Submitted by Maria.Kapsalaki on Thu, 11/23/2017 - 16:09
Experiments are presented on turbulent buoyant free-line and wall plumes, whereby the buoyancy source is emitted from a horizontal line source, in one case free of the presence of a wall and in the other placed immediately adjacent to a wall. The dynamics of turbulent entrainment, whereby ambient fluid is mixed in to the plume, are explored. The velocity field and scalar edge of the plumes are measured. From this the time-averaged plume-width and volume flux are compared.
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 aim of this study was to ascertain the validity of using computational fluid dynamics (CFD) techniques to predict the behaviour of three dimensional gravity induced natural convection buoyant plumes from a vertical heated cylinder in a large quiescent enclosure. The calculated velocity distributions and turbulence quantities over the cylinder were compared to a wide range of experimental measurements. The laminar boundary layer on an isothermal vertical plate was also modelled. The CFX4.