Turbine blade cooling rib structure method and system based on level set topology optimization, configuration and blade device

Abstract

This invention belongs to the field of aero-engine cooling design and flow heat transfer optimization technology. It provides a method, system, configuration, and blade for constructing turbine blade cooling fringe based on level set topology optimization. The method includes: constructing a fluid-structure interaction (FSI) computational model encompassing the fluid domain of the cooling channel and the solid domain of the blade wall; defining a level set function to implicitly represent the two-phase region; establishing a unified set of governing equations covering the entire computational domain based on this function; introducing a velocity suppression mechanism in the solid domain to perform single-domain coupling solution of fluid flow and solid heat conduction; constructing an optimization model based on the physical field solution, with cooling performance as the objective function and fringe volume fraction as the constraint; calculating the sensitivity of the objective function to the level set function; using this sensitivity to drive the level set function update to evolve the fringe boundary; iterating until convergence to output the final fringe geometry. This invention does not require pre-setting the fringe type and can automatically generate irregular fringe structures with high heat transfer efficiency and low flow resistance.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine cooling design and flow heat transfer optimization, and relates to the construction technology of turbulence ribs in turbine blade cooling channels. Specifically, it relates to a method, system, configuration and blade for constructing turbine blade cooling turbulence ribs based on horizontal set topology optimization. This method is particularly suitable for the design of core components of high-temperature power equipment such as aero-engines and gas turbines that need to improve heat transfer performance by automatically generating complex fluid disturbance structures. Background Technology

[0002] With the continuous improvement of the thrust-to-weight ratio of aero engines, the turbine inlet temperature has far exceeded the melting point limit of high-temperature alloy materials. Efficient internal cooling technology for turbine blades has become the core key to ensuring the safe and reliable operation of engines. As the most mainstream heat transfer enhancement element in the cooling channel, the baffle rib significantly improves the convective heat transfer coefficient of the channel wall by disturbing the fluid boundary layer near the wall, inducing secondary flow, and destroying the heat transfer dead zone.

[0003] However, existing turbine blade rib designs mainly rely on parametric regular structures such as rectangles, waves, and W-shapes. While these traditional design methods can improve heat transfer to some extent, they have significant limitations: their geometry is constrained by preset functional expressions, and the optimization process can only perform local optimization within a limited parameter space (such as rib height, spacing, and inclination angle), making it difficult to break through the constraints of fixed topology configurations and achieve the best match between heat transfer performance and flow resistance across the entire cooling channel.

[0004] In recent years, topology optimization methods have been widely used in the field of lightweight solid structure design due to their advantages of high design freedom and the ability to automatically generate irregular and innovative configurations. However, their application in fluid heat transfer and fluid-structure interaction scenarios still faces the following three core technical bottlenecks:

[0005] 1. The physical properties of the fluid domain and the solid domain are very different (e.g., the flow velocity in the solid domain needs to be forced to zero). Traditional methods are difficult to achieve seamless coupling and unified numerical solution of the two-phase media under a single computational framework, and it is difficult to perform unified modeling of the fluid-solid domain.

[0006] 2. Low efficiency in large-scale sensitivity calculation: The conjugate heat transfer process in the cooling channel involves complex fluid-structure interaction effects. When dealing with a large number of design variables, the traditional discrete adjoint method or direct differential method has high sensitivity calculation costs, which restricts the optimization efficiency and reduces the efficiency of large-scale sensitivity calculation.

[0007] 3. The shape evolution of the ribs during the optimization process is random and complex, often accompanied by drastic changes such as hole nucleation, boundary merging and topological splitting. This makes it difficult for traditional density methods or parameterization methods to accurately and smoothly describe such dynamic evolution processes, and easily produces gray-scale units or jagged boundaries.

