A numerical calculation method and system for variable periodic surface in computational domain of adjustable turbine blades

Abstract

The present invention relates to the technical field of numerical analysis of hot-end components of gas turbines, and in particular to a variable periodic surface numerical calculation method for the computational domain of adjustable turbine blades. The method establishes a computational domain grid, calculates the circumferential motion of the blade trailing edge within the current time step, changes the grid node positions on the computational domain periodic surface, obtains the updated computational domain grid, performs unsteady numerical iterative calculations for the current time step, and integrates the unsteady calculation results at each time step to obtain the aero-thermal characteristics of the turbine blade during the dynamic adjustment process. The method adaptively shifts the computational domain grid as the blade moves, achieving reasonable displacement avoidance of the periodic surface for the blade. The method has strong adaptability and compatibility, and is applicable to numerical analysis of changes in the motion and motion patterns of adjustable blades. The method addresses the problem that existing numerical analysis methods cannot obtain the aero-thermal characteristics of the dynamic process of adjustable blades with variable installation angles under real conditions.

Description

Technical Field

[0001] The present invention relates to a field, specifically a method, system, device and storage medium for the numerical calculation of variable periodic surfaces in the calculation domain of adjustable turbine blades, and more particularly a method for real-time transformation of the circumferential position of the periodic surface grid according to the trailing edge displacement of the adjustable blade to be suitable for the numerical calculation of turbine blades. Background Art

[0002] Turbine blades are a key component of the hot-end of aircraft engines and heavy-duty gas turbines. Numerical methods are often used to analyze and calculate the aero-thermal characteristics of turbine blades. Currently, some advanced aircraft engines being developed adjust the installation angle of turbine blades to achieve complex control of gas flow and thrust at varying altitudes and speeds. Therefore, analyzing the aero-thermal characteristics of turbine blades during this dynamic process is crucial.

[0003] Previous numerical analyses have used a virtual periodic surface between the cascade channels to demarcate the computational domain of one or more turbine blades from the entire turbine blade cycle. This approach then performs meshing and numerical analysis separately, significantly reducing computational effort. However, this approach struggles with the dynamic process of turbine blades undergoing variable setting angles. During this dynamic process, the trailing edge of the blade, as it rotates about the actuating axis, can penetrate the periodic surface established during preprocessing, resulting in negative volume meshing and computational failure. Because the two extreme positions of the adjustable blade at its maximum and minimum setting angles overlap within the computational domain, even with adjustments to the shape of the periodic surface dividing the cascade channels during preprocessing, it is impossible to achieve a dynamic, unsteady blade adjustment without interference with the periodic surface. Consequently, numerical analysis of the aero-thermal characteristics of the variable setting angle requires either full-cycle calculations or separate modeling and discrete calculations for each blade setting angle. The former is difficult to implement under current computing hardware conditions and consumes a lot of computing resources. The latter not only requires a huge pre-processing workload but can only obtain static results at each installation angle, and cannot reflect the dynamic aero-thermal characteristics of turbine blades under real conditions.

[0004] Therefore, there is an urgent need for a numerical calculation method that can handle the dynamic process of variable installation angle of adjustable turbine blades. Summary of the Invention

[0005] In response to the problem that the numerical analysis methods in the existing technology cannot obtain the aero-thermal characteristics of the dynamic process of the variable installation angle of the adjustable blade under real conditions, the present invention provides a numerical calculation method, system, equipment and storage medium for the variable periodic surface in the calculation domain of the adjustable turbine blade.

