Investigation of stormwater drainage systems with experimental and numerical methods

In this thesis, a present stormwater system was investigated with experimental and numerical modeling. The stormwater system consists of a manhole and four pipes. The selected structure is useless because it is overflowing. A 1:10 scaled physical model of the structure was set up for experimental modeling. Later, the same scaled model was modeled with Computational Fluid Dynamics (CFD) for good validation. CFD method defined problems in the structure and so empirical methods and CFD were compared for applications in stormwater design. Four new structure were designed and tested with CFD for applicability in this problem. Firstly, the problem and the characteristics of flow were investigated with the experimental model. And then numerical model was set up that using ANSYS CFX software. CFD results and experimental results were compared well done. Parameters were water levels, outlet discharge and pressure at a fixed point. It proved that a validated CFD model is a good tool to design and test stormwater systems. CFD analysis and regulations based on the Manning equation were compared for stormwater design and performance. It concludes that regulations and Manning Equation are not sufficient for some specific applications. This work also shows that CFD is a valid tool to investigate special geometries for specific problems. New four modifications were tested successfully for the problem. Different mesh structures and turbulence models were also investigated for such stormwater structures.