CN-115563893-B - MPS numerical simulation method and device for interaction of river sediment and water body

CN115563893BCN 115563893 BCN115563893 BCN 115563893BCN-115563893-B

Abstract

The invention discloses a method and a device for simulating MPS (program product phase) numerical simulation of interaction of river sediment and water, which comprise the steps of establishing a MPS numerical model of interaction of river sediment and water, setting boundary conditions, setting flow rate parameters, selecting sediment materials, setting parameters of a rheological equation according to the selected sediment materials, inputting the boundary conditions, the flow rate parameters and the sediment materials into the MPS numerical model for solving, obtaining the wave crest and wave trough values of river sediment deformation and sediment-water interface, comparing and verifying the wave crest and wave trough values of sediment deformation and sediment-water interface calculated through actual measurement, if the verification conditions are met, executing, if the verification conditions are not met, repeating the steps, and analyzing the influence of flow rate parameters and sediment material elements on the change of the river sediment form according to the river sediment deformation and the wave crest and wave trough values of sediment-water interface which meet the verification conditions.

Inventors

FU LEI
WANG JUNMIN
WEN JINHUA
WANG SHIWU
PENG ZHENHUA
JI YUYU

Assignees

浙江省水利河口研究院(浙江省海洋规划设计研究院)

Dates

Publication Date: 20260505
Application Date: 20220919

Claims (9)

1. The MPS numerical simulation method for the interaction of river sediment and water is characterized by comprising the following steps of: S11, establishing an MPS numerical model of the interaction of river sediment and water, wherein a basic equation of the MPS numerical model comprises a water flow motion equation, a rheology equation and a multiphase flow MPS equation; s12, setting boundary conditions, setting flow rate parameters, selecting a sediment material, and setting parameters of the rheological equation according to the selected sediment material; S13, inputting the boundary conditions, the flow velocity parameters and the sediment materials into the MPS numerical model for solving to obtain river sediment deformation and the wave crest and wave trough values of the sediment-water body interface; S14, comparing and verifying the sediment deformation and the crest and trough values of the sediment-water body interface calculated by the MPS numerical model by adopting the measured crest and trough values of the sediment deformation and the sediment-water body interface, if the sediment deformation and the crest and trough values of the sediment-water body interface meet the verification conditions, performing S15, and if the sediment deformation and the trough values of the sediment-water body interface do not meet the verification conditions, performing S12-S14; S15, analyzing the influence of flow velocity parameters and sediment material elements on the change of the morphology of the river sediment according to the deformation of the river sediment and the wave crest and wave trough values of the sediment-water body interface which meet the verification conditions; The water flow motion equation, the rheology equation and the multiphase flow MPS equation are specifically as follows: ① Equation of motion of water flow: ; ; Wherein ρ is the fluid density, t is the time, u is the velocity vector, d is the calculation dimension, n 0 is the calculation initial space particle density, p is the pressure, R is the distance between two adjacent space particles, W is the core equation, R e is the space particle search radius, μ is the dynamic viscosity coefficient of the fluid, V is the volume function, V is the volume integral, f is the volume force, and subscripts i, j in the above formula respectively represent different particles in the calculation space range; ② Rheological equation: ; ; Wherein mu 0 is an initial dynamic viscosity coefficient, k is a consistency coefficient, pi is a strain tensor, n is a flow index, τ 0 is a yield stress, and E m is a strain rate tensor; ③ Multiphase flow MPS equation: ; ; ; ; ; Wherein, C 1 is the spatial fraction of the first phase particle on the multiphase flow interface, C 2 is the spatial fraction of the second phase particle on the multiphase flow interface, R is the position vector of the spatial particle, R e is the search radius of the spatial particle, eta is the physical variable of the fluid, subscripts PF1 and PF2 represent the statistics of the spatial particles of different phase fluids within the range of the search radius R e , and subscript PFA represents the statistics total number of the spatial particles of all phase fluids within the range of the search radius R e .
2. The MPS numerical simulation method for river sediment and water interaction according to claim 1, wherein the calculation boundary conditions are as follows: ① Setting of free surface boundaries of water ; Wherein < n * > is the spatial particle density, n 0 is the initial spatial particle density, and β is the recognition constant; ② Setting the interaction boundary of the bottom mud and the water body: ; 。
3. The MPS numerical simulation method for interaction of river sediment and water body according to claim 1, wherein a high-order precision gradient operator and a Laplacian operator are adopted by a rheology equation, and the method is characterized by comprising the following steps: ① High order precision gradient operator: ; ; Wherein phi is a general variable, R is a position vector of the space particle, and R e is a space particle searching radius; ② High-order precision laplacian: 。
4. The MPS numerical simulation method for river sediment and water interaction according to claim 1, wherein a density smooth transition operator used in a multiphase flow MPS equation is as follows: 。
5. The MPS numerical simulation method for river sediment and water interaction according to claim 1, wherein a viscosity smooth transition operator used in a multiphase flow MPS equation is as follows: 。
6. The MPS numerical simulation method for interaction between river bottom mud and a water body according to claim 1, wherein the boundary conditions, the flow velocity parameters and the bottom mud materials are input into the MPS numerical model for solving, the computing basic units are spatial particles, and the spatial particle scale is determined according to the calculated regional range.
7. An MPS numerical simulation apparatus for the interaction of river sediment with a body of water, for performing the method of claim 1, the apparatus comprising: The establishing module is used for establishing an MPS numerical model of the interaction of the river sediment and the water body, wherein a basic equation of the MPS numerical model comprises a water flow motion equation, a rheology equation and a multiphase flow MPS equation; The setting module is used for setting boundary conditions, setting flow rate parameters, selecting a sediment material, and setting parameters of the rheological equation according to the selected sediment material; the solving module is used for inputting the boundary conditions, the flow velocity parameters and the sediment materials into the MPS numerical model to solve, so as to obtain the deformation of the sediment of the river channel and the wave crest and wave trough values of the sediment-water body interface; The verification module is used for comparing and verifying the sediment deformation obtained by calculation of the MPS numerical model and the crest and trough values of the sediment-water body interface by adopting the crest and trough values of the actually measured sediment deformation and the sediment-water body interface, if the sediment deformation and the crest and trough values of the sediment-water body interface meet the verification conditions, the analysis module is carried out, and if the sediment deformation and the crest and trough values of the sediment-water body interface do not meet the verification conditions, the module is set to the verification module; The analysis module is used for analyzing the influence of the flow velocity parameters and the sediment material elements on the change of the river sediment morphology according to the deformation of the river sediment and the wave crest and wave trough values of the sediment-water body interface which meet the verification conditions.
8. An electronic device, comprising: One or more processors; A memory for storing one or more programs; The one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of any of claims 1-6.
9. A computer readable storage medium having stored thereon computer instructions which, when executed by a processor, implement the steps of the method according to any of claims 1-6.