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

[0007] The present invention provides a method for numerically calculating a variable period surface for a calculation domain of an adjustable turbine blade, which is characterized by comprising the following steps:

[0008] S1: Obtain the calculation domain, blade motion law and basic geometric characteristic dimensions of the turbine blade, establish the calculation domain grid, and set the total calculation time and time step according to requirements; the calculation domain includes the middle section around the blade, the blade leading edge extension section and the blade trailing edge extension section; the basic geometric characteristic dimensions of the blade include the distance between the blade rotation axis and the trailing edge point of the blade mid-span, the initial angle between the blade chord line and the forehead line at the rated power of the turbine, namely the blade installation angle, the axial coordinate value of the node at the intersection of the blade leading edge extension section and the fluid domain around the middle section of the blade, and the axial coordinate value of the node at the intersection of the blade trailing edge extension section and the fluid domain around the middle section of the blade; the blade motion law is a designed motion function rotating around the actuating axis or a discrete time and angle correspondence table;

[0009] S2: Calculate the circumferential motion of the blade trailing edge in the current time step based on the computational domain grid, blade motion law, and basic geometric characteristic dimensions of the blade;

[0010] S3: Change the grid node positions on the periodic surface of the computational domain according to the circumferential motion of the blade trailing edge;

[0011] S4: According to the changed grid node positions on the periodic surface of the computational domain, the volume unit nodes in the fluid domain are adjusted to obtain an updated computational domain grid;

[0012] S5: Perform unsteady numerical iterative calculations for the current time step based on the updated computational domain grid until convergence;

[0013] S6: Determine whether the current time step is the set total calculation time; if yes, end the calculation and execute S7; if not, return to S2 and start calculating the circumferential motion of the blade trailing edge in the next time step;

[0014] S7: The unsteady calculation results at each time step are integrated to obtain the aero-thermal characteristics of the turbine blades during the dynamic adjustment process.

[0015] Furthermore, the specific operations of S2 are:

[0016] According to the blade motion law, obtain the angle of rotation of the blade along the actuation axis at the current time step;

[0017] Calculate the distance the trailing edge of the blade moves based on the angle the blade rotates along the actuation axis at the current time step;

[0018] According to the distance the blade trailing edge moves, the circumferential motion of the blade trailing edge in the current time step is calculated.

[0019] Furthermore, based on the angle of rotation of the blade along the actuation axis at the current time step, the method for calculating the distance moved by the trailing edge of the blade is:

[0020] Δl=l c Δβ (1)

[0021] Among them, l c is the distance between the blade rotation axis and the trailing edge point in the middle of the blade span; Δβ is the angle of rotation of the blade along the actuation axis at the current time step; Δl is the distance moved by the trailing edge of the blade.

[0022] Furthermore, based on the distance the blade trailing edge moves, the method for calculating the circumferential motion of the blade trailing edge in the current time step is:

[0023] Δd=Δlcosα (2)

[0024] Among them, α is the initial angle between the blade chord line and the front line at the current moment, that is, the blade installation angle, and Δd is the circumferential motion of the blade trailing edge in the current time step.

[0025] Furthermore, the specific operations of S3 are:

[0026] Get the coordinates (r, θ, z) of each node on the periodic surface of the current time step;

[0027] According to the coordinates (r, θ, z) of each node on the periodic surface of the current time step, the positions of the grid nodes on the periodic surface of the computational domain in the middle section around the blade are changed;

[0028] According to the coordinates of each node on the periodic surface of the current time step (r, θ, z), the position of the grid node on the periodic surface of the calculation domain of the extended section of the blade trailing edge is changed.

[0029] Furthermore, the method for changing the positions of the mesh nodes on the periodic surface of the computational domain in the middle section around the blade is as follows:

[0030] Set the coordinates of the grid nodes on the periodic surface of the computational domain in the middle section around the blade after the change of position to (r', θ', z'), so that r' = r, z' = z;

[0031] According to the circumferential motion of the trailing edge of the blade in the current time step and the coordinates (r, θ, z) of each node on the periodic surface of the current time step, the circumferential displacement is calculated. That is, according to the axial and radial coordinate values ​​of each node on the periodic surface of the current time step, the circumferential displacement, i.e., the avoidance distance, is calculated. Specifically, it is:

[0032]

[0033] According to the coordinates of each node (r, θ, z) on the periodic surface of the current time step and the avoidance distance, θ' is calculated to obtain the position coordinates of the grid nodes on the periodic surface of the computational domain in the middle section around the blade after the change, specifically:

[0034] θ'=θ+Δδ (4)

[0035] Among them, Δδ is the circumferential displacement, Δd is the circumferential motion of the trailing edge of the blade in the current time step, z1 is the axial coordinate value of the node at the junction of the extended section of the leading edge of the blade and the fluid domain in the middle part around the blade, and z2 is the axial coordinate value of the node at the junction of the extended section of the trailing edge of the blade and the fluid domain in the middle part around the blade.

