Method and system for solving dynamic characteristic numerical value of gas-liquid two-phase sealed rotor

Abstract

The invention discloses a gas-liquid two-phase sealing rotor dynamic characteristic numerical value solving method and system. The method comprises the steps that the flow pattern of a gas-liquid two-phase working medium is judged; setting the types of a gas-phase working medium and a liquid-phase working medium according to the flow pattern of the gas-phase working medium and the liquid-phase working medium; a heterogeneous Euler-Euler model is adopted to solve the physical property parameters of a sealed inlet and outlet, the Weber number of a gas phase medium of the sealed inlet and outlet is solved according to the physical property parameters of the sealed inlet and outlet, and the diameter of a liquid drop or a bubble is checked through the Weber number; a rotor elliptical multi-frequency vortex motion model and a heterogeneous Euler-Euler model are adopted to calculate fluid exciting force and rotor vortex motion displacement under a time domain; the fluid exciting force and the rotor vortex displacement in the time domain are converted into frequency domain signals, and an impedance coefficient is solved according to the frequency domain signals; according to the flow pattern of the gas-liquid two-phase working medium, the characteristic coefficient of the impedance coefficient is extracted, and the method and the system can accurately calculate the dynamic characteristic value of the gas-liquid two-phase sealing rotor.

Description

Technical Field

[0001] The invention belongs to the technical field of rotary machinery and relates to a method and system for numerically solving dynamic characteristics of a gas-liquid two-phase sealed rotor. Background Art

[0002] Due to the limited proven oil and gas resources on land and the increasing global demand for energy, the exploration and exploitation of fossil energy stored in offshore and offshore areas has attracted the attention of many countries. The exploitation and transportation of oil and gas at sea also brings more challenges to the design and safe and stable operation of advanced mixed impeller machinery used in the industry, such as wet gas compressors and multi-phase pumps. Directly transporting gas-liquid two-phase working fluids can eliminate the gas-liquid separation device, which can save costs and reduce the size and weight of the production system when the space on the offshore oil and gas production platform is limited.

[0003] In addition to controlling the leakage of working fluid, the sealing structure in the impeller machinery will also affect the stability of the shaft system due to the force exerted by the working fluid in the sealing section on the rotor when the rotor is statically eccentric or vortex eccentric. The mixing of gas phase components into liquid phase working fluid or the mixing of liquid phase components into gas phase working fluid will have a significant impact on the stable operation of the shaft system and the safety of the unit. At present, the research on the dynamic characteristics of dynamic seal rotors used in gas-liquid two-phase environments is mainly concentrated in the experimental field, and there is a lack of sufficient understanding of the flow field details of the gas-liquid two-phase working fluid inside the seal. At the same time, a large number of studies on gas-liquid two-phase seals are limited to smooth sealing structures, and there is still a lack of sufficient research on the leakage characteristics and rotor dynamic characteristics of other liquid phase seal types in gas-liquid two-phase environments.

[0004] Developing a numerical calculation method that can accurately evaluate the leakage characteristics and rotor dynamic characteristics of the impeller machinery rotary seal in a two-phase environment can not only effectively obtain the two-phase flow field inside the seal, but also evaluate the stability of the sealed rotor system in a gas-liquid two-phase environment more quickly and economically than conducting experiments. At the same time, the development of a numerical method for the dynamic characteristics of two-phase sealed rotors also provides a convenient means for studying advanced low-leakage, high-damping sealing structures in a two-phase environment. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a method and system for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor, which can accurately calculate the dynamic characteristics of a gas-liquid two-phase sealed rotor.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] In one aspect, the present invention provides a method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor, comprising:

[0008] Determine the flow pattern of gas-liquid two-phase working fluid;

[0009] Set the types of gas phase working medium and liquid phase working medium according to the flow pattern of gas-liquid two-phase working medium;

[0010] The inhomogeneous Euler-Euler model is used to solve the physical property parameters of the seal inlet and outlet, and the Weber number of the gas phase medium of the seal inlet and outlet is solved according to the physical property parameters of the seal inlet and outlet, and the droplet or bubble diameter is checked by the Weber number;

[0011] The rotor elliptical multi-frequency vortex model and the non-homogeneous Euler-Euler model are used to calculate the fluid exciting force and rotor vortex displacement in the time domain.

