A side type inlet / outlet water port bidirectional fluid simulation system based on RSM turbulent flow model

Abstract

This invention discloses a two-way fluid simulation system for side-mounted inlets / outlets based on the RSM turbulence model. Belonging to the field of energy and power engineering, the system includes: a global geometric modeling module for constructing a coupled geometric model encompassing the tailrace tunnel and side-mounted inlets / outlets; a physical parameter configuration module for setting flow and pressure boundaries under two-way flow conditions; a mesh generation module for structured mesh generation and local refinement of the model; an RSM solution module for closed-loop solution of the two-way flow field using the Reynolds stress model to obtain state data; and a multi-index evaluation module for extracting and analyzing the flow regime within the diffuser section, the velocity distribution of the trash rack, flow distribution, and turbulence parameters. This invention can systematically evaluate the differences in hydraulic characteristics of different vertical expansion methods in the diffuser section, providing a reliable scientific basis for the design of the inlet / outlet shape of pumped storage power stations.

Description

Technical Field

[0001] This invention relates to the field of energy and power engineering, and specifically to a two-way fluid simulation system for side inlet / outlet based on the RSM turbulence model. Background Technology

[0002] Side-mounted inlets / outlets are crucial hydraulic structures in pumped-storage power plants, handling bidirectional flow during both power generation and pumping operations. Their internal flow regime, velocity distribution, and orifice flow distribution directly impact their hydraulic performance. Among these, the diffuser section, a key structural element of the side-mounted inlet / outlet, significantly influences flow uniformity, flow distribution, and turbulence characteristics through its design.

[0003] Current research on the vertical expansion methods of diffuser sections in side-mounted inlets / outlets remains insufficient. Existing studies largely focus on the hydraulic improvement effects of bidirectional symmetrical expansion of the top and bottom plates, while research on unidirectional expansion of the bottom plate is relatively limited. Furthermore, there is a lack of systematic comparative analysis and clear selection criteria regarding the differences in hydraulic characteristics of different vertical expansion methods under bidirectional flow conditions in side-mounted inlets / outlets, particularly their applicability under different inflow conditions in tailrace tunnels. In addition, existing design codes lack specific guidelines for selecting vertical expansion methods in diffuser sections, thus failing to provide effective support for the design of diffuser sections in side-mounted inlets / outlets.

[0004] Currently, there is a lack of a good technology that can effectively solve the above problems.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a two-way fluid simulation system for side inlet / outlet based on the RSM turbulence model, in order to solve the above-mentioned problems.

[0007] The technical solution of the present invention is as follows:

[0008] This invention provides a two-way fluid simulation system for a side-mounted inlet / outlet based on the RSM turbulence model. The system comprises: a global geometric modeling module, a physical parameter configuration module, a mesh generation module, an RSM solving module, and a multi-index evaluation module. The global geometric modeling module constructs a coupled geometric model including the tailrace tunnel, side-mounted inlet / outlet, open channel, and reservoir area, and builds corresponding simulation models based on different vertical expansion methods of the diffuser sections. The physical parameter configuration module sets the flow and pressure boundaries for the simulation models under two-way flow conditions, wherein the reservoir surface adopts a rigid cover assumption, and the solid wall boundary adopts... No slip condition; the mesh generation module is used to perform structured mesh generation on the simulation model with completed physical parameter configuration, and to refine the mesh in key local areas; the RSM solution module is used to numerically solve the flow field under bidirectional flow conditions based on the mesh generation results using the Reynolds stress model (RSM) to obtain the corresponding flow field state data; the multi-index evaluation module is used to extract and analyze the internal flow regime of the diffuser section, the velocity distribution of the trash rack section, the orifice flow distribution, and turbulence characteristic parameters based on the flow field state data, so as to output the hydraulic characteristic evaluation results of different vertical expansion modes of the diffuser section under inflow and outflow conditions.

[0009] Optionally, when constructing the coupled geometric model, the global geometric modeling module sets the outer extension distance of the tunnel section boundary and the lateral boundary range of the reservoir area based on the characteristic diameter of the tailrace tunnel and the total width of the side inlet / outlet.

[0010] Optionally, when constructing the simulation model, the global geometry modeling module constructs multiple simulation models with different vertical expansion methods, provided that the overall expansion constraint of the diffusion segment remains consistent.

[0011] Optionally, the vertical expansion method includes unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates.

[0012] Optionally, the physical parameter configuration module is used to configure a flow boundary on the tailrace tunnel side boundary according to the operating flow rate, and configure a static pressure boundary on the reservoir side boundary according to the water level conditions, so as to form boundary condition configuration results corresponding to the inflow and outflow conditions.

[0013] Optionally, the meshing module uses an O-type mesh layout to perform topological partitioning of the circular cross-section of the tailrace tunnel, and uses a hexahedral structured mesh to partition the remaining areas of the coupled geometric model.

[0014] Optionally, when the mesh division module densifies the local key areas, it at least refines the mesh in the diversion pier head area and the anti-vortex beam area.

[0015] Optionally, the mesh generation module further includes a mesh independence verification unit, which is used to generate at least five mesh systems based on different global mesh sizes, and determine the mesh resolution used for the final simulation based on the calculation errors of key physical quantities between adjacent mesh systems.

[0016] Optionally, the RSM solving module achieves model closure by simultaneously solving the continuity equation, the Navier-Stokes equation, and the Reynolds stress transport equation during numerical solution; wherein the Reynolds stress transport equation includes transient terms, convection terms, turbulent diffusion terms, molecular viscous diffusion terms, shear force generation terms, pressure strain terms, viscous dissipation terms, and system rotation generation terms.

[0017] Optionally, when analyzing the flow field state data, the multi-index evaluation module calculates the velocity non-uniformity coefficient by extracting the flow velocity at each measuring point on the cross-section of the trash rack, and calculates the degree of non-uniformity of flow distribution at each orifice based on the flow statistics of each orifice. At the same time, it extracts the internal flow regime of the diffusion section, the global turbulent kinetic energy distribution, and the vertical turbulence intensity of the cross-section of the trash rack.