[0036] Furthermore, the method for changing the position of the grid nodes on the periodic surface of the computational domain of the blade trailing edge extension section is as follows:

[0037] Set the grid node coordinates on the periodic surface of the calculation domain of the blade trailing edge extension after the change of position to (r", θ", z"), so that r" = r, z" = z;

[0038] According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step (r, θ, z), θ' is calculated to obtain the position of the grid nodes on the periodic surface of the calculation domain of the extended section of the blade trailing edge after the change, specifically:

[0039]

[0040] A numerical calculation system for variable periodic surfaces in the computational domain of adjustable turbine blades, comprising:

[0041] Data acquisition and computational domain mesh establishment module: used to obtain the computational domain, blade motion law, and basic geometric characteristic dimensions of the turbine blade, establish the computational domain mesh, and set the total computation time and time step according to requirements;

[0042] Circumferential motion calculation module: used to calculate the circumferential motion of the blade trailing edge in the current time step based on the computational domain grid, blade motion law and basic geometric characteristic dimensions of the blade;

[0043] Grid node position change module: used to change the grid node position on the periodic surface of the calculation domain according to the circumferential motion of the blade trailing edge;

[0044] Computational domain grid update module: used to adjust the volume unit nodes in the fluid domain according to the changed grid node positions on the computational domain periodic surface to obtain the updated computational domain grid;

[0045] Unsteady numerical iterative calculation module: used to perform unsteady numerical iterative calculation of the current time step according to the updated computational domain grid until convergence;

[0046] Time step determination module: determines whether the current time step is the set total calculation time; if yes, the calculation ends and S7 is executed; if not, the module returns to S2 and starts calculating the circumferential motion of the blade trailing edge in the next time step;

[0047] Turbine blade aero-thermal characteristics acquisition module: used to integrate the unsteady calculation results at each time step to obtain the aero-thermal characteristics of the turbine blade during the dynamic adjustment process.

[0048] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0049] A computer-readable storage medium stores a computer program, wherein the computer program implements the steps of the above method when executed by a processor.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The present invention provides a variable periodic surface numerical calculation method for the calculation domain of an adjustable turbine blade. The method obtains the calculation domain of the turbine blade, the blade motion law and the basic geometric characteristic size of the blade, establishes a calculation domain grid, calculates the circumferential motion of the blade trailing edge in the current time step, changes the grid node position on the calculation domain periodic surface according to the circumferential motion of the blade trailing edge, adjusts the volume unit node in the fluid domain, obtains an updated calculation domain grid, performs unsteady numerical iterative calculation of the current time step until convergence, and finally determines whether the current time step is the set total calculation time length; if so, terminates the calculation, and integrates the unsteady calculation results under each time step to obtain a dynamic adjustment process. The aero-thermal characteristics of the turbine blade under the process are analyzed; if not, the calculation of the circumferential motion of the blade trailing edge in the next time step begins. This method achieves reasonable displacement avoidance of the periodic surface grid by making the displacement in the computational domain grid adaptively change with the circumferential motion of the blade trailing edge, avoiding the problem of geometric interference and computational collapse caused by the subsequent blade motion. The calculated values ​​are adapted to the dynamic analysis of the variable installation angle and motion law, realizing the numerical analysis of the turbine blade under dynamic conditions, thereby reflecting the aero-thermal characteristics of the dynamic process of the adjustable blade with variable installation angle under real conditions. This method has strong adaptability and compatibility and is suitable for numerical analysis of changes in the motion and motion law of the adjustable blade. At the same time, this method uses cylindrical coordinates for calculation. The periodic surface grid node only changes one variable and there is no judgment and iteration process. The computational complexity is small and the computational efficiency is high, which can meet the numerical analysis calculation requirements under current hardware conditions.

