A hydrodynamic load mapping method in the analysis of energy-saving guide wheel structure

Abstract

A hydrodynamic load mapping method for energy-saving guide wheel structure analysis is proposed. First, the hydrodynamic loads obtained from CFD analysis using a scaled model are extracted and expressed as average pressure and pulsating pressure. Data conversion from the scaled model to the full-scale model is performed, followed by formatting of the hydrodynamic load data and mapping the loads to the structure. Considering the load application method, to facilitate the extraction of model information such as loading elements or nodes required for load processing, and taking into account the complexity of load processing, the APDL language of ANSYS software is used for load mapping and application. Simultaneously, when using ANSYS software for structural analysis, it also facilitates handling all computational tasks within the same software. This method can adapt to the use of scaled models in CFD to calculate hydrodynamic pressure, significantly improving the computational efficiency of obtaining water pressure during the CFD stage. This method is applicable to both regular and irregular mesh generation of the structural model.

Description

Technical Field

[0001] This invention belongs to the field of marine ship construction and design, and specifically relates to a hydrodynamic load mapping and loading method in the analysis of energy-saving guide wheel structures. Background Technology

[0002] Employing energy-efficient guide wheels is one of the effective ways to improve ship speed, fuel economy, and design green and environmentally friendly vessels. In the structural analysis calculations required for energy-efficient guide wheel design, the water pressure exerted on the guide wheel by the CFD must be applied to the guide wheel structure. Currently, CFD analysis uses scaled models to improve computational efficiency, resulting in a significant difference between the computational mesh and the structural mesh. Even when CFD uses a full-scale model, it can only utilize a larger mesh for calculation, which is still far from the mesh size used in structural analysis. Therefore, the water pressure load obtained through CFD must be processed to map it onto the actual structural mesh.

[0003] There are two problems when mapping loads obtained from CFD onto the structure. One is the transformation from scaled model loads to full-scale structural loads. The other is that due to the difference between the CFD calculation grid and the structural calculation grid, accurate interpolation needs to be performed again so that the loads can be easily applied to the structure. At the same time, due to the huge number of load points during the mapping process, a reasonable algorithm needs to be constructed to improve the mapping processing efficiency.

[0004] To address the above problems and improve the convenience of structural analysis, this invention takes the loads calculated by CFD on a scaled model as input and aims to transform these input loads into loads applicable to the structure. It provides a method for transforming and processing CFD loads from scaled models to structural calculation loads. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a hydrodynamic load mapping method for energy-saving guide wheel structure analysis, the technical solution of which is as follows:

[0006] A hydrodynamic load mapping method for energy-saving guide wheel structure analysis is described below:

[0007] S1: Extract the hydrodynamic loads obtained from the CFD analysis of the scaled model and express them as average pressure and pulsating pressure.

[0008] S101: Design state for structural analysis of energy-saving guide wheels. This clarifies the design state for both structural and CFD hydrodynamic analysis, facilitating subsequent load transfer. It includes the definition of analysis conditions and coordinate systems.

[0009] 1) Determine the operating conditions for structural analysis of the energy-saving guide wheel. The operating conditions are the hydrodynamic pressure under different combinations of incoming flow direction and propeller direction. Each operating condition is determined by the corresponding incoming flow direction angle. α and propeller azimuth angle β Characterization.

[0010] 2) The coordinate system for structural analysis of the energy-saving guide wheel is based on the ship coordinate system. The model coordinate system is defined as follows: the origin o is taken as the center position of the propeller, and the coordinate axis direction is consistent with the ship coordinate axis direction.

[0011] S102: For each working condition, the hydrodynamic analysis software directly outputs the pressure load as a function of coordinates, and the pressure load is automatically decomposed into average pressure and pulsating pressure by the software.

[0012] For specific analysis conditions L m The pressure output format is (X,Y,Z,P,C), where P is the average pressure on the surface of the model guide wheel; and C is the single-peak pulsating pressure on the surface of the model guide wheel.

[0013] Operating conditions L m The pressure data directly output by the hydrodynamic analysis software is denoted as database Am0.

[0014] S2: Data conversion from scaled-down model to full-scale model

[0015] For each working condition, the scaled model pressure load data (X,Y,Z,P,C) output by the hydrodynamic analysis software is converted into the corresponding data (Xs,Ys,Zs,Ps) of the full-scale energy-saving guide wheel.

[0016] S201: Coordinate Transformation

[0017] The real-scale coordinates Xs, Ys, Zs are given by multiplying the scaled model coordinates X, Y, Z by the scaling ratio, as follows: ; ; .

