Proportional valve control method based on high-pressure multi-medium annular gap flow prediction
By constructing a unified control equation for multiple media and a fluid-structure interaction feedback algorithm, precise flow control of a miniature proportional valve under high-pressure multiphase flow conditions was achieved, solving the problem of large flow prediction error in existing technologies and improving control accuracy and system adaptability.
Patent Information
- Application Number
- CN202511917796.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-03-17
AI Technical Summary
Existing technologies for predicting annular slit flow in micro proportional valves under high pressure and multiphase flow conditions suffer from insufficient accuracy, leading to decreased flow control precision, hysteresis, and poor stability, making it difficult to meet the requirements of high-pressure multi-media dynamic flow.
A unified control equation for multiple media with phase transition criteria is constructed. Combined with slip velocity boundary conditions modified by molecular dynamics, a fluid-structure interaction real-time feedback algorithm and a characteristic scale reduced-order model are adopted to achieve efficient and accurate prediction of flow characteristics under high-pressure complex working conditions. The opening compensation value is calculated by a PID controller and proportional valve control command is generated.
It improves the accuracy and computational efficiency of high-pressure multi-medium flow prediction, with errors controlled within 5%, and flow control accuracy improved to ±1%. It enhances the system's adaptability to complex coupled operating conditions and supports the design optimization of miniature proportional valves.
Smart Images
Figure CN121676520A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of hydraulic control element dynamics analysis, and more particularly to a proportional valve control method based on high-pressure multi-medium annular gap flow prediction. BACKGROUND
[0002] For micro proportional valve annular gap flow prediction, the existing technology generally uses a laminar flow model based on the Navier-Stokes equation, simplifies the medium as a single-phase incompressible fluid, and assumes that the gap height is constant. For high-pressure multi-medium working conditions, the existing improved technology introduces the medium bulk modulus parameter to correct the compressibility effect, but does not cover the phase change effect of the gas phase medium, resulting in a gas-liquid mixed flow prediction deviation of more than 30%; or research uses fluid-structure coupling simulation to calculate the valve body deformation, but ignores the transient gap fluctuation caused by the micron-level vibration of the moving iron core group under high pressure, and the actual measurement response delay is more than 5 milliseconds; and the proposed multi-medium equivalent viscosity method fails to establish the slip boundary conditions of the oil-water-gas interface, making it impossible to accurately simulate the outlet medium separation phenomenon. Due to the oversimplified medium phase state, the ignored wall slip effect, the static gap parameters, and the high computational complexity, the existing method is difficult to meet the demand for high-pressure multi-medium dynamic flow prediction, thereby causing the micro proportional valve to have decreased flow control accuracy, delayed response, and poor stability under high-pressure and multi-phase flow working conditions due to the complex and variable flow field characteristics (such as cavitation, phase separation, and complex vortex).
[0003] Therefore, how to improve the accuracy of micro proportional valve annular gap flow prediction under high-pressure and multi-phase flow working conditions, and thereby improve the valve control performance is a problem that needs to be solved by those skilled in the art. SUMMARY
[0004] In view of the above problems, the present application is proposed to provide a proportional valve control method based on high-pressure multi-medium annular gap flow prediction, which overcomes the above problems or at least partially solves the above problems, relates to the numerical modeling and characteristic prediction of multi-phase medium flow in the annular gap of a micro proportional valve, constructs a multi-medium unified control equation containing a phase change criterion, combines a slip velocity boundary condition modified by molecular dynamics, and develops a fluid-structure coupling real-time feedback algorithm and a characteristic scale reduction model, to realize efficient and accurate prediction of flow characteristics under high-pressure complex working conditions, improve the calculation efficiency by 90%, and control the multi-phase flow prediction error within 5%, based on the accurate prediction results to realize accurate control of the proportional valve.
[0005] To achieve the above purpose, the present application adopts the following technical solutions: In a first aspect, the present application provides a proportional valve control method based on high-pressure multi-medium annular gap flow prediction, comprising the following steps: Step 1: Collecting real-time state signals of the micro proportional valve; Step 2: Input the collected real-time status signal into the multiphase flow transient coupling equation to calculate the velocity field and pressure field inside the micro proportional valve, and correct the velocity field. Step 3: Calculate the gas phase distribution based on the corrected velocity field and real-time state signal; Step 4: Calculate the transient fluid load based on the gas phase distribution and pressure field; Step 5: Input the transient fluid load into the structural dynamics equation of the micro proportional valve and calculate the structural displacement of the micro proportional valve; Step 6: Calculate the opening compensation value based on the structural displacement using a PID controller, and convert the opening compensation value into a PWM duty cycle correction value; Step 7: Generate proportional valve control commands based on the PWM duty cycle correction.