[0018] The beneficial effects of this invention are as follows:

[0019] This invention constructs a coupled geometric model including a tailrace tunnel, side inlets / outlets, open channels, and a reservoir. It then configures the flow and pressure boundaries under bidirectional flow conditions and uses structured mesh generation and RSM closed-loop solution to obtain flow field data for the side inlets / outlets under different vertical expansion modes in the diffuser section. Furthermore, by extracting and analyzing the flow regime within the diffuser section, the velocity distribution across the trash rack cross-section, the orifice flow distribution, and turbulence characteristic parameters, it generates hydraulic characteristic evaluation results for different vertical expansion modes in the diffuser section under inflow and outflow conditions, thus providing a basis for selecting the vertical expansion mode of the side inlet / outlet diffuser section. Attached Figure Description

[0020] Figure 1 This is a diagram illustrating the architecture of a two-way fluid simulation system with a side inlet / outlet based on the RSM turbulence model, according to the present invention.

[0021] Figure 2 This is a schematic diagram of a side-type inlet / outlet according to the present invention;

[0022] Figure 3 This is a schematic diagram of a side-type inlet / outlet calculation model and mesh generation according to the present invention;

[0023] Figure 4 This invention provides a trend chart for grid independence verification data.

[0024] Figure 5 This is a trend chart of flow velocity data in the cross section of a trash rack according to the present invention;

[0025] Figure 6 This is a schematic diagram of the internal flow regime under three different expansion modes of the diffusion section according to the present invention;

[0026] Figure 7 This invention provides a flow velocity trend chart for a trash rack.

[0027] Figure 8 This is a schematic diagram of an orifice flow distribution according to the present invention;

[0028] Figure 9 This is a schematic diagram illustrating the variation of turbulent kinetic energy along the diffusion section under three different expansion modes according to the present invention;

[0029] Figure 10 This is a schematic diagram of the turbulence strength of a trash rack according to the present invention;

[0030] Figure 11 This is yet another schematic diagram of the internal flow regime under three different expansion modes of a diffusion section according to the present invention;

[0031] Figure 12 This is another trend chart of flow velocity data for a trash rack according to the present invention;

[0032] Figure 13 This is yet another schematic diagram of an orifice flow distribution according to the present invention;

[0033] Figure 14 This is another schematic diagram illustrating the variation of turbulent kinetic energy along the diffusion section under three different expansion modes according to the present invention.

[0034] Figure 15 This is a schematic diagram of a side-type inlet / outlet with different expansion methods according to the present invention;

[0035] Figure 16 This is a schematic diagram illustrating the variation of turbulent kinetic energy along the diffusion section under two different expansion modes according to the present invention;

[0036] Figure 17 This is a schematic diagram of the flow velocity distribution of a trash rack according to the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0039] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] As mentioned earlier, existing research on the vertical expansion methods of diffuser sections in side-mounted inlets / outlets remains insufficient. Existing studies largely focus on the hydraulic improvement effects of bidirectional symmetrical expansion of the top and bottom plates, while research on unidirectional expansion of the bottom plate is relatively limited. Furthermore, there is a lack of systematic comparative analysis and clear selection criteria regarding the differences in hydraulic characteristics of different vertical expansion methods under bidirectional flow conditions in side-mounted inlets / outlets, particularly their applicability under different inflow conditions in tailrace tunnels. In addition, existing design codes lack specific guidelines for selecting vertical expansion methods for diffuser sections, thus failing to provide effective support for the design of diffuser sections in side-mounted inlets / outlets.

[0041] To address this issue, the present invention provides a two-way fluid simulation system for side-mounted inlet / outlet water flow based on the RSM turbulence model. The above problems are solved using the following method. (See below for details.) Figures 1 to 17 To illustrate the invention in detail:

[0042] This invention describes a two-way fluid simulation system with a side inlet / outlet based on the RSM turbulence model, which mainly includes the following modules:

[0043] Global geometry modeling module: The global geometry modeling module is used to construct a coupled geometric model including the tailrace tunnel, side inlet / outlet, open channel and reservoir area, and to construct the corresponding simulation model based on different vertical expansion methods of the diffusion section;

[0044] Physical parameter configuration module: The physical parameter configuration module is used to set the flow boundary and pressure boundary under bidirectional flow conditions for the simulation model, wherein the reservoir surface adopts the rigid cover assumption and the solid wall boundary adopts the no-slip condition;

[0045] Mesh generation module: The mesh generation module is used to perform structured mesh generation on the simulation model with completed physical parameter configuration, and to refine the mesh in key local areas;

[0046] RSM Solver Module: The RSM solver module is used to numerically solve the flow field under bidirectional flow conditions based on the mesh generation results and the Reynolds stress model (RSM) to obtain the corresponding flow field state data.

[0047] Multi-index evaluation module: The multi-index evaluation module is used to extract and analyze the internal flow regime of the diffusion section, the velocity distribution of the trash rack cross section, the flow distribution of the orifice, and the turbulence characteristic parameters based on the flow field state data, so as to output the hydraulic characteristic evaluation results of different vertical expansion modes of the diffusion section under the inflow and outflow conditions.

[0048] The present invention provides a two-way fluid simulation system for side-mounted inlets / outlets based on the RSM turbulence model. This system constructs a coupled geometric model including a tailrace tunnel, side-mounted inlets / outlets, an open channel, and a reservoir. By configuring the flow and pressure boundaries under two-way flow conditions and combining structured mesh generation and RSM closed-loop solution, it obtains flow field data for the side-mounted inlets / outlets under different vertical expansion modes in the diffuser section. Furthermore, by extracting and analyzing the flow regime within the diffuser section, the velocity distribution across the trash rack cross-section, the orifice flow distribution, and turbulence characteristic parameters, it generates hydraulic characteristic evaluation results for different vertical expansion modes in the diffuser section under inflow and outflow conditions, thus providing a basis for selecting the vertical expansion mode of the side-mounted inlet / outlet diffuser section.

[0049] To further illustrate and explain the above embodiments, based on the above embodiments,

[0050] In another embodiment of the present invention, the global geometric modeling module is used to construct a coupled geometric model including a tailrace tunnel, side inlets / outlets, open channels, and a reservoir area; wherein, the boundary of the tailrace tunnel is set at a distance of 17 to 23 times the diameter from the lower bend of the S-curve, and the lateral boundary of the reservoir area is set at 3 to 7 times the total width of the side inlets / outlets.

