, providing the velocity gradients along suitable directions, parallel to the slot axis. Testing of the formulae showed a good fit to the experimental data. The authors emphasise the simplicity and user-friendliness of the method for predicting the air velocity in front of a suction opening and for correctly dimensioning a local exhaust ventilation system.