Solid-liquid two-phase flow field analysis method and device, simulation system and computer storage medium

Abstract

The invention relates to a solid-liquid two-phase flow field analysis method and device, a simulation system and a computer storage medium, and belongs to the technical field of flow field analys.The solid-liquid two-phase flow field analysis method comprises the steps that a solid-liquid two-phase flow field model is constructed, dividing the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between a fluid and a rigid body in the solid-liquid two-phase flow field model; performing discrete analysis on the particles according to the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determining the particle volume fraction in each grid, and calculating the drag force of the fluid to the particles based on the particle volume fraction and a preset drag force model; and determining the motion state of each particle in the flow field based on the drag force and the contact force during particle collision, and determining the distribution state of each particle in the flow field based on the motion state. According to the invention, fine analysis of the solid-liquid two-phase flow field can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of flow field analysis, and in particular to a solid-liquid two-phase flow field analysis method, device, simulation system and computer storage medium. Background Art

[0002] Unlike the pure water environment in the laboratory, the actual marine environment contains numerous discrete particle phases with different physical parameters such as size, shape and density, distributed in the form of sedimentation or suspension.

[0003] Currently, solid-liquid two-phase flow field calculations use the Euler model to solve the fluid motion process in the time domain, and the Euler or Lagrangian model to describe the motion process of the discrete particle phase. The Euler model takes into account particle volume, particle-particle collisions, and particle-wall collisions. The calculation results are closer to the actual solid-liquid two-phase flow field, but it requires the flow field grid size to be much larger than the particle size and uses the Monte Carlo method to calculate the particle volume fraction. This is not suitable for the calculation of fine flow fields. For fine flow field calculations, the grid is usually small, resulting in the particle volume generally being much larger than the grid volume. Existing technologies cannot accurately calculate the particle volume fraction in the grid, resulting in inaccurate flow field analysis.

[0004] It can be seen that the existing technology cannot accurately calculate the particle volume fraction in the fine flow field, resulting in inaccurate analysis of the flow field. Summary of the Invention

[0005] In view of this, it is necessary to provide a solid-liquid two-phase flow field analysis method, device, simulation system and computer storage medium to solve the problem that the existing technology cannot accurately calculate the particle volume fraction in the fine flow field, resulting in inaccurate analysis of the flow field.

[0006] In order to solve the above problems, in a first aspect, the present application provides a solid-liquid two-phase flow field analysis method, comprising: Construct a solid-liquid two-phase flow field model, and divide the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model; The particles are discretized based on the particle volume of each particle in the solid-liquid two-phase flow model and the grid volume of the multi-layer grid model to determine the particle volume fraction in each grid. The drag force of the fluid on the particles is calculated based on the particle volume fraction and the preset drag model. The motion state of each particle in the flow field is determined based on the drag force and the contact force when the particles collide, and the distribution state of each particle in the flow field is determined based on the motion state.

[0007] As a possible implementation of the present application, the solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model, including: The first-layer grid height calculation formula and boundary layer thickness calculation formula are used to calculate the first-layer grid height and boundary layer thickness in the multi-layer grid model. The first-layer grid height calculation formula is:

[0008] The boundary layer thickness calculation formula is:

[0009] in, is the first layer grid height, is the friction velocity of the fluid near the wall of the rigid body, is the fluid density, is the dynamic viscosity, is the boundary layer thickness, is the Reynolds number, L is the model characteristic length, is a dimensionless parameter that measures the grid size of the boundary layer; The solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the first layer grid height, boundary layer thickness, growth rate between adjacent boundary layer grids of the multi-layer grid model, and the number of boundary layer grid layers.

[0010] As a possible implementation of the present application, a discrete analysis of the particles is performed based on the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model to determine the particle volume fraction in each grid, including: Discretize particles whose volume is larger than the volume of a single grid into a first number of discrete particles, where the first number is the number of grids interfering with the particles, and the volume of each discrete particle satisfies a Gaussian distribution; The particle volume fraction of each grid is determined by the ratio of the particle volume of each discrete particle to the grid volume of a single grid.

[0011] As a possible implementation of the present application, the volume probability density function of discrete particles is:

[0012] in, The volume of the i-th particle is The probability of and are the expectation and variance of the discretized particle volume, respectively.

