Experimental calibration and validation of sewer/surface flow exchange equations in steady and unsteady flow conditions

JOURNAL OF HYDROLOGY

卷:552

Article

Rubinato, Matteo¹  Martins, Ricardo^1,2,3  Kesserwani, Georges¹  Leandro, Jorge^2,3,4  Djordjevic, Slobodan⁵  Shucksmith, James¹ 

[1] Univ Sheffield, Dept Civil & Struct Engn, Mappin Bldg, Sheffield S1 3JD, S Yorkshire, England

[2] Univ Coimbra, Fac Sci & Technol, Dept Civil Engn, MARE Marine & Environm Sci Ctr, P-3004517 Coimbra, Portugal

[3] Univ Coimbra, Fac Sci & Technol, IMAR Inst Marine Res, P-3004517 Coimbra, Portugal

[4] Tech Univ Munich, Chair Hydrol & River Basin Management, Dept Civil Geo & Environm Engn, Arcisstr 21, D-80333 Munich, Germany

[5] Univ Exeter, Ctr Water Syst, North Pk Rd, Exeter EX4 4QF, Devon, England

关键词: Sewer and free surface interactions;    Discharge coefficients;    Experimental and numerical validations;    Steady and unsteady modelling;   

DOI  :  10.1016/j.jhydrol.2017.06.024

来源: Elsevier

【 摘 要 】

The linkage between sewer pipe flow and floodplain flow is recognised to induce an important source of uncertainty within two-dimensional (2D) urban flood models. This uncertainty is often attributed to the use of empirical hydraulic formulae (the one-dimensional (1D) weir and orifice steady flow equations) to achieve data-connectivity at the linking interface, which require the determination of discharge coefficients. Because of the paucity of high resolution localised data for this type of flows, the current understanding and quantification of a suitable range for those discharge coefficients is somewhat lacking. To fulfil this gap, this work presents the results acquired from an instrumented physical model designed to study the interaction between a pipe network flow and a floodplain flow. The full range of sewer-to-surface and surface-to-sewer flow conditions at the exchange zone are experimentally analysed in both steady and unsteady flow regimes. Steady state measured discharges are first analysed considering the relationship between the energy heads from the sewer flow and the floodplain flow; these results show that existing weir and orifice formulae are valid for describing the flow exchange for the present physical model, and yield new calibrated discharge coefficients for each of the flow conditions. The measured exchange discharges are also integrated (as a source term) within a 2D numerical flood model (a finite volume solver to the 2D Shallow Water Equations (SWE)), which is shown to reproduce the observed coefficients. This calibrated numerical model is then used to simulate a series of unsteady flow tests reproduced within the experimental facility. Results show that the numerical model overestimated the values of mean surcharge flow rate. This suggests the occurrence of additional head losses in unsteady conditions which are not currently accounted for within flood models calibrated in steady flow conditions. (C) 2017 The Author(s). Published by Elsevier B.V.

【 授权许可】

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