Prediction of natural convection from an array of horizontal line heat sources in a large space.

The buoyant plume characteristics of heat sources and their relation to geometric factors are of fundamental importance to the effectiveness of the displacement ventilation. The interactions in buoyant plumes from an array of horizontal line heat sources are investigated systematically with Mach-Zehnder interferometer. Based on the discussion about convective flow patterns of a single lime heat source, the characteristic velocity and temperature to character the accumulating buoyancy effects of an array of horizontal line heat sources are proposed. The accumulating buoyancy effect Grasholff number is suggested and defined. A combined natural and "forced" convection model is proposed for predicting the natural convection from horizontal line heat sources. The measurements for natural convection are performed. The agreement between the analytical results and experimental data is satisfactory.