[0051] The aforementioned boundary range is set to keep the computational domain boundary away from the mainstream evolution region inside the inlet / outlet, so as to reduce the impact of artificial boundary conditions on the calculation results of the flow regime inside the diffusion section, the velocity distribution of the trash rack cross section, and the orifice flow distribution; at the same time, while ensuring that boundary interference is controllable, the grid size and computational resource consumption are taken into account.

[0052] Specifically, establish a mathematical model for the side-type inlet / outlet of the pumped storage power station, such as... Figure 3 As shown, the model simulation scope includes the tailrace tunnel, side inlets / outlets, open channel, and reservoir area. The tailrace tunnel boundary is 20D from the lower bend of the S-curve (D is the diameter of the tailrace tunnel), the reservoir area boundary along the flow direction is 3A (A is the length of the open channel along the flow direction), and the reservoir area lateral boundary is 5B (B is the total width of the side inlets / outlets).

[0053] In another embodiment of the present invention, when constructing the simulation model, the global geometry modeling module constructs multiple simulation models with different vertical expansion methods, provided that the overall expansion constraint of the diffusion segment remains consistent.

[0054] Specifically, the vertical expansion methods include unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates.

[0055] For the side-type inlet / outlet shape, the total expansion angle of the diffuser section remains unchanged (β=3.7°). The vertical expansion methods are changed to unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates. The effects of tunnel slope and S-curve (the gate shaft section is followed by a straight transition section and a straight tailrace tunnel) are not considered. Mathematical models are established for calculation, and the hydraulic characteristics of the side-type inlet / outlet under bidirectional flow conditions are compared and analyzed based on head loss, the internal flow regime of the aforementioned diffuser section, the velocity distribution of the trash rack cross-section, the orifice flow distribution, the overall turbulent kinetic energy distribution, and the turbulent intensity along the vertical line of the trash rack cross-section. Under dead water conditions, the submersion depth at the center of the inlet / outlet orifice is 12.00m, and the operating flow rate under outflow conditions is 123.48m³. 3 / s, operating flow rate under inflow conditions: 138.62m³ / s 3 / s.

[0056] In another embodiment of the present invention, the physical parameter configuration module is used to set the flow boundary and pressure boundary under bidirectional flow conditions for the simulation model; wherein, the reservoir surface adopts the rigid cover assumption, and the solid wall boundary adopts the no-slip condition.

[0057] Specifically, the tailrace tunnel cross-sectional boundary is given based on the average flow velocity according to the power station's operating flow rate, the solid wall boundary adopts the no-slip condition, the reservoir boundary is given based on the static water pressure according to the dead water level of the reservoir, and the reservoir surface adopts the rigid cover assumption.

[0058] In another embodiment of the present invention, the physical parameter configuration module is used to configure a flow boundary on the tailrace tunnel side boundary according to the operating flow rate, and configure a static pressure boundary on the reservoir side boundary according to the water level conditions, so as to form boundary condition configuration results corresponding to the inflow and outflow conditions.

[0059] In another embodiment of the present invention, the mesh generation module is used to perform structured mesh generation on the geometric model and to perform densification processing on local key areas.

[0060] like Figure 3 As shown, the mesh generation module divides the established mathematical model into meshes. For example, based on the uniform variation of the global mesh size from 0.6m to 0.2m, five mesh systems are obtained, with a total number of meshes of 3.42 million, 5.65 million, 8.73 million, 10.21 million, and 12.84 million, respectively. The mesh scale with a total number of meshes of 10.21 million is selected.

[0061] In another embodiment of the present invention, the meshing module uses an O-type mesh layout to perform topological partitioning of the circular cross-section of the tailrace tunnel, and uses a hexahedral structured mesh to partition the remaining areas of the coupled geometric model.

[0062] Specifically, except for the tunnel which uses an O-type mesh, the rest of the model uses a hexahedral mesh structure. The overall mesh size of the model is 0.3m, while the mesh size of the diversion pier heads and anti-vortex beam sections is locally refined, with the mesh size set to vary from 0.05m to 0.2m.

[0063] In another embodiment of the present invention, when the mesh division module performs densification processing on local key areas, it at least refines the mesh in the diversion pier head area and the anti-vortex beam area.

[0064] In this embodiment, the input to the RSM solver module includes at least the simulation model after physical parameter configuration, the corresponding mesh generation result, the flow boundary conditions, the static pressure boundary conditions, and the fluid property parameters. The RSM solver module outputs at least the velocity field, pressure field, turbulent kinetic energy field, and statistical results for each cross-section used for subsequent evaluation by discretizing and solving the governing equations. The aforementioned governing equations characterize the three-dimensional incompressible turbulent flow characteristics of a side-mounted inlet / outlet under bidirectional flow conditions. The continuity equation describes mass conservation, the Navier-Stokes equation describes momentum conservation, and the Reynolds stress transport equation closes the Reynolds stress term.

[0065] For the flow inside the inlet / outlet, it is incompressible flow, and the governing equations are the continuity equation and the Navier-Stokes equation. The continuity equation is:

[0066] (1)

[0067] The Navier-Stokes equation is:

[0068] (2)

[0069] The turbulent kinetic energy k equation is:

[0070] (3)

[0071] The equation for the dissipation rate ε is:

[0072] (4)

[0073] In the formula, For time; The density of the liquid; For along The velocity component in the direction; Pressure; The fluid's kinematic viscosity coefficient; This refers to the volume force acting on a unit mass of water. It is turbulent kinetic energy; The turbulent dissipation rate; The viscosity coefficient is the coefficient of turbulent motion. ; The term representing the turbulent kinetic energy generation caused by the average velocity gradient; general parameters of the model. , , , , Among them, the aforementioned The turbulent kinetic energy is the energy source, and the distribution of turbulent kinetic energy described later corresponds to the distribution of this turbulent kinetic energy field. The general parameters of the above model are used to complete the calculation of the governing equations in the numerical solution of RSM, and remain consistent in the comparative analysis of different vertical expansion methods.

[0074] Based on the governing equations, a Reynolds stress RSM turbulence model is introduced to close the Reynolds stress term in the Reynolds equations. The Reynolds stress transport equation is as follows:

[0075] (5)

[0076] In the formula, For transient terms; For convection terms; For turbulent diffusion; This is the molecular viscosity diffusion term; This is the shear force generation term; This is the pressure strain term; This is a viscous dissipation term; This generates terms for system rotation.

