Method and device for simulating multi-physical processes of bird impact on an aeroengine blade

Abstract

The application provides a kind of bird impact simulation calculation method and device for the multi-physical process of bird impact on aero-engine blade in the field of aviation, reads the initial parameters of the geometric model of bird and engine blade, respectively assigns the initial parameters to SPH particle and the finite element of engine blade;Search the particle adjacent to the SPH particle;Based on the search results, the update parameters of the SPH particle and the finite element are calculated respectively;Determine whether the finite element is converted into SPH particle;If not, the unconverted finite element updates the finite element parameters according to the update parameters of the finite element;If yes, the converted finite element calculates the update parameters of the SPH particle using the SPH update parameter calculation method, and updates the SPH particle parameters;According to the updated SPH particle parameters and the updated finite element parameters, the bird body breaking, engine blade deformation and equivalent stress change diagram can be visualized and displayed.The application realizes the multi-physical process of real-time reproduction of broken bird body and blade damage fragments and their secondary impact on the blade structure.

Description

Technical Field

[0001] This invention belongs to the aerospace field, specifically relating to a method and apparatus for simulating and calculating the multi-physical process of bird impact on aero-engine blades. Background Technology

[0002] Bird strikes on aircraft engine fan blades pose a serious threat to the operational safety of aircraft engines. Statistics show that engine fan blades are among the most frequently struck parts of an aircraft during flight. The impact force of a bird can cause significant deformation or even tearing of the engine blades, and the remains of the bird, after being shredded by the blades, can clog engine pipes. Therefore, after an aircraft engine is struck by a bird, it often experiences surge, fire, or even stalls. Clearly, bird strikes on aircraft engine blades are extremely dangerous, and researching bird strikes on fan blades is of significant scientific importance for developing theories on the safety and strength design of fan blades.

[0003] Currently, research on bird impacts on aero-engine blades generally falls into two main categories: experimental and numerical simulation. Experimental methods are limited by experimental equipment and are costly. Numerical simulations primarily rely on mesh-based Euler methods, finite element method (FEM) methods, and hybrid methods such as the Arbitrary Lagrange-Euler (ALE) method. However, these methods all have certain limitations when simulating the multi-physics processes of bird impacts on aero-engine blades, failing to fully reproduce these processes. For example, the FEM method fixes the mesh to the material, making it constrained by the mesh and prone to distortions such as mesh warping when simulating large deformations. The Euler method struggles to handle interface problems such as free surfaces and deformable interfaces, and cannot accurately track debris motion. The ALE method requires re-meshing at the beginning of each time step, resulting in low computational efficiency.

[0004] Therefore, a technology is needed to further address the aforementioned problems. Summary of the Invention

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method and apparatus for simulating the multi-physics process of bird impacts on aero-engine blades, thereby resolving the issues raised in the prior art.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] One embodiment of the present invention provides a multi-physics simulation calculation method for bird impact on aero-engine blades, the method comprising:

[0008] Step 1: Establish a three-dimensional geometric model of the bird and engine blades, mesh the bird and engine blades, and obtain the finite element of the engine blades and a smooth particle hydrodynamic (SPH) particle corresponding to each bird mesh.

[0009] Step 2: Read the initial parameters and assign them to the finite element methods of the SPH particles and engine blades respectively;

[0010] Step 3: Calculate the SPH and the time step of the finite element method respectively, and take the smaller value as the common step size for this round of calculation;

[0011] Step 4: Use a linked list search method to search for neighboring particles of the SPH particle;

[0012] Step 5: Calculate the update parameters of the SPH particles and the update parameters of the finite element based on the search results;

[0013] Step 6: Determine whether the finite element has been converted into SPH particles. If not, update the finite element parameters according to the update parameters of the finite element. If yes, calculate the update parameters of the SPH particles using the SPH update parameter calculation method and update the SPH particle parameters.

[0014] The total computation time is updated using the common step size calculated in this round. If the updated total computation time does not reach the preset time, steps 3 to 6 above are executed repeatedly.

[0015] Step 7: After the above iterative calculations are completed, visualize the bird body breakage, engine blade deformation, and equivalent stress changes based on the updated SPH particle parameters and the updated finite element parameters.

[0016] Optionally, the initial parameters include:

[0017] Bird body parameters and engine blade material parameters.

[0018] Optionally, the step of calculating the updated parameters of the SPH particles based on the search results includes:

[0019] If background particles are found, the contact force of the found background particles is calculated, and the contact force is added as an external force to the calculation of the SPH momentum equation.

[0020] Optionally, the updated parameters of the SPH particle include at least: mass, velocity, position, and energy.

[0021] Optionally, the step of calculating the updated parameters of the finite element includes:

[0022] If background particles are found, obtain the reverse contact force of the same magnitude exerted by the background particles on the SPH particles, and add the reverse contact force as an external force to the calculation of solving the finite element dynamic equations.

[0023] Optionally, the updated parameters of the finite element method include at least: velocity, stress, and displacement.

[0024] Optionally, the step of determining whether the finite element method has been converted into SPH particles includes:

[0025] Determine whether the damage factor of the finite element is equal to 1;

[0026] If the damage factor is equal to 1, the finite element is confirmed to be in failure. If the failed finite element is not connected to any unfailed finite element, the failed finite element is confirmed to be transformed into an SPH particle.

[0027] Another embodiment of the present invention provides a multi-physics simulation calculation device for bird impact on aero-engine blades, the device comprising:

[0028] The model building unit is used to build a three-dimensional geometric model of the bird and the engine blade, to mesh the bird and the engine blade, and to obtain the finite element of the engine blade and a smooth particle hydrodynamic (SPH) particle corresponding to each bird mesh.

