Hydraulic model study of a manhole junction

The object of this investigation was the experimental investigation of the hydraulics of a flow-through manhole with one lateral connection. An attempt was made to use the conservation of momentum principle to develop a mathematical relationship which satisfied the data obtained in the model study. Three forms of the momentum equation were developed by statistical evaluation of loss coefficients. The best of the three equations was chosen on the basis of its ability to predict flow depths and its consistency with hydraulic concepts. A procedure was then developed for using this equation to obtain a value of the required outlet pipe invert 'drop for a given set of flow conditions. The use of the procedure was illustrated by the solution of an example problem·of a system of three pipes.