Axisymmetric Shallow Submerged Turbulent Jets

The modification of a jet flow pattern by a nearby free surface has previously received scant attention. An approximate mathematical model, employing an image jet and utilizing approximations to the P-function is developed to model momentum flux distributions downstream from a shallow submerged axisymmetric turbulent jet with a small initial inclination to the horizontal. The mathematical model is shown to compare well with two independent data sets—one for a horizontal jet and one for a jet with small inclination to the horizontal. In both cases the maximum velocity migrates upward toward the free surface downstream from the nozzle. The flow pattern is shown to be strongly affected by very small inclinations of the nozzle from the horizontal. Some of the observed and predicted effects might readily be erroneously attributed to density differences between the effluent and the reservoir.