[0029] The parameter reading unit is used to read the initial parameters and assign them to the finite element method of the SPH particles and the engine blades respectively;

[0030] The time step calculation unit is used to calculate the time step of SPH and finite element separately, and take the smaller value as the common step of this round of calculation.

[0031] The search unit is used to search for particles near the SPH particle using a linked list search method.

[0032] The parameter calculation unit updates the parameters of the SPH particles and the parameters of the finite element based on the search results.

[0033] The conversion judgment and parameter update unit is used to determine whether the finite element has been converted into SPH particles. If not, the finite element parameters of the unconverted finite element are updated according to the update parameters of the finite element. If so, the updated parameters of the SPH particles of the converted finite element are calculated using the SPH update parameter calculation method, and the SPH particle parameters are updated.

[0034] The visualization unit is used to visualize the bird body breakage, engine blade deformation, and equivalent stress changes based on the updated SPH particle parameters and updated finite element parameters after the loop calculation is completed.

[0035] Another embodiment of the present invention provides an electronic device including a processor and a machine-readable storage medium storing machine-executable instructions that can be executed by the processor, the processor being prompted by the machine-executable instructions to perform the method described above.

[0036] In another embodiment of the present invention, a computer-readable storage medium is provided, wherein a computer program is stored therein, and the computer program, when executed by a processor, implements the method described above.

[0037] The embodiments of the present invention have the following beneficial effects:

[0038] This invention introduces a novel SPH-FEM coupled simulation technique, which not only includes a contact algorithm between the SPH and FEM methods, but also dynamically transforms the finite element model after complete damage failure into SPH particles for continued computation using a transformation algorithm. Contact algorithms are then used to calculate the interactions between the transformed particles and the untransformed finite element model, as well as between the transformed particles and free SPH particles. This allows for the calculation of not only the interaction between the bird and the blade, but also the interactions between the damaged fragments and the blade, and the interactions between the fragments and the bird, thus reproducing multi-physics processes. This provides a new approach to studying the multi-physics processes of bird impacts on aero-engine blades.

[0039] This invention not only overcomes the shortcomings of traditional experimental methods, eliminating the need for significant manpower, material resources, and financial investment, but also overcomes the deficiencies of traditional numerical simulation methods. It establishes a professional numerical simulation technology for solving the multi-physical processes of bird impacts on aero-engine blades. This technology can not only obtain the final results of blade structural deformation and damage, but also reproduce in real time the motion of broken bird bodies and damaged blade fragments and their secondary impact on the blade structure, thus addressing the multi-physical processes.

[0040] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a flowchart of a simulation calculation method for the multi-physics process of bird impact on an aero-engine blade according to an embodiment of this application.

[0043] Figure 2 This is a schematic diagram of a bird particle model according to an embodiment of this application.

[0044] Figure 3 This is a schematic diagram of a two-dimensional spatial linked list search method according to an embodiment of this application.

[0045] Figure 4 A time history diagram of a bird striking at 75% leaf height according to an embodiment of this application.

[0046] Figure 5 This is a graph showing the variation of Mises equivalent stress over time at different positions at 25% leaf height for a bird device according to an embodiment of this application.

[0047] Figure 6 This is a graph showing the variation of Mises equivalent stress over time at different positions at 50% leaf height for a bird device according to an embodiment of this application.

[0048] Figure 7 This is a graph showing the variation of Mises equivalent stress over time at different positions at 75% leaf height for a bird device according to an embodiment of this application.

[0049] Figure 8 This is a graph showing the equivalent stress at the leading edge impact point over time according to an embodiment of this application.

[0050] Figure 9 This is a schematic diagram of a simulation computing device for the multi-physics process of bird impact on an aero-engine blade according to an embodiment of this application.

[0051] Figure 10 This is a block diagram of a simulation computing device for the multiphysics process of bird impact on an aero-engine blade according to an embodiment of this application.

[0052] Figure 11 This is a schematic diagram of the structure of a server according to an embodiment of this application. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0054] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as merely or implying relative importance.

[0055] During their research, the inventors discovered that in actual bird strikes on aircraft engine blades, the impact area can shatter into fragments. These fragments, during their ejection, can cause significant damage to the engine's internal structure. Furthermore, the bird's bones and flesh will be damaged, forming debris that further harms the engine blades. Existing numerical simulation methods cannot accurately simulate this multi-physical process and require further improvement.

[0056] Therefore, this invention proposes a simulation calculation method for the multi-physics process of bird impact on aero-engine blades. On the one hand, it can not only simulate the small and large deformation processes of the blade during bird impact, but also calculate the motion of the fragments after the blade and bird body are damaged and their secondary impact on the structure, thus achieving a complete reproduction of the multi-physics process in bird impact on aero-engine blades. On the other hand, this invention adopts a coupled SPH and FEM algorithm. The SPH method simulates the bird body and the fragments generated by the damage, which can overcome the defects of the FEM method and improve the ability of the FEM method to solve practical engineering problems. By simulating small deformations using the FEM method, the low efficiency and accuracy of the single SPH method can be overcome, and the calculation efficiency is greatly improved.

[0057] This invention not only overcomes the shortcomings of traditional experimental methods, eliminating the need for significant manpower, material resources, and financial investment, but also overcomes the deficiencies of traditional numerical simulation methods. It establishes a professional numerical simulation technology for solving the multi-physical processes of bird impacts on aero-engine blades. This technology can not only obtain the final results of blade structural deformation and damage, but also reproduce in real time the motion of broken bird bodies and damaged blade fragments and their secondary impact on the blade structure, thus addressing the multi-physical processes.