[0052] A numerical calculation system for variable periodic surfaces in the calculation domain of adjustable turbine blades. The system implements the above-mentioned numerical calculation method for variable periodic surfaces in the calculation domain of adjustable turbine blades through the settings of a data acquisition and calculation domain grid establishment module, a circumferential motion calculation module, a grid node position change module, a calculation domain grid update module, a non-steady numerical iterative calculation module, a time judgment module and a turbine blade aero-thermal characteristics acquisition module. The system has a simple structure and low requirements on hardware conditions.

[0053] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0054] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of a numerical calculation method of a variable periodic surface for the calculation domain of an adjustable turbine blade according to the present invention.

[0056] Figure 2 This is a structural diagram of a variable periodic surface numerical calculation system for the calculation domain of adjustable turbine blades according to the present invention.

[0057] Figure 3 Schematic diagram of a circumferential cross section of a variable period calculation method applied to a fluid domain with adjustable blade variable cascades in an embodiment of the present invention.

[0058] Figure 4 3D schematic diagram of the fluid domain applied to the adjustable blade variable cascade in an embodiment of the present invention.

[0059] Among them, 1-the extended part of the leading edge of the blade, 2-the middle part around the blade, 3-the extended part of the trailing edge of the blade, 4-the rotation axis of the blade, 5-the rotation angle of the blade at each time step, 6-the leading edge point of the blade, 7-the trailing edge point of the blade, 8-the installation angle of the blade, 9-the periodic surface of the computational domain of the middle part around the blade after the position change, 10-the periodic surface after the blade rotates in one time step, 11-the interface between the extended part of the leading edge of the blade and the fluid domain of the middle part around the blade, 12-the interface between the extended part of the trailing edge of the blade and the fluid domain of the middle part around the blade. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0061] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0062] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0063] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0064] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0065] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0066] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0067] The present invention discloses a numerical calculation method for variable periodic surface in the calculation domain of adjustable turbine blades. Figure 1 , including the following steps:

[0068] S1: Obtain the calculation domain, blade motion law and basic geometric characteristic dimensions of the turbine blade, establish the calculation domain grid, and set the total calculation time and time step according to the requirements; Figure 2 Taking the circumferential cross-sectional diagram of the variable period calculation method of the variable cascade fluid domain of the adjustable blade as an example, the calculation domain includes the middle section 2 around the blade, the blade leading edge extension section 1 and the blade trailing edge extension section 3; the basic geometric characteristic dimensions of the blade include the distance between the blade rotation axis 4 and the trailing edge point 7 of the blade mid-span, the initial angle between the blade chord line and the forehead line at the rated power of the turbine, namely the blade installation angle 8, the axial coordinate value of the node at the interface 11 between the blade leading edge extension section 1 and the fluid domain around the middle section of the blade, and the axial coordinate value of the node at the interface 12 between the blade trailing edge extension section and the fluid domain around the middle section of the blade; the blade motion law is a designed motion function rotating around the actuating axis or a discrete time and angle correspondence table; the calculation domain grid is imported into the numerical solver, the boundary conditions are set, and the calculation domain is initialized.

[0069] S2: Calculate the circumferential motion of the blade trailing edge in the current time step based on the computational domain grid, blade motion law, and basic blade geometric characteristic dimensions. Specifically:

[0070] S2.1: According to the blade motion law, obtain the angle of rotation of the blade along the actuation axis at the current time step. That is, according to the designed blade motion law and the current time and time step in the blade motion law, obtain the angle 5 of rotation of the blade along the actuation axis at the current time step. Specifically,

[0071] Δβ=f'(t)·Δt (1)

[0072] Where f'(t) is the blade rotation angular velocity, t is the time of blade motion, Δt is the time step, and f'(t) is the derivative of the blade rotation displacement function f(t) with respect to time t.

