Method and device for predicting cavitation erosion in gas phase condensation process, and electronic equipment

Abstract

The present invention discloses a method and device for predicting cavitation erosion in a gas phase condensation process, and an electronic device, comprising: calculating the potential power in each unit based on the energy generated when the cavitation bubble collapses; dividing the potential power in each unit by the unit volume to obtain the potential power density; simplifying the potential power density; calculating the gas phase condensation rate; constructing a modified cavitation prediction calculation model based on the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero; establishing a three-dimensional hydrofoil model and sequentially performing flow channel extraction and calculation domain processing to obtain a three-dimensional fluid calculation domain model; meshing the three-dimensional fluid calculation domain model to obtain a grid model; performing fluid simulation calculation on the grid model to obtain calculation data; based on the calculation data, using the modified cavitation prediction calculation model to calculate and obtain a cavitation erosion cloud map; and obtaining a cavitation erosion prediction result based on the cavitation erosion cloud map.

Description

Technical Field

[0001] The present application relates to the field of fluid dynamics, and in particular to a method and device for predicting cavitation erosion in a gas phase condensation process, and electronic equipment. Background Art

[0002] Cavitation is a common phenomenon in fluid machinery. When the local pressure of the liquid drops below a critical value (close to the saturated vapor pressure), bubbles are formed. When the bubbles enter the high-pressure area, they collapse due to the change in internal and external pressures. The energy released can cause material fatigue and surface erosion, a phenomenon called cavitation. Cavitation is widely present in equipment such as centrifugal pumps, marine propellers, and high-speed inducers. It may seriously damage components and increase vibration, noise, and maintenance costs. For example, turbine runners and fluid bearings may need to be replaced or repaired after several weeks of operation. Therefore, from an industrial perspective regarding design and maintenance, predicting cavitation erosion remains a major concern.

[0003] At present, based on different theories of cavitation erosion mechanisms, a variety of theoretical models for cavitation prediction have been proposed: the IFM model is based on the assumption that cavitation damage is mainly dominated by pressure gradient. It is believed that when the pressure gradient in a certain area is greater than the threshold of cavitation generation, the pressure gradient is determined to be one of the energies that cause cavitation. The TAI model is based on three assumptions: the first assumption is that cavitation is caused by the collapse of cavitation bubbles in the near-wall area, and those cavitation bubbles far away from the solid surface have less erosion, so only the cavitation intensity in the near-wall area needs to be calculated to obtain an accurate cavitation distribution. The second assumption points out that cavitation damage is mainly dominated by the change in cavitation volume. The greater the volume change rate of the bubble, the stronger the cavitation intensity. The third assumption is that the intensity of cavitation increases with the increase in the number of collapsed cavitation bubbles. Based on the above assumptions, an expression that can be used to represent the instantaneous local cavitation erosion on the surface of the material is defined. The GLM model is based on the following assumptions: the energy generated when the cavitation collapses is approximately equal to the product of the pressure at the moment of collapse and the volume of the cavitation bubble. Cavitation is considered to occur only when the local instantaneous cavitation rate is greater than a certain threshold, otherwise it is considered that no cavitation occurs at this time.

[0004] The prediction results of these three typical methods are quite different from the experimental results, and they cannot simulate and predict accurate results well. In addition, the above cavitation calculation method does not consider the gas-liquid phase change rate in the flow field. The gas-liquid phase change rate represents the description of the degree of the two reverse processes of evaporation and condensation of the cavitation phenomenon in the cavitation model. The phase change rate can be positive or negative. The positive value represents the liquid phase evaporation process, and the negative value represents the gas phase condensation process. The absolute value of the phase change rate reflects the degree of the corresponding process. The gas phase condensation process during the collapse of the cavitation bubble should be considered for cavitation prediction calculations. Therefore, it is necessary to construct a cavitation prediction calculation method during the gas phase condensation process. Summary of the invention

[0005] In view of this, the embodiments of the present application provide a method and device, and an electronic device for predicting cavitation erosion in the gas phase condensation process, which can obtain cavitation erosion prediction results more accurately.