[0018] Where λ is the scaling ratio.

[0019] S202: Load Transition .

[0020] in:

[0021] P s : Total pressure on the surface of the guide wheel of the actual ship, i.e., actual dimensional load, Pa.

[0022] V 0s : Actual ship's incoming current velocity, m / s.

[0023] V0m : Velocity of the incoming current for the model ship, m / s.

[0024] n s : Propeller speed of the actual ship, 1 / s.

[0025] n m : Propeller speed of the model ship, 1 / s.

[0026] S3: Formatting of hydrodynamic load data

[0027] The real-scale hydrodynamic load data processed in step S2 is processed to form an inputPm file, which is then read into the structural analysis software.

[0028] S4: Load-to-structure mapping and application

[0029] Hydrodynamic load mapping is performed by limiting the search range for each structural element during the mapping process to reduce load processing time. The specific operation is as follows:

[0030] S401: Define an array prelem to store the loads applied to the structural model elements. The data format is (Nu, Pele).

[0031] The array `prelem` is a J-row, 2-column array, where J is the number of elements to be loaded, Nu is the element number of the structural model, and Pele is the load value of the structural element.

[0032] S402: For each element i of the structure, perform load search and interpolation calculations to extract the center coordinates (x, y) of the structural element. i ,y i ,z i ) and unit number Nu i Based on the file inputPm, with (x i ,y i ,z i Centered on the inputPm, within a certain range, the load points in the inputPm are searched to obtain the load value Pele of the element. i .

[0033] The calculated element load value Pele i and the corresponding unit number Nu i Stored in the array prelem.

[0034] S403: Select the element to be loaded, and apply the structural load in the structural analysis software using the sfe command combined with a loop statement based on the data information in the prelem array.

[0035] Furthermore, in the above-mentioned hydrodynamic load mapping method for energy-saving guide wheel structure analysis, in step S101, the structural analysis should cover all typical operating conditions, using... Indicates the first m Each operating condition.

[0036] Furthermore, in the above-mentioned hydrodynamic load mapping method for energy-saving guide wheel structure analysis, in step S102, the database Am0 is a k-row, 5-column matrix.

[0037] Furthermore, in step S3, the structural analysis software used is ANSYS. When importing the hydrodynamic load database into ANSYS, each line of data must contain no more than 10 data points. The load data is then processed and saved as a txt file with the following format:

[0038] inputPm(a,1)=Am(1+a,1),Am(2+a,1),…,Am(8+a,1),Am(9+a,1),Am(10+a,1).

[0039] inputPm(a,2)=Am(1+a,2),Am(2+a,2),…,Am(8+a,2),Am(9+a,2),Am(10+a,2).

[0040] inputPm(a,3)=Am(1+a,3),Am(2+a,3),…,Am(8+a,3),Am(9+a,3),Am(10+a,3).

[0041] inputPm(a,4)=Am(1+a,4),Am(2+a,4),…,Am(8+a,4),Am(9+a,4),Am(10+a,4).

[0042] Where a = 10 × (k - 1), inputPm(a, 1) is the x-coordinate data, inputPm(a, 2) is the y-coordinate data, inputPm(a, 3) is the z-coordinate data, and inputPm(a, 4) is the pressure data.

[0043] Furthermore, in the above-mentioned hydrodynamic load mapping method for energy-saving guide wheel structure analysis, the search range in step S4 is determined based on the geometry of the energy-saving guide wheel, and the search range is defined using polar coordinates.

[0044] Using the YZ plane as a reference, a fixed search angle is given. θ ,angle θ The angle is determined by combining the CFD load spacing magnified to real scale and the structural mesh size. θ The corresponding arc length is 3 to 5 times the average size of the structural mesh.

[0045] The above-mentioned hydrodynamic load mapping method in the analysis of an energy-saving guide wheel structure further includes, in step S4, the load value Pele i The specific calculation process is as follows:

[0046] Using the XY plane as a reference, find the coordinates (x, y) of the distance from the center of the element. i ,y i ,z i The nearest load points are labeled A, B, C, and D, and the pressure at each load point is labeled P. A ,P B ,P C ,P D The coordinates of the load points are denoted as (x, y, y). A ,y A ,z A ),(x B ,y B ,z B ), (x C ,y C ,z C ),(x D ,y D ,z D The load values ​​on the element are calculated using a weighted average interpolation method. The weights for the interpolation are the center coordinates of the element (x, y, y). i ,y i ,z i The distances between the load points A, B, C, and D and the load points are denoted as d. A d B d C d D And denote the values ​​of load points A, B, C, and D as P. A , P B , P C , P D Then the load value on this unit is:

[0047] Pele i = (P A d A + P B d B + P C d C + P D d D ) / 4.