[0006] Preferably, the real-time status signals include the inlet and outlet pressure difference signal ΔP, the valve core displacement signal x, and the medium temperature signal T.
[0007] Preferably, the transient coupling equations for multiphase flow are constructed using the compressible Navier–Stokes equations, including the continuity equation and the momentum equation; The continuity equation is expressed as: ; The momentum equation is expressed as: ; in, , These represent the velocity field and pressure field of the mixed fluid, respectively. For the density field of the mixed fluid, based on the inlet and outlet pressure difference signals It is obtained by calculation with the medium temperature signal T and corrected by the pressure-bulk elastic modulus relationship; It is the viscous stress tensor; The volume derivative of the density of the mixed fluid; As the driving force, based on the inlet and outlet pressure difference signal Calculated; The divergence of the velocity vector; For physical strength.
[0008] Preferably, the wall sliding velocity at each time step is calculated using multi-scale order reduction based on the slip boundary condition constraints, thereby correcting the velocity field; the slip boundary condition constraints are expressed as follows:
[0009]
[0010] in, The wall sliding velocity; The momentum relaxation coefficient is obtained from wall material calibration experiments. The mean free path of fluid molecules is determined by the medium temperature signal T and the inlet / outlet pressure difference signal. Calculated; Represents the velocity field; The normal velocity gradient of the wall is obtained by numerical difference calculation of the velocity field v in the normal direction of the wall. For wall points; For adjacent grid nodes along the normal direction.
[0011] Preferably, the specific process of step 3 is as follows: Step 31: Construct a joint snapshot matrix of flow field and slip amount based on the corrected velocity field and the wall slip velocity distribution determined by the wall slip velocity; Step 32: Perform singular value decomposition on the joint snapshot matrix of flow field and slip, and extract the first r dominant modes of POD with an energy percentage > 99%. The dominant mode base of POD Projecting to a lower-dimensional subspace yields a reduced-order flow field solution. , where a is the time-varying coefficient vector; Step 33: Based on the reduced-order flow field solution Real-time prediction of gas phase distribution within the valve ; indicates as:
[0012] Where x represents the valve core displacement signal; Denotes the dominant mode basis of the POD projected onto the lower-dimensional subspace; This represents the time-varying coefficient vector corresponding to the dominant mode basis of the i-th POD. gas phase volume fraction It is composed of the reduced-order flow field solution and the slip correction term.
[0013] Preferably, based on gas phase distribution Viscous stress tensor Calculating transient fluid loads using pressure field p , The deformation of the structure is obtained by integrating the fluid's pull on the valve body / wall surface; the specific process is as follows: Step 41: Based on the pressure field Corrected velocity field v and gas phase distribution Calculate the equivalent viscosity at each wall area integral point. ; Step 42: Calculate the viscous stress tensor based on the equivalent viscosity. ; Step 43: Calculate the wall traction force based on the viscous stress tensor. , The normal pressure load represents the pressure field, and n represents the wall normal. Step 44: Project the wall traction force onto the structural nodes by numerical integration to obtain the transient fluid loads at the node level. S represents a structural node.
[0014] Preferably, transient fluid loads The structural dynamics equations are input as the driving source and the structural displacement u of the valve / pipe wall is solved step-by-step using a partitioned iterative algorithm; the structural dynamics equations are expressed as follows: ; in, The mass matrix of the valve body reflects its inertial characteristics; It represents acceleration, which is the second derivative of the structural displacement u with respect to time; This represents the damping matrix, which simulates energy dissipation during motion. The velocity is represented by the first derivative of the structural displacement u with respect to time. This represents the stiffness matrix, which describes the structure's ability to resist deformation.
[0015] Preferably, step 5 further includes using a structural displacement correction method for the transient coupling of multiphase flow, the specific process of which is as follows: Step 51: Map the structural displacements to the fluid-structure coupling boundary nodes to obtain the mapping results; Step 52: Update the mesh coordinates of the fluid boundary mesh in real time using the elastic body deformation algorithm based on the mapping results; Step 53: Perform a quality assessment on the updated mesh coordinates, and perform local smoothing / reconstruction based on the quality assessment results to update the wall geometry boundary; in order to ensure the stability of subsequent solutions; Step 54: Calculate the instantaneous flow area and pressure drop gradient based on the updated wall geometry boundary, and feed them back to the multiphase flow transient coupling equation for correction.