[0006] According to a first aspect of an embodiment of the present application, a cavitation erosion prediction method considering a gas phase condensation process is provided, comprising:

[0007] S1: Based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference inside and outside the cavitation, the potential energy power in each unit is calculated;

[0008] S2: Divide the potential power in each unit by the unit volume to obtain the potential power density;

[0009] S3: Considering that bubble collapse is mainly caused by pressure changes, the potential power density is simplified;

[0010] S4: Calculate the gas phase condensation rate;

[0011] S5: constructing a modified cavitation prediction calculation model according to the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero;

[0012] S6: Establish a three-dimensional hydrofoil model;

[0013] S7: performing flow channel extraction and computational domain processing on the three-dimensional hydrofoil model in sequence to obtain a three-dimensional fluid computational domain model;

[0014] S8: Meshing the three-dimensional fluid calculation domain model to obtain a mesh model;

[0015] S9: performing fluid simulation calculation on the grid model to obtain calculation data;

[0016] S10: Based on the calculation data, using the modified cavitation prediction calculation model, calculate and obtain a cavitation erosion cloud map;

[0017] S11: Obtaining a cavitation erosion prediction result according to the cavitation erosion cloud map.

[0018] According to a second aspect of an embodiment of the present application, a cavitation erosion prediction device considering a gas phase condensation process is provided, comprising:

[0019] The first calculation module is used to calculate the potential power in each unit based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference between the inside and outside of the cavitation;

[0020] The second calculation module is used to divide the potential power in each unit by the unit volume to obtain the potential power density;

[0021] A third calculation module is used to simplify the potential power density by taking into account that the bubble collapse is mainly caused by the change of pressure;

[0022] A fourth calculation module, used for calculating the gas phase condensation rate;

[0023] A construction module is used to construct a modified cavitation prediction calculation model according to the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero;

[0024] Model building module, used to build a three-dimensional hydrofoil model;

[0025] A model processing module, used for sequentially performing flow channel extraction and computational domain processing on the three-dimensional hydrofoil model to obtain a three-dimensional fluid computational domain model;

[0026] A grid division module, used for gridding the three-dimensional fluid calculation domain model to obtain a grid model;

[0027] A fifth calculation module, used for performing fluid simulation calculation on the grid model based on CFD to obtain calculation data;

[0028] A sixth calculation module, configured to calculate and obtain a cavitation erosion cloud map based on the calculation data and using the modified cavitation erosion prediction calculation model;

[0029] The result output module is used to obtain the cavitation erosion prediction result according to the cavitation erosion cloud map.

[0030] According to a third aspect of an embodiment of the present application, there is provided an electronic device, including:

[0031] one or more processors;

[0032] A memory for storing one or more programs;

[0033] When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in the first aspect.

[0034] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0035] This application introduces the gas phase condensation rate into the cavitation prediction calculation, which can better predict the erosion range of the material surface and make the simulation results more consistent with the experimental results, which has guiding significance for further research on cavitation damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0037] Figure 1 The figure is a flow chart of a method for predicting cavitation erosion considering a vapor phase condensation process according to an exemplary embodiment.

[0038] Figure 2 The figure is a flow chart of cavitation collapse judgment of a modified cavitation prediction model according to an exemplary embodiment.

[0039] Figure 3 is a fluid calculation domain of a hydrofoil according to an exemplary embodiment.

[0040] Figure 4 is a grid model diagram shown according to an exemplary embodiment.

[0041] Figure 5 1 is a comparison diagram of cavitation erosion cloud maps and experimental results according to an exemplary embodiment, wherein (a) is a cavitation erosion prediction cloud map without using the correction scheme; (b) is a cavitation erosion prediction cloud map using the correction scheme; and (c) is an experimental result diagram.

[0042] Figure 6 It is a block diagram of a cavitation erosion prediction device considering a gas phase condensation process according to an exemplary embodiment. DETAILED DESCRIPTION

[0043] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings.

[0044] Figure 1 is a flow chart of a construction method for cavitation erosion prediction calculation considering a gas phase condensation process according to an exemplary embodiment, such as Figure 1 As shown, the method may include the following steps:

[0045] S1: Based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference inside and outside the cavitation, the potential energy power in each unit is calculated;

[0046] S2: Divide the potential power in each unit by the unit volume to obtain the potential power density;

[0047] S3: Considering that bubble collapse is mainly caused by pressure changes, the potential power density is simplified;

[0048] S4: Calculate the gas phase condensation rate;

[0049] S5: constructing a modified cavitation prediction calculation model according to the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero;

[0050] S6: Establish a three-dimensional hydrofoil model;

[0051] S7: performing flow channel extraction and computational domain processing on the three-dimensional hydrofoil model in sequence to obtain a three-dimensional fluid computational domain model;

[0052] S8: Meshing the three-dimensional fluid calculation domain model to obtain a mesh model;

[0053] S9: performing fluid simulation calculation on the grid model based on CFD to obtain calculation data;

[0054] S10: Based on the calculation data, using the modified cavitation prediction calculation model, calculate and obtain a cavitation erosion cloud map;

[0055] S11: Obtaining a cavitation erosion prediction result according to the cavitation erosion cloud map.