[0012] The fluid exciting force and rotor vortex displacement in the time domain are converted into frequency domain signals, and the impedance coefficient is solved according to the frequency domain signals;

[0013] According to the flow pattern of the gas-liquid two-phase working fluid, the characteristic coefficient of the impedance coefficient is extracted.

[0014] The method for numerically solving the dynamic characteristics of the gas-liquid two-phase sealed rotor of the present invention is further improved in that:

[0015] Furthermore, the process of determining the flow pattern of the gas-liquid two-phase working medium is:

[0016] Obtain a Baker flow pattern diagram and physical property parameters of the gas-liquid two-phase working fluid, and determine the flow pattern of the gas-liquid two-phase working fluid according to the Baker flow pattern diagram and the physical property parameters of the gas-liquid two-phase working fluid, wherein the flow pattern of the gas-liquid two-phase working fluid is mist flow or bubble flow.

[0017] Further, according to the liquid mass flow rate G l , gas mass flow rate G g , the ratio of liquid density to water density under standard conditions Δ l , the ratio of gas density to air density under standard conditions Δ g 、Liquid viscosity μ l , liquid density ρ l , Flow area A m , Liquid surface tension σ l Determine the horizontal and vertical coordinates in the Baker flow pattern diagram;

[0018] The fitted line boundaries of the mist flow and bubble flow patterns are obtained in the Baker flow pattern diagram, and the flow pattern of the gas-liquid two-phase working fluid is determined by combining the horizontal and vertical coordinates of the Baker flow pattern diagram.

[0019] Furthermore, the process of setting the types of gas-phase working medium and liquid-phase working medium according to the flow pattern of the gas-liquid two-phase working medium is:

[0020] When the flow pattern of the gas-liquid two-phase working fluid is a mist flow, the gas phase working fluid is set as a continuous medium and the liquid phase working fluid is a dispersed droplet; when the flow pattern of the gas-liquid two-phase working fluid is a bubble flow, the liquid phase working fluid is set as a continuous medium and the gas phase working fluid is a dispersed bubble.

[0021] Furthermore, based on the small displacement vortex theory, the rotor elliptical multi-frequency vortex model and the inhomogeneous Euler-Euler model are used to calculate the fluid exciting force and rotor vortex displacement in the time domain.

[0022] Furthermore, the fast Fourier transform is used to transform the fluid exciting force and rotor vortex displacement in the time domain into frequency domain signals, and the impedance coefficient is solved according to the frequency domain signals.

[0023] Furthermore, the process of extracting the characteristic system of the impedance coefficient according to the flow pattern of the gas-liquid two-phase working medium is as follows:

[0024] When the flow pattern of the gas-liquid two-phase working medium is mist flow, the frequency-dependent rotor dynamic characteristic coefficient is extracted from the impedance coefficient; when the flow pattern of the gas-liquid two-phase working medium is bubble flow, the frequency-independent rotor dynamic characteristic coefficient is extracted from the impedance coefficient.

[0025] Furthermore, when the flow type of the gas-liquid two-phase working fluid is bubbling flow, the real part and the imaginary part of the impedance coefficient are linearly fitted with the square of the vortex frequency and the vortex frequency respectively to obtain the frequency-independent stiffness coefficient, damping coefficient and virtual mass coefficient.

[0026] In a second aspect of the present invention, the present invention provides a numerical solution system for dynamic characteristics of a gas-liquid two-phase sealed rotor, comprising:

[0027] A judgment module, used to judge the flow pattern of the gas-liquid two-phase working medium;

[0028] A setting module, used to set the type of gas phase working medium and liquid phase working medium according to the flow pattern of the gas-liquid two-phase working medium;

[0029] A calibration module, used to solve the physical property parameters of the seal inlet and outlet by using the inhomogeneous Euler-Euler model, solve the Weber number of the gas phase medium of the seal inlet and outlet according to the physical property parameters of the seal inlet and outlet, and calibrate the droplet or bubble diameter by the Weber number;

[0030] A calculation module is used to calculate the fluid exciting force and rotor vortex displacement in the time domain using a rotor elliptical multi-frequency vortex model and a non-homogeneous Euler-Euler model;

[0031] A solution module is used to convert the fluid exciting force and rotor vortex displacement in the time domain into frequency domain signals, and solve the impedance coefficient according to the frequency domain signals;

[0032] The extraction module is used to extract the characteristic coefficient of the impedance coefficient according to the flow pattern of the gas-liquid two-phase working medium.

