Dpiv technology-based test device for flow capacity of gullies and its checking method

Abstract

The invention discloses a rainwater port overflow capability test apparatus based on a digital particle image velocimetry (DPIV) technology, and a check method thereof. The apparatus comprises a waterpower experiment model portion and a flow field measurement portion, wherein the waterpower experiment model portion comprises a rainwater simulation subsystem, a land surface converging subsystem and a rainwater discharge subsystem, and the flow field measurement portion comprises a high-speed image acquisition subsystem and an image real-time processing analysis subsystem. The overflow capability of a rainwater port is checked by use of the apparatus and the method provided by the invention, the real city land surface runoff process can be quite accurately reflected, constructed land surface features accord with actual city land surface structure features quite well, the flow speed distribution feature of the water incoming periphery of the rainwater port can be accurately measured by use of the DPIV technology, different installation forms of the rainwater port, different land surface materials and overflow features of different overflow states are accurately determined, and a technical reference is provided for engineering design and actual operation management.

Description

Technical field [0001] The invention discloses a rainwater outlet flow capacity test device based on DPIV technology and a checking method thereof, and belongs to the field of municipal water supply and drainage public facilities. Background technique [0002] As an important rainwater discharge infrastructure, urban road gutters convert the surface runoff state of rainwater into underground pipe network flow. Therefore, gutter layout and water collection capacity are directly related to the smooth discharge of rainwater. [0003] According to domestic literature search, the current design and calculation of the drainage capacity of the gully mainly adopts the "Outdoor Drainage Design Specification" (GB50014-2006, 2011 edition) drainage indicators, and the drainage capacity of the gully is related to the road slope, gutter type, grate Factors such as the depth of the front water are related. Due to the complicated factors of the gutter discharge capacity and the large value specifi...

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Problems solved by technology

[0004] The above methods for checking the flow capacity of gullies have the following shortcomings: (1) It is difficult to determine the calculation parameters

In the process of calculating the flow capacity of gullies using calculation formulas, there is a problem that the coefficients of different flow regimes (weir flow and orifice inflow) are difficult to determine accurately, because of the different forms of gullies and different surface materials, resulting in the depth of water in front of the gullies. There are changes, the correlation coefficient in the calculation formula is difficult to accurately determine, and there are errors between the calculation results and the actual flow state; (2) The water distribution method using channels is unscientific

Because the horizontal velocity of the real surface runoff process is relatively gentle, the rainfall in the sky falls to the surface to form runoff, and the velocity of the flow along the surface is relatively gentle. After adopting the channel water distribution method, the flow velocity along the tangential direction of the surface was increased during the experiment. There are large errors between the experimental process and the actual surface runoff process; (3) The factors affecting the underlying surface are not considered enough

With the development of sponge city construction, various permeable pavement materials are used on the surface, which will more obviously disturb the flow of surface runoff and directly affect the water collection process of rainwater outlets. Therefore, various permeable pavement materials and engineering renovation measures for sponge cities are required Carry out simulation to make the calibration of the water collection capacity of the stormwater outlet more accurate; (4) It is difficult to test the surface runoff process

It is difficult to measure the hydraulic state of the process from rainfall to runoff, and then to the confluence of stormwater outlets. It is difficult to test the flow state and flow field distribution characteristics of rainwater on the surface, so it is difficult to guide the optimal allocation of stormwater outlets and surface materials in engineering practice.

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