Source Buoyancy Flux Research Articles

Horizontal Round Buoyant Jet in Shallow Water

A common outfall configuration in practice involves a buoyant discharge through a horizontal circular pipe into a shallow body of water. A detailed experimental study of the near‐field flow and mixing characteristics is presented. The proximity of the bed and the free surface has a significant influence on the flow pattern. Experimental results are adequately represented by length and buoyancy scales defined by source momentum and source buoyancy flux. Jet path, centerline dilution and horizontal and vertical half widths are compared with an integral model in an unconfined environment.

Buoyant Contaminant Plumes in Groundwater

Buoyant contaminant groundwater plumes occur when liquid wastes which have densities different from groundwater are released from various land disposal activities (e.g., landfills, infiltration lagoons, injection wells). By using mass and momentum conservation equations, an analytical model for plume characteristics and behavior (namely, trajectory, concentration, and boundary) is developed for steady flow in a homogeneous, isotropic aquifer. The model predicts that plume behavior and characteristics are different close to the source from those far from the source. Solutions of the model yield dimensionless relations for the plume characteristics and behavior in each region in terms of length and concentration scales representing the combined effects of the source buoyancy flux and size and the ambient groundwater flow and dispersion. Experimental results, from a series of tests in a homogeneous, isotropic sand medium with a salt water discharge, are in reasonable agreement with model predictions. The model results have application to field problems under similar conditions.

Effective source flux parameters for use in analytical plume rise models

The derivation of analytical or closed form plume rise and growth formulas is reviewed in order to clarify (a) the relationship between the various forms of the formulas which appear in the literature and (b) the relationship between the different source momentum and buoyancy flux definitions which appear in the literature. In particular, the effective source radius, source momentum flux parameter, and source buoyancy flux parameter, consistent with the assumptions inherent in analytical models, are discussed. The importance of using corrected source flux terms is illustrated by comparing predictions with field observations of a plume from a large industrial source.

A note on the maximum ground level concentration for inversion-limited chimney plumes

A model is proposed for the determination of the maximum ground level concentration for buoyant chimney plumes whose rise is limited by the inversion overlying a convective atmospheric boundary layer. Manins' critical parameter for inversion penetration is shown to be equivalent to a geometric constraint on the solution for maximum plume rise in the author's model for unrestricted plume rise. A proposed solution for maximum surface concentration based on an effective source rate at the inversion modified for inversion entrainment has the same functional form as a previous solution for the unrestricted case. Experimental analysis suggests the existence of the critical value of source buoyancy flux in terms of ambient parameters, and supports the validity of the form and order of magnitude of the maximum surface concentration.