[0077] It should be noted that the aforementioned set of governing equations are used together in the bidirectional flow numerical solution process of this embodiment. Specifically, the continuity equation and the Navier-Stokes equation are used to establish the basic flow control relationship, the Reynolds stress transport equation is used to achieve turbulent closure, and the aforementioned equations relating turbulent kinetic energy k and dissipation rate ε are used to provide the turbulent scale quantities required in the solution process. All the aforementioned equations employ a unified solution caliber under different vertical expansion methods, the same working boundary conditions, and the same grid convergence criteria to ensure the comparability of comparison results between different simulation models. The flow field state data output by the RSM solution module includes at least the velocity distribution inside the diffuser section, the velocity distribution across the trash rack cross-section, the flow statistics for each orifice, and the turbulent kinetic energy field distribution.

[0078] In another embodiment of the present invention, the RSM solving module achieves model closure by simultaneously solving the continuity equation, the Navier-Stokes equation, and the Reynolds stress transport equation when performing numerical solutions; wherein, the Reynolds stress transport equation includes transient terms, convection terms, turbulent diffusion terms, molecular viscous diffusion terms, shear force generation terms, pressure strain terms, viscous dissipation terms, and system rotation generation terms.

[0079] In another embodiment of the present invention, the mesh generation module further includes a mesh independence verification unit, used to generate at least five mesh systems based on different global mesh sizes, and to determine the mesh resolution used for the final simulation based on the calculation errors of key physical quantities between adjacent mesh systems. The key physical quantities are flow field evaluation quantities extracted under the same operating conditions, the same expansion method, and the same monitoring location, including at least one or more of the following: cross-sectional velocity distribution of the trash rack, orifice flow distribution, and velocity non-uniformity coefficient; the calculation error is the difference in calculation results for the corresponding key physical quantities between two adjacent mesh systems.

[0080] Specifically, based on the uniform variation of the global grid size from 0.6m to 0.2m, five grid systems were obtained, with a total number of grids of 3.42 million, 5.65 million, 8.73 million, 10.21 million, and 12.84 million, respectively.

[0081] Furthermore, the five grid systems mentioned above were subjected to independence verification.

[0082] like Figure 4 As shown, plot the curves of key physical quantities such as computation time and computation error as a function of the number of grids, and observe the trend. When the trend region is flat and the computation error of the corresponding key physical quantities between two adjacent grids is less than 3%, it can be considered that grid independence has been achieved.

[0083] As shown in the figure, the computational error is relatively small (within 3%) when the number of grids is 10.21 million, and the computation time is approximately 22 hours. Afterward, as the global grid size continues to decrease, the computational error remains essentially constant, but the computational efficiency significantly decreases. Therefore, a grid scale of 10.21 million grids is selected, with hexahedral grids used for all parts except the tunnel, which uses an O-type grid. The overall grid size of the model is 0.3m, with localized refinement at the diversion pier heads and anti-vortex beam sections, ranging from 0.05m to 0.2m.

[0084] In another embodiment of the present invention, the multi-index evaluation module is used to perform unified post-processing on the flow field state data under different working conditions and different vertical expansion modes, and output the hydraulic characteristic evaluation results corresponding to the flow state inside the diffusion section, the velocity distribution of the trash rack cross section, the velocity non-uniformity, the orifice flow distribution, the turbulent kinetic energy distribution, and the vertical turbulence intensity of the trash rack cross section.

[0085] The velocity non-uniformity coefficient is calculated based on the velocity statistics of each measuring point on the cross-section of the trash rack, and is used to characterize the dispersion of velocity distribution within the same cross-section. When comparing different vertical expansion methods, the same measuring point arrangement, the same cross-section position, and the same statistical caliber are used for calculation.

[0086] Specifically, the multi-index evaluation module first extracts the cross-sectional velocity distribution at the beginning section (Y=0), the middle section 1 (Y=1 / 3L), the middle section 2 (Y=2 / 3L), and the end section (Y=L) of the diffuser section to analyze the internal flow regime of the diffuser section. Then, it extracts the statistical values ​​of the velocity at each orifice screen cross-section to analyze the velocity distribution and velocity non-uniformity of the screen cross-section. Next, it statistically analyzes the calculated flow rate at each orifice cross-section and compares it with the theoretical distribution benchmark for each orifice under the same operating condition to characterize the orifice flow distribution. Then, it extracts the variation of turbulent kinetic energy along the diffusion and adjustment sections in the middle of the orifice to characterize the overall turbulent kinetic energy distribution. Finally, it extracts the turbulence intensity distribution at the measuring points corresponding to the vertical line in the screen cross-section to evaluate the flow stability near the screen. This results in a unified evaluation of different vertical expansion modes under both inflow and outflow conditions.

[0087] The aforementioned turbulent kinetic energy distribution corresponds to the turbulent kinetic energy field distribution in the RSM solution results; the uniformity of the aforementioned velocity distribution is evaluated based on the velocity non-uniformity coefficient; and the aforementioned orifice flow distribution is evaluated based on the degree of deviation between the actual statistical flow rate of each orifice and the theoretical distribution benchmark under the same working conditions.

[0088] In another embodiment of the present invention, the multi-index evaluation module specifically evaluates the hydraulic characteristics of the vertical expansion mode of the diffuser section. The expansion mode includes unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates. The evaluation covers the turbulent kinetic energy difference analysis under both outflow and inflow conditions. Specifically, the "straight inflow" refers to the straight inflow condition of the tailrace tunnel connected to the side inlet / outlet, while the "non-uniform inflow" refers to the inclined inflow or vertical bend inflow condition of the tailrace tunnel connected to the side inlet / outlet.

[0089] Under outflow conditions, the vertical expansion of the diffuser section has little impact on the flow distribution of the side inlet / outlet (the flow non-uniformity is less than 10%). When the expansion method is bidirectional symmetrical expansion, the flow state inside the diffuser section is better, the mainstream of the trash rack section is located in the middle of the orifice, the velocity distribution is the most uniform, the velocity non-uniformity coefficients of the middle and side orifices are 1.851 and 1.569 respectively (both less than 2.0), the overall turbulent kinetic energy of the middle orifice is the smallest, the turbulence intensity of the trash rack section is the smallest, and the maximum turbulence intensity of the middle and side orifices is 0.41 and 0.29 respectively, and the hydraulic indicators of the inlet / outlet are optimal.