[0048] Where, distance d A d B dC d D Calculated from the coordinates of the load point and the coordinates of the element center point: .

[0049] .

[0050] .

[0051] .

[0052] Furthermore, in step S403, the hydrodynamic load mapping method in the above-mentioned energy-saving guide wheel structure analysis is further improved by using the APDL language of ANSYS software to process the load mapping application.

[0053] From the perspective of load application method, this invention uses the APDL language of ANSYS software to process load mapping application in order to facilitate the extraction of model information such as loading elements or nodes required for load processing and to take into account the complexity of load processing. At the same time, when using ANSYS software for structural analysis, it is also convenient to process all calculation tasks in the same software.

[0054] This method can adapt to the use of scaled models in CFD to calculate hydrodynamic pressure, significantly improving the computational efficiency of obtaining water pressure during the CFD stage. It is also applicable to both regular and irregular mesh generation of structural models. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the sail coordinate system definition.

[0056] Figure 2 This is a schematic diagram of the load search range for the structural model.

[0057] Figure 3 This is a schematic diagram of the load interpolation element search process for the structural model.

[0058] Figure 4 This is a schematic diagram of CFD load mapping applied to the structural model.

[0059] Figure 5 This is a schematic diagram of the hydrodynamic load mapping application method.

[0060] Figure 6 This is a schematic diagram after processing the x-coordinate data.

[0061] Figure 7 This is a schematic diagram after processing the y-coordinate data.

[0062] Figure 8 This is a schematic diagram after processing the z-coordinate data.

[0063] Figure 9 This is a schematic diagram of the pressure data P after processing.

[0064] Figure 10 This is a schematic diagram of the surface pressure distribution of the energy-saving guide wheel obtained through scaled model analysis.

[0065] Figure 11 This is a schematic diagram after data conversion and processing. Detailed Implementation

[0066] The present invention will be described in detail with reference to specific embodiments.

[0067] like Figure 5 This paper presents a hydrodynamic load mapping method in the analysis of an energy-saving guide wheel structure.

[0068] S1: Extract the hydrodynamic loads obtained from the CFD analysis of the scaled model and express them as average pressure and pulsating pressure. Conduct hydrodynamic analysis using professional hydrodynamic analysis software and extract the dynamic water pressure based on the energy-saving guide wheel analysis conditions.

[0069] S101: Design status of energy-saving guide wheel undergoing structural analysis

[0070] The design conditions for structural analysis and CFD hydrodynamic analysis are clearly defined to facilitate the subsequent load transfer, including the definition of analysis conditions and coordinate system.

[0071] 1) Determine the operating conditions for structural analysis of the energy-saving guide wheel, which are the hydrodynamic pressures under different combinations of incoming flow direction and propeller direction. Each operating condition is determined by the corresponding incoming flow direction angle. α and propeller azimuth angle β Characterization. The structural analysis should cover all typical operating conditions, using L... m (α m ,β m ) indicates the first m Each operating condition.

[0072] 2) Coordinate system for structural analysis of the energy-saving guide wheel: Based on the ship coordinate system, the model coordinate system is defined as follows:

[0073] The origin o is taken as the center position of the propeller. The coordinate axis direction is consistent with the ship's coordinate axis direction, such as... Figure 1 As shown.

[0074] S102: For each working condition, the hydrodynamic analysis software directly outputs the pressure load as a function of coordinates. Furthermore, the pressure load is automatically decomposed by the software into mean pressure and fluctuating pressure. This is tailored to specific analysis conditions. L mThe pressure output format is (X, Y, Z, P, C), where P is the average pressure and C is the pulsating pressure. Operating condition. L m The pressure data directly output by the hydrodynamic analysis software is denoted as database Am0, which is a k-row, 5-column matrix.

[0075] In this embodiment, the pressure distribution on the surface of the energy-saving guide wheel (partial data) obtained through scaled model analysis is shown in one working condition as follows: Figure 10 As shown.

[0076] S2: Data conversion from scaled model to full-scale model

[0077] For each working condition, the scaled model pressure load data (X,Y,Z,P,C) output by the hydrodynamic analysis software is converted into the corresponding data (Xs,Ys,Zs,Ps) of the full-scale energy-saving guide wheel.