[0008] Therefore, there is an urgent need to develop a new method for constructing ribs that can overcome the limitations of regular geometry, achieve unified and efficient solutions for fluid-structure interaction fields, and automatically drive the evolution of complex topologies based on the level set method, so as to meet the cooling performance requirements of the next generation of high-performance aero-engine turbine blades. Summary of the Invention

[0009] The purpose of this invention is to provide a method, system, configuration, and blade for constructing turbine blade cooling ribs based on horizontal set topology optimization, in order to solve the technical problems of low design freedom of traditional ribs and the difficulty of existing topology optimization methods in efficiently handling fluid-structure interaction heat transfer and complex topology evolution, and to realize the automatic generation of high-performance irregular rib structures to improve the overall cooling efficiency of turbine blades.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] In a first aspect, the present invention provides a method for constructing cooling fringe ribs for turbine blades based on level set topology optimization, the method comprising the following steps:

[0012] Step S1: Construct a fluid-structure interaction calculation model that includes the cooling channel fluid domain, the blade wall solid domain and their interface, and define a level set function to implicitly represent the cooling channel fluid domain and the blade wall solid domain;

[0013] Step S2: Based on the level set function, establish a unified set of control equations covering the entire computational domain, introduce a flow velocity suppression mechanism in the solid domain of the blade wall, perform single-domain coupling solution of fluid flow and solid heat conduction, and obtain the fluid-structure interaction physical field solution.

[0014] Step S3: Based on the fluid-structure interaction physical field solution, construct an optimization model with cooling performance as the objective function and the volume fraction of the turbulence ribs as the constraint, and calculate the current objective function value;

[0015] Step S4: Based on the optimization model, calculate the sensitivity of the objective function to the level set function, and drive the level set function to update in order to evolve the topological boundary of the fringe rib;

[0016] Step S5: Determine whether the convergence condition is met based on the current objective function value. If it is met, output the final rib geometry. If it is not met, re-execute the fluid-structure interaction solution, optimization model construction, and level set function update based on the updated level set function until the convergence condition is met and the final rib geometry is output.

[0017] Furthermore, in step S1, the positive value of the horizontal set function corresponds to the fluid domain of the cooling channel, the negative value corresponds to the solid domain of the blade wall, and its zero isovalue corresponds to the interface between the two.

[0018] Furthermore, in step S2, the unified set of governing equations includes a continuity equation describing the conservation of mass, a momentum equation describing the conservation of momentum, and an energy equation describing the conservation of energy.

[0019] When establishing the momentum equation, a Brinkman penalty term is introduced as the velocity suppression mechanism. The expression for the Brinkman penalty term is:

[0020] ;

[0021] in, For level set functions, For fluid velocity vector, , This is the preset maximum penalty coefficient.

[0022] Further, in step S3, the objective function is the average temperature of the outer wall surface of the blade's combustion side or the Nusselt number ratio of the cooling channels.

[0023] Furthermore, in step S3, the volume fraction of the turbulence rib is the ratio of the volume occupied by the turbulence rib to the total volume of the cooling channel, and its value ranges from 10% to 30%.

[0024] Further, in step S4, the sensitivity is calculated using the adjoint method, including:

[0025] S41. Construct the Lagrangian function L, wherein the expression for the Lagrangian function L of the adjoint equation is: ;

[0026] in, The average temperature of the wall surface. The accompanying velocity vector, As an accompanying temperature scalar, For the residuals of the continuous equation, This is the residual of the momentum equation. The residual of the energy equation, Let Ω be the infinitesimal volume within the physical domain. Represents the Hamiltonian operator. The density of the cooling fluid, The velocity vector of the fluid. This refers to the static pressure of the fluid within the cooling channel. The molecular dynamic viscosity of the cooling fluid. The volume force source term vector, For enthalpy, The effective thermal conductivity of the cooling fluid, This refers to the temperature of the fluid within the cooling channel;

[0027] S42. By taking the variation of the Lagrangian function with respect to the state variables and setting it to zero, the adjoint equations are obtained. Solving the adjoint equations yields the gradient of the objective function with respect to the level set function, thus obtaining the sensitivity.

[0028] Further, in step S4, the level set function is updated by solving the Hamilton-Jacobi type evolution equation, the expression of which is:

[0029] ;

[0030] in, Normal velocity, Let t be the level set function, and t be the pseudo-time of the level set evolution.