Description

MPS numerical simulation method and device for interaction of river sediment and water body Technical Field The application relates to the technical field of hydraulic engineering resources and environments, in particular to an MPS numerical simulation method and device for interaction of river sediment and water. Background Substrate sludge pollution is one of the main sources of endogenous pollution of urban river channels and is also a prominent research difficulty worldwide. Urban river channels are mostly located in plain river network areas, and are generally characterized by poor fluidity, slow flow speed and extremely easy formation of serious siltation, so that the endogenous pollution of bottom mud caused by the poor fluidity is greatly influenced on the water ecological environment of the river channels. At present, the research on the pollution of the sediment at home and abroad is mostly limited to field observation and a still water model test, and the related research on the morphological change and the efficient capture of the interface of the sediment and the overlying water body by utilizing a mathematical model is still a scientific research hot spot worldwide. The traditional sediment-water body numerical model is based on a grid method. The grid method has long history, mature development and wide application, but because of the limitation of the numerical simulation of the grid method based on Euler's perspective, the simulation technology such as VOF (Volume of Fluid) needs to be used when the free surface of the water body or the multiphase flow interface is treated. In addition, in the simulation of river sediment-water interaction, the grid method has certain defects in the process of processing the convection item and the source item in the control equation, and if the control equation is processed improperly, the stability and convergence of calculation can be affected. Furthermore, considering the problems of calculation efficiency and precision, the grid method is mostly replaced by a simple source term or analysis Jie Gong in the calculation of the grid method, and the interaction between the sediment and the water body and the change of the interface form are difficult to be expressed in a specific way. Disclosure of Invention The embodiment of the application aims to provide a method and a device for simulating the MPS value of the interaction of river sediment and water, which are used for solving the technical problems of the interaction of river sediment-overlying water interface, deformation of water-sand interface (wave crest and wave trough) and capture in the related technology. According to a first aspect of an embodiment of the present application, there is provided an MPS numerical simulation method for interaction of river sediment and a water body, including: S11, establishing an MPS numerical model of the interaction of river sediment and water, wherein a basic equation of the MPS numerical simulation model comprises a water flow motion equation, a rheology equation and a multiphase flow MPS equation; s12, setting boundary conditions, setting flow rate parameters, selecting a sediment material, and setting parameters of the rheological equation according to the selected sediment material; S13, inputting the boundary conditions, the flow velocity parameters and the sediment materials into the MPS numerical model for solving to obtain river sediment deformation and the wave crest and wave trough values of the sediment-water body interface; S14, comparing and verifying the sediment deformation and the crest and trough values of the sediment-water body interface calculated by the MPS numerical model by adopting the measured crest and trough values of the sediment deformation and the sediment-water body interface, if the sediment deformation and the crest and trough values of the sediment-water body interface meet the verification conditions, performing S15, and if the sediment deformation and the trough values of the sediment-water body interface do not meet the verification conditions, performing S12-S14; s15, analyzing the influence of flow velocity parameters and sediment material elements on the change of the river sediment morphology according to the deformation of the river sediment and the peak and trough values of the sediment-water body interface which meet the verification conditions. Further, the water flow motion equation, the rheology equation and the multiphase flow MPS equation are specifically as follows: ① Equation of motion of water flow: Wherein ρ is the fluid density, t is the time, u is the velocity vector, d is the calculation dimension, n 0 is the calculation initial space particle density, p is the pressure, R is the distance between two adjacent space particles, W is the core equation, R e is the space particle search radius, μ is the dynamic viscosity coefficient of the fluid, V is the volume function, V is the volume integral, f is the vol