[0078] S201: Coordinate Transformation

[0079] The real-scale coordinates Xs, Ys, Zs are given by multiplying the scaled model coordinates X, Y, Z by the scaling ratio, as follows: ; ; .

[0080] Where λ is the scaling ratio.

[0081] S202: Load Transformation

[0082] The real-scale load Ps is given by P, C, and related parameters as follows: .

[0083] Where: P s : Total pressure on the surface of the guide wheel of the actual ship, i.e., actual dimensional load, Pa.

[0084] P: Average pressure on the surface of the model guide wheel, Pa.

[0085] V 0s : Actual ship's incoming current velocity, m / s.

[0086] V 0m : Velocity of the incoming current for the model ship, m / s.

[0087] n s : Propeller speed of the actual ship, 1 / s.

[0088] n m : Propeller speed of the model ship, 1 / s.

[0089] C: Single-peak pulsating pressure on the surface of the model guide wheel, Pa.

[0090] In this embodiment, a working condition after data conversion processing (partial data) is as follows: Figure 11 As shown.

[0091] The real-scale hydrodynamic load data processed in step S2 needs to be converted according to the data format requirements of the structural analysis software before being applied to the structural analysis. Taking the general-purpose structural analysis software ANSYS as an example, the data needs to be converted to its usable format. The hydrodynamic load database is large, and ANSYS has strict requirements on the data format when importing loads; each line of data must not exceed 10 characters. The obtained load file is then processed and saved as a txt file for structural load mapping. The data format is denoted as:

[0092] inputPm(a,1)=Am(1+a,1),Am(2+a,1),…,Am(8+a,1),Am(9+a,1),Am(10+a,1).

[0093] inputPm(a,2)=Am(1+a,2),Am(2+a,2),…,Am(8+a,2),Am(9+a,2),Am(10+a,2).

[0094] inputPm(a,3)=Am(1+a,3),Am(2+a,3),…,Am(8+a,3),Am(9+a,3),Am(10+a,3).

[0095] inputPm(a,4)=Am(1+a,4),Am(2+a,4),…,Am(8+a,4),Am(9+a,4),Am(10+a,4).

[0096] Where a = 10 × (k - 1), inputPm(a, 1) is the x-coordinate data, inputPm(a, 2) is the y-coordinate data, inputPm(a, 3) is the z-coordinate data, and inputPm(a, 4) is the pressure data.

[0097] Since the data processing in this step only involves outputting data in a specified format, it can be easily implemented using Excel, MATLAB, or other common software. This example contains a total of 43,421 rows; the x-coordinate data after processing is as follows: Figure 6 As shown.

[0098] After processing, the y-coordinate data is as follows: Figure 7 As shown.

[0099] After processing, the z-coordinate data is as follows: Figure 8 As shown.

[0100] Pressure data P after processing Figure 9 As shown.

[0101] S4: Load-to-structure mapping and application

[0102] S401: Use ANSYS structural finite element analysis software to establish a structural finite element analysis model and read in the inputPm file generated in step 3.

[0103] S402: Hydrodynamic Load Mapping Processing: After the scaled model from CFD analysis is enlarged to a full-scale model, the corresponding mesh differs significantly from the mesh used in structural analysis. In particular, the structural analysis mesh is much finer, and due to the special shape of the energy-saving guide wheel, the structural mesh inevitably contains a large number of triangular or transitional elements. Therefore, load interpolation calculations, i.e., load mapping processing, are needed to map the hydrodynamic loads onto the structural model. Considering the large number of load points, the search range for each structural element is limited during the mapping process to reduce load processing time and thus improve efficiency. The specific steps are as follows:

[0104] 1) Define an array prelem to store the loads applied to the structural model elements. The data format is (Nu, Pele).

[0105] The prelem is a J-row, 2-column array, where J is the number of elements to be loaded, Nu is the element number of the structural model, and Pele is the load value of the structural element.

[0106] 2) For each element i of the structure, the two main operations of load search and interpolation calculation are as follows:

[0107] (1) Extract the center coordinates (x) of the structural unit i ,y i ,z i ) and unit number Nu i ;

[0108] (2) Based on the database inputPm, with (x i ,y i ,z i Centered on the load point in inputPm, a search is performed within a certain range. The search range is determined based on the geometry of the energy-saving guide wheel, using polar coordinates to define the search area. Figure 2 As shown. Using the YZ plane as a reference, a fixed search angle is given. θ The size of this angle determines the search efficiency. When θ If the search range is too large, efficiency decreases due to the increased search area. θIf the angle is too small, the spacing of CFD loads magnified to the real scale is usually larger than that of the structural mesh, which may result in the inability to find load points in certain directions. Therefore, to improve search efficiency and ensure search success, the angle... θ The angle is typically determined by combining the CFD load spacing magnified to real scale and the structural mesh size. θ The corresponding arc length is 3 to 5 times the average size of the structural mesh.