[0031] Secondly, the present invention provides a turbine blade cooling fringe construction system based on level set topology optimization, including a fluid-structure interaction modeling unit, a fluid-structure interaction solution unit, an optimization model construction unit, a topology evolution driving unit, and an iterative control and output unit.

[0032] Specifically, the fluid-structure interaction modeling unit is used to construct a fluid-structure interaction calculation model that includes the fluid domain of the cooling channel, the solid domain of the blade wall, and their interface, and defines a level set function to implicitly represent the fluid domain of the cooling channel and the solid domain of the blade wall.

[0033] The fluid-structure interaction (FSI) solution unit is used to establish a unified set of governing equations covering the entire computational domain based on the horizontal set function, introduce a flow velocity suppression mechanism in the solid domain of the blade wall, perform single-domain coupling solution of fluid flow and solid heat conduction, and obtain the fluid-structure interaction physical field solution.

[0034] The optimization model building unit is used to construct an optimization model with cooling performance as the objective function and the volume fraction of the turbulence ribs as the constraint condition based on the solution of the fluid-structure interaction physical field, and to calculate the current objective function value;

[0035] The topology evolution driving unit is used to calculate the sensitivity of the objective function to the level set function based on the optimization model, and drive the level set function to update in order to evolve the topological boundary of the fringe rib.

[0036] The iterative control and output unit is used to determine whether the convergence condition is met based on the evolved horizontal set field and the current objective function value. If the condition is not met, the evolved horizontal set field is used as the horizontal set function for the next iteration step. If the condition is met, the iteration is terminated, and the final spoiler rib geometry that satisfies the spoiler rib volume fraction constraint and the objective function converges is output.

[0037] Thirdly, the present invention provides a turbine blade cooling rib configuration, which is an irregular topological structure constructed by the above method, and its shape is either an interlaced oblique rib or an aircraft-shaped rib.

[0038] The staggered rib configuration includes multiple sets of inclined ribs arranged alternately along the fluid flow direction, with adjacent inclined ribs having opposite inclination directions, and the angle between the major axis of the inclined ribs and the flow direction being 30°~60°.

[0039] The aircraft-shaped spoiler rib includes multiple streamlined cross-section ribs, which have smooth leading edges and sharp trailing edges, and are arranged in an array within the cooling channel to induce longitudinal vortices.

[0040] Fourthly, the present invention provides an aero-engine turbine blade, including a blade body and the aforementioned friction rib configuration disposed in its internal cooling channel.

[0041] This invention integrates fluid-structure interaction (FSI) solution, adjoint sensitivity analysis, and level set topology optimization to construct a unified single-domain governing equation model. This model implicitly represents both solid and fluid regions and dynamically drives the evolution of the fringe boundary using level set functions, thereby automatically generating irregular, high-efficiency cooling structures. While significantly improving the Nusselt number ratio and overall cooling efficiency of cooling channels, it drastically reduces the computational cost of the optimization process, providing an efficient and reliable solution for the cooling design of high-performance aero-engine turbine blades.

[0042] Compared with the prior art, the beneficial effects that the at least one technical solution adopted in the embodiments of the present invention can achieve include at least:

[0043] 1. Compared to traditional methods that rely on pre-defined parametric rib shapes such as rectangles and W-shapes, which can only be adjusted within a local parameter space, this invention overcomes geometric limitations by automatically evolving boundaries through level set topology optimization. It requires no pre-defined shape and can generate complex and efficient structures such as staggered oblique ribs and aircraft-shaped spoiler ribs, achieving global synergistic optimization of heat transfer and flow performance within the cooling channel.

[0044] 2. Compared to existing optimization processes that often neglect solid heat conduction or use simplified thermal boundary conditions, leading to design results that deviate from reality, this invention solves for fluid flow and solid heat conduction simultaneously in a unified equation set, performing high-precision fluid-structure interaction modeling to accurately describe the heat transfer behavior at the solid-liquid interface and in high-gradient regions, ensuring that the optimization results reflect the real heat transfer process.