[0016] Preferably, in step 7, the PWM duty cycle correction is converted into a PWM wave or analog voltage to generate a proportional valve control command, which drives the electromagnetic coil of the miniature proportional valve to achieve real-time closed-loop control of the valve core opening, ensuring that the flow output error is less than ±1%. The opening compensation value Δx can suppress the influence of flow nonlinearity, making the actual flow rate close to the set value.
[0017] As can be seen from the above technical solution, compared with the prior art, this invention discloses a proportional valve control method based on high-pressure multi-medium annular gap flow prediction. By establishing a high-precision multiphase flow-valve core dynamics coupled numerical model, the multiphase flow characteristics inside the micro proportional valve under high pressure can be accurately predicted. The predicted characteristics include, but are not limited to, the transient flow field structure at the valve orifice and within the cavity, key physical phenomena (such as cavitation intensity distribution, gas phase volume fraction change, and local flow state transition), and key quantitative parameters reflecting the flow state. These prediction results are intuitively represented in numerical form, providing direct and reliable theoretical support for the key structural optimization of the micro proportional valve. It can accurately locate the structural bottlenecks or key geometric parameters that affect valve control performance (such as accuracy, stability, noise, and lifespan).
[0018] This invention significantly improves the prediction accuracy and computational efficiency of multiphase flow characteristics under high pressure by constructing a set of governing equations for multiphase media with phase transition criteria, integrating molecular-scale corrected slip velocity boundary conditions with a multi-scale order reduction modeling method. Compared with existing traditional models that are only applicable to single media or static boundary conditions, this invention can achieve high-precision flow prediction with errors controlled within 5% under high-pressure oil / water / gas mixture conditions of 10–50 MPa, and improves computational efficiency by more than 90% through the characteristic scale order reduction algorithm, greatly reducing engineering simulation time. At the same time, through the fluid-structure interaction dynamic feedback mechanism, the prediction model can automatically adjust the flow field solution parameters according to the real-time structural response, enhancing the system's adaptability to complex coupled conditions and providing reliable and real-time modeling support for the design and optimization of high-pressure flow control components such as micro proportional valves. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0020] Figure 1 A schematic diagram of the proportional valve control method based on high-pressure multi-medium annular gap flow prediction provided by the present invention. Detailed Implementation
[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] This invention discloses a proportional valve control method based on high-pressure multi-media annular gap flow prediction, such as... Figure 1 As shown, it includes the following steps: S1: Acquire the real-time status signal of the miniature proportional valve; S2: Input the collected real-time state signal into the multiphase flow transient coupling equation to calculate the velocity field and pressure field inside the micro proportional valve, and correct the velocity field. S3: Calculate the gas phase distribution based on the corrected velocity field and real-time state signal; S4: Calculate transient fluid loads based on gas phase distribution and pressure field; S5: Input the transient fluid load into the structural dynamics equation of the micro proportional valve and calculate the structural displacement of the micro proportional valve; S6: Calculate the opening compensation value based on the structural displacement, and convert the opening compensation value into the PWM duty cycle correction value; S7: Generates proportional valve control commands based on PWM duty cycle correction.
[0023] Furthermore, the real-time status signals include inlet and outlet pressure differential signals, valve core displacement signals, and medium temperature signals.
[0024] Furthermore, the opening compensation value Or PWM duty cycle correction It can suppress the effects of nonlinear flow and make the actual flow rate approach the set value.
[0025] Furthermore, in S7, the PWM duty cycle correction is converted into a PWM wave or analog voltage to generate a proportional valve control command, which drives the electromagnetic coil of the miniature proportional valve to achieve real-time closed-loop control of the valve core opening, ensuring that the flow output error is less than ±1%.
[0026] Furthermore, a set of governing equations for multiphase media is constructed using the compressible Navier–Stokes equations, including continuity equations and momentum equations. The continuity equation is expressed as: ; The momentum equation is expressed as: ; in, , These represent the velocity field and pressure field of the mixed fluid, respectively. For the density field of the mixed fluid, based on the inlet and outlet pressure difference signals It is obtained by calculation with the medium temperature signal T and corrected by the pressure-bulk elastic modulus relationship; For viscous stress tensors, for Newtonian fluids ; The volume derivative of the density of the mixed fluid; Driven by pressure; The divergence of the velocity vector; Physical force, such as gravity.
