OUTFLOW CHARACTERISTICS FROM CIRCULAR PIPE

The characteristics of jets issued by partially filled pipes are studi ed. The main flow features of such jets are specified, based on system atic observations and accounting for the Froude similarity. The end de pth ratio, i.e., the depth at the section of issue normalized to the a pproach flow depth is predicted with the momentum equation. Further, a n expression for the drawdown curve, from the approach Bow to the end section is presented. Then, the lower and the upper trajectories of th e jet issued into the atmosphere are studied, and expressions are give n for the lower trajectory and the axial jet thickness. The analysis a ccounts for a novel dimensionless axial coordinate in which effects of approach filling and approach Froude number are included. The dimensi onless coordinate in the streamwise direction may be considered as the expansion of a familiar term known in hypercritical plane flow. Addit ional data refer to the modular limit of pipe outflows and to submerge nce effects. Photographs illustrate the flow features.