[0073] S2.2: Calculate the distance the trailing edge of the blade moves based on the angle the blade rotates along the actuation axis at the current time step, i.e.:

[0074] Δl=l c Δβ (2)

[0075] Among them, l c is the distance between the blade rotation axis and the trailing edge point in the middle of the blade span; Δβ is the angle of rotation of the blade along the actuation axis at the current time step; Δl is the distance moved by the trailing edge of the blade.

[0076] S2.3: Calculate the circumferential motion of the blade trailing edge in the current time step based on the distance the blade trailing edge moves, that is:

[0077] Δd=Δlcosα (3)

[0078] Among them, α is the initial angle between the blade chord line and the front line, that is, the blade installation angle 8, and Δd is the circumferential motion of the blade trailing edge in the current time step, that is, the projection distance of the blade trailing edge movement in the circumferential direction in the cylindrical coordinate system of the cascade. The circumferential motion of the blade trailing edge Δd obtained in this step is also the maximum displacement that the periodic surface should avoid in this method.

[0079] S3: According to the circumferential motion of the blade trailing edge, the grid node positions on the periodic surface of the computational domain are changed as follows:

[0080] Since the positions and distances of the calculation domain of the middle section 2 around the blade and the calculation domain of the blade trailing edge extension section 3 relative to the blade are different, the avoidance methods of the periodic surface are also different. Therefore, all nodes on the periodic surface of the calculation domain of the middle section 2 around the blade and the calculation domain of the blade trailing edge extension section 3 are changed in different ways respectively;

[0081] S3.1: Get the coordinates (r, θ, z) of each node on the periodic surface at the current time step;

[0082] S3.2: According to the coordinates (r, θ, z) of each node on the periodic surface of the current time step, change the position of the grid nodes on the periodic surface of the computational domain in the middle section around the blade, that is:

[0083] The coordinates of the mesh nodes on the computational domain periodic surface 9 of the middle section around the blade after the change are set to (r', θ', z'). Since the turbine's meridian flow path is constant, the radial coordinate r and axial coordinate z of the nodes on the periodic surface remain unchanged after the blade rotates. Only the circumferential position changes, so r' = r and z' = z.

[0084] According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step (r, θ, z), the circumferential displacement is calculated as follows:

[0085]

[0086] According to the coordinates of each node (r, θ, z) on the periodic surface of the current time step and the avoidance distance, θ' is calculated to obtain the position coordinates of the grid nodes on the periodic surface of the computational domain of the middle section 2 around the blade after the change, specifically:

[0087] θ'=θ+Δδ (5)

[0088] Among them, Δδ is the circumferential displacement, Δd is the circumferential motion of the trailing edge of the blade in the current time step, z1 is the axial coordinate value of the node at the junction of the extended section of the leading edge of the blade and the fluid domain in the middle part around the blade, and z2 is the axial coordinate value of the node at the junction of the extended section of the trailing edge of the blade and the fluid domain in the middle part around the blade.

[0089] S3.3: Change the positions of the grid nodes on the periodic surface of the calculation domain of the blade trailing edge extension section 3 according to the coordinates (r, θ, z) of each node on the periodic surface of the current time step.

[0090] The grid node coordinates on the periodic surface of the blade trailing edge extension section 3 calculation domain are set to (r", θ", z"). Since the blade trailing edge extension section 3 calculation domain does not interfere with the blade, a rotation around the z axis is performed on the entire surface. After the rotation, the radial coordinate value r and the axial coordinate value z of the node on the periodic surface remain unchanged before and after the change, so r" = r, z" = z;

[0091] According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step (r, θ, z), θ' is calculated to obtain the position of the grid node on the periodic surface of the calculation domain of the blade trailing edge extension part 3 after the change. The periodic surface of the calculation domain of the blade trailing edge extension part 3 needs to be kept at the interface 12 between the blade trailing edge extension part and the fluid domain of the middle section around the blade and the calculation domain of the middle section 2 around the blade, that is, the circumferential displacement of the node on the periodic surface of the blade trailing edge extension part 3 is consistent with the circumferential displacement value of the node at the interface 12 between the blade trailing edge extension part and the fluid domain of the middle section around the blade. Therefore, the specific method of calculating θ' is:

[0092]

[0093] See also Figure 3 , we get the changed periodic surface of the computational domain, that is, the periodic surface 10 after the blade rotates in one time step.