[0027] Furthermore, based on the slip boundary condition constraints, the velocity field is calculated using multi-scale order reduction to determine the wall slip velocity at each time step, thus correcting the velocity field; the slip boundary condition constraints are expressed as:
[0028]
[0029] in, The wall sliding velocity; The momentum relaxation coefficient is obtained from wall material calibration experiments. The mean free path of fluid molecules is determined by the medium temperature signal T and the inlet / outlet pressure difference signal. Calculated; Represents the velocity field; The normal velocity gradient of the wall is obtained by numerical difference calculation of the velocity field v in the normal direction of the wall. For wall points; For adjacent grid nodes along the normal direction; Furthermore, the specific process of S3 is as follows: S31: Construct a joint snapshot matrix of flow field and slip amount based on the corrected velocity field and the wall slip velocity distribution determined by the wall slip velocity; S32: Perform singular value decomposition on the joint snapshot matrix of flow field and slip, and extract the first r dominant modes of POD with an energy percentage > 99%. The dominant mode base of POD Projecting to a lower-dimensional subspace yields a reduced-order flow field solution. , where a is the time-varying coefficient vector; S33: Based on the reduced-order flow field solution Real-time prediction of gas phase distribution within the valve ; indicates as:
[0030] Where x represents the valve core displacement signal; The i-th POD dominant mode basis projected onto the lower-dimensional subspace; This represents the time-varying coefficient vector corresponding to the dominant mode basis of the i-th POD. gas phase volume fraction It is composed of the reduced-order flow field solution and the slip correction term.
[0031] Furthermore, based on the gas phase distribution Viscous stress tensor Calculating transient fluid loads using pressure field p , The deformation of the structure is obtained by integrating the fluid's pull on the valve body / wall surface; the specific process is as follows: S41: According to the pressure field Corrected velocity field v and gas phase distribution Calculate the equivalent viscosity at each wall area integral point. ; S42: Calculate the viscous stress tensor based on the equivalent viscosity. ; S43: Calculate the wall traction force based on the viscous stress tensor. , The normal pressure load represents the pressure field, and n represents the wall normal. S44: Project the wall traction force onto the structural nodes by numerical integration to obtain the transient fluid loads at the node level. S represents a structural node. The normal pressure load pn is obtained through the pressure field p, and is derived from the viscous stress tensor. Calculate the wall shear load components The normal pressure load and the shear load together constitute the transient fluid load.
[0032] Furthermore, transient fluid loads The structural dynamics equation is input as the driving source, and the structural displacement u of the valve / pipe wall is solved step by step through a partitioned iterative algorithm. The opening compensation signal Δx is then calculated based on the structural displacement u. The structural dynamics equation is expressed as follows: ; in, The mass matrix of the valve body reflects its inertial characteristics; It represents acceleration, which is the second derivative of the structural displacement u with respect to time; This represents the damping matrix, which simulates energy dissipation during motion. The velocity is represented by the first derivative of the structural displacement u with respect to time. The stiffness matrix represents the structure's ability to resist deformation. The transient fluid load is substituted into the structural dynamics equations of the miniature proportional valve and projected onto the valve core and sleeve walls, forming the driving source for the structural dynamics equations, thereby obtaining the structural displacement u(t).
[0033] Furthermore, S5 also includes a method for correcting the transient coupling of multiphase flow using structural displacement, the specific process of which is as follows: S51: Map the structural displacements to the fluid-structure coupling boundary nodes to obtain the mapping results; S52: The mesh coordinates of the fluid boundary mesh are updated in real time using an elastic body deformation algorithm based on the mapping results; S53: Perform a quality assessment on the updated mesh coordinates, and perform local smoothing / reconstruction based on the quality assessment results to update the wall geometry boundary; in order to ensure the stability of subsequent solutions; S54: Calculate the instantaneous flow area and pressure drop gradient based on the updated wall geometry and feed them back to the multiphase flow transient coupling equation for correction. Dynamic meshing is used to correct the equation, achieving closed-loop coupling of flow field prediction, structural response, and geometric update. This process directly overcomes the flow prediction deviation caused by valve sleeve expansion under high-pressure conditions greater than 10 MPa (error reduced from >3% in the traditional model to ±0.8%), generating a high-precision opening compensation signal for control decisions. Provide physical evidence.