[0058] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0059] like Figure 1 The diagram shows a flowchart of a multi-physics simulation calculation method for bird impact on aero-engine blades proposed in an embodiment of the present invention. The method includes the following steps:

[0060] Step 1: Establish a three-dimensional geometric model of the bird and engine blades, mesh the bird and engine blades, and obtain the finite element of the engine blades and a smooth particle hydrodynamic (SPH) particle corresponding to each bird mesh.

[0061] The geometric model can be established using existing technologies, such as Hypermesh software. After detailed and uniform mesh generation, the bird's mesh file is imported into the program and converted into SPH particles according to the principle of converting one mesh into one particle. The blades remain as meshes, and the specific process is as follows:

[0062] 1) First, use Hypermesh software to create a geometric model.

[0063] 2) Mesh the geometric model in Hypermesh.

[0064] 3) The bird body mesh file, generated after mesh generation, is converted into particles: Following the principle of one mesh corresponding to one particle, the volume of the hexahedral mesh is the volume of the SPH particle, and the centroid of the mesh is the centroid of the SPH particle, which is also the initial position of the SPH particle. This yields the particle model of the bird body. The volume of a single SPH particle determines its mass, and the centroid of the SPH particle directly determines the initial position of the material. The blades still use the mesh obtained from the mesh generation process; that is, the blade mesh is used to obtain the finite element method.

[0065] In this embodiment, the height of a single blade is 1.05m, and the hub radius is 0.65m. To reduce computational load without affecting the simulation results, three adjacent blades are selected as the research object. Mesh nodes are fixed at the bottom surface of the blade root, and the total number of element meshes for the three adjacent blades is 15316. The bird's geometric model is based on a real sparrow, with a length of 0.175m and a width of 0.22m. The bird's body mainly consists of two parts: flesh and bones. Figure 2 A bird particle model was presented, divided into bird flesh and blood and bird skeleton. The bird skeleton is further divided into three parts: a pair of symmetrical wing bones and a bird spine. SPH discretization was performed on the bird skeleton and bird flesh and blood, generating a total of 6024 SPH particles.

[0066] Step 2: Read the initial parameters and assign them to the finite element methods of the SPH particles and engine blades respectively;

[0067] In this embodiment, the initial parameters read include bird body parameters and blade material parameters. The bird body parameters include: for the fluid-like blood and flesh, the initial density is 900 kg / m³. For the solid skeleton, a Johnson-Cook constitutive model with a damage model is used, with a Young's modulus of 10 GPa, a Poisson's ratio of 0.3, a material parameter of 7.14, and a reference pressure. Take 9.3 GPa.

[0068] The parameters of the blades read are shown in the table below. All parameters and the parameters used for contact force are K=20000000 and n=3.

[0069]

[0070] The obtained parameters are used in the following formula:

[0071] The governing equations of bird motion and the discretization of SPH:

[0072] The governing equations for the motion of a bird's flesh and blood fluid and its deformable skeleton solid can be written in the following general form, including the continuity equation and the momentum equation, respectively:

[0073] (1)

[0074] (2)

[0075] This invention employs Einstein's superscript notation convention for summation. , These represent the 1, 2, and 3 components in the Cartesian coordinate system, respectively. Density, in kg / m³. Speed, in m / s Other external forces, such as gravity. Represents the components of the total stress tensor, derived from isotropic pressure. and stress deviator tensor composition

[0076] (3)

[0077] It is the Kronecker function, when hour, ;when hour, .

[0078] SPH discretization is performed on equations (1) and (2) respectively, and the discretized equation system is as follows:

[0079] (4)

[0080] (5)

[0081] in, , This represents two SPH particles. , , They represent particles respectively The density, velocity, and total stress tensor, Represents particles quality For particles The total number of SPH particles within the supported domain. For particles For particles The smoothing kernel function used in this invention is a modified kernel function, which can improve the unit decomposition characteristics of particles near the boundary or irregularly distributed particles, and achieve the zero-order and first-order uniformity of particle approximation. The particle's spatial position vector. This defines the smooth length of the region of influence of the kernel function. Artificial viscosity, introduced to prevent non-physical penetration when particles approach each other, is expressed in the following form:

[0082] (6)

[0083] in, The relative velocity vector of the particles in space. Let be the particle's spatial relative position vector. The other variables in equation (6) are calculated as follows:

[0084] (7)

[0085] (8)

[0086] (9)

[0087] (10)

[0088] In the formula and This is a standard constant, and its value depends on the problem being applied. Related to bulk viscosity, Used to prevent particles from penetrating each other at high Mach numbers. For the material's sound velocity, Used to prevent numerical divergence when particles get close to each other.

[0089] Equation of state for bird flesh and blood:

[0090] When a bird strikes an aircraft engine fan blade at high speed, the bird's flesh and blood are widely considered as a fluid. This paper uses Monaghan's weakly compressible equation of state to calculate its pressure term, namely:

[0091] (11)

[0092] In the formula: Background pressure, in Pa; Density, expressed in kg / m³; This is the initial density, expressed in kg / m³. The reference pressure is in Pa, and the maximum fluid velocity is assumed to be... Then the reference pressure ; This is a material parameter, and in most cases it is 7. Together with B, it is used to control the oscillation range of fluid density at its normal density during the calculation process (generally not exceeding 1%).