[0033] The gas-liquid two-phase sealed rotor dynamic characteristics numerical solution system of the present invention is further improved in that:

[0034] Furthermore, the process of determining the flow pattern of the gas-liquid two-phase working medium is:

[0035] Obtain a Baker flow pattern diagram and physical property parameters of the gas-liquid two-phase working fluid, and determine the flow pattern of the gas-liquid two-phase working fluid according to the Baker flow pattern diagram and the physical property parameters of the gas-liquid two-phase working fluid, wherein the flow pattern of the gas-liquid two-phase working fluid is mist flow or bubble flow.

[0036] The present invention has the following beneficial effects:

[0037] The method and system for numerically solving the dynamic characteristics of the gas-liquid two-phase sealed rotor described in the present invention introduces the Baker flow pattern diagram to determine the flow pattern of the two-phase working fluid in the rotary seal of the impeller machinery during specific operation. It has a wide range of applications and covers most two-phase flow conditions. In addition, during the numerical calculation process, the Weber number of the bubbles or droplets at the inlet and outlet of the seal is checked, and the appropriate bubble or droplet diameter is selected based on the check result so that it will not rupture further, ensuring that the numerical simulation is as close to the actual working condition as possible. At the same time, the gas (liquid) working fluid is set as a discrete phase or a continuous phase in the pre-processing of the numerical calculation based on the flow pattern judgment result, and different force-displacement linear equations and rotor dynamic characteristic coefficient extraction methods are used for different flow patterns. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 It is the calculation domain and local grid diagram of gas-liquid two-phase labyrinth seal;

[0040] Figure 2 It is the Baker flow diagram;

[0041] Figure 3 This is a schematic diagram of the rotor's multi-frequency elliptical vortex motion;

[0042] Figure 4 is the frequency-independent direct stiffness coefficient diagram;

[0043] Figure 5 This is the flow chart for numerical solution of dynamic characteristics of gas-liquid two-phase sealed rotor. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0045] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0046] Embodiment 1

[0047] refer to Figures 1 to 5 The method for numerically solving the dynamic characteristics of the gas-liquid two-phase sealed rotor of the present invention includes:

[0048] 1) Obtaining a Baker flow pattern diagram and physical property parameters of the gas-liquid two-phase working fluid, and judging the flow pattern of the gas-liquid two-phase working fluid according to the Baker flow pattern diagram and the physical property parameters of the gas-liquid two-phase working fluid, wherein the flow pattern of the gas-liquid two-phase working fluid is a mist flow or a bubble flow.

[0049] 2) When the flow pattern of the gas-liquid two-phase working fluid is a mist flow, the gas phase working fluid is set as a continuous medium and the liquid phase working fluid is a dispersed droplet; when the flow pattern of the gas-liquid two-phase working fluid is a bubble flow, the liquid phase working fluid is set as a continuous medium and the gas phase working fluid is a dispersed bubble.

[0050] 3) The diameter of the droplet or bubble is selected as 0.01 times the sealing gap. Under the selected working condition, the non-homogeneous Euler-Euler model is used to solve the physical parameters of the sealing inlet and outlet. The Weber number of the gas phase medium of the sealing inlet and outlet is solved according to the physical parameters of the sealing inlet and outlet, and the droplet or bubble diameter is calibrated by the Weber number.

[0051] 4) According to the small displacement vortex theory, the rotor elliptical multi-frequency vortex model and the inhomogeneous Euler-Euler model are used to calculate the fluid excitation force and rotor vortex displacement in the time domain.

[0052] 5) Fast Fourier transform is used to convert the fluid excitation force and rotor vortex displacement in the time domain into frequency domain signals, and the impedance coefficient is solved based on the frequency domain signals.

[0053] 6) When the flow pattern is mist flow, the frequency-dependent rotor dynamic characteristic coefficients are extracted; when the flow pattern is bubbling flow, the frequency-independent rotor dynamic characteristic coefficients are extracted.

[0054] In step 1), according to the liquid mass flow rate G l , gas mass flow rate G g , the ratio of liquid density to water density under standard conditions Δ l , the ratio of gas density to air density under standard conditions Δ g 、Liquid viscosity μ l , liquid density ρ l , Flow area A m , Liquid surface tension σ l Determine the horizontal and vertical coordinates in the Baker flow pattern diagram.

