Using swirling mixing jets for homogeneous blowing

A feeling of freshness is obtained by ventilators that create a movement in the ambient air. The aim of a ventilation system is to obtain a velocity d istribution as uniform as possible on a surface as large as possible. To en sure the "comfort" conditions, the air velocity must be in the range 0.3 to 0.6 m/s. This should be obtained as close to the system as possible, and i n a large volume. Using single simple or swirling jets leads to bad velocit y distribution on small areas. To ensure large flow rates, it should be nec essary to use numerous distributed jets. It is proposed here to study a sys tem that consists of a central swirling jet surrounded by inclined swirling jets. In this study, the influences of the main parameters are presented. These parameters are:the relative rotation directions (central jet versus s urrounding jets), the relative flow rates (central jet versus surrounding j ets), the difference between the angle of the central jet velocity and the angle of the surrounding jets velocity, the angle between the axis of the c entral jet and the axis of the surrounding jets, the distance between the s ystem and the roof, the distance between the surrounding jets and the centr al jet. It is shown that a good combination of these parameters leads to a good velocity distribution.