[0093] Deformation motion equations and FEM discretization of fan blades:

[0094] During a bird strike, the deformation motion of the fan blades is a three-dimensional mechanical problem, and the specific formula is as follows:

[0095] (12)

[0096] (13)

[0097] (14)

[0098] (15)

[0099] (16)

[0100] (17)

[0101] (18)

[0102] In the formula: Indicates stress, The number of units Indicates physical strength. Represents surface force. Indicates density, Indicates the damping coefficient. The displacement vector of a point. Represents displacement boundary conditions. and Let these represent the first and second derivatives of displacement with respect to time, i.e., velocity and acceleration, respectively. Indicates strain, Represents the elasticity matrix. This represents the direction cosine of the slope normal direction in the principal coordinate system. express Nodal displacement pairs node Partial derivatives of coordinates, express Nodal displacement pairs node Partial derivatives of coordinates.

[0103] The differential equations and mechanical boundary conditions are discretized using the finite element method to obtain the finite element equations and dynamic equations of motion. These equations are then used to calculate parameters such as acceleration in the finite element method, as shown in the following formulas:

[0104] (19)

[0105] (20)

[0106] In the formula: Represents the overall stiffness matrix. Represents the displacement vector of the element node. This represents a known structural load vector; These represent nodal velocity and displacement, respectively. These represent the system's mass matrix, damping matrix, stiffness matrix, and nodal load vector, respectively.

[0107] Constitutive models of bird skeletons and leaves:

[0108] The blade material model employs both elastoplastic and damage-inducing Johnson-Cook constitutive models. First, the dynamic equations of the separation device are derived using the elastoplastic model. ,in , The ratio is Poisson's ratio; then the principal stresses in the three directions are calculated. Calculate the von Mises equivalent stress

[0109] (twenty one)

[0110] Then, the von Mises equivalent stress was compared with the yield strength calculated by the Johnson-Cook constitutive model with damage. The size, if but If remain unchanged, The stress then returns to the yield surface proportionally. .

[0111] The following describes the Johnson-Cook constitutive model with damage, which describes the dynamic mechanical characteristics of metallic materials, such as large deformation and high strain rate, through flow stress and failure strain. The expression for its flow stress is:

[0112] (twenty two)

[0113] In the formula: g represents the cumulative damage plastic strain. To accumulate plastic strain, To customize the reference strain rate, At room temperature The melting point of the material. is a material constant. This indicates that the material is undamaged. This indicates that the material has completely failed. This is the fracture plastic strain, which is related to the material's stress triaxiality, strain rate, and temperature. As the initial pressure, For material constants, For stress triaxiality, This represents the average value of the normal stress.

[0114] Step 3: Calculate the SPH and the time step of the finite element method respectively, and take the smaller value as the common step size for this round of calculation;

[0115] For the SPH leapfrog integral, the time step must satisfy a stability condition. The Courant-Friedrich-Lewy (CFL) condition is applied to estimate the time step, and the specific expression is as follows:

[0116] (twenty three)

[0117] (twenty four)

[0118] (25)

[0119] in, An external force acting on a unit mass. The dynamic viscosity of the fluid is used, and the minimum value is taken as the time step for SPH calculation. It is a dimensionless parameter with an adjustable value. For particles and particles The stickiness between them.

[0120] The time step is calculated as follows using the finite element method:

[0121] (26)

[0122] in , , These represent the material's density, elastic modulus, and Poisson's ratio, respectively. For safety reasons, This is the smallest unit size.

[0123] (27)

[0124] In the SPH-FEM coupling algorithm of this invention embodiment, each round of calculation requires calculating the SPH and the time step of the finite element method. The calculated SPH time step and finite element time step The two values ​​are compared, and the smaller one is taken as the common step size for this round of calculation.

[0125] Step 4: Use a linked list search method to search for neighboring particles of the SPH particle.

[0126] The linked list search method involves setting up a series of temporary grids across the entire problem domain, where each temporary grid must cover all particles within the problem domain. The size of the grid space is consistent with the size of the particle support domain. If the size of the support domain of the smooth kernel function is... The temporary space grid size is also set to be All particles within the problem domain are assigned to different spatial grids. For a given particle... Its nearest neighbor particles can only appear in the same grid or in closely adjacent grids, such as Figure 3 The shaded area is shown. For one-dimensional, two-dimensional, and three-dimensional problems, the search range of the linked list search method is 3, 9, and 27 grids, respectively. The specific steps of the linked list search method are described below:

[0127] Before each time step begins, update the temporary mesh settings, including mesh size and position, and assign a unique number to each mesh; based on the current position of the SPH particles, allocate all SPH particles to the temporary mesh space and establish a particle list within the mesh; based on the particle... The system searches for adjacent grid cells based on their grid number and stores their grid numbers; it then searches for SPH particles in all adjacent grid cells. SPH particles within the compacted domain .

[0128] Step 5: Calculate the update parameters of the SPH particles and the update parameters of the finite element based on the search results.

[0129] The particles within its search range are paired with the particles to determine the type of the pair. If background particles are found, contact forces are calculated for them, and these contact forces are added as external forces to the calculation of the SPH momentum equation.

[0130] Here, A represents any type of SPH particle. Taking SPH particle A as an example, contact calculations are performed on the background particles searched within its support domain, and the contact force is added to the momentum equation calculation of SPH particle A in the form of an external force.

[0131] For background particles, they passively acquire the same reverse contact force as the SPH real particles, and this reverse contact force is transmitted to the finite element nodes. The contact force is added as an external force to the FEM dynamic equations. Background particles possess the properties of SPH particles; their particle mass, position, velocity, stress, etc., are consistent with the corresponding finite element nodes. Background particles are only passively searched by real SPH particles, increasing the number of particles in the SPH particle's neighbor list, without performing SPH numerical integration themselves. Their data updates are determined by the corresponding finite element nodes through finite element integration calculations.