[0013] As a possible implementation of the present application, the drag model is:

[0014]

[0015]

[0016] in, is the fluid density, is the sliding velocity of the particle; is the particle drag coefficient, Re is the Reynolds number, is the porosity, is the volume fraction of particles in the grid.

[0017] As a possible implementation of the present application, the calculation formula for the contact force when particles collide is:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] in, is the contact force when particles collide, F c,n is the normal contact force during the collision process, F c,t is the tangential contact force; K n is the normal stiffness term of the particle, N n is the normal damping term; K t is the tangential stiffness term of the particle, N t is the tangential damping term; N damp is the damping coefficient, r eq is the equivalent particle radius, m eq is the equivalent particle mass, E eq is the equivalent Young's modulus.

[0025] As a possible implementation of the present application, the motion state of each particle in the flow field is determined based on the drag force and the contact force when the particles collide, including: Calculate the particle acceleration based on the drag force on the particle in the flow field and the contact force when the particles collide; The real-time velocity of the particle is calculated based on the acceleration, the initial velocity of the particle and the duration of the particle movement, and the motion state of the particle in the flow field is determined based on the real-time velocity.

[0026] In a second aspect, the present application further provides a solid-liquid two-phase flow field analysis device, comprising: A grid model construction module is used to construct a solid-liquid two-phase flow field model, which is divided into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model; The drag calculation module is used to perform a discrete analysis of the particles based on the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determine the particle volume fraction in each grid, and calculate the drag force of the fluid on the particles based on the particle volume fraction and the preset drag model; The particle distribution state determination module is used to determine the motion state of each particle in the flow field based on the drag force and the contact force when the particles collide, and to determine the distribution state of each particle in the flow field based on the motion state.

[0027] In a third aspect, the present application further provides a simulation system, including a memory and a processor, wherein: Memory, used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the solid-liquid two-phase flow field analysis method of any of the above embodiments.

[0028] In a fourth aspect, the present application also provides a computer-readable storage medium for storing computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the solid-liquid two-phase flow field analysis method of any of the above-mentioned embodiments.

[0029] The beneficial effects of the present application are: the solid-liquid two-phase flow field analysis method provided by the present application can realize the fine division of the solid-liquid two-phase flow field model by dividing the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model, and perform discrete analysis on the particles according to the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determine the particle volume fraction in each grid, and calculate the drag of the fluid on the particles based on the particle volume fraction and the preset drag model, and perform discrete analysis on large particles, so as to more accurately calculate the particle volume fraction of the particles in the grid, and then accurately calculate the drag force on the particles in the flow field, and determine the motion state of each particle in the flow field based on the drag force and the contact force when the particles collide, and determine the distribution state of each particle in the flow field based on the motion state, so as to more accurately analyze the fine solid-liquid two-phase flow field. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic flow chart of a solid-liquid two-phase flow field analysis method provided in an embodiment of the present application; Figure 2 A schematic diagram of grid division provided in an embodiment of the present application; Figure 3 A schematic flow chart of a particle volume fraction calculation method provided in an embodiment of the present application; Figure 4 A schematic diagram of particle dispersion provided in an embodiment of the present application; Figure 5 A schematic flow chart of a method for determining a particle motion state provided in an embodiment of the present application; Figure 6 A schematic diagram of particle distribution provided in an embodiment of the present application; Figure 7 A schematic structural diagram of a solid-liquid two-phase flow field analysis device provided in an embodiment of the present application; Figure 8 A schematic diagram of the structure of a simulation system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present application to illustrate the principles of the present application, and are not used to limit the scope of the present application.

[0033] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] A specific embodiment of the present application, such as Figure 1 As shown, a solid-liquid two-phase flow field analysis method is disclosed, comprising: S101, constructing a solid-liquid two-phase flow field model, and dividing the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model.