[0055] The fitted line boundaries of the mist flow and bubble flow patterns are obtained in the Baker flow pattern diagram, and the flow pattern of the two-phase working fluid is determined in combination with the horizontal and vertical coordinates.

[0056] In step 3), the Weber number of the bubble flow is less than 3.2, and the Weber number of the mist flow is less than 10.6.

[0057] In step 4), in the pre-processing of numerical calculation, the dynamic mesh technology is used to set the multi-frequency elliptical vortex trajectory for the rotor surface and perform unsteady solution to obtain the fluid excitation force and rotor vortex displacement in the time domain.

[0058] In this embodiment, according to the small displacement vortex theory, the maximum displacement of the rotor vortex should be less than 10% of the sealing gap.

[0059] In this embodiment, the force-displacement linear equation of the small displacement vortex theory is used to extract the rotor dynamic characteristic coefficient.

[0060] In this embodiment, when the flow type is mist flow, the virtual mass and acceleration terms in the force-displacement linear equation are removed, and when the flow type is bubble flow, the virtual mass and acceleration terms in the force-displacement linear equation are retained.

[0061] In step 6), when the flow type is bubbling flow, the real part and the imaginary part of the impedance coefficient are linearly fitted with respect to the square of the eddy frequency and the eddy frequency, respectively, to obtain the frequency-independent stiffness coefficient, damping coefficient and virtual mass coefficient.

[0062] Embodiment 2

[0063] This embodiment uses the gas-liquid two-phase labyrinth seal experimentally measured by Zhang et al. (Zhang M, Childs DW. Experimental study on the performance of a see-through labyrinth seal with two-phase, mainly-liquid mixtures[J]. ASME Journal of Engineering for GasTurbines and Power, 2021, 143(1): 011015). The geometric parameters of the labyrinth seal are shown in Table 1. The calculation domain and local grid diagram are shown in Table 1. Figure 1 The entire numerical solution method is shown as Figure 5 shown.

[0064] Table 1

[0065]

[0066] The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor described in this embodiment includes:

[0067] 1) Since the continuous phase and the discrete phase need to be given in the numerical simulation process of two-phase flow, and the discrete phase is in the form of a given droplet or bubble diameter. Therefore, the numerical method used to study the two-phase flow model is closer to the morphology of bubbles in liquid or droplets in gas, and is suitable for mist flow and bubble flow in actual situations. Before carrying out numerical simulation calculations, it is necessary to judge the morphology of the two-phase flow based on experimental measurements and the physical properties of the gas-liquid two-phase working fluid obtained from NIST in combination with the Baker flow pattern diagram. Figure 2 It is the Baker flow pattern diagram. The horizontal and vertical coordinates of the Baker flow pattern diagram are calculated by the physical properties of the gas-liquid two-phase working fluid respectively.

[0068] The horizontal axis of the Baker flow diagram contains the liquid mass flow rate G l , the ratio of liquid density to water density under standard conditions Δ l , the ratio of gas density to air density under standard conditions Δ g 、Liquid viscosity μ l , liquid density ρ l , gas mass flow rate G g and the liquid surface tension σ l The vertical axis of the Baker flow diagram contains the gas mass flow rate G g , Flow area A m , the ratio of liquid density to water density under standard conditions Δ l And the ratio of gas density to air density under standard conditions Δ gThe above parameters are obtained based on the labyrinth seal rotor dynamic characteristics test results and NIST query results, and the X-axis and Y-axis are calculated using the following formulas.

[0069]

[0070]

[0071] In the Baker flow pattern diagram, the bubbly flow is located on the right side of the lines C4 and L3 in the diagram. By fitting the two lines C4 and L3, the boundary of the bubbly flow pattern can be obtained, namely:

[0072]

[0073] L3:x=-1.028449y+6.319154

[0074] In the Baker flow pattern diagram, the mist flow is located between the C3 and C4 lines in the diagram. The C3 line is fitted to obtain the boundary of the mist flow pattern, namely:

[0075]

[0076] According to the comparison, the gas-liquid two-phase flow pattern in the labyrinth seal is in the bubbling flow region in the Baker flow pattern diagram.

[0077] 2) The physical parameters of the seal inlet and outlet are obtained by using the steady-state method to solve the RANS equation.