[0132] Applying this contact force to the SPH particle requires the following modification to the SPH momentum equation:

[0133] (28)

[0134] Applying contact forces to finite element nodes requires replacing the nodal loads in the finite element dynamics equations with external forces. :

[0135] (29)

[0136] SPH (Speed-Pulse Phosphorus) calculations are performed using the equations for conservation of momentum, mass, and energy. The updated parameters for the SPH particles include at least: mass, velocity, position, and energy. Finite element analysis (FEM) calculations are performed using the dynamic equations to calculate strain, stress, displacement, and damage values. The updated parameters for the FEM include at least: velocity, stress, and displacement.

[0137] Step 6: Determine whether the finite element method has been converted into SPH particles;

[0138] When the finite element reaches complete yield damage failure, i.e., the finite element damage factor calculated by the Jhonson-Cook constitutive model containing damage. When the finite element is determined to be in failure, the finite element that is not connected to any unfailed element is confirmed to be transformed into SPH free particles.

[0139] If not, proceed to step 6-1, whereby the unconverted finite element parameters are updated according to the finite element update parameters.

[0140] If so, proceed to step 6-2, where the converted finite element method calculates the update parameters of the SPH particles using the SPH update parameter calculation method, and updates the SPH particle parameters.

[0141] In other words, for finite elements that are determined to be converted, the parameters are calculated and updated according to the SPH calculation process, and the parameters are updated accordingly; for finite elements that are not converted, the calculation and updates are still performed according to the finite element parameter calculation method.

[0142] Step 7: Calculate whether the total duration has reached the specified duration.

[0143] After the parameter update is completed, the total calculation time is updated using the common step size of the current calculation. If the updated total calculation time does not reach the preset time, the above steps 3 to 6 are executed repeatedly.

[0144] Step 8: After the above iterative calculations are completed, visualize the bird body breakage, engine blade deformation, and equivalent stress changes based on the updated SPH particle parameters and the updated finite element parameters.

[0145] During the process of birds colliding with aero-engine blades, the impact point is mostly concentrated at 65%-78% of the blade height. When the blade is hit by a bird, the blade deforms as a whole and a notch appears on the leading edge. Therefore, this invention selects condition 3, that is, the impact point is at 75% of the blade height, to conduct a specific analysis of the process of birds colliding with fan blades.

[0146] The above process calculates the process of bird impact with an engine blade, including bird fragmentation and debris, blade deformation, damage, and fracture. It obtains data such as velocity components, stress, contact force, and damage values ​​at different times. Post-processing of the calculation results can then be performed using existing software like Tecplot. The calculated data can be visualized using Tecplot to obtain the deformation and damage of the blade and bird under different operating conditions. Figure 4 As shown, the research object consists of 5 different parts: PID 1 represents the finite element of the leaf, PID 2 represents the damaged SPH particles transformed after the SPH particles of the bird's skeleton are damaged, PID 3 represents the free SPH particles transformed after the finite element of the leaf is damaged, PID 4 represents the SPH particles of the bird's skeleton, and PID 5 represents the SPH particles of the bird's flesh and blood.

[0147] For the multi-structured bird body, at time 0, the initial velocity of the bird's body impacting the blade head-on is 187 m / s, and the initial tangential velocity is 301 m / s, with the tangential velocity direction opposite to the blade's rotation direction. At 0.4 ms, the bird's body impacts the leading edge of the blade at an angle, cutting the bird into two main parts, left and right, each containing a large wing fragment. After being cut, a small portion of the cut flesh splatters, while most of the flesh continues its original motion along the blade, consistent with fluid motion characteristics. Regarding the bird's skeleton, the right wing did not impact the leading edge of the blade and remains relatively intact. The left wing was cut, but the cut portion did not splatter like the fluid flesh; instead, it broke into several small fragments, retaining some of its original shape. The spine in the bird's skeleton was completely cut by the leading edge of the blade, breaking into several segments. Due to the excessive rebound force from the impact, it bounced back and moved in the opposite direction, consistent with solid motion properties.

[0148] Figure 5 , Figure 6 , Figure 7 The equivalent stress over time is depicted at three different locations at the impact point of the multi-structured bird at 25%, 50%, and 75% leaf height.

[0149] For condition 1, the impact point is at 25% of the blade height, with a forward impact velocity of 187 m / s and a tangential velocity of 191 m / s. The linear velocity at the impact point is relatively low. When the bird impacts the leading edge of the blade, the stress is mainly concentrated at the impact point, with a small impact area. At 0.6 ms, the stress is mainly transmitted vertically along the leading edge of the impacting middle blade, with no stress fluctuations on the left and right blades, and slight deformation at the impact point. At 1.2 ms, the cut left half of the bird, partially subjected to the contact force of the middle blade, begins to rebound to the back of the leftmost blade. Stress load appears on the leading edge of the left blade back, but the stress is small and dispersed, causing no significant deformation of the left blade. A small area of ​​stress concentration appears at the leading edge of the pressure front of the right blade, but the stress is minor and has no impact on the right blade. However, under this operating condition, there are fewer damage particles generated from the failure of bird skeleton materials, and there are many large bone fragments. After entering the compressor with the airflow in the intake duct, they can easily cause engine blockage, leading to engine surge or even stalling. Moreover, the large bone fragments carry a lot of kinetic energy, which causes greater damage to the engine interior.