[0094] S4: According to the changed grid node positions on the periodic surface of the computational domain, the volume unit nodes in the fluid domain are adjusted to obtain the updated computational domain grid. Specifically:

[0095] After the mesh nodes on the periodic surface of the computational domain are displaced, the spring and diffusion methods in the dynamic mesh of the solver are used to automatically smooth, adjust or update the volume element nodes in the computational domain to obtain the updated computational domain mesh.

[0096] S5: Based on the updated computational domain grid, perform unsteady numerical iterative calculations for the current time step until convergence;

[0097] S6: Determine whether the current time step is the set total calculation time; if yes, end the calculation and execute S7; if not, return to S2 and start calculating the circumferential motion of the blade trailing edge in the next time step;

[0098] S7: The unsteady calculation results at each time step are integrated to obtain the aero-thermal characteristics of the turbine blades during the dynamic adjustment process.

[0099] See also Figure 4 The present invention provides a variable period surface numerical calculation system for the calculation domain of adjustable turbine blades, comprising:

[0100] Data acquisition and computational domain mesh establishment module: used to obtain the computational domain, blade motion law, and basic geometric characteristic dimensions of the turbine blade, establish the computational domain mesh, and set the total computation time and time step according to requirements;

[0101] Circumferential motion calculation module: used to calculate the circumferential motion of the blade trailing edge in the current time step based on the computational domain grid, blade motion law and basic geometric characteristic dimensions of the blade;

[0102] Grid node position change module: used to change the grid node position on the periodic surface of the calculation domain according to the circumferential motion of the blade trailing edge;

[0103] Computational domain grid update module: used to adjust the volume unit nodes in the fluid domain according to the changed grid node positions on the computational domain periodic surface to obtain the updated computational domain grid;

[0104] Unsteady numerical iterative calculation module: used to perform unsteady numerical iterative calculation of the current time step according to the updated computational domain grid until convergence;

[0105] Time step determination module: determines whether the current time step is the set total calculation time; if yes, ends the calculation and executes S7; if not, returns to S2 and starts calculating the circumferential motion of the blade trailing edge in the next time step;

[0106] Turbine blade aero-thermal characteristics acquisition module: used to integrate the unsteady calculation results at each time step to obtain the aero-thermal characteristics of the turbine blade during the dynamic adjustment process.

[0107] The present invention provides a terminal device comprising: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of each of the aforementioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of each module / unit in each of the aforementioned apparatus embodiments are implemented.

[0108] The computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to accomplish the present invention.

[0109] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0110] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0111] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.

[0112] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0113] The above description is merely a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and replacements, and these modifications and replacements are also within the scope of protection covered by the claims.