[0045] 3. To address the high cost of sensitivity calculation in traditional topology optimization, this invention employs the adjoint method to analytically solve the gradient of the objective function, avoiding numerous numerical differential trial calculations and significantly improving computational efficiency. Simultaneously, by introducing the Brinkman penalty term, the complexity of explicit interface processing is eliminated, and convergence is achieved in only 30–50 iterations under typical operating conditions, greatly shortening the design cycle while ensuring accuracy.

[0046] 4. Under the same constraint of turbulence rib volume fraction, the irregular structure generated by the present invention can effectively enhance fluid disturbance and suppress flow separation. Compared with traditional rectangular ribs, W-shaped ribs or wave-shaped ribs, the Nusselt number ratio is increased by 1% to 296%, the overall cooling efficiency is increased by 4.6% to 46.4%, and the average wall temperature is significantly reduced.

[0047] 5. The method of the present invention does not rely on specific geometric priors or empirical rules, and is applicable to various internal heat transfer scenarios. It can be extended to engineering scenarios involving efficient heat transfer such as gas turbine blades, high-temperature heat exchangers, and microchannel heat dissipation of electronic devices, and has good universality and scalability. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a flowchart of the turbine blade cooling fringe construction method based on level set topology optimization according to the present invention;

[0050] Figure 2 The execution flow of the turbine blade cooling turbulence rib structure of the present invention;

[0051] Figure 3 This is an architectural diagram of the turbine blade cooling fringe construction system based on level set topology optimization of the present invention;

[0052] Figure 4 The spoiler rib configuration is an interlaced oblique rib shape;

[0053] Figure 5 The spoiler rib configuration is in the shape of an aircraft-shaped spoiler rib;

[0054] Among them, 301 is the fluid-structure interaction modeling unit; 302 is the fluid-structure interaction solution unit; 303 is the optimization model construction unit; 304 is the topology evolution driving unit; and 305 is the iterative control and output unit. Detailed Implementation

[0055] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0056] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features of the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0057] This invention provides a method for constructing turbine blade cooling fringe based on level set topology optimization. See [link to relevant documentation]. Figure 1 and Figure 2 As shown, the method includes the following steps:

[0058] Step S1: Construct a fluid-structure interaction calculation model that includes the cooling channel fluid domain, the blade wall solid domain and their interface, and define a level set function to implicitly represent the cooling channel fluid domain and the blade wall solid domain;

[0059] Step S2: Based on the level set function, establish a unified set of control equations covering the entire computational domain, introduce a flow velocity suppression mechanism in the solid domain of the blade wall, perform single-domain coupling solution of fluid flow and solid heat conduction, and obtain the fluid-structure interaction physical field solution.

[0060] Step S3: Based on the fluid-structure interaction physical field solution, construct an optimization model with cooling performance as the objective function and the volume fraction of the turbulence ribs as the constraint, and calculate the current objective function value;

[0061] Step S4: Based on the optimization model, calculate the sensitivity of the objective function to the level set function, and drive the level set function to update in order to evolve the topological boundary of the fringe rib;

[0062] Step S5: Determine whether the convergence condition is met based on the current objective function value. If it is met, output the final rib geometry. If it is not met, re-execute the fluid-structure interaction solution, optimization model construction, and level set function update based on the updated level set function until the convergence condition is met and the final rib geometry is output.

[0063] The construction principle of the turbine blade cooling fringe of this invention is as follows: the topological configuration of the fringe is implicitly represented by a horizontal set function, and a velocity suppression mechanism (such as a Brinkman penalty term) is introduced into the unified governing equation to achieve single-domain coupled solution of the fluid and solid domains; at the same time, the sensitivity of the objective function to the horizontal set function is efficiently calculated, and this sensitivity is used to drive the horizontal set function to update and evolve the topological boundary of the fringe. This mechanism abandons the explicit tracking and partitioning modeling of the fluid-structure interface in traditional methods, transforming the complex fluid-structure coupled multiphysics optimization problem into a partial differential equation solution problem on a single continuous field.