[0150] For condition 2, the impact point is at 50% blade height, and the tangential linear velocity is 246 m / s, which is relatively high. Figure 6 It can also be seen that at the initial impact time of 0.2 ms, the stress on the leading edge of the blade is relatively large, and the stress concentration range is significantly larger than that in condition 1, with obvious deformation at the impact point. At 0.6 ms, small bone fragments from the cut left half of the bird's body splash onto the back of the leftmost blade, resulting in significant stress concentration at the impact point. However, since the impact point is located at the center of the blade's back, where the blade is thicker and has a stronger stress-bearing capacity, it does not cause significant deformation. At 1.2 ms, the right half of the bird's body impacts the leading edge of the pressure surface of the right blade. This part of the bird's body still retains relatively complete wing bones, and since the impact point is located on the pressure surface, it cannot cut the bird's body. Therefore, the right blade experiences significant stress concentration and obvious deformation. Under this condition, the leading edges of the middle and right blades are subjected to significant impact contact forces, resulting in obvious indentation deformation. However, the overall deformation of the blades is not significantly affected. Compared to condition 1, the number and size of large bird fragments in condition 2 are relatively reduced, thus reducing damage to the engine's internal structure.

[0151] For condition 3, the impact point is located at 75% blade height, and the tangential linear velocity is 301 m / s, which is extremely high. Figure 7As shown, at the initial impact moment, the stress is high and concentrated, exceeding the blade's yield stress, causing complete yield failure of the material at this point, physically manifested as detachment. In numerical calculations, the mesh element at this point is automatically deleted, and the background particles fixed on the element nodes are transformed into free SPH particles. These free SPH particles represent the detached blade fragments and continue to participate in the calculation process. At 0.6 ms, stress still shows a large-scale concentration and propagates throughout the entire middle blade, resulting in large overall blade oscillation amplitude. At 1.2 ms, the shredded fragments impact the back of the left blade and the apex of the right blade, respectively, causing a large impact contact force on the right blade and resulting in significant deformation. Under this condition, the number of large bird skeleton fragments is further reduced, and there is more completely damaged skeletal material, with less impact on the subsequent compressor internal blockage. However, this condition causes significant damage to the blade, not only causing large deformation and reducing aerodynamic performance, but also potentially causing partial detachment of the blade structure, resulting in permanent damage. Moreover, the detached blade fragments are even more destructive to the engine. Therefore, bird strikes to the engine fan can cause significant damage to the engine under all three operating conditions, making bird strike resistant design crucial for the engine.

[0152] Figure 8 The diagram shows the stress variation over time at the leading edge impact point under three operating conditions. In conditions 1 and 2, the peak stress values ​​at the impact point are similar, causing some deformation to the blade at the impact point. In condition 3, the tangential velocity is high, and the peak stress at the impact point is significantly higher than in the other two conditions, causing some finite elements at the impact center to completely yield, have their mesh removed, and spontaneously detach. Therefore, avoiding bird strikes at higher points on the blade is also a protective measure. The preceding calculations yielded details of blade deformation and equivalent stress variation curves under different operating conditions. Analysis of these results reveals the blade failure mechanism, bird fragmentation, and the splashing patterns of blade debris, further improving and refining protective measures for aero-engine blades.

[0153] This invention introduces a novel SPH-FEM coupled simulation technique, which not only includes a contact algorithm between the SPH and FEM methods, but also dynamically transforms the finite element model after complete damage failure into SPH particles for continued computation using a transformation algorithm. Contact algorithms are then used to calculate the interactions between the transformed particles and the untransformed finite element model, as well as between the transformed particles and free SPH particles. This allows for the calculation of not only the interaction between the bird and the blade, but also the interactions between the damaged fragments and the blade, and the interactions between the fragments and the bird, thus reproducing multi-physics processes. This provides a new approach to studying the multi-physics processes of bird impacts on aero-engine blades.

[0154] This invention also provides a multi-physics simulation calculation device for bird impact on aero-engine blades, such as... Figure 9 The diagram shown is a schematic representation of the device structure.

[0155] Model building unit 90 is used to build a three-dimensional geometric model of the bird and engine blades, mesh the bird and engine blades, and obtain the finite element of the engine blades and a smooth particle hydrodynamic (SPH) particle corresponding to each bird mesh.

[0156] The parameter reading unit 91 is used to read the initial parameters and assign them to the SPH particles and the finite element of the engine blades respectively;

[0157] The time step calculation unit 92 is used to calculate the time step of SPH and finite element respectively, and take the smaller value as the common step of this round of calculation.

[0158] Search unit 93 is used to search for particles near the SPH particle using a linked list search method;

[0159] The parameter calculation unit 94 updates the parameters of the SPH particles and the parameters of the finite element based on the search results.

[0160] The conversion judgment and parameter update unit 95 is used to determine whether the finite element has been converted into SPH particles. If not, the finite element parameters of the unconverted finite element are updated according to the update parameters of the finite element. If so, the finite element parameters of the converted finite element are calculated using the SPH update parameter calculation method, and the SPH particle parameters are updated.

[0161] Visualization unit 96 is used to visualize the bird body breakage, engine blade deformation, and equivalent stress changes based on the updated SPH particle parameters and updated finite element parameters after the loop calculation is completed.

[0162] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0163] In summary, this invention introduces a novel SPH-FEM coupled simulation technique, which not only includes a contact algorithm between the SPH and FEM methods, but also dynamically transforms the finite element model after complete damage failure into SPH particles for continued computation using a transformation algorithm. Contact algorithms are then used to calculate the interactions between the transformed particles and the untransformed finite element model, as well as between the transformed particles and free SPH particles. This allows for the calculation of not only the interaction between the bird and the blade, but also the interactions between the damaged fragments and the blade, and the interactions between the fragments and the bird, thus reproducing multi-physics processes. This provides a new approach for studying the multi-physics processes of bird impacts on aero-engine blades.