[0056] This application introduces the gas phase condensation rate into the cavitation prediction calculation, which can better predict the erosion range of the material surface and make the simulation results more consistent with the experimental results, which has guiding significance for further research on cavitation damage.

[0057] In the specific implementation of S1: based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference between the inside and outside of the cavitation, the potential energy power in each unit is calculated;

[0058] Specifically, by calculating the bubble potential energy E pot The distribution of cavitation characteristics is used to judge the cavitation characteristics. Its value is equal to the product of the cavitation volume and the pressure difference inside and outside the cavitation. Therefore, the potential energy power in each unit is calculated. The potential energy power P in each unit pot The expression is:

[0059]

[0060] Where D is the material derivative, is the bubble potential energy, For environmental pressure, is the saturated vapor pressure, is the cavitation volume, and t is the time.

[0061] In a specific implementation of S2: dividing the potential power in each unit by the unit volume to obtain the potential power density;

[0062] Specifically, the potential power P in each unit pot Divide by the unit volume V cell The potential power density P can be obtained den , the expression is written as:

[0063]

[0064] Where D is the material derivative, is the cell volume, is the gas volume fraction, For environmental pressure, is the saturated vapor pressure, and t is the time.

[0065] In the specific implementation of S3: considering that bubble collapse is mainly caused by pressure changes, the potential power density is simplified;

[0066] Specifically, considering that bubble collapse is mainly caused by pressure changes rather than a simple pressure difference inside and outside the cavitation bubble, and the material derivative of pressure can better reflect the pressure fluctuation during cavitation collapse, The term is omitted to reduce the computational requirements. den Simplify to get:

[0067]

[0068] In the specific implementation of S4: according to the condensation of vapor often accompanying the cavitation collapse process, the gas phase condensation rate is calculated;

[0069] Specifically, in order to capture the occurrence of collapse events in the cavitation process and improve the accuracy of cavitation prediction, it is necessary to calculate the gas phase condensation rate. The gas phase condensation rate R cond The formula is as follows:

[0070]

[0071] In the formula, is the condensation coefficient, is the bubble radius, For environmental pressure, is the saturated vapor pressure, is the density of the fluid medium, is the instantaneous gas volume fraction, and t is the time.

[0072] In the specific implementation of S5: constructing a modified cavitation prediction calculation model according to the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero;

[0073] Specifically, if a grid , it indicates that it is an evaporation phenomenon, and no cavitation prediction calculation is performed. , it indicates that it is a condensation phenomenon, the bubble collapse has occurred, and the cavitation prediction calculation is performed. The judgment process is as follows Figure 2 shown.

[0074] In the specific implementation of S6: establishing a three-dimensional hydrofoil model;

[0075] Specifically, due to its good symmetry, in order to improve the calculation efficiency and reduce the calculation resources, only half of the calculation domain is constructed. Solidworks software is used for modeling to obtain the hydrofoil model.

[0076] S7: performing flow channel extraction and computational domain processing on the three-dimensional hydrofoil model in sequence to obtain a three-dimensional fluid computational domain model; this step may include the following sub-steps:

[0077] S71: extracting flow channels from the hydrofoil model to obtain a three-dimensional flow channel model;

[0078] S72: Extend the inlet of the three-dimensional flow channel model by 2 times the length of the hydrofoil chord, and extend the outlet by 5 times the length of the hydrofoil chord, to obtain a three-dimensional fluid calculation domain ( Figure 3 ).

[0079] In the specific implementation of S8: meshing the three-dimensional fluid calculation domain model to obtain a mesh model;

[0080] Specifically, the three-dimensional fluid calculation domain model is imported into the ICEM meshing software, structured meshing is performed, and then the hydrofoil area is locally encrypted to obtain a mesh model. Figure 4 shown.

