Author(s): Xiaohang Pang; Geoffrey O’Loughlin
Linked Author(s):
Keywords: Stormwater inlets; Pipe hydraulics; Hydraulic head; Energy loss; Flow transitions; Priming
Abstract: Stormwater drainage system designers and analysts commonly define hydraulic grade lines (HGLs) along pipe systems, based on energy losses. Hydraulic behaviour at stormwater pits is complex, and information on HGL changes at pits is incomplete, especially for part-full flows and transitions to full-pipe flow. The paper describes the first phase of a laboratory study of pressure changes at pits. Several configurations of a straight through flow pit, with one inlet pipe, a top inflow, and an outlet pipe were examined using an experimental rig at the University of Technology, Sydney. Stepped triangular flow hydrographs were directed through the rig, with flowrates and HGLs being recorded electronically. Typical results are presented, showing the diversity and complexity of flow mechanisms. A classification of pit flow configurations is presented, as an aid to developing algorithms to define energy and pressure changes over the full cycle of filling and emptying of pipe systems.
Year: 2011