[0034] Furthermore, the opening compensation value will be added in S6. The signal is converted into a PWM wave or analog voltage to generate a proportional valve control command. This command drives the solenoid coil of the miniature proportional valve, achieving real-time closed-loop control of the valve core opening and ensuring that the flow output error is less than ±1% of the set value. (Opening compensation value) It can suppress the effects of nonlinear flow, making the actual flow rate approach the set value. On the other hand, in one specific embodiment, a proportional valve control system based on high-pressure multi-media annular gap flow prediction includes a data acquisition module, a signal conditioning module, a main control calculation module, a power drive module, a communication module, and an actuator module; The data acquisition module collects sensor signals by integrating multiple sensors; The signal conditioning module performs differential amplification, anti-aliasing filtering, and ADC conversion on the sensor signal to obtain the real-time status signal; The main control calculation module predicts the flow characteristic parameters and structural displacement within the output valve based on real-time status signals, and obtains the opening compensation value by performing fuzzy PID control based on the structural displacement. The power drive module generates proportional valve control commands based on the opening compensation value; The communication module transmits proportional valve control commands to the actuator module; The actuator module controls the miniature proportional valve according to the proportional valve control command.
[0035] Furthermore, the real-time status signals include inlet and outlet pressure difference signals. The valve core displacement signal x and the medium temperature signal T.
[0036] Furthermore, the main control computing module uses a high-performance embedded processor (such as a GPU / FPGA) to run real-time algorithms.
[0037] Furthermore, the communication module supports industrial bus protocols such as CAN, RS-485, and Ethernet.
[0038] Furthermore, the power drive module converts the compensation data into an analog signal through PWM filtering, or converts the compensation data into a direct output voltage through DAC, to generate proportional valve control commands.
[0039] Furthermore, the power drive module is also equipped with overvoltage or overcurrent protection circuits.
[0040] This invention features a tightly coupled hardware and software algorithm module: the data acquisition module collects in-situ pressure differential signals, valve core displacement signals, and medium temperature signals of the miniature proportional valve in real time. After analog front-end conditioning and ADC digitization, these signals are transmitted to the main control calculation module. The main control calculation module calls the multiphase flow transient coupling equation and predicts the flow characteristic parameters inside the valve in real time based on the digital sensor data, including quantitative indicators such as cavitation intensity, phase distribution, and local pressure gradient. It calculates the structural displacement using parameters such as the cavitation index, dynamic flow coefficient Cv, and transient hydrodynamic fluctuation spectrum output by the model, and calculates the opening compensation value through a fuzzy PID controller. Or PWM duty cycle correction To suppress the effects of nonlinear flow and make the actual flow rate approach the set value, the power drive module will output the opening compensation value. The voltage is converted into a PWM wave or analog voltage to drive the proportional valve solenoid coil, thereby achieving real-time closed-loop control of the valve core opening and ensuring that the error between the flow output and the set value is less than ±1%. The system of this invention adopts a high-precision closed-loop control method for a micro proportional valve that integrates fluid characteristic prediction. Differential pressure signals at inlet and outlet collected by the sensor The transient coupling equation of the multiphase flow is obtained by using the medium temperature signal T as the boundary condition input, and combining it with slip boundary correction to obtain the velocity field, pressure field, and gas phase distribution. Then, the gas phase region is determined based on the local pressure and saturated vapor pressure. The control unit calculates the spatial gradient of the gas phase distribution to locate the cavitation zone, and performs frequency domain analysis on the predicted transient fluid load to extract the main vibration frequency, thereby generating the PWM duty cycle correction amount. This allows the valve core to operate away from the main vibration frequency band, thereby achieving a flow error of ≤±0.8%.
[0041] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A proportional valve control method based on high pressure multi-medium annular gap flow prediction, characterized in that, The method comprises the following steps: Step 1: collecting real-time state signals of the micro proportional valve; Step 2: inputting the collected real-time state signals into a multiphase flow transient coupling equation to calculate a velocity field and a pressure field in the micro proportional valve and correct the velocity field; Step 3: calculating a gas phase distribution according to the corrected velocity field and the real-time state signals; Step 4: calculating a transient fluid load according to the gas phase distribution and the pressure field; Step 5: inputting the transient fluid load into a structural dynamics equation of the micro proportional valve to calculate a structural displacement of the micro proportional valve; Step 6: calculating an opening compensation value according to the structural displacement and converting the opening compensation value into a PWM duty cycle correction amount; Step 7: generating a proportional valve control instruction according to the PWM duty cycle correction amount.