Claims

1. A numerical calculation method for variable periodic surfaces in the calculation domain of adjustable turbine blades, characterized in that: The following steps are involved: S1: Obtain the calculation domain, blade motion law and basic geometric characteristic dimensions of the turbine blade, establish the calculation domain grid, and set the total calculation time and time step according to requirements; the calculation domain includes the middle section around the blade, the blade leading edge extension section and the blade trailing edge extension section; the basic geometric characteristic dimensions of the blade include the distance between the blade rotation axis and the trailing edge point of the blade mid-span, the initial angle between the blade chord line and the forehead line at the rated power of the turbine, namely the blade installation angle, the axial coordinate value of the node at the intersection of the blade leading edge extension section and the fluid domain around the middle section of the blade, and the axial coordinate value of the node at the intersection of the blade trailing edge extension section and the fluid domain around the middle section of the blade; the blade motion law is a designed motion function rotating around the actuating axis or a discrete time and angle correspondence table; S2: Calculate the circumferential motion of the blade trailing edge in the current time step based on the computational domain grid, blade motion law, and basic geometric characteristic dimensions of the blade; S3: According to the circumferential motion of the blade trailing edge, the grid node positions on the periodic surface of the computational domain are changed. Specifically: S3.1: Get the coordinates of each node on the periodic surface at the current time step ; S3.2: According to the coordinates of each node on the periodic surface of the current time step , change the position of the grid nodes on the periodic surface of the computational domain in the middle section around the blade, that is: The coordinates of the grid nodes on the periodic surface of the computational domain in the middle section around the blade after the position change are set to Since the meridional flow channel of the turbine is constant, the radial coordinate value of the node on the periodic surface after the blade rotates is and axial coordinate values It remains unchanged before and after the change, and only the circumferential position changes, so , ; According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step , calculate the displacement in the circumferential direction, specifically: According to the coordinates of each node on the periodic surface of the current time step and avoidance distance, calculate , the position coordinates of the grid nodes on the periodic surface of the computational domain in the middle section around the blade after the change are obtained, specifically: in, is the displacement in the circumferential direction, is the circumferential motion of the blade trailing edge in the current time step, is the axial coordinate value of the node at the junction of the extended section of the leading edge of the blade and the fluid domain in the middle part around the blade, is the axial coordinate value of the node at the junction of the extended section of the blade trailing edge and the fluid domain in the middle section around the blade; S3.3: According to the coordinates of each node on the periodic surface of the current time step , change the position of the mesh nodes on the periodic surface of the computational domain of the blade trailing edge extension section: The grid node coordinates on the periodic surface of the calculation domain of the blade trailing edge extension section after the change are set to Since the calculation domain of the blade trailing edge extension section has no interference with the blade, a rotation around the z axis is performed on the blade as a whole. After the rotation, the radial coordinate values ​​of the nodes on the periodic surface are and axial coordinate values remains unchanged before and after the change, so , ; According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step ,calculate , get the position of the grid nodes on the periodic surface of the calculation domain of the blade trailing edge extension section after the change, calculate The specific method is: S4: According to the changed grid node positions on the periodic surface of the computational domain, the volume unit nodes in the fluid domain are adjusted to obtain an updated computational domain grid; S5: Based on the updated computational domain grid, perform unsteady numerical iterative calculations for the current time step until convergence; S6: Determine whether the current time step is the set total calculation time; if yes, end the calculation and execute S7; if not, return to S2 and start calculating the circumferential motion of the blade trailing edge in the next time step; S7: The unsteady calculation results at each time step are integrated to obtain the aero-thermal characteristics of the turbine blades during the dynamic adjustment process.

2. The method for numerical calculation of variable periodic surface for the calculation domain of adjustable turbine blades according to claim 1 is characterized in that: The specific operations of S2 are: According to the blade motion law, obtain the angle of rotation of the blade along the actuation axis at the current time step; Calculate the distance the trailing edge of the blade moves based on the angle the blade rotates along the actuation axis at the current time step; According to the distance the blade trailing edge moves, the circumferential motion of the blade trailing edge in the current time step is calculated.

3. The numerical calculation method of variable period surface for the calculation domain of adjustable turbine blades according to claim 2 is characterized in that: The method for calculating the distance moved by the trailing edge of the blade is as follows: in, is the distance between the blade rotation axis and the trailing edge point of the blade mid-span; is the angle of rotation of the blade along the actuation axis at the current time step; is the distance the trailing edge of the blade moves.

4. The method for numerical calculation of variable periodic surface for the calculation domain of adjustable turbine blades according to claim 2, characterized in that: According to the distance the blade trailing edge moves, the method for calculating the circumferential motion of the blade trailing edge in the current time step is: in, is the initial angle between the blade chord line and the front line at the current moment, i.e. the blade installation angle, is the circumferential motion of the trailing edge of the blade in the current time step.