[0078] Specifically, the commercial software ANSYS ICEM is used to perform structured meshing of the labyrinth seal, and the mesh is encrypted on the wall to meet the needs of the RNG k-ε turbulence model for y+. The mesh is then imported into ANSYS CFX 18.2, and the inlet total pressure, total temperature, outlet static pressure, and speed are set. After numerical solution, the density ρ, gas-liquid relative velocity U, temperature, and bubble diameter L of the seal inlet and outlet liquid working fluid are obtained, and the surface tension σ between the gas and liquid is obtained by query. The Weber number We of the seal inlet and outlet gas medium is:

[0079]

[0080] Among them, the Weber number of the bubbles is less than 3.2, so under the calculation conditions, the bubbles in the liquid will not burst due to the excessive Weber number.

[0081] 3) In the process of numerical solution of rotor dynamic characteristics, the result of steady-state calculation is substituted as the initial field. In the pre-processing process of solution, dynamic mesh technology is used to set a multi-frequency elliptical vortex model for the rotor surface. The schematic diagram of the vortex model is shown in Figure 3 As shown, the vortex trajectory of the rotor surface is:

[0082]

[0083] Among them, D x With D y It indicates the displacement of the rotor axis from the stator axis in the X and Y directions; a and b are the major and minor axes of the elliptical trajectory respectively; Ω0 is the reference frequency of the rotor vortex, and other frequencies are multiples of the reference frequency, with a total of N frequencies selected; t is time, and when selecting parameters, the maximum vortex displacement (N·a) needs to be less than 0.1 times the sealing gap, and the maximum frequency should contain a time step of 30 steps or more.

[0084] In this numerical calculation, the reference frequency is selected as 20 Hz, the frequency number N is 10; the major axis and minor axis of the elliptical vortex trajectory are 0.02 and 0.01 times the sealing gap respectively; the time step is 0.0002 s.

[0085] During the solution process, the fluid exciting force and rotor displacement acting on the rotor in the X and Y directions in the time domain are recorded synchronously.

[0086] 4) Under the conditions of mist flow and bubbling flow, the physical parameters of the working fluid, such as density, speed of sound and compressibility, are quite different, resulting in different frequency correlations of the sealed rotor dynamic characteristic coefficients. At the same time, under the condition of bubbling flow, due to the high density of the working fluid, the influence of virtual mass and acceleration terms on the rotor dynamic characteristics cannot be ignored.

[0087] For mist flow, the force-displacement linear equation is:

[0088]

[0089] For bubbly flow, the linear force-displacement equation is:

[0090]

[0091] The force-displacement linear equation is transformed into the frequency domain form using fast Fourier transform, where H ij is the impedance coefficient, we get:

[0092]

[0093] For mist flow, H ij =K ij +jΩC ij , Ω is the vortex frequency, and the frequency-dependent stiffness coefficient and damping coefficient can be obtained by directly solving the impedance coefficient; for bubbly flow, H ij =K ij +jΩC ij -Ω 2 M ij , the real and imaginary parts of the impedance coefficient need to be respectively related to Ω 2A linear fit is performed with Ω, and the frequency-independent stiffness coefficient, damping coefficient and virtual mass coefficient are obtained from its slope and intercept. In this embodiment, the real part and imaginary part of the impedance coefficient need to be respectively related to Ω 2 Perform a linear fit with Ω, Figure 4 The calculated frequency-independent direct stiffness coefficients are given.

[0094] Embodiment 3

[0095] The gas-liquid two-phase sealed rotor dynamic characteristics numerical solution system of the present invention comprises:

[0096] A judgment module, used to judge the flow pattern of the gas-liquid two-phase working medium;

[0097] A setting module, used to set the type of gas phase working medium and liquid phase working medium according to the flow pattern of the gas-liquid two-phase working medium;

[0098] A calibration module, used to solve the physical property parameters of the seal inlet and outlet by using the inhomogeneous Euler-Euler model, solve the Weber number of the gas phase medium of the seal inlet and outlet according to the physical property parameters of the seal inlet and outlet, and calibrate the droplet or bubble diameter by the Weber number;

[0099] A calculation module is used to calculate the fluid exciting force and rotor vortex displacement in the time domain using a rotor elliptical multi-frequency vortex model and a non-homogeneous Euler-Euler model;

[0100] A solution module is used to convert the fluid exciting force and rotor vortex displacement in the time domain into frequency domain signals, and solve the impedance coefficient according to the frequency domain signals;

[0101] The extraction module is used to extract the characteristic coefficient of the impedance coefficient according to the flow pattern of the gas-liquid two-phase working medium.