[0090] Under inflow conditions, the vertical expansion of the diffuser section has little impact on the hydraulic characteristics of the inlet / outlet. The flow pattern inside the diffuser section is good, the velocity distribution of the trash rack cross section is uniform, the velocity non-uniformity coefficient of the middle and side holes is less than 1.5, the flow distribution at the orifices is uniform (the degree of flow non-uniformity is less than 10%), and the overall turbulent kinetic energy inside the inlet / outlet is reduced by 7 times compared with the outflow conditions. All hydraulic indicators of the inlet / outlet meet the design requirements.

[0091] In this embodiment, the "straight inflow" refers to an inflow condition where the connection section with the side inlet / outlet is a straight tailrace tunnel, and the mainstream position of the inflow is not significantly deviated from the center of the orifice. The "uneven inflow" refers to an inflow condition where the mainstream position of the inflow is significantly offset from the center of the orifice due to factors such as inclined tunnels, vertical bends, or vertical S-bends. The aforementioned significant offset is used to distinguish different inflow types, and its specific determination can be made by comprehensively considering the mainstream position of the trash rack cross-section, the symmetry of the velocity distribution, and the turbulent kinetic energy distribution.

[0092] When the tailrace tunnel connected to the side inlet / outlet has a straight inflow, a bidirectional symmetrical expansion method using the top and bottom plates is recommended for the vertical expansion of the diffuser section. When the tailrace tunnel connected to the side inlet / outlet has an uneven inflow, a unidirectional expansion method using the top plate is recommended. In this case, the overall turbulent kinetic energy of the inlet / outlet is smaller (reduced by 40% compared to the straight tunnel inflow), the mainstream flow of the trash rack section is located in the middle of the orifice, and the velocity distribution is most uniform. In the actual engineering layout of the side inlet / outlet of a pumped storage power station, the hydraulic characteristics of the optimal vertical expansion method of the diffuser section should be selected based on the inflow conditions of the tailrace tunnel.

[0093] In another embodiment of the present invention, a two-way fluid simulation system for side inlet / outlet based on the RSM turbulence model further includes a mathematical model verification module.

[0094] The established mathematical model was used for calculations under the conditions of dead water level (corresponding to a submergence depth of 12.00m at the orifice center) and an operating flow rate of 123.48m³ under outflow conditions. 3 / s, operating flow rate under inflow conditions: 138.62m³ / s 3 / Furthermore, using the velocity distribution along the vertical line of each orifice trash rack cross-section as a comparison object, the numerical calculation results were compared one by one with the corresponding hydraulic model test results to verify the mathematical model's ability to characterize the internal flow characteristics of the inlet / outlet.

[0095] Figure 5 The figure shows the velocity distribution of the trash rack cross-section under different operating conditions, based on numerical calculations and model test results. As can be seen from the figure, the numerical calculation values ​​and hydraulic model test values ​​of the velocity distribution of each orifice trash rack cross-section under bidirectional flow conditions with side inlets / outlets show consistent trends, and the mainstream position and velocity distribution patterns of the corresponding cross-sections are basically consistent, indicating that the RSM turbulence model can be used for the hydraulic characteristic analysis of the inlet / outlet in this embodiment. In another embodiment of the invention, the variation patterns of hydraulic characteristics such as internal flow regime, velocity distribution, flow rate distribution, turbulent kinetic energy, and turbulence intensity under bidirectional flow conditions with side inlets / outlets are analyzed under outflow conditions.

[0096] Specifically, analyze the variation of the flow regime along the diffusion section:

[0097] Four typical cross-sections were selected: the beginning section of the diffusion section (Y=0), the middle section 1 of the diffusion section (Y=1 / 3L), the middle section 2 of the diffusion section (Y=2 / 3L), and the end section of the diffusion section (Y=L). (L is the total length of the diffusion section, and the Y=0 section is the beginning section of the diffusion section.)

[0098] Figure 6The diagram illustrates the internal flow patterns of the diffuser section under different expansion methods. As shown, the velocity variation along the flow path is basically the same under different expansion methods and outflow conditions. At the initial section of the diffuser section, due to the presence of the diversion side piers, the flow velocity exhibits stratification upon entering the diffuser section. The velocity in the middle of the section is slightly higher than that on the sides, with a maximum velocity of approximately 3.2 m / s. At the middle section 1 of the diffuser section, due to the effect of the planar diffusion angle, the cross-sectional area is larger than that at the initial section, resulting in a decrease in velocity. The maximum velocity in the central orifice is approximately 2.8 m / s, and the maximum velocity in the side orifices is approximately 2.0 m / s. At the middle section 2 of the diffuser section, due to the different vertical expansion methods, the velocity distribution changes. The main flow in the unidirectional expansion of the top plate is located in the lower middle part of the orifice, the main flow in the unidirectional expansion of the bottom plate is located in the upper middle part of the orifice, while the main flow in the bidirectional symmetrical expansion of the top and bottom plates is located in the middle of the orifice. At the final section of the diffuser section, due to the combined effect of the planar and vertical diffusion angles, the velocity gradually decreases, with the maximum velocity in the central orifice.

[0099] Analysis of the vertical velocity along the cross-section of the trash rack under different expansion patterns in the diffusion section:

[0100] like Figure 7 As shown in Table 1 below, the variation of the velocity non-uniformity coefficient across the trash rack cross-section is illustrated. The distance from the bottom plate is dimensionless, given as the ratio of the distance h from the bottom plate to the orifice height H.

[0101] Table 1. Velocity non-uniformity coefficient of trash rack cross section (outflow conditions)

[0102]

[0103] As shown in the figure, the velocity distribution pattern of the trash rack cross-section is basically the same under different expansion modes, but the mainstream position varies greatly. The maximum velocity in the central holes is about 1.3 m / s, and the maximum velocity in the side holes is about 1.0 m / s. The mainstream positions for unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates are located at h / H=0.3, 0.7, and 0.5, respectively.