[0164] This invention eliminates the need for experimental platforms and venues required for conducting experiments, thus greatly reducing the consumption of manpower, material resources, and financial resources. At the same time, it allows for repeated calculations without affecting the results, eliminating the randomness inherent in experiments. It can clearly capture every detail of the process of a bird colliding with an aero-engine blade, making it a good supplement to conducting actual experiments.

[0165] Compared with similar numerical simulation methods, this invention has at least the following advantages: it overcomes the shortcomings of traditional numerical simulation methods, and in simulating the process of bird impact on aero-engine blades, it can not only obtain the final blade deformation damage and bird fragmentation results, but also reproduce the motion of damaged fragments and their secondary damage process to the blade in real time, and deeply analyze the dynamic deformation process and the influencing factors of damage velocity. Therefore, this invention provides a good solution to the problem of three-dimensional high-fidelity simulation of the multi-physics process of bird impact on aero-engine blades, and is a technology with great practical value.

[0166] This invention also provides an apparatus for simulating the multi-physics process of bird impact on aero-engine blades, comprising a memory and one or more programs, wherein the programs are stored in the memory and configured to be executed by one or more processors. The programs contain instructions for performing the following operations: Step 1: Establishing a three-dimensional geometric model of the bird and the engine blade, meshing the bird and the engine blade to obtain the finite element method of the engine blade and a smoothed particle hydrodynamic (SPH) particle corresponding to each bird mesh; Step 2: Reading initial parameters and assigning them to the SPH particle and the finite element method of the engine blade; Step 3: Calculating the time step of the SPH and the finite element method respectively, and taking the smaller value as the common step size for this round of calculation; Step 4: Using a linked list search method. Step 5: Search for particles near the SPH particle; Step 6: Calculate the update parameters of the SPH particle and the update parameters of the finite element based on the search results; Step 7: Determine whether the finite element has been converted into an SPH particle; if not, update the finite element parameters according to the update parameters of the finite element; if yes, calculate the update parameters of the SPH particle using the SPH update parameter calculation method and update the SPH particle parameters; Update the total calculation time using the common step size of the current calculation, and repeat steps 3 to 6 until the updated total calculation time reaches the preset time; Step 8: After the above cyclic calculation is completed, visualize the bird body breakage, engine blade deformation and equivalent stress change diagrams based on the updated SPH particle parameters and the updated finite element parameters.

[0167] Figure 10This is a block diagram illustrating an apparatus 800 for simulating the multiphysics process of bird impact on an aero-engine blade, according to an exemplary embodiment. For example, apparatus 800 may be a mobile phone, computer, digital broadcasting terminal, messaging device, game console, tablet device, medical device, fitness equipment, personal digital assistant, etc.

[0168] Reference Figure 10 The device 800 may include one or more of the following components: a processing component 802, a memory 804, a power supply component 806, a multimedia component 808, an audio component 810, an input / output (I / O) interface 812, a sensor component 814, and a communication component 816.

[0169] Processing component 802 typically controls the overall operation of device 800, such as operations associated with display, telephone calls, data communication, camera operation, and recording operations. Processing component 802 may include one or more processors 820 to execute instructions to perform all or part of the steps of the methods described above. Furthermore, processing component 802 may include one or more modules to facilitate interaction between processing component 802 and other components. For example, processing component 802 may include a multimedia module to facilitate interaction between multimedia component 808 and processing component 802.

[0170] Memory 804 is configured to store various types of data to support the operation of device 800. Examples of this data include instructions for any application or method operating on device 800, contact data, phonebook data, messages, pictures, videos, etc. Memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0171] Power supply component 806 provides power to various components of device 800. Power supply component 806 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to device 800.

[0172] Multimedia component 808 includes a screen that provides an output interface between the device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe action but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 808 includes a front-facing camera and / or a rear-facing camera. When the device 800 is in an operating mode, such as a shooting mode or a video mode, the front-facing camera and / or the rear-facing camera may receive external multimedia data. Each front-facing camera and rear-facing camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0173] Audio component 810 is configured to output and / or input audio signals. For example, audio component 810 includes a microphone (MIC) configured to receive external audio signals when device 800 is in an operating mode, such as call mode, recording mode, and voice information processing mode. The received audio signals may be further stored in memory 804 or transmitted via communication component 816. In some embodiments, audio component 810 also includes a speaker for outputting audio signals.

[0174] I / O interface 812 provides an interface between processing component 802 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0175] Sensor assembly 814 includes one or more sensors for providing status assessments of various aspects of device 800. For example, sensor assembly 814 can detect the on / off state of device 800, the relative positioning of components such as the display and keypad of device 800, and can also detect changes in the position of device 800 or a component of device 800, the presence or absence of user contact with device 800, the orientation or acceleration / deceleration of device 800, and temperature changes of device 800. Sensor assembly 814 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 814 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 814 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0176] Communication component 816 is configured to facilitate wired or wireless communication between device 800 and other devices. Device 800 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 816 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 816 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency information processing (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0177] In an exemplary embodiment, the apparatus 800 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the methods described above.

[0178] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 804 including instructions, which can be executed by a processor 820 of the device 800 to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0179] Figure 11 This is a schematic diagram of the server structure in some embodiments of the present invention. The server 1900 can vary considerably depending on its configuration or performance, and may include one or more central processing units (CPUs) 1922 (e.g., one or more processors) and memory 1932, and one or more storage media 1930 (e.g., one or more mass storage devices) for storing application programs 1942 or data 1944. The memory 1932 and storage media 1930 can be temporary or persistent storage. The program stored in the storage media 1930 may include one or more modules (not shown in the diagram), each module including a series of instruction operations on the server. Furthermore, the CPU 1922 may be configured to communicate with the storage media 1930 and execute the series of instruction operations in the storage media 1930 on the server 1900.