[0109] (4) Using the XY plane as a reference, find the coordinates (x, y) of the distance from the center of the unit. i ,y i ,z i The nearest load points are numbered A, B, C, and D respectively. Figure 3 As shown. The pressure at the load point is denoted as P. A ,P B ,P C ,P D The coordinates of the load points are denoted as (x, y, y). A ,y A ,z A ),(x B ,y B ,z B ), (x C ,y C ,z C ),(x D ,y D ,z D Considering the positional difference between the CFD load points magnified to real scale and the load points of the structural model elements, a weighted average interpolation method is used to calculate the load values ​​on the elements. The weights for interpolation are the center coordinates of the element (x, y, y). i ,y i ,z i The distances between the load points A, B, C, and D and the load points are denoted as d. A d B d C d D And denote the values ​​of load points A, B, C, and D as P. A , P B , P C , P D Then the load value on this unit is:

[0110] Pele i = (P A d A + P B d B + P C d C + P D d D) / 4

[0111] Where, distance d A d B d C d D Calculated from the coordinates of the load point and the coordinates of the element center point: .

[0112] .

[0113] .

[0114] .

[0115] (5) The calculated element load value Pele i and the corresponding unit number Nu i Stored in the array prelem.

[0116] The array prelem calculated in this embodiment is shown in the following example:

[0117] Unit number Pressure load value 87138 -0.00985886 87139 -0.00538320 87140 -0.00952213 87141 -0.01269840 87142 -0.01428698 87143 -0.00410450 87144 9.94285816 87145 -0.00950620 87146 -0.00429260 87147 -0.00205614 Unit number Pressure load value 95263 -0.00821988 95264 0.00911545 95265 -0.01097484 95266 -0.01371017 95267 0.00464349 95268 -0.00234123 95269 -0.00793140 95270 0.00629017 95271 -0.05289261 95272 -0.04536773

[0118] S403: Select the element to be loaded, and apply the structural load in ANSYS structural analysis software using the sfe command combined with a loop statement based on the data information in the prelem array:

[0119] ×do,j,1,J

[0120] sfe,prs_elem(j,1),,pres,,-prs_elem(j,2)

[0121] ×enddo

[0122] The final load after loading in this embodiment is as follows: Figure 4 As shown.

Claims

1. A method for mapping and loading hydrodynamic loads in energy saving wheel structure analysis, characterized by, The specific operation is as follows: S1: extract the hydrodynamic load obtained by the CFD analysis of the scale model, and express it in the form of average pressure and fluctuating pressure S101: the design state of the energy-saving guide wheel for carrying out structural analysis is defined, and the design state of the structural analysis and the CFD hydrodynamic analysis is defined, including the analysis working condition and the definition of the coordinate system: 1) Determine the working condition of energy-saving guide wheel development structure analysis, the working condition is the direction of incoming flow α Different from the direction of propeller β Hydrodynamic pressure under different combinations 2) the coordinate system for carrying out structural analysis of the energy-saving guide wheel, taking the ship coordinate system as the reference, the model coordinate system is defined as follows: the coordinate origin O is taken as the center position of the propeller, and the coordinate axis direction is consistent with the ship coordinate axis direction; S102: for each working condition, the pressure load is directly output by the hydrodynamic analysis software in the form of a coordinate function, and the pressure load is automatically decomposed into average pressure and fluctuating pressure by the software; For a specific analysis working condition Lm, the pressure output format is (X, Y, Z, P, C), wherein P is the average pressure of the model guide wheel surface; and C is the single-peak fluctuating pressure of the model guide wheel surface; Working condition L m The pressure data directly output by the water power analysis software is recorded as database Am0; S2: data conversion from the scale model to the full-scale model For each working condition, the scale model pressure load data (X, Y, Z, P, C) output by the hydrodynamic analysis software is converted into the corresponding data (Xs, Ys, Zs, Ps) of the full-scale energy-saving guide wheel, S201: coordinate conversion The full-scale coordinates Xs, Ys and Zs are given by multiplying the scale model coordinates X, Y and Z by the scale ratio as follows: ; ; ； Wherein λ is the scale ratio; S202: load conversion ； Wherein: P s : total pressure on the hull guide wheel surface, i.e. full-scale load, Pa; V 0s : actual ship flow velocity, m / s; V 0m : model ship incoming flow velocity, m / s; n s : real ship propeller rotation speed, 1 / s; n m : model ship propeller rotation speed, 1 / s; S3: formatting processing of the hydrodynamic load data The full-scale hydrodynamic load data processed in step S2 is processed to form an inputPm file, and the inputPm file is read into the structural analysis software; S4: mapping processing and application of the load to the structure The hydrodynamic load mapping processing, in the mapping processing process, for each structural element, the search range is limited to reduce the load processing time, and the specific operation is as follows: S401: define an array prelem for storing the load applied to the structural model element, the array prelem is a J-row 2-column array, J is the number of elements that need to be loaded, and the data format is (Nu, Pele), Nu is the structural model element number, and Pele is the structural element load value; S402: For each unit i of the structure, load search and interpolation calculation are performed to extract the center coordinates (x i ,y i ,z i ) and the unit number Nu i of the structure unit; based on the file inputPm, search for the load points in inputPm within a certain range with (x i ,y i ,z i ) as the center to obtain the load value Pele i of the unit; The calculated cell load value Pele i and the corresponding cell number Nu i are stored in the array prelem; S403: select the element that needs to be loaded, according to the data information in the array prelem, the structural load is applied in the structural analysis software by using the sfe command combined with the loop statement.