[0064] In some embodiments of step S1 above, within the three-dimensional design area, the cooling channel fluid domain is clearly defined. Solid domain of blade wall and the fluid-structure interface between the two The positive value of the horizontal set function corresponds to the fluid domain of the cooling channel, and the negative value corresponds to the solid domain of the blade wall. Its zero iso-face corresponds to the interface between the two. The horizontal set function is initialized to an initial field covering the design region to initiate the topology evolution process.

[0065] Specifically, the process of implicitly characterizing the fluid domain of the cooling channel and the solid domain of the blade wall by defining a level set function is as follows:

[0066] First, define the level set function. Using level set functions Characterize any spatial point within the design area The structural distribution state, For the coordinates of any spatial point within the design area, the expression for the level set function is:

[0067] ;

[0068] in, Representing a spatial point To the structural boundary ( The signed distance function of the 0 isosurface. The boundary surface of the rib.

[0069] Secondly, according to The fluid region and the solid region are divided. At that time, the corresponding solid domain of the blade wall (turbulence rib material); At that time, the corresponding cooling channel fluid domain (cooling medium); At this time, it is the solid-liquid interface (turbulence rib boundary).

[0070] Secondly, regarding the level set function Perform initialization. ,in For the amplitude of small disturbances (range 10) -3 ~10 -2 ), It is a random function that follows a standard normal distribution and is used to provide the initial evolution seed.

[0071] Finally, initialize the equations. ,in To initialize pseudo-time, This is a sign function used to preserve the distance function properties of the level set function and avoid function distortion during iteration.

[0072] In some embodiments of step S2 above, a single-domain coupled solution of fluid flow and solid heat conduction is performed to obtain the fluid-structure interaction physical field solution. Specifically, in each iteration, based on the current level set function, a unified set of governing equations covering the entire computational domain is established according to the fluid domain of the cooling channel and the solid domain of the blade wall. A Brinkman penalty term is introduced in the solid domain of the blade wall to suppress the fluid velocity. The fluid flow and solid heat conduction processes are coupled and solved in the same unified set of governing equations to obtain the fluid-structure interaction physical field solution for the current iteration step.

[0073] Specifically, a unified governing equation can be used to describe the energy transfer process in the solid-fluid region, achieving close coupling of fluid-solid heat transfer. The specific expression of the unified governing equation is as follows:

[0074] (1) The continuity equation for the conservation of mass can be expressed as:

[0075] ;

[0076] (2) The momentum equation describing the conservation of momentum can be expressed as:

[0077] ;

[0078] In establishing the momentum equation, a Brinkman penalty term is introduced as the velocity suppression mechanism. The expression for the Brinkman penalty term is:

[0079] ;

[0080] in, For fluid velocity vector, , The maximum penalty coefficient is preset, when When it approaches 1 (solid region), The fluid velocity is forcibly suppressed to approach 0; when When it approaches 0 (fluid region), This does not affect the normal flow of the fluid, thereby achieving unified numerical calculation of the solid and fluid regions;

[0081] (3) The energy equation describing energy conservation can be expressed as:

[0082] ;

[0083] in, For the medium density (fluid density is taken as fluid density in the fluid domain) The solid domain takes the solid density. ), For fluid velocity vector, For pressure, For dynamic viscosity (fluid domain) solid domain And the value is extremely large). For enthalpy, For temperature, For Brinkman's penalty item, For effective thermal conductivity.

[0084] Numerical solutions for fluid-structure interaction are obtained by employing the continuity equation, momentum equation, and energy equation. Specifically, this includes ensuring that the continuity equation... Momentum equation Energy equation .

[0085] In some embodiments of step S3 above, the objective function is the average temperature of the outer wall surface on the combustion side of the blade or the Nusselt number ratio of the cooling channels:

[0086] The expression for the average temperature of the outer wall surface of the blade on the combustion side is as follows:

[0087] ,in, This represents the average temperature of the outer wall surface on the combustion side of the blade. For local temperature, For fluid-structure interface;

[0088] The expression for the Nusselt number ratio is:

[0089] ;

[0090] In the formula, Nussel for cooling channels, The average Nusselt number for smooth circular tubes with the same equivalent diameter. The equivalent diameter of the channel. The wall heat transfer coefficient is... The Reynolds number of the cooling channel. The thermal conductivity of the cold air. Let be the Prandtl number of the air conditioner, taken as 0.7.