[0104] As shown in the table, the velocity non-uniformity coefficient of the middle and side holes under different vertical expansion methods in the diffuser section meets the requirement of the current design code for pumped storage power stations not exceeding 2.0. For the middle hole, the velocity non-uniformity coefficients of the top plate unidirectional expansion and the top-bottom plate bidirectional symmetrical expansion are basically the same. The bottom plate unidirectional expansion has a more uneven velocity distribution. The velocity non-uniformity coefficient of the middle hole in the top-bottom plate bidirectional symmetrical expansion is 1.851 (0.3% lower than the top plate unidirectional expansion and 1% lower than the bottom plate unidirectional expansion). For the side holes, the velocity non-uniformity coefficient of the bottom plate unidirectional expansion is the largest, followed by the top plate unidirectional expansion. The velocity distribution of the side holes in the top-bottom plate bidirectional symmetrical expansion is the most uniform. The velocity non-uniformity coefficient of the side holes in the top-bottom plate bidirectional symmetrical expansion is 1.569 (4.4% lower than the top plate unidirectional expansion and 5.2% lower than the bottom plate unidirectional expansion).

[0105] Analysis of flow distribution at each orifice of the side-mounted inlet / outlet:

[0106] Figure 8 The diagram illustrates the flow distribution at the inlet / outlet under different vertical expansion methods in the diffuser section. The flow unevenness (the ratio of actual to theoretical flow distribution at the orifice) characterizes the flow distribution at each orifice of the side-type inlet / outlet. As shown in the figure, different expansion methods have minimal impact on flow distribution. The flow rate at the central orifice is slightly greater than that at the side orifices. The flow unevenness at each orifice is less than the 10% requirement of the current design specifications for pumped storage power stations, and is all between 2% and 3%, indicating a very uniform flow distribution. The flow unevenness is relatively smaller compared to conventional side-type inlet / outlet shapes. It should be noted that the shape of the diversion pier head, as a fixed structural condition in the mathematical model of this embodiment, remains consistent in the comparative calculations of different vertical expansion methods; therefore, it does not affect the validity of the relative comparison conclusions between different vertical expansion methods.

[0107] Analysis of the global turbulent kinetic energy distribution under bidirectional flow conditions with side-mounted inlet / outlet:

[0108] Extract the contour maps of turbulent kinetic energy changes along the diffusion and adjustment sections in the middle of the orifice (4.5m from the bottom of the orifice, 9m above the orifice), as shown below. Figure 9 As shown in the figure, it can be seen that under outflow conditions, there is a negative correlation between the turbulent kinetic energy inside the inlet / outlet and the flow velocity; the higher the flow velocity, the lower the turbulent kinetic energy. Specifically, the variation law of turbulent kinetic energy along the flow path is basically the same for both the top and bottom plate unidirectional expansion. The turbulent kinetic energy is greatest near the end of the diffuser section, with the central hole having the maximum at 0.4 and the side holes at 0.24. This is because the water flow direction at the end of the diffuser section rotates at the same angle as the expansion, increasing the velocity gradient and causing flow separation. The backflow in the separation zone increases the turbulent kinetic energy. The turbulent kinetic energy is relatively small during the bidirectional symmetrical expansion of the top and bottom plates, with the maximum value of approximately 0.24 in the central and side holes (a 40% reduction in turbulent kinetic energy compared to the previous two expansion methods). The turbulent kinetic energy is also relatively small at the trash rack, where the turbulent kinetic energy distribution is more uniform.

[0109] Analysis of the influence of different vertical expansion patterns of the diffusion section on the turbulence intensity of the trash rack cross-section:

[0110] Extract the turbulence intensity of the vertical line at the midpoint of the trash rack cross-section, such as Figure 10As shown, the vertical turbulence intensity of the trash rack cross-section is obtained by post-processing the statistical results of velocity fluctuations at the corresponding measuring points, and a comparative analysis is performed under the same measuring line position, the same working conditions, and the same solution settings. It can be seen that, for the central hole, the maximum values ​​of the turbulence intensity of the diffuser section's unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates are 0.51, 0.44, and 0.41, respectively. The turbulence intensity of the central hole trash rack cross-section under bidirectional symmetrical expansion of the top and bottom plates is reduced by 19.6% compared to the unidirectional expansion of the top plate and by 6.8% compared to the unidirectional expansion of the bottom plate. For the side holes, the maximum values ​​of the turbulence intensity of the diffuser section's unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates are 0.36, 0.35, and 0.29, respectively. The turbulence intensity of the side hole trash rack cross-section under bidirectional symmetrical expansion of the top and bottom plates is reduced by 19.4% compared to the unidirectional expansion of the top plate and by 17.1% compared to the unidirectional expansion of the bottom plate. The turbulence intensity is highest at the unidirectional expansion of the top plate of the diffuser section, followed by the unidirectional expansion of the bottom plate, and lowest at the bidirectional symmetrical expansion of the top and bottom plates. The reason for the high turbulence intensity at the unidirectional expansion of the top plate of the diffuser section is that the mainstream position is located at h / H=0.3, the flow velocity at the top is low, and under outflow conditions, the water flow at the top of the trash rack section flows in both the flow direction (at the inlet / outlet end) and the vertical direction (anti-vortex beam). The flow pattern in this area is poor, the water exchange is more intense, and the turbulence intensity is high.

[0111] In summary, the difference in the expansion mode of the diffuser under outflow conditions has a significant impact on the internal flow regime, the flow velocity of the trash rack, the turbulence intensity, and the turbulence kinetic energy of the diffuser at the inlet / outlet, but a relatively small impact on the orifice flow distribution.

[0112] In another embodiment of the present invention, the variation law of internal flow regime, velocity distribution, flow rate distribution and turbulent kinetic energy under the inflow condition and the bidirectional flow condition of the side inlet / outlet is analyzed.

[0113] Specifically, analyze the variation of the flow regime along the diffusion section:

[0114] Figure 11The diagram illustrates the internal flow patterns of the diffuser section under different expansion modes. As shown, the velocity variation along the diffusion path is the same under different expansion modes and inflow conditions. At the end section of the diffuser, the velocity distribution exhibits a "smaller at the top, larger at the bottom" characteristic. The maximum velocity in the central orifice is approximately 1.2 m / s, while the maximum velocity in the side orifices is approximately 0.8 m / s. This is due to the flow direction of the water at the orifice and the vertical movement of the water flow in the anti-vortex beam, creating a small backflow zone at the top of the diffuser end. At the middle section (section 2), due to the bidirectional contraction of the diffuser in both the horizontal and vertical planes, the velocity gradually increases. The velocity in the central orifice is less than that in the side orifices, with a maximum velocity of approximately 0.8 m / s in the central orifice and approximately 1.2 m / s in the side orifices. At the middle section (section 1), as the diffuser continues to contract, the velocity continues to increase. The velocity in the central orifice remains less than that in the side orifices, with a maximum velocity of approximately 1.6 m / s in the central orifice and approximately 2.0 m / s in the side orifices. At the beginning section of the diffuser, due to the presence of the middle and side diversion piers, the flow velocity at the beginning section of the diffuser exhibits a stratification phenomenon, with the flow velocity in the middle of the section being slightly lower than that on both sides, and the maximum flow velocity being approximately 3.2 m / s.

