The Velocity Characteristics of Ventilated Rooms

Measured and calculated values of the velocity characteristics of a modeled room with ventilation arrangements are reported. The measurements were obtained by laser-Doppler anemometry and the calculations by the solution, in finite-difference form, of two-dimensional, elliptic, partial-differential equations representing conservation of mass, momentum, turbulence energy and dissipation rate. The results demonstrate that the precision of calculation is adequate for design purposes although, for slots much smaller than the width of the room, three-dimensional effects become important. They quantify, for example, the extent to which a decrease in supply area leads to an increase in air velocities for a given mass flow rate.