[0081] In the specific implementation of S9: performing fluid simulation calculation on the grid model based on CFD to obtain calculation data; this step may include the following sub-steps:

[0082] S91: Import the mesh model into Fluent software, define the unit in Scale Mesh in General and select the calculation method;

[0083] Specifically, the mesh model is imported into Fluent software, the unit is defined as mm in Scale Mesh in General, and Transient is selected in Time.

[0084] S92: Define the multiphase flow model and turbulence model in the Models module;

[0085] Specifically, click Multiphase in the Models module, click Mixture in the pop-up window, click Phase, select water-liquid in phase-1, select water-vapor in phase-2, click Phase Interaction and select Heat, Mass, Reactions, adjust the Number of Mass Transfer Mechanisms to 1, select Cavitation in Mechanisms, click Schnerr-Sauer in the pop-up window, because the calculation of cavitation erosion must consider the effect of fluid on the wall, so the SST kw turbulence model is used, click Viscous in the Models module, and select k-omega SST.

[0086] S93: Define two-phase liquid medium in Material module;

[0087] Specifically, click Fluid in the Material module, click Fluent DatebaseMaterials in the pop-up window, select water-liquid and water-vapor, and set the Density of water-liquid to 998kg / m 3 , Viscosity is set to 0.001002kg / (m·s); Density of water-vapor is set to 0.023kg / m 3 , Viscosity is set to 0.0000102kg / (m·s).

[0088] S94: Click the fluid option in the Cell Zone Conditions module and select the defined two-phase liquid medium in the Material Name option;

[0089] Specifically, click the fluid option in the Cell Zone Conditions module and select water-liquid and water-vapor in the Material Name option.

[0090] S95: Define boundary conditions in the Boundary Conditions module;

[0091] Specifically, the inlet adopts velocity inlet, the outlet adopts pressure outlet, and the rest of the boundaries except the inlet and outlet temperature values ​​are set as no-slip boundary conditions.

[0092] In this embodiment, the inlet velocity is set to 6.97 m / s, the outlet pressure is set to 29 kPa, and the temperature is set to 297.15 K.

[0093] S96: Set the calculation method in the Solution Methods module;

[0094] Specifically, the Coupled algorithm is selected as the calculation method. The gradient discretization method in the Coupled algorithm adopts the least square method based on the unit cell. The gas phase volume fraction in the Coupled algorithm adopts the QUICK format. The pressure, momentum, turbulent kinetic energy and dissipation in the Coupled algorithm all adopt the second-order upwind format.

[0095] S97: Set the convergence residual in the Monitors module;

[0096] Specifically, the convergence residual is set to 10 -6 .

[0097] S98: Select the entry in the Compute from drop-down option in the Solution Initialization module and click the Initialize option to complete the initialization;

[0098] S99: Set the number of steps in the Run Calculation tab of the Calculation Activities module and click the Calculate option to start the calculation and obtain the calculation data;

[0099] Specifically, in the Run Calculation tab, set the number of iterations to 2000, the time step to 0.00002, and the number of iterations to 40. In the Autosave tab, set the automatic save to save every 4 iterations. In the Date Flie Quantities tab, select parameters such as dp-dX, dp-dY, dp-dZ, dp-dt, and Volumefraction (vapor).

[0100] In the specific implementation of S10: based on the calculation data, using the modified cavitation prediction calculation model, calculate and obtain the cavitation erosion cloud map; this step may include the following sub-steps:

[0101] S101: importing the calculated data into Tecplot software;

[0102] S102: click Specify Equations in the Alter option in the Data module, enter the modified cavitation prediction calculation model in the Equation(s) box in the pop-up window and click Compute;

[0103] S103: Select a coordinate plane;

[0104] S104: Click the Zone Style button and check the structure to be observed in the Show Zone column of the pop-up window;

[0105] Specifically, the upper surface of the structural hydrofoil observed in this embodiment.

[0106] S105: Check the Contour option, click the Details button, and select the name of the modified cavitation prediction calculation model in the pop-up menu;

[0107] Specifically, the uncorrected cavitation prediction calculation formula is as follows:

[0108]

[0109] The modified cavitation prediction calculation formula is as follows:

[0110]

[0111] Where: For environmental pressure, is the saturated vapor pressure, is the component of pressure in the X direction, is the component of velocity in the X direction; is the component of pressure in the Y direction, is the component of velocity in the Y direction; is the component of pressure in the Z direction, is the component of velocity in the Z direction, is the gas volume fraction, and t is the time.