[0115] Analysis of the vertical velocity along the midline of the trash rack cross-section under different vertical expansion patterns in the diffusion section:

[0116] Figure 12 Table 2 shows the variation of the velocity non-uniformity coefficient of the trash rack cross-section under different vertical expansion modes of the diffusion section.

[0117] Table 2. Velocity non-uniformity coefficient of trash rack cross section (inflow conditions)

[0118]

[0119] As shown in the figure, the velocity distribution pattern of the trash rack cross-section is basically the same under different expansion methods under different inflow conditions. The velocity distribution of the central and side holes both exhibit a "smaller at the top and larger at the bottom" characteristic, with the velocity in the central hole being slightly lower than that in the side holes. The maximum velocity in the central hole is about 0.8 m / s, while the maximum velocity in the side holes is about 1.0 m / s. This is because the water area in the side holes is wider than that in the central hole under different inflow conditions, resulting in a larger overall inflow rate. As shown in the table, the velocity non-uniformity coefficient of the central and side holes under different vertical expansion methods in the diffuser section meets the design specification requirement of not exceeding 2.0, and is less than 1.5. Different expansion methods in the diffuser section have little impact on the velocity non-uniformity coefficient of the trash rack cross-section under inflow conditions.

[0120] Analysis of inlet / outlet flow distribution under different vertical expansion modes in the diffuser section:

[0121] Figure 13 The figure shows the flow distribution at the inlet / outlet under different vertical expansion methods in the diffuser section. As can be seen from the figure, under the inlet condition, different expansion methods have little impact on the flow distribution. The flow rate at the side holes is slightly greater than that at the center holes. The unevenness of the flow rate at each orifice is less than 10% as required by the design specifications, and is between 5% and 10%. The flow rate distribution at the orifices is relatively uniform.

[0122] Analysis of the turbulent kinetic energy inside the inlet / outlet under inflow conditions:

[0123] The changes in turbulent kinetic energy along the diffusion and adjustment sections in the middle of the orifice are as follows: Figure 14 As shown in the diagram, the turbulent kinetic energy inside the inlet / outlet is relatively small under inflow conditions (the maximum value is 7 times lower than under outflow conditions). Different expansion modes in the diffuser section have little impact on the turbulent kinetic energy inside the inlet / outlet. The maximum value is 0.04 in the central hole and 0.05 in the side holes. The turbulent kinetic energy at the trash rack is between 0.04 and 0.05, indicating a relatively uniform distribution. Analysis suggests that the overall turbulent kinetic energy is smaller under inflow conditions because the inflow conditions follow a pressure gradient (pressure decreases along the flow direction), accelerating the water flow. This accelerated flow and the flow field characteristics following the pressure gradient suppress turbulence.

[0124] In another embodiment of the present invention, it is analyzed that when the tailrace tunnel has a certain slope or a vertical bend (including a vertical S-bend), the mainstream position of the outflow velocity of the trash rack section is in the upper part of the orifice, and the top and bottom plate expansion method is selected at this time.

[0125] like Figure 15 The side inlet / outlet body diagrams of two different expansion methods are shown. Based on the original body diagram of the side inlet / outlet of the pumped storage power station (with a slope of i=0.08 in the transition section and the inclined tunnel section), mathematical models of unidirectional expansion of the top plate of the diffusion section and bidirectional symmetrical expansion of the top and bottom plates are established for calculation and analysis of the advantages and disadvantages of the two expansion methods.

[0126] A detailed analysis of the distribution of turbulent kinetic energy along the orifice in the diffusion and adjustment sections under different expansion modes of inflow conditions in inclined tunnels is conducted.

[0127] Figure 16 The figure shows the distribution of turbulent kinetic energy along the orifice in the diffuser and adjustment sections under different expansion modes of the inflow conditions in an inclined tunnel. As can be seen from the figure, the maximum turbulent kinetic energy is 0.24 when the roof expands unidirectionally (40% lower than in a straight tunnel). The turbulent kinetic energy distribution in the middle and side orifices is relatively uniform, and the distribution pattern along the orifice is basically the same as in the case of a straight tunnel with bidirectional symmetrical expansion of the roof and floor. When the roof and floor expand symmetrically in both directions, the turbulent kinetic energy increases, reaching its maximum between the middle and end of the diffuser section. The maximum turbulent kinetic energy in the middle orifice is 0.45, and in the side orifices it is 0.25, exceeding 0.40, which is more unfavorable than the case of a straight tunnel with unidirectional expansion of the roof in the diffuser section.

[0128] Analysis of the reasons reveals that, under the conditions of the inclined tunnel, the main flow of water is located in the middle and upper part of the cross-section for a short period after entering the diffusion section. The expansion at the top of the diffusion section is conducive to the diffusion of the main flow to the outside. However, the bidirectional symmetrical expansion of the top and bottom plates of the diffusion section maintains the total expansion angle unchanged, which to some extent reduces the vertical expansion angle at the top, restricts the diffusion of the water flow, and increases the turbulent kinetic energy.

[0129] Analysis of the velocity distribution across the cross-section of the trash rack in the vertical expansion section of the diffuser under inclined flow conditions: unidirectional expansion of the top plate and bidirectional symmetrical expansion of the top and bottom plates.

