Flow establishment and initial entrainment of heated water surface jets

Mathematical models to predict water temperature distributions resulting from heated water surface discharges usually consider three subregions of the flow field: an outlet region or zone of flow establishment (ZFE); a zone of fully established jet flow; and a far field with mostly passive dispersion. Of these three regions, the second zone can be treated mathematically most readily using integral techniques; the third zone requires input specifying mean flow and turbulence of the ambient flow field; and the first zone depends essentially on the geometry of the outlet and the discharge characteristics in terms of the velocity and temperature of the water. The results of an experimental study dealing with the outlet region zone are reported. The discharge channel had a rectangular cross section and led into a deep, wide reservoir. The aspect ratio (width-to-depth ratio) of the channel, the volumetric discharge rate, and the discharge temperature were varied. A cross-flow was imposed in some of the experiments. (U.S.)