[0112] S106: setting the image and the scale respectively;

[0113] S107: Output the set cloud map in the form of a picture to obtain a cavitation erosion cloud map.

[0114] Compare the cavitation erosion cloud map with the experimental results to determine the rationality of the correction scheme; Figure 5As shown in the figure, it can be found that compared with the experimental result diagram (c), the cavitation cloud diagram (a) calculated by the uncorrected cavitation prediction model predicts that the cavitation area is mainly concentrated in the middle upstream of the hydrofoil and does not predict the cavitation risk at the trailing edge. The cavitation cloud diagram (b) calculated by the modified cavitation prediction model can predict the two strip-shaped cavitation areas caused by the collapse of cavitation bubbles at the tail of the hydrofoil, which is consistent with the cavitation areas shown in the experimental results. Therefore, the modified cavitation prediction calculation formula can more accurately predict the cavitation distribution of the hydrofoil surface, can accurately identify the severe cavitation areas, and can also accurately predict the cavitation area caused by the collapse of cavitation bubbles at the trailing edge.

[0115] Corresponding to the aforementioned embodiment of the cavitation erosion prediction method taking into account the gas phase condensation process, the present application also provides an embodiment of the cavitation erosion prediction device taking into account the gas phase condensation process.

[0116] Figure 6 is a block diagram of a cavitation erosion prediction device considering a gas phase condensation process according to an exemplary embodiment. Figure 6 , the device comprises:

[0117] The first calculation module 1 is used to calculate the potential power in each unit based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference between the inside and outside of the cavitation;

[0118] The second calculation module 2 is used to divide the potential power in each unit by the unit volume to obtain the potential power density;

[0119] A third calculation module 3 is used to simplify the potential power density by taking into account that the bubble collapse is mainly caused by the change of pressure;

[0120] The fourth calculation module 4 is used to calculate the gas phase condensation rate;

[0121] Construction module 5, used to construct a modified cavitation prediction calculation model according to the simplified potential power density and gas phase condensation rate, wherein the gas phase condensation rate is less than zero;

[0122] Model building module 6, used to build a three-dimensional hydrofoil model;

[0123] A model processing module 7 is used to sequentially perform flow channel extraction and computational domain processing on the three-dimensional hydrofoil model to obtain a three-dimensional fluid computational domain model;

[0124] A grid division module 8 is used to grid the three-dimensional fluid calculation domain model to obtain a grid model;

[0125] A fifth calculation module 9 is used to perform fluid simulation calculation on the grid model based on CFD to obtain calculation data;

[0126] A sixth calculation module 10 is used to calculate and obtain a cavitation erosion cloud map based on the calculation data and using the modified cavitation erosion prediction calculation model;

[0127] The result output module 11 is used to obtain the cavitation erosion prediction result according to the cavitation erosion cloud map.

[0128] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0129] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0130] Correspondingly, the present application also provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the cavitation erosion prediction method considering the gas phase condensation process as mentioned above.

[0131] Accordingly, the present application also provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implements the cavitation erosion prediction method considering the gas phase condensation process as described above.

[0132] Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0133] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A cavitation erosion prediction method considering the gas phase condensation process, characterized in that: include: S1: Based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference inside and outside the cavitation, the potential energy power in each unit is calculated; S2: Divide the potential power in each unit by the unit volume to obtain the potential power density; S3: Considering that bubble collapse is mainly caused by pressure changes, the potential power density is simplified; S4: Calculate the gas phase condensation rate; S5: constructing a modified cavitation prediction calculation model according to the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero; S6: Establish a three-dimensional hydrofoil model; S7: performing flow channel extraction and computational domain processing on the three-dimensional hydrofoil model in sequence to obtain a three-dimensional fluid computational domain model; S8: Meshing the three-dimensional fluid calculation domain model to obtain a mesh model; S9: performing fluid simulation calculation on the grid model to obtain calculation data; S10: Based on the calculation data, using the modified cavitation prediction calculation model, calculate and obtain a cavitation erosion cloud map; S11: Obtaining a cavitation erosion prediction result according to the cavitation erosion cloud map.