[0130] The flow regime (including velocity contour lines) of the trash rack cross-section was extracted, and three survey lines were selected for each orifice to obtain the velocity distribution of the middle and side orifice trash rack cross-section under different expansion modes in the diffusion section, such as... Figure 17 As shown in the diagram, due to the inclined arrangement of the water conveyance tunnel, the mainstream flow after entering the diffuser section is located in the upper middle part of the orifice. When the diffuser section adopts unidirectional expansion of the top plate (top plate expansion angle β), there is a certain slope in the vertical direction, which weakens the effect of the inclined flow to a certain extent. At this time, the mainstream position of the trash rack section is exactly at h / H=0.5 (i.e., the center of the orifice). When the diffuser section adopts bidirectional symmetrical expansion of the top and bottom plates (top plate expansion angle β / 2), the weakening effect of the top plate expansion angle on the inclined flow is reduced by half. At this time, the mainstream position of the trash rack section is located at h / H=0.6. The velocity distribution patterns of the trash rack section are basically the same for unidirectional expansion of the top plate and bidirectional symmetrical expansion of the top and bottom plates, but the low velocity zone area at the bottom of the middle and side orifices is relatively smaller when the top plate expands unidirectionally, and the velocity distribution of the section is more uniform.

[0131] It should be understood that, in the embodiments of the present invention, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0132] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0133] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the aforementioned global geometric modeling module, physical parameter configuration module, mesh generation module, RSM solution module, multi-index evaluation module, and mathematical model verification module have been described in conjunction with the foregoing embodiments, and will not be repeated here.

[0134] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, or they may be electrical, mechanical, or other forms of connection.

[0135] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0136] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0137] From the above description of the embodiments, those skilled in the art will clearly understand that the present invention can be implemented in hardware, firmware, or a combination thereof. When implemented in software, the above-described functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transmission of a computer program from one place to another. Storage media can be any available medium accessible to a computer. For example, but not limited to, computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code having the form of instructions or data structures and accessible to a computer. Furthermore, any connection can suitably be a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. As used in this invention, disk and disc include compressed optical discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, wherein disks typically magnetically copy data, while discs optically copy data using lasers. The combinations described above should also be included within the scope of protection for computer-readable media.

[0138] In summary, the above description is merely a preferred embodiment of the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A two-way fluid simulation system with a side inlet / outlet based on the RSM turbulence model, characterized in that, include: The module includes a global geometric modeling module, a physical parameter configuration module, a mesh generation module, an RSM solution module, and a multi-index evaluation module. The global geometric modeling module is used to construct a coupled geometric model that includes the tailrace tunnel, side inlet / outlet, open channel and reservoir area, and to construct the corresponding simulation model based on different vertical expansion methods of the diffusion section. The physical parameter configuration module is used to set the flow boundary and pressure boundary under the bidirectional flow condition for the simulation model. The surface of the reservoir area adopts the assumption of a rigid cover, and the solid wall boundary adopts the condition of no slippage. The mesh generation module is used to perform structured mesh generation on the simulation model with completed physical parameter configuration, and to perform densification processing on local key areas. The RSM solver module is used to numerically solve the flow field under bidirectional flow conditions based on the mesh generation results and the Reynolds stress model (RSM) to obtain the corresponding flow field state data. The multi-index evaluation module is used to extract and analyze the internal flow regime of the diffusion section, the velocity distribution of the trash rack cross section, the flow distribution of the orifice, and the turbulence characteristic parameters based on the flow field state data, so as to output the hydraulic characteristic evaluation results of different vertical expansion modes of the diffusion section under the inflow and outflow conditions.

2. The side-mounted inlet / outlet bidirectional fluid simulation system based on the RSM turbulence model according to claim 1, characterized in that: When constructing the coupled geometric model, the global geometric modeling module sets the outer extension distance of the tunnel section boundary and the lateral boundary range of the reservoir area based on the characteristic diameter of the tailrace tunnel and the total width of the side inlet / outlet.

3. The side-mounted inlet / outlet bidirectional fluid simulation system based on the RSM turbulence model according to claim 1, characterized in that: When constructing the simulation model, the global geometry modeling module constructs multiple simulation models with different vertical expansion methods, while maintaining a consistent overall expansion constraint in the diffusion segment.

4. The side-mounted inlet / outlet bidirectional fluid simulation system based on the RSM turbulence model according to claim 3, characterized in that: The vertical expansion methods include unidirectional expansion of the top plate, unidirectional expansion of the bottom plate, and bidirectional symmetrical expansion of the top and bottom plates.

5. The bidirectional fluid simulation system for side-mounted inlet / outlet based on the RSM turbulence model according to claim 1, characterized in that: The physical parameter configuration module is used to configure the flow boundary on the tailrace tunnel side boundary according to the operating flow rate, and configure the static pressure boundary on the reservoir side boundary according to the water level conditions, so as to form the boundary condition configuration results corresponding to the inflow and outflow conditions.

6. The side-mounted inlet / outlet bidirectional fluid simulation system based on the RSM turbulence model according to claim 1, characterized in that: The meshing module uses an O-type mesh layout to perform topological partitioning of the circular cross-section of the tailrace tunnel, and uses a hexahedral structured mesh to partition the remaining areas of the coupled geometric model.

7. A two-way fluid simulation system for side-mounted inlet / outlet based on the RSM turbulence model according to claim 6, characterized in that: When the grid division module densifies the local key areas, it at least refines the grid in the diversion pier head area and the anti-vortex beam area.

8. The side-mounted inlet / outlet bidirectional fluid simulation system based on the RSM turbulence model according to claim 1, characterized in that: The mesh generation module also includes a mesh independence verification unit, which is used to generate at least five mesh systems based on different global mesh sizes, and determine the mesh resolution used for the final simulation based on the calculation errors of key physical quantities between adjacent mesh systems.

9. A two-way fluid simulation system for side-mounted inlet / outlet based on the RSM turbulence model according to claim 1, characterized in that: When performing numerical solutions, the RSM solution module achieves model closure by simultaneously solving the continuity equation, the Navier-Stokes equation, and the Reynolds stress transport equation. The Reynolds stress transport equation includes transient terms, convection terms, turbulent diffusion terms, molecular viscous diffusion terms, shear force generation terms, pressure strain terms, viscous dissipation terms, and system rotation generation terms.

10. A two-way fluid simulation system for side-mounted inlet / outlet based on the RSM turbulence model according to claim 1, characterized in that: When analyzing the flow field state data, the multi-index evaluation module calculates the velocity non-uniformity coefficient by extracting the flow velocity at each measuring point on the cross-section of the trash rack, and calculates the degree of non-uniformity of flow distribution at each orifice based on the flow statistics of each orifice. At the same time, it extracts the internal flow regime of the diffusion section, the global turbulent kinetic energy distribution, and the vertical turbulence intensity of the cross-section of the trash rack.

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