[0035] In the embodiments of the present application, for flow field simulations with high precision requirements, it is necessary to construct a high-precision grid model, such as the flow field model when the propeller moves in seawater. In actual seawater, it is not pure water, and there are many particles in the seawater. To ensure the authenticity of the model, the solid-liquid two-phase flow field model should contain rigid bodies, fluids, and particles. When constructing a high-precision grid model of the propeller and seawater, the volume of a single grid will be smaller than the volume of the particles. When calculating the particle volume fraction of the grid, the part of the particles that exceeds the grid volume will be ignored, resulting in inaccurate calculation of the particle volume fraction. Therefore, it is necessary to update the calculation method of the particle volume fraction. Taking the movement of the propeller in water as an example, a three-dimensional model of the propeller is first constructed. The radial cross-section of the propeller hub is circular, and the axial cross-section is rectangular. A single propeller blade is obtained by surface closing the airfoil curves at different radial distances. The blades are circumferentially arrayed to complete the construction of the standard propeller model. The solid-liquid two-phase flow field model is completed by performing Boolean operations on the peripheral fluid domain and the propeller solid domain. Specifically, the propeller design parameters are shown in Table 1: Table 1: Propeller design parameters

[0036] Furthermore, NS groups are created based on the actual working process of the propeller to facilitate the subsequent giving of specific boundary conditions according to the actual working process. Inlet groups are created at the inflow, outlet groups are created at the outlet, wall groups are created on the propeller surface, interface1 groups are created on the outer surface of the rotating domain, interface2 groups are created on the inner surface of the stationary domain, and Symmtry groups are created on the circumferential surface of the stationary domain. The above groups are all groups in the simulation software to realize the creation of the propeller model.

[0037] Furthermore, pre-processing software can be used to perform geometric cleaning on the solid-liquid two-phase flow field model to ensure that the solid-liquid two-phase flow field model does not have redundant structures, slits, repeated surfaces, etc.

[0038] In an embodiment of the present application, when meshing the constructed solid-liquid two-phase flow field model, considering the refined requirements of the propeller flow field analysis, it is necessary to perform refined meshing on the solid-liquid two-phase flow field model. The solid-liquid two-phase flow field model can be divided into a multi-layer mesh model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model, that is, the solid-liquid two-phase flow field model can be divided into a multi-layer mesh model according to the distance between the fluid in the solid-liquid two-phase flow field model and the propeller rigid body. The specific division method of the multi-layer mesh model will be described in detail later in this application.

[0039] Furthermore, to ensure mesh accuracy, the mesh file size can be checked using the General-Scale function. If the size is too large (or too small), adjust the mesh file size by multiplying it by the corresponding scaling factor. The propeller's rotational motion causes the coexistence of multiscale vortex structures in the flow field. Since the Large Eddy Simulation (LES) model better captures multiscale vortex structures, the LES turbulence model is selected in the Viscous toolbar to solve the propeller transient flow field. The Cell-Zone-Conditions section contains multiple fluid calculation domains, including the stationary domain and the rotating domain, for which physical properties must be set separately. The stationary domain remains at the default settings. In the rotating domain, select the Mesh Motion function, set the X-axis as the rotation axis, and set the speed to 600 rpm, the design speed of the DTMB4119 propeller. Set boundary conditions in the Boundary Conditions toolbar, using velocity inlets and pressure outlets to closely resemble the actual flow through the propeller. The inlet velocity is based on the DTMB4119 propeller design condition, which is the advance coefficient. =0.833 (v is the inlet velocity, n is the rotation speed, and D is the propeller diameter). Interface surfaces are used between the stationary domain and the rotating domain to implement data exchange to avoid the synchronous rotation of the peripheral fluid calculation domain, which leads to the consumption of a large amount of computing resources. Symmetry is used on the peripheral wall to simulate the infinite fluid domain. The SIMPLEC algorithm is selected to solve the velocity-pressure coupling of the transient flow field, which can better balance the calculation efficiency and speed. The transient flow field time step is set to the time it takes for the propeller to rotate 1°. The velocity field file is output every 1° rotation, and the flow field calculation result is output every 10° rotation to ensure that complete propeller flow field data is obtained.

[0040] S102, performing a discrete analysis on the particles based on the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determining the particle volume fraction in each grid, and calculating the drag force of the fluid on the particles based on the particle volume fraction and a preset drag model.

[0041] In the embodiments of this application, because the solid-liquid two-phase flow field model is finely meshed, the volume of the particles in the solid-liquid two-phase flow field model is generally much larger than the volume of a single mesh, necessitating discretization of the particles. Specifically, the particles can be discretized into multiple discrete particles, each with a volume less than or equal to the volume of a single mesh. The particle volume fraction in each mesh is then calculated, and the drag force of the fluid on the particles is then calculated using a preset drag model. The specific steps for particle discretization and the specific drag model are described in detail later in this application.

