Determination method and device for unit-width sediment discharge of approach channel and forebay of pumping station

Abstract

The embodiment of the invention provides a determination method and device for the unit-width sediment discharge of an approach channel and a forebay of a pumping station. The method comprises the steps that the outer boundary layer flow speed, the flow period, the sediment particle size, the ratio of sediment to water density, and the water kinematic viscosity coefficient of water bodies of the approach channel and the forebay of the pumping station are obtained; the Shields number and the friction factor of a reciprocating flow sediment-containing movable bed surface are obtained; and on thebasis of all the parameters, boundary layer asymmetry analysis of the movable bed surface is carried out, and the erosion depth and the boundary layer thickness are obtained, so that the instantaneous unit-width sediment discharge of a volume meter under the reciprocating flow condition is obtained. According to the embodiment, design calculation is carried out through the determined related boundary layer thickness of the movable bed surface and determined phase difference parameters, the phase residual of the sediment discharge after the flow velocity is reduced and the phase drift of the relative flow velocity are reflected, the relation between the instantaneous sediment discharge and the flow velocity times is given, and negative net sediment transport generated by the large phase difference effect in asymmetric flow is judged.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of water conservancy engineering, and in particular to a method and a device for determining the single-width sediment delivery rate of a pumping station diversion canal and a forebay. Background technique [0002] In the reciprocating flow of the diversion channel of the pumping station and the sandy bed surface of the forebay, the single-width sediment transport rate is dynamically changed. The instantaneous single-width sediment transport rate widely used in engineering is derived based on the theory of constant flow, which fails to reflect the asymmetric development and phase difference of the reciprocating flow boundary layer. [0003] This leads to its disadvantages: it cannot reflect the phase drift and phase residue of the sediment delivery rate relative to the flow velocity, and cannot give the relationship between the instantaneous sediment delivery rate and the flow veloc...

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Problems solved by technology

[0003] This leads to its disadvantages: it cannot reflect the phase drift and phase residue of the sediment delivery rate relative to the flow velocity, and cannot give the relationship between the instantaneous sediment delivery rate and the flow velocity times, and is not suitable for the negative net sediment delivery caused by the large phase difference in the asymmetric flow. situation

But so far, how to give the instantaneous single-width sediment delivery rate of the pumping station diversion channel and the sandy bed surface of the forebay under the condition of reciprocating flow, there are no achievements and methods for reference

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