Numerical Model for Hydraulic Performance of Under-drained Perforated Pipe Surrounded by Loose Aggregate

Urbanization significantly alters the hydrological cycle, leading to reduced infiltration, increased flooding, and reduced water quality. Proper management of storm-water runoff is necessary to mitigate these undesired impacts. The use of Best Management Practices (BMP) and Low Impact Development (LID) is becoming more common day by day for this purpose and perforated pipes are one of the main components of these LIDs and BMPs. This poster presents results from a CFD model that combines both porous media flow and pipe flow. The model was developed in ANSYS FLUENT to examine the hydraulic behavior (stage-discharge relationship) of a porous pipe shrouded in loose aggregate for use as an underdrain in storm water management. The model was validated against the experimental data of Murphy et al. (2014) and was then used to undertake a detailed parametric study of porous pipe underdrain performance.