[0042] S103 , determining the motion state of each particle in the flow field based on the drag force and the contact force when the particles collide, and determining the distribution state of each particle in the flow field based on the motion state.

[0043] In an embodiment of the present application, after determining the drag force exerted on the particles in the flow field, the motion state of the particles in the flow field can be analyzed in combination with the contact force when the particles collide with each other and when the particles collide with the model wall. Based on the motion state of the particles in the flow field, the distribution state of each particle in the flow field can be determined.

[0044] The solid-liquid two-phase flow field analysis method provided in the present application can realize the fine division of the solid-liquid two-phase flow field model by dividing the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model, and perform discrete analysis on the particles according to the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determine the particle volume fraction in each grid, and calculate the drag of the fluid on the particles based on the particle volume fraction and the preset drag model. Discrete analysis is performed on large particles, which can more accurately calculate the particle volume fraction of the particles in the grid, and then accurately calculate the drag force on the particles in the flow field, and determine the motion state of each particle in the flow field based on the drag and the contact force when the particles collide, and determine the distribution state of each particle in the flow field based on the motion state, which can more accurately analyze the fine solid-liquid two-phase flow field.

[0045] In some possible embodiments of the present application, the solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model, including: The first-layer grid height calculation formula and boundary layer thickness calculation formula are used to calculate the first-layer grid height and boundary layer thickness in the multi-layer grid model. The first-layer grid height calculation formula is:

[0046] The boundary layer thickness calculation formula is:

[0047] in, is the first layer grid height, is the friction velocity of the fluid near the wall of the rigid body, is the fluid density, is the dynamic viscosity, is the boundary layer thickness, is the Reynolds number; The solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the first layer grid height, boundary layer thickness, growth rate between adjacent boundary layer grids of the multi-layer grid model, and the number of boundary layer grid layers.

[0048] In the embodiment of the present application, in order to ensure the quality of meshing, a polyhedral unstructured grid is used to mesh the solid-liquid two-phase flow field model, such as Figure 2 As shown in the figure, the propeller's rotation significantly increases the turbulence of the flow field. In order to capture the wake motion trajectory and the flow separation phenomenon near the wall, the grid model needs to be divided into boundary layer grids. The rationality of the boundary layer grid division is determined by the boundary layer thickness and the first layer grid height. The calculation process of the first layer grid height and boundary layer thickness is as follows:

[0049]

[0050]

[0051] in, is the first layer grid height, is the friction velocity of the fluid near the wall of the rigid body, is the fluid density, is the dynamic viscosity, is the boundary layer thickness, is the Reynolds number.

[0052] Specifically, the first boundary layer height of the propeller grid model is 0.05 mm, the growth rate between adjacent boundary layer grids is 1.2, and a total of 10 layers of boundary layer grids are divided. The solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the first layer grid height, boundary layer thickness, the growth rate between adjacent boundary layer grids of the multi-layer grid model, and the number of boundary layer grid layers.

[0053] The embodiment of the present application obtains a multi-layer grid model by performing fine grid division on the solid-liquid two-phase flow field model, thereby ensuring the accuracy of the multi-layer grid model and being able to more accurately analyze the flow field of the solid-liquid two-phase flow field model.

[0054] In some possible embodiments of the present application, Figure 3 As shown in the figure, the particles are discretely analyzed based on the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model to determine the particle volume fraction in each grid, including: S301, discretizing particles whose volume is larger than the volume of a single grid into a first number of discrete particles, where the first number is the number of grids interfering with the particles, and the volume of each discrete particle satisfies a Gaussian distribution; S302 : Determine the particle volume fraction of each grid according to the ratio of the particle volume of each discrete particle to the grid volume of a single grid.

[0055] In the embodiment of the present application, when discretizing particles whose volume is larger than the volume of a single grid, the Gaussian distribution concept can be combined to discretize the particles, such as Figure 4 As shown, when i The volume of the particle is much larger than that of the i When the size of the grid is N, the volume of the large particle is divided into N parts by using the idea of ​​differentiation. The volume of the discrete particles is Satisfies Gaussian distribution ,in, and are the expectation and variance of the discretized particle volume, that is, the discretized particle volume has a volume gradient along the radial direction, and the discretized particle volume is smaller than the single grid size, then the particle volume fraction is ,in, is the particle volume of the jth discrete particle, is the grid volume of the grid where the jth discrete particle is located, The particle volume fraction of the grid where the jth discrete particle is located is integrated over the volume fractions of all particles in the flow field to obtain the particle distribution in the entire flow domain.

