Assessment of inlet efficiency through a 3D simulation: numerical and experimental comparison.

Inlet efficiency is a requirement for characterizing the flow transfers between surface and sewer flow during rain events. The dual drainage approach is based on the joint analysis of both upper and lower drainage levels, and the flow transfer is one of the relevant elements to define properly this joint behaviour. This paper presents the results of an experimental and numerical investigation about the inlet efficiency definition. A full scale (1:1) test platform located in the Technical University of Catalonia (UPC) reproduces both the runoff process in streets and the water entering the inlet. Data from tests performed on this platform allow the inlet efficiency to be estimated as a function of significant hydraulic and geometrical parameters. A reproduction of these tests through a numerical three-dimensional code (Flow-3D) has been carried out simulating this type of flow by solving the RANS equations. The aim of the work was to reproduce the hydraulic performance of a previously tested grated inlet under several flow and geometric conditions using Flow-3D as a virtual laboratory. This will allow inlet efficiencies to be obtained without previous experimental tests. Moreover, the 3D model allows a better understanding of the hydraulics of the flow interception and the flow patterns approaching the inlet.

[1]  Jorge Leandro,et al.  Numerical and experimental investigation of a gully under surcharge conditions , 2015 .

[2]  Manuel Gómez,et al.  Methodology to estimate hydraulic efficiency of drain inlets , 2011 .

[3]  Leslie M. Smith,et al.  The renormalization group, the ɛ-expansion and derivation of turbulence models , 1992 .

[4]  Bruce M. Savage,et al.  Flow over ogee spillway : Physical and numerical model case study , 2001 .

[5]  J. Smagorinsky,et al.  GENERAL CIRCULATION EXPERIMENTS WITH THE PRIMITIVE EQUATIONS , 1963 .

[6]  Theo G. Schmitt,et al.  Analysis and modeling of flooding in urban drainage systems , 2004 .

[7]  C. W. Hirt,et al.  Volume of fluid (VOF) method for the dynamics of free boundaries , 1981 .

[8]  S. Orszag,et al.  Renormalization group analysis of turbulence. I. Basic theory , 1986 .

[9]  O. Ubbink.  Numerical prediction of two fluid systems with sharp interfaces , 1997 .

[10]  S. Djordjević,et al.  Experimental and numerical investigation of interactions between above and below ground drainage systems. , 2012, Water science and technology : a journal of the International Association on Water Pollution Research.

[11]  Manuel Gómez,et al.  Experimental campaign to determine grated inlet clogging factors in an urban catchment of Barcelona , 2013 .

[12]  J A E ten Veldhuis,et al.  The efficiency of asset management strategies to reduce urban flood risk. , 2011, Water science and technology : a journal of the International Association on Water Pollution Research.