[0102] In this embodiment, the process of determining the flow pattern of the gas-liquid two-phase working medium is:

[0103] Obtain a Baker flow pattern diagram and physical property parameters of the gas-liquid two-phase working fluid, and determine the flow pattern of the gas-liquid two-phase working fluid according to the Baker flow pattern diagram and the physical property parameters of the gas-liquid two-phase working fluid, wherein the flow pattern of the gas-liquid two-phase working fluid is mist flow or bubble flow.

[0104] The division of modules in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present application may be integrated into a processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0105] Embodiment 4

[0106] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the target detection method for surface cracks of a wind turbine blade are implemented, for example, comprising: determining the flow pattern of a gas-liquid two-phase working medium; setting the types of the gas-phase working medium and the liquid-phase working medium according to the flow pattern of the gas-liquid two-phase working medium; solving the physical property parameters of the seal inlet and outlet by using a non-homogeneous Euler-Euler model, solving the Weber number of the gas-phase medium of the seal inlet and outlet according to the physical property parameters of the seal inlet and outlet, and verifying the diameter of the droplet or bubble by the Weber number; calculating the fluid exciting force and the rotor eddy displacement in the time domain by using a rotor elliptical multi-frequency vortex model and a non-homogeneous Euler-Euler model; converting the fluid exciting force and the rotor eddy displacement in the time domain into frequency domain signals, and solving the impedance coefficient according to the frequency domain signals; and extracting the characteristic coefficient of the impedance coefficient according to the flow pattern of the gas-liquid two-phase working medium. The memory may include a memory, such as a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk memory, etc. The processor, network interface, and memory are interconnected through an internal bus, and the internal bus may be an industrial standard architecture bus, a peripheral component interconnection standard bus, an extended industrial standard architecture bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory is used to store programs. Specifically, the program may include a program code, and the program code includes computer operation instructions. The memory may include a memory and a non-volatile memory, and provide instructions and data to the processor.

[0107] Embodiment 5

[0108] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the target detection method for cracks on the surface of a wind turbine blade are implemented, for example, including: determining the flow pattern of a gas-liquid two-phase medium; setting the type of gas-phase medium and liquid-phase medium according to the flow pattern of the gas-liquid two-phase medium; solving the physical parameters of the seal inlet and outlet using a non-homogeneous Euler-Euler model, solving the Weber number of the gas-phase medium of the seal inlet and outlet according to the physical parameters of the seal inlet and outlet, and verifying the droplet or bubble diameter by the Weber number; calculating the fluid excitation force and rotor eddy displacement in the time domain using a rotor elliptical multi-frequency vortex model and a non-homogeneous Euler-Euler model; converting the fluid excitation force and rotor eddy displacement in the time domain into frequency domain signals, solving the impedance coefficient according to the frequency domain signals; extracting the characteristic coefficient of the impedance coefficient according to the flow pattern of the gas-liquid two-phase medium. Specifically, the computer-readable storage medium includes, but is not limited to, for example, volatile memory and / or non-volatile memory. The volatile memory may include a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include a read-only memory (ROM), a hard disk, a flash memory, an optical disk, a magnetic disk, etc.

[0109] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0110] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0111] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0112] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor, characterized in that: include: Determine the flow pattern of gas-liquid two-phase working fluid; Set the types of gas phase working medium and liquid phase working medium according to the flow pattern of gas-liquid two-phase working medium; The inhomogeneous Euler-Euler model is used to solve the physical property parameters of the seal inlet and outlet, and the Weber number of the gas phase medium of the seal inlet and outlet is solved according to the physical property parameters of the seal inlet and outlet, and the droplet or bubble diameter is checked by the Weber number; The rotor elliptical multi-frequency vortex model and the inhomogeneous Euler-Euler model are used to calculate the fluid exciting force and rotor vortex displacement in the time domain. The fluid exciting force and rotor vortex displacement in the time domain are converted into frequency domain signals, and the impedance coefficient is solved according to the frequency domain signals; According to the flow pattern of the gas-liquid two-phase working fluid, the characteristic coefficient of the impedance coefficient is extracted.

2. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 1 is characterized in that: The process of determining the flow pattern of the gas-liquid two-phase working medium is as follows: Obtain a Baker flow pattern diagram and physical property parameters of the gas-liquid two-phase working fluid, and determine the flow pattern of the gas-liquid two-phase working fluid according to the Baker flow pattern diagram and the physical property parameters of the gas-liquid two-phase working fluid, wherein the flow pattern of the gas-liquid two-phase working fluid is mist flow or bubble flow.

3. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 2 is characterized in that: According to the liquid mass flow rate G l , gas mass flow rate G g , the ratio of liquid density to water density under standard conditions Δ l , the ratio of gas density to air density under standard conditions Δ g 、Liquid viscosity μ l , liquid density ρ l , Flow area A m , Liquid surface tension σ l Determine the horizontal and vertical coordinates in the Baker flow pattern diagram; The fitted line boundaries of the mist flow and bubble flow patterns are obtained in the Baker flow pattern diagram, and the flow pattern of the gas-liquid two-phase working fluid is determined by combining the horizontal and vertical coordinates of the Baker flow pattern diagram.

4. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 1 is characterized in that: The process of setting the types of gas phase working medium and liquid phase working medium according to the flow pattern of the gas-liquid two-phase working medium is: When the flow pattern of the gas-liquid two-phase working fluid is a mist flow, the gas phase working fluid is set as a continuous medium and the liquid phase working fluid is a dispersed droplet; when the flow pattern of the gas-liquid two-phase working fluid is a bubble flow, the liquid phase working fluid is set as a continuous medium and the gas phase working fluid is a dispersed bubble.

5. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 1, characterized in that: According to the small displacement vortex theory, the rotor elliptical multi-frequency vortex model and the inhomogeneous Euler-Euler model are used to calculate the fluid exciting force and rotor vortex displacement in the time domain.

6. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 1, characterized in that: Fast Fourier transform is used to transform the fluid exciting force and rotor vortex displacement in the time domain into frequency domain signals, and the impedance coefficient is solved according to the frequency domain signals.

7. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 1, characterized in that: The process of extracting the characteristic system of the impedance coefficient according to the flow pattern of the gas-liquid two-phase working medium is as follows: When the flow pattern of the gas-liquid two-phase working medium is mist flow, the frequency-dependent rotor dynamic characteristic coefficient is extracted from the impedance coefficient; when the flow pattern of the gas-liquid two-phase working medium is bubble flow, the frequency-independent rotor dynamic characteristic coefficient is extracted from the impedance coefficient.

8. The method for numerically solving the dynamic characteristics of a gas-liquid two-phase sealed rotor according to claim 7, characterized in that: When the flow pattern of the gas-liquid two-phase working fluid is bubbling flow, the real part and the imaginary part of the impedance coefficient are linearly fitted with the square of the vortex frequency and the vortex frequency respectively to obtain the frequency-independent stiffness coefficient, damping coefficient and virtual mass coefficient.

9. A numerical solution system for dynamic characteristics of gas-liquid two-phase sealed rotor, characterized in that: include: A judgment module, used to judge the flow pattern of the gas-liquid two-phase working medium; A setting module, used to set the type of gas phase working medium and liquid phase working medium according to the flow pattern of the gas-liquid two-phase working medium; A calibration module, used to solve the physical property parameters of the seal inlet and outlet by using the inhomogeneous Euler-Euler model, solve the Weber number of the gas phase medium of the seal inlet and outlet according to the physical property parameters of the seal inlet and outlet, and calibrate the droplet or bubble diameter by the Weber number; A calculation module is used to calculate the fluid exciting force and rotor vortex displacement in the time domain using a rotor elliptical multi-frequency vortex model and a non-homogeneous Euler-Euler model; A solution module is used to convert the fluid exciting force and rotor vortex displacement in the time domain into frequency domain signals, and solve the impedance coefficient according to the frequency domain signals; The extraction module is used to extract the characteristic coefficient of the impedance coefficient according to the flow pattern of the gas-liquid two-phase working medium.

10. The gas-liquid two-phase sealed rotor dynamic characteristics numerical solution system according to claim 9, characterized in that: The process of determining the flow pattern of the gas-liquid two-phase working medium is as follows: Obtain a Baker flow pattern diagram and physical property parameters of the gas-liquid two-phase working fluid, and determine the flow pattern of the gas-liquid two-phase working fluid according to the Baker flow pattern diagram and the physical property parameters of the gas-liquid two-phase working fluid, wherein the flow pattern of the gas-liquid two-phase working fluid is mist flow or bubble flow.

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