Three-Dimensional Buoyant Wall Jets Released Into a Coflowing Turbulent Boundary Layer

Experiments have been conducted in a water flume to simulate finite-length line sources of heat that issue horizontally at ground level into a coflowing turbulent shear flow. The downstream development of each buoyant jet is documented by detailed mean temperature measurements, which are analyzed to determine the jet trajectory, spread rates, and distance to the point of liftoff from the surface. In addition, a three-dimensional, parabolic, numerical model based on the fundamental conservation equations is developed. Model predictions of several buoyant jets compare reasonably with the experimental data and suggest that the strength of the streamwise vorticity plays an important role in governing liftoff of a buoyant wall jet from the surface.