[0180] Server 1900 may also include one or more power supplies 1926, one or more wired or wireless network interfaces 1950, one or more input / output interfaces 1958, one or more keyboards 1956, and / or one or more operating systems 1941, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0181] A non-transitory computer-readable storage medium that, when instructions in the storage medium are executed by a processor of a device (server or terminal), enables the device to perform... Figure 1 This paper presents a multi-physics simulation calculation method for bird impact on aero-engine blades.

[0182] A non-transitory computer-readable storage medium, wherein when the instructions in the storage medium are executed by a processor of a device (server or terminal), the device is able to perform the aforementioned... Figure 1 The description of the data processing method in the corresponding embodiments is already provided and will not be repeated here. Furthermore, the beneficial effects of using the same method will also not be repeated. For technical details not disclosed in the computer program products or computer program embodiments related to this application, please refer to the description of the method embodiments of this application.

[0183] Furthermore, it should be noted that this application also provides a computer program product or computer program, which may include computer instructions, which may be stored in a computer-readable storage medium. The processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor may execute the computer instructions, causing the computer device to perform the aforementioned actions. Figure 1 The description of the data processing method in the corresponding embodiments is already provided and will not be repeated here. Furthermore, the beneficial effects of using the same method will also not be repeated. For technical details not disclosed in the computer program products or computer program embodiments related to this application, please refer to the description of the method embodiments of this application.

[0184] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0185] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0186] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-physics simulation calculation method for bird impact on aero-engine blades, characterized in that, The method includes: Step 1: Establish a three-dimensional geometric model of the bird and engine blades, mesh the bird and engine blades, and obtain the finite element of the engine blades and a smooth particle hydrodynamic (SPH) particle corresponding to each bird mesh. Step 2: Read the initial parameters and assign them to the finite element methods of the SPH particles and engine blades respectively; Step 3: Calculate the SPH and the time step of the finite element method respectively, and take the smaller value as the common step size for this round of calculation; Step 4: Use a linked list search method to search for neighboring particles of the SPH particle; Step 5: Calculate the update parameters of the SPH particles and the update parameters of the finite element based on the search results; Step 6: Determine whether the finite element has been converted into SPH particles. If not, update the finite element parameters according to the update parameters of the finite element. If yes, calculate the update parameters of the SPH particles using the SPH update parameter calculation method and update the SPH particle parameters. The step of determining whether the finite element method has been converted into SPH particles includes: Determine whether the damage factor of the finite element is equal to 1; If the damage factor is equal to 1, the finite element is confirmed to be in failure. If the failed finite element is not connected to any unfailed finite element, the failed finite element is confirmed to be converted into SPH particles. The total computation time is updated using the common step size calculated in this round. If the updated total computation time does not reach the preset time, steps 3 to 6 above are executed repeatedly. Step 7: After the above iterative calculations are completed, visualize the bird body breakage, engine blade deformation, and equivalent stress changes based on the updated SPH particle parameters and the updated finite element parameters.

2. The method according to claim 1, characterized in that, The initial parameters include: Bird body parameters and engine blade material parameters.

3. The method according to claim 1, characterized in that, The step of calculating the updated parameters of the SPH particles based on the search results includes: If background particles are found, the contact force of the found background particles is calculated, and the contact force is added as an external force to the calculation of the SPH momentum equation.

4. The method according to claim 1 or 3, characterized in that, The updated parameters of the SPH particles include at least: mass, velocity, position, and energy.

5. The method according to claim 1, characterized in that, The steps for calculating the updated parameters of the finite element include: If background particles are found, obtain the reverse contact force of the same magnitude exerted by the background particles on the SPH particles, and add the reverse contact force as an external force to the calculation of solving the finite element dynamic equations.

6. The method according to claim 1 or 5, characterized in that, The updated parameters of the finite element method include at least: velocity, stress, and displacement.

7. A multi-physics simulation and calculation device for bird impact on aero-engine blades, characterized in that, The device includes: The model building unit is used to build a three-dimensional geometric model of the bird and the engine blade, to mesh the bird and the engine blade, and to obtain the finite element of the engine blade and a smooth particle hydrodynamic (SPH) particle corresponding to each bird mesh. The parameter reading unit is used to read the initial parameters and assign them to the finite element method of the SPH particles and the engine blades respectively; The time step calculation unit is used to calculate the time step of SPH and finite element separately, and take the smaller value as the common step of this round of calculation. The search unit is used to search for particles near the SPH particle using a linked list search method. The parameter calculation unit updates the parameters of the SPH particles and the parameters of the finite element based on the search results. The conversion judgment and parameter update unit is used to determine whether the finite element has been converted into SPH particles. If not, the finite element parameters of the unconverted finite element are updated according to the update parameters of the finite element. If so, the updated parameters of the SPH particles of the converted finite element are calculated using the SPH update parameter calculation method, and the SPH particle parameters are updated. The transformation judgment and parameter update unit includes: Determining whether a finite element method can be converted into an SPH particle element: This is used to determine whether the damage factor of the finite element method is equal to 1. If the damage factor is equal to 1, the finite element is confirmed to be in failure. If the failed finite element is not connected to any unfailed finite element, the failed finite element is confirmed to be converted into SPH particles. The visualization unit is used to visualize the bird body breakage, engine blade deformation, and equivalent stress changes based on the updated SPH particle parameters and updated finite element parameters after the loop calculation is completed.

8. An electronic device, characterized in that, The method includes a processor and a machine-readable storage medium storing machine-executable instructions that can be executed by the processor, the processor being prompted by the machine-executable instructions to perform the method of any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-6.

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