2. The method according to claim 1, characterized in that The potential power P in each unit pot The calculation formula is as follows: ； Where D is the material derivative, is the bubble potential energy, For environmental pressure, is the saturated vapor pressure, is the cavitation volume, and t is the time.

3. The method according to claim 1, characterized in that Potential power density P den The calculation formula is as follows: ； Where D is the material derivative, is the cell volume, is the gas volume fraction, For environmental pressure, is the saturated vapor pressure, and t is the time.

4. The method according to claim 1, characterized in that The simplified potential power density is as follows: 。 5. The method according to claim 1, characterized in that The gas phase condensation rate R cond The calculation formula is as follows: ； In the formula, is the condensation coefficient, is the bubble radius, For environmental pressure, is the saturated vapor pressure, is the density of the fluid medium, is the instantaneous gas volume fraction, and t is the time.

6. The method according to claim 1, characterized in that The three-dimensional hydrofoil model is sequentially subjected to flow channel extraction and computational domain processing to obtain a three-dimensional fluid computational domain model, including: S71: extracting flow channels from the hydrofoil model to obtain a three-dimensional flow channel model; S72: Extend the inlet of the three-dimensional flow channel model by n times the chord length of the waterfoil, and extend the outlet by m times the chord length of the waterfoil, to obtain a three-dimensional fluid calculation domain model, wherein n≥2 and m≥5.

7. The method according to claim 1, characterized in that Perform fluid simulation calculation on the grid model based on CFD to obtain calculation data, including: S91: Import the mesh model into Fluent software, define the unit in Scale Mesh in General and select the calculation method; S92: Define the multiphase flow model and turbulence model in the Models module; S93: Define two-phase liquid medium in Material module; S94: Click the fluid option in the Cell Zone Conditions module and select the defined two-phase liquid medium in the Material Name option; S95: Define boundary conditions in the Boundary Conditions module; S96: Set the calculation method in the Solution Methods module; S97: Set the convergence residual in the Monitors module; S98: Select the entry in the Compute from drop-down option in the Solution Initialization module and click the Initialize option to complete the initialization; S99: Set the number of steps in the Run Calculation tab of the Calculation Activities module and click the Calculate option to start the calculation and obtain the calculation data.

8. The method according to claim 1, characterized in that Based on the calculation data, using the modified cavitation prediction calculation model, the cavitation erosion cloud map is calculated, including: S101: importing the calculated data into Tecplot software; S102: click Specify Equationgs in the Alter option in the Data module, enter the modified cavitation prediction calculation model in the Equation(s) box in the pop-up window and click Compute; S103: Select a coordinate plane; S104: Click the Zone Style button and check the structure to be observed in the Show Zone column of the pop-up window; S105: Check the Coutour option, click the Details button, and select the name of the modified cavitation prediction calculation model in the pop-up menu; S106: setting the image and the scale respectively; S107: Output the set cloud map in the form of a picture to obtain a cavitation erosion cloud map.

9. A cavitation erosion prediction device considering the gas phase condensation process, characterized in that: include: The first calculation module is used to calculate the potential power in each unit based on the fact that the energy generated when the cavitation collapses is approximately equal to the product of the cavitation volume and the pressure difference between the inside and outside of the cavitation; The second calculation module is used to divide the potential power in each unit by the unit volume to obtain the potential power density; A third calculation module is used to simplify the potential power density by taking into account that the bubble collapse is mainly caused by the change of pressure; A fourth calculation module, used for calculating the gas phase condensation rate; A construction module is used to construct a modified cavitation prediction calculation model according to the simplified potential power density and the gas phase condensation rate, wherein the gas phase condensation rate is less than zero; Model building module, used to build a three-dimensional hydrofoil model; A model processing module, used for sequentially performing flow channel extraction and computational domain processing on the three-dimensional hydrofoil model to obtain a three-dimensional fluid computational domain model; A grid division module, used for gridding the three-dimensional fluid calculation domain model to obtain a grid model; A fifth calculation module, used for performing fluid simulation calculation on the grid model to obtain calculation data; A sixth calculation module, configured to calculate and obtain a cavitation erosion cloud map based on the calculation data and using the modified cavitation erosion prediction calculation model; The result output module is used to obtain the cavitation erosion prediction result according to the cavitation erosion cloud map.

10. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 8.

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