5. The variable period surface numerical calculation system for the calculation domain of adjustable turbine blades is characterized by: include: Data acquisition and computational domain mesh establishment module: used to obtain the computational domain, blade motion law and basic geometric characteristic dimensions of the turbine blade, establish the computational domain mesh, and set the total computation time and time step as required; the computational domain includes the middle section around the blade, the blade leading edge extension section and the blade trailing edge extension section; the blade basic geometric characteristic dimensions include the distance between the blade rotation axis and the trailing edge point of the blade mid-span, the initial angle between the blade chord line and the forehead line at the rated power of the turbine, i.e., the blade installation angle, the axial coordinate value of the node at the intersection of the blade leading edge extension section and the fluid domain around the middle section of the blade, and the axial coordinate value of the node at the intersection of the blade trailing edge extension section and the fluid domain around the middle section of the blade; the blade motion law is a designed motion function rotating around the actuating axis or a discrete time and angle correspondence table; Circumferential motion calculation module: used to calculate the circumferential motion of the blade trailing edge in the current time step based on the computational domain grid, blade motion law and basic geometric characteristic dimensions of the blade; Grid node position change module: used to change the grid node positions on the periodic surface of the computational domain according to the circumferential motion of the blade trailing edge. Specifically: S3.1: Get the coordinates of each node on the periodic surface at the current time step ; S3.2: According to the coordinates of each node on the periodic surface of the current time step , change the position of the grid nodes on the periodic surface of the computational domain in the middle section around the blade, that is: The coordinates of the grid nodes on the periodic surface of the computational domain in the middle section around the blade after the position change are set to Since the meridional flow channel of the turbine is constant, the radial coordinate value of the node on the periodic surface after the blade rotates is and axial coordinate values It remains unchanged before and after the change, and only the circumferential position changes, so , ; According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step , calculate the displacement in the circumferential direction, specifically: According to the coordinates of each node on the periodic surface of the current time step and avoidance distance, calculate , the position coordinates of the grid nodes on the periodic surface of the computational domain in the middle section around the blade after the change are obtained, specifically: in, is the displacement in the circumferential direction, is the circumferential motion of the blade trailing edge in the current time step, is the axial coordinate value of the node at the junction of the extended section of the leading edge of the blade and the fluid domain in the middle part around the blade, is the axial coordinate value of the node at the junction of the extended section of the blade trailing edge and the fluid domain in the middle section around the blade; S3.3: According to the coordinates of each node on the periodic surface of the current time step , change the position of the grid nodes on the periodic surface of the calculation domain of the blade trailing edge extension section; The grid node coordinates on the periodic surface of the calculation domain of the blade trailing edge extension section after the change are set to Since the calculation domain of the blade trailing edge extension section has no interference with the blade, a rotation around the z axis is performed on the blade as a whole. After the rotation, the radial coordinate values ​​of the nodes on the periodic surface are and axial coordinate values remains unchanged before and after the change, so , ; According to the circumferential motion of the blade trailing edge in the current time step and the coordinates of each node on the periodic surface of the current time step ,calculate , get the position of the grid nodes on the periodic surface of the calculation domain of the blade trailing edge extension section after the change, calculate The specific method is: Computational domain grid update module: used to adjust the volume unit nodes in the fluid domain according to the changed grid node positions on the computational domain periodic surface to obtain the updated computational domain grid; Unsteady numerical iterative calculation module: used to perform unsteady numerical iterative calculation of the current time step according to the updated computational domain grid until convergence; Time step determination module: determines whether the current time step is the set total calculation time; if yes, the calculation ends and S7 is executed; if not, the module returns to S2 and starts calculating the circumferential motion of the blade trailing edge in the next time step; Turbine blade aero-thermal characteristics acquisition module: used to integrate the unsteady calculation results at each time step to obtain the aero-thermal characteristics of the turbine blade during the dynamic adjustment process.

6. A terminal device comprising 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 method according to any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

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