[0056] The embodiment of the present application incorporates all flow field grids that interfere with the particles into the calculation process of the particle volume fraction, thereby significantly improving the calculation accuracy of the particle volume fraction. Moreover, since the particle volume after differentiation is smaller than the flow field grid size, it is no longer limited by the ratio of the particle volume to the flow field grid size, and has high applicability and calculation accuracy for flow field calculations with fine grid division.

[0057] In some possible embodiments of the present application, the volume probability density function of discrete particles is:

[0058] in, The volume of the i-th particle is The probability of and are the expectation and variance of the discretized particle volume, respectively.

[0059] In the embodiment of the present application, when the volume of the particle is larger than the volume of the fluid grid, the number of all fluid grids interfering with the particle is first counted. N = n x * n y * n z ( n i Respectively represent x, y, z The particle volume isv particle,i Divided into N parts, the volume of the discrete particles N j Satisfies Gaussian distribution N j ~ Ɲ ( μ 0, Σ0) means that the discretized particle size has a volume gradient along the radial direction, where μ 0 and Σ0 are the expectation and variance of the discretized particle volume, respectively.

[0060] In the embodiment of the present application, the large-sized particles are discretized to meet the size relationship between the particles and the flow field grid, that is, v particle(Nj) < v fluid(j) , the particle volume fraction within the fluid grid unit is By integrating the particle volume fractions in all fluid grids in the computational domain, the overall particle discrete phase distribution characteristics of the flow field are obtained.

[0061] In some possible embodiments of the present application, the drag model is:

[0062]

[0063]

[0064] in, is the fluid density, is the sliding velocity of the particle; is the particle drag coefficient, Re is the Reynolds number, is the porosity, is the volume fraction of particles in the grid.

[0065] In an embodiment of the present application, the mathematical form of the drag model shown above can be encoded according to the drag model in the mathematical form to obtain the drag model in the code language form, and then the drag model in the code language form is coupled to the particle volume fraction calculation module to realize the calculation of the drag force exerted on the particles in the flow field.

[0066] In some possible embodiments of the present application, the calculation formula for the contact force when particles collide is:

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] in, is the contact force when particles collide, F c,n is the normal contact force during the collision process, F c,t is the tangential contact force; K n is the normal stiffness term of the particle, N n is the normal damping term; K t is the tangential stiffness term of the particle, N t is the tangential damping term; N damp is the damping coefficient, r eq is the equivalent particle radius, m eq is the equivalent particle mass, E eq is the equivalent Young's modulus.

[0074] In an embodiment of the present application, the movement process of the discrete phase of particles is divided into three stages. The first is the movement of isolated particles driven by the drag force of the fluid. During the movement of the particles, collisions will occur between particles and between particles and the model wall. The model wall includes the model boundary surface and the rigid body surface. The contact force during the collision is composed of normal contact force and tangential contact force. The normal contact force is closely related to the Poisson's ratio, shear modulus or Young's modulus of the material, and the tangential contact force is closely related to the resistance coefficient, static friction coefficient and rolling friction coefficient of the material. The above formula can be used to calculate the contact force during the particle collision process.

[0075] In some possible embodiments of the present application, Figure 5 As shown in Figure 2, the motion state of each particle in the flow field is determined based on the drag force and the contact force when the particles collide, including: S501, calculating the acceleration of the particle based on the drag force on the particle in the flow field and the contact force when the particle collides; S502 : Calculate the real-time velocity of the particle based on the acceleration, the initial velocity of the particle and the duration of the particle movement, and determine the movement state of the particle in the flow field based on the real-time velocity.

[0076] In the embodiment of the present application, isolated particles in the flow field will start to move under the action of fluid drag, and the motion state is calculated by Newton's law of motion. i The acceleration and velocity of each particle are calculated as follows:

[0077]

[0078] in, is the acceleration of the i-th particle, is the velocity of the i-th particle, t is the movement time of the particle, is the initial velocity of the ith particle, is the fluid drag force received by the i-th particle, is the particle density, is the particle volume fraction of the grid where the i-th particle is located.