2. The proportional valve control method based on high pressure multi- medium annular gap flow prediction according to claim 1, characterized in that, The real-time state signals include an inlet-outlet pressure difference signal, a valve core displacement signal and a medium temperature signal.
3. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 4, wherein, In step 7, the PWM duty cycle correction amount is converted into a PWM wave or an analog voltage to generate the proportional valve control instruction, drive an electromagnetic coil of the micro proportional valve and realize real-time closed-loop control of a valve core opening degree.
4. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 1, wherein, The compressible Navier-Stokes equation set is adopted to construct a multiphase medium control equation set, including a continuity equation and a momentum equation; The continuity equation is expressed as: ； The momentum equation is expressed as: ； wherein, , are the velocity field and the pressure field of the mixture fluid, respectively; is the density field of the mixture fluid; is the viscous stress tensor; is the material derivative of the mixture fluid density; is the pressure driving force; is the divergence of the velocity vector; is the body force.
5. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 1, wherein, The velocity field is calculated by multi-scale reduction based on a slip boundary condition constraint to obtain a wall surface slip velocity at each time and correct the velocity field; the slip boundary condition constraint is expressed as: where, is the wall slip velocity; is the momentum relaxation coefficient; is the mean free path of the fluid molecules; denotes the velocity field; is the wall normal velocity gradient; is the wall point; is the normal adjacent grid node; n denotes the wall normal.
6. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 5, wherein, The specific process of step 3 is as follows: Step 31: constructing a flow field-slip amount joint snapshot matrix according to the corrected velocity field and the wall surface slip velocity distribution; Step 32: Perform singular value decomposition on the combined snapshot matrix of flow field and slip, and truncate the first r POD dominant modes whose energy ratio is >99% The POD dominant mode bases are projected to the low-dimensional subspace to obtain the reduced-order flow field solution where a is the time-varying coefficient vector; Step 33: Reduced order flow field solution Real-time prediction of in-valve gas phase distribution ; is represented as: wherein x represents a spool displacement signal; represents the i-th POD dominant mode basis projected to the low-dimensional subspace; represents the time-varying coefficient vector corresponding to the i-th POD dominant mode basis.
7. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 1, wherein, Calculating transient fluid loads from gas phase distribution, viscous stress tensor and pressure field ; the specific process is: Step 41 : Calculate the modified velocity field v and gas phase distribution Step 42: Calculate the equivalent viscosity at each wall surface point Step 43: Calculate the modified velocity field v and gas phase distribution Step 44: Calculate the equivalent viscosity at each wall surface point Step 42: Calculate viscous stress tensor from equivalent viscosity ; Step 43: Calculate wall traction force from viscous stress tensor , denotes the normal pressure load of the pressure field, n denotes the wall normal; Step 44: Numerically integrate the wall drag force and project it to the structural nodes to obtain the transient fluid load at the node level , S represents the structural node.
8. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 1, wherein, The transient fluid loads The structural displacements u of the valve / wall are solved time step by time step by a domain decomposition iterative algorithm, as the driving source input to the structural dynamics equation, which is expressed as: ； wherein, represents a mass matrix of the valve body; represents an acceleration; represents a damping matrix; represents a velocity; represents a stiffness matrix.
9. The proportional valve control method based on high pressure multi- medium annular gap flow prediction of claim 8, wherein, Step 5 further comprises correcting the multiphase flow transient coupling method by using the structural displacement, and the specific process is as follows: Step 51: mapping the structural displacement to fluid-structure coupling boundary nodes to obtain a mapping result; Step 52: updating grid coordinates of a fluid boundary grid in real time by using an elastomer deformation algorithm according to the mapping result; Step 53: performing quality evaluation on the updated grid coordinates, performing local smoothing / reconstruction according to the quality evaluation result and updating a wall surface geometric boundary; Step 54: calculating a transient through-flow area and a pressure drop gradient according to the updated wall surface geometric boundary and feeding back to the multiphase flow transient coupling equation for correction.