The steady flow of heated water from a channel into a reservoir or lake
has been studied analytically and experimentally. A three-dimensional
buoyant-jet-type model has been developed to predict the main trajectory,
velocity, and temperature distributions in that portion of the
plume in which the flow is dominated by the momentum and the buoyancy
of the discharge and has free boundaries. The interaction between
turbulent mixing, buoyant spreading, and surface cooling, which are
crucial for the development of any thermal plume, can be illustrated
with the aid of the model. The effects of weak cross currents and weak
wind on the development of a surface plume are also incorporated into
the model. The model does not apply to heated water discharges which
cling to a shoreline due to a particular shoreline configuration or to
wind or current conditions. The effects of cold water wedge penetration
into an outlet channel can be accommodated by the model.
Experimental results on temperature and velocity distributions in free-jet-type three-dimensional thermal plumes have been used to verify some
of the assumptions made in the numerical model, particularly those regarding
Gaussian velocity and temperature distributions and lateral
spread coefficients. In addition, the measurements have been used to
illustrate changes in total flow rate, total heat storage, and dimensions
of a surface plume. The distribution of temperatures, velocities,
and Richardson numbers in an experimental surface plume has been illustrated
using different types of contour plots. There is reasonable agreement
between the results of the experiments and the proposed analytical
Surface Discharge of Heated Water, Part I: Three-Dimensional Jet-Type Surface Plumes in Theory and in the Laboratory.
St. Anthony Falls Hydraulic Laboratory.
Retrieved from the University of Minnesota Digital Conservancy,
Content distributed via the University of Minnesota's Digital Conservancy may be subject to additional license and use restrictions applied by the depositor.