[0079] Based on this, the motion state of each particle in the particle group can be calculated. In combination with the contact force between particles and the contact force between particles and the wall, the distribution state of particles in the flow field can be determined, such as Figure 6 The figure shows a possible particle distribution diagram.

[0080] This application significantly improves the calculation accuracy of particle volume fraction by incorporating all flow field grids that interfere with particles into the calculation process of particle volume fraction. The particle volume is discretized based on Gaussian distribution, and the discretized particle volume is matched to the flow field grid to ensure that the volume of the discrete particles is less than or equal to the grid volume. By integrating the volume fractions of all fluid grid particles that interfere with particles in the flow field, the precise capture of large-scale particle distribution characteristics is finally achieved, breaking through the limitations of the flow field grid size and particle size ratio in traditional solid-liquid two-phase flow calculations.

[0081] In order to better implement the solid-liquid two-phase flow field analysis method in the embodiment of the present application, based on the solid-liquid two-phase flow field analysis method, correspondingly, Figure 7 As shown, the embodiment of the present application further provides a solid-liquid two-phase flow field analysis device, and the solid-liquid two-phase flow field analysis device 700 includes: A grid model construction module 710 is used to construct a solid-liquid two-phase flow field model, and divide the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model; a drag calculation module 720 for performing a discrete analysis of the particles based on the particle volume of each particle in the solid-liquid two-phase flow model and the grid volume of the multi-layer grid model, determining the particle volume fraction in each grid, and calculating the drag of the fluid on the particles based on the particle volume fraction and a preset drag model; The particle distribution state determination module 730 is used to determine the motion state of each particle in the flow field based on the drag force and the contact force when the particles collide, and to determine the distribution state of each particle in the flow field based on the motion state.

[0082] The solid-liquid two-phase flow field analysis device 700 provided in the above embodiment can implement the technical solution described in the above solid-liquid two-phase flow field analysis method embodiment. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above solid-liquid two-phase flow field analysis method embodiment, which will not be repeated here.

[0083] like Figure 8 As shown, the present application also provides a simulation system 800. The simulation system 800 includes a processor 801, a memory 802 and a display 803. Figure 8 Only some of the components of the simulation system 800 are shown, but it should be understood that implementation of all of the shown components is not required, and more or fewer components may be implemented instead.

[0084] In some embodiments, the processor 801 may be a central processing unit (CPU), a microprocessor, or other data processing chip, used to run program codes or process data stored in the memory 802, such as the solid-liquid two-phase flow field analysis method in this application.

[0085] In some embodiments, processor 801 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, processor 801 may be local or remote. In some embodiments, processor 801 may be implemented on a cloud platform. In some embodiments, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, multiple clouds, or any combination thereof.

[0086] In some embodiments, the memory 802 may be an internal storage unit of the simulation system 800, such as a hard disk or memory of the simulation system 800. In other embodiments, the memory 802 may also be an external storage device of the simulation system 800, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the simulation system 800.

[0087] Furthermore, the memory 802 may include both an internal storage unit of the simulation system 800 and an external storage device. The memory 802 is used to store application software installed in the simulation system 800 and various data.

[0088] In some embodiments, display 803 can be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. Display 803 is used to display information about simulation system 800 and to display a visual user interface. Components 801-803 of simulation system 800 communicate with each other via a system bus.

[0089] In some embodiments, when the processor 801 executes the solid-liquid two-phase flow field analysis program in the memory 802, the following steps may be implemented: Construct a solid-liquid two-phase flow field model, and divide the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model; The particles are discretized based on the particle volume of each particle in the solid-liquid two-phase flow model and the grid volume of the multi-layer grid model to determine the particle volume fraction in each grid. The drag force of the fluid on the particles is calculated based on the particle volume fraction and the preset drag model. The motion state of each particle in the flow field is determined based on the drag force and the contact force when the particles collide, and the distribution state of each particle in the flow field is determined based on the motion state.

[0090] It should be understood that, when the processor 801 executes the solid-liquid two-phase flow field analysis program in the memory 802 , in addition to the above functions, it can also implement other functions. For details, please refer to the description of the corresponding method embodiment above.

[0091] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, it can implement the steps or functions in the solid-liquid two-phase flow field analysis method provided in the above-mentioned method embodiments.