2. The method according to claim 1, wherein, In step S101, the structure analysis should cover all typical operating conditions, with the i-th operating condition being represented by . m th operating condition.

3. The method according to claim 1, wherein, In step S102, the database Am0 is a k-row 5-column matrix.

4. The method according to claim 1, wherein, The structural analysis software is ANSYS software, when the hydrodynamic load database is read into the ANSYS software, it is required that each row of data is not more than 10, the load data is processed, and saved in the txt file format, and the data format is as follows: inputPm(a,1)=Am(1+a,1),Am(2+a,1),…,Am(8+a,1),Am(9+a,1),Am(10+a,1); inputPm(a,2)=Am(1+a,2),Am(2+a,2),…,Am(8+a,2),Am(9+a,2),Am(10+a,2); inputPm(a,3)=Am(1+a,3),Am(2+a,3),…,Am(8+a,3),Am(9+a,3),Am(10+a,3); inputPm(a,4)=Am(1+a,4),Am(2+a,4),…,Am(8+a,4),Am(9+a,4),Am(10+a,4); Wherein, a=10×(k-1), inputPm(a,1) is x coordinate data, inputPm(a,2) is y coordinate data, inputPm(a,3) is z coordinate data, inputPm(a,4) is pressure data.

5. The method for mapping and loading hydrodynamic loads in energy-saving guide wheel structure analysis according to claim 1, characterized in that, The determination of the search range in step S4 is based on the geometric shape of the energy-saving guide wheel, and a polar coordinate is used to demarcate the search range. With YZ plane as the reference, a fixed search angle is given θ , angle θ According to the CFD load spacing amplified to the full scale and the structure grid size, the angle θ The corresponding arc length is 3-5 times the average size of the structure grid.

6. The method for mapping and loading hydrodynamic loads in energy-saving guide wheel structure analysis according to claim 1, characterized in that, In step S4, the load value Pele i The specific calculation process is as follows: Take XY plane as the reference, find the nearest load point to the center coordinate (x i ,y i ,z i ) of the element, the load point number is recorded as A, B, C, D respectively, the pressure at the load point is recorded as P A ,P B ,P C ,P D , the coordinate value at the load point is recorded as (x A ,y A ,z A ), (x B ,y B ,z B ), (x C ,y C ,z C ), (x D ,y D ,z D ) respectively, the load value on the element is calculated by weighted average interpolation method; the weight value of interpolation is the distance between the center coordinate (x i ,y i ,z i ) of the element and the position of the load points A, B, C, D, which is recorded as d A , d B , d C , d D respectively; and the value of the load points A, B, C, D is recorded as P A , P B , P C , P D , then the load value on the element is: Pele i = (P A d A + P B d B + P C d C + P D d D ) / 4; where the distance d A , d B , d C , d D is calculated from the coordinates of the load point and the coordinates of the center point of the element. ； ； ； 。 7. The method for mapping and loading hydrodynamic loads in energy-saving guide wheel structure analysis according to claim 1, characterized in that, In step S403, the APDL language of the ANSYS software is used to process the load mapping application.

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