Operating inlet pressure head assessment for multi-outlet submain manifolds in a low-pressurized water distribution network system

Abstract Multi-outlet pipes can be used to distribute and collect fluids and have applications in various engineering fields, especially in the water supply system. The hydraulic design of a submain unit pipeline with multiple outlets is a very important concern for the proper hydraulic performance of irrigation water distribution systems. The operating inlet pressure head, H0I, is a main hydraulic component for the proper hydraulically efficient design and evaluation of pressure head distribution along the line. The energy-gradient ratio (EGR) approach is a useful tool to identify first which type of pressure profile occurs for a given uniform design slope with other hydraulic variables initially known and then, comprehensively evaluate its definite hydraulic characteristics along the line. Knowing the hydraulic properties of any type of pressure profile regarded enables the design engineer to evaluate pressure parameters through the line sections in a simple way. The procedure is simplified by regarding the localized head loss along the pipe but neglecting the change in kinetic head. The present analytical technique performs sufficiently accurate in comparison with the computer-aided software design technique, for all performed simulations.