[0092] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, such as a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0093] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A solid-liquid two-phase flow field analysis method, characterized in that: include: Constructing a solid-liquid two-phase flow field model, and dividing the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model; performing a discrete analysis on the particles according to the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determining the particle volume fraction in each grid, and calculating the drag force of the fluid on the particles based on the particle volume fraction and a preset drag model; The motion state of each particle in the flow field is determined based on the drag force and the contact force when the particles collide, and the distribution state of each particle in the flow field is determined based on the motion state.

2. The solid-liquid two-phase flow field analysis method according to claim 1, characterized in that: The solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model, comprising: The first layer grid height calculation formula and the boundary layer thickness calculation formula are used to calculate the first layer grid height and the boundary layer thickness in the multi-layer grid model, wherein the first layer grid height calculation formula is: The boundary layer thickness calculation formula is: in, is the first layer grid height, is the friction velocity of the fluid near the wall of the rigid body, is the fluid density, is the dynamic viscosity, is the boundary layer thickness, is the Reynolds number, L is the model characteristic length, is a dimensionless parameter that measures the grid size of the boundary layer; The solid-liquid two-phase flow field model is divided into a multi-layer grid model according to the first layer grid height, the boundary layer thickness, the growth rate between adjacent boundary layer grids of the multi-layer grid model, and the number of layers of the boundary layer grids.

3. The solid-liquid two-phase flow field analysis method according to claim 1, characterized in that: The discrete analysis of the particles is performed based on the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model to determine the particle volume fraction in each grid, including: Discretize particles whose volume is larger than the volume of a single grid into a first number of discrete particles, where the first number is the number of grids interfering with the particles, and the volume of each discrete particle satisfies a Gaussian distribution; The particle volume fraction of each grid is determined by the ratio of the particle volume of each discrete particle to the grid volume of a single grid.

4. The solid-liquid two-phase flow field analysis method according to claim 3, characterized in that: The volume probability density function of the discrete particles is: in, The volume of the i-th particle is The probability of and are the expectation and variance of the discretized particle volume, respectively.

5. The solid-liquid two-phase flow field analysis method according to claim 3, characterized in that: The drag model is: in, is the fluid density, is the sliding velocity of the particle; is the particle drag coefficient, Re is the Reynolds number, is the porosity, is the volume fraction of particles in the grid.

6. The solid-liquid two-phase flow field analysis method according to claim 5, characterized in that: The calculation formula of the contact force when the particles collide is: in, is the contact force when particles collide, F c,n is the normal contact force during the collision process, F c,t is the tangential contact force; K n is the normal stiffness term of the particle, N n is the normal damping term; K t is the tangential stiffness term of the particle, N t is the tangential damping term; N damp is the damping coefficient, r eq is the equivalent particle radius, m eq is the equivalent particle mass, E eq is the equivalent Young's modulus.

7. The solid-liquid two-phase flow field analysis method according to claim 6, characterized in that: The determining of the motion state of each particle in the flow field based on the drag force and the contact force when the particles collide includes: Calculate the particle acceleration based on the drag force on the particle in the flow field and the contact force when the particles collide; The real-time velocity of the particle is calculated based on the acceleration, the initial velocity of the particle and the duration of the particle movement, and the movement state of the particle in the flow field is determined based on the real-time velocity.

8. A solid-liquid two-phase flow field analysis device, characterized in that: include: A grid model construction module is used to construct a solid-liquid two-phase flow field model, and divide the solid-liquid two-phase flow field model into a multi-layer grid model according to the distance between the fluid and the rigid body in the solid-liquid two-phase flow field model; a drag calculation module, configured to perform a discrete analysis on the particles based on the particle volume of each particle in the solid-liquid two-phase flow field model and the grid volume of the multi-layer grid model, determine the particle volume fraction in each grid, and calculate the drag of the fluid on the particles based on the particle volume fraction and a preset drag model; The particle distribution state determination module is used to determine the motion state of each particle in the flow field based on the drag force and the contact force when the particles collide, and to determine the distribution state of each particle in the flow field based on the motion state.

9. A simulation system, characterized in that: comprising a memory and a processor, wherein, The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the solid-liquid two-phase flow field analysis method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps of the solid-liquid two-phase flow field analysis method described in any one of claims 1 to 7.

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