[0091] In addition, depending on actual needs, the heat transfer coefficient or the overall cooling efficiency can be used as the objective function. At the same time, the constraints are clearly defined as the total volume of the cooling channel remaining unchanged and the volume fraction of the turbulence fins being limited.

[0092] Preferably, the volume fraction of the turbulence ribs is the ratio of the volume occupied by the turbulence ribs to the total volume of the cooling channel, and its value ranges from 10% to 30%.

[0093] In some embodiments of step S4 above, the sensitivity is calculated using an adjoint method, including:

[0094] S41. Construct the Lagrangian function L, wherein the expression for the Lagrangian function L of the adjoint equation is: ;

[0095] in, The average temperature of the wall surface. The accompanying velocity vector, As an accompanying temperature scalar, For the residuals of the continuous equation, This is the residual of the momentum equation. The residual of the energy equation, Let Ω be the infinitesimal volume within the physical domain. Represents the Hamiltonian operator. The density of the cooling fluid, The velocity vector of the fluid. This refers to the static pressure of the fluid within the cooling channel. The molecular dynamic viscosity of the cooling fluid. The volume force source term vector, For enthalpy, The effective thermal conductivity of the cooling fluid, This refers to the temperature of the fluid within the cooling channel;

[0096] S42, By analyzing the Lagrange function with respect to the state variable... and Find the variational equation and set it to zero to obtain the adjoint equation system. Solve the adjoint equation system to obtain the gradient of the objective function with respect to the level set function, and obtain the sensitivity.

[0097] Specifically, the adjoint equations include:

[0098] The accompanying continuity equation is expressed as:

[0099] ;

[0100] The accompanying momentum equation is expressed as follows:

[0101] ;

[0102] The accompanying energy equation is expressed as follows:

[0103] ;

[0104] Furthermore, the boundary conditions for the adjoint equation are:

[0105] At the import / export boundary, the accompanying velocity normal component is zero. The accompanying temperature normal gradient is zero. ,in The unit normal vector at the boundary; at the fluid-structure boundary Accompanied by continuous velocity Accompanied by continuous heat flow Solving the adjoint equation yields and Then, the sensitivity of the objective function to the level set function is:

[0106] ;

[0107] in, , Based on the sensitivity expression, the optimization direction for thickening or thinning the fringe is determined.

[0108] In some embodiments of step S4 above, the sensitivity can be used to determine the normal velocity term of the Hamilton-Jacobi type level set evolution equation, driving the update of the current level set function to obtain the evolved level set field to characterize the topologically evolved perturbation rib boundary. Specifically, the level set function is updated by solving the Hamilton-Jacobi type evolution equation, the expression of which is:

[0109] ;

[0110] in, Let t be the normal velocity, and t be the pseudo-time of the level set evolution. The normal velocity can be obtained from the average wall temperature. and level set function The following formula is used to calculate the result. This invention utilizes Hamilton-Jacobi type evolution equations to achieve the natural growth, disappearance, splitting, and topological changes of the geometry of the turbulence ribs.

[0111] Step S5 involves repeatedly solving the original fluid-structure interaction equations, the adjoint equations, calculating sensitivity, and updating the topology. During the iteration process, an adaptive local mesh refinement technique can be employed to refine the mesh near the zero isosurface of the level set function and in regions with large temperature and velocity gradients. Iteration stops when the rate of change of the objective function is less than 1%, ultimately generating the optimal fringe structure.

[0112] Based on the same inventive concept, this invention also provides a turbine blade cooling fringe construction system based on level set topology optimization, as described in the following embodiments. Since the principle of the turbine blade cooling fringe construction system based on level set topology optimization is similar to that of the turbine blade cooling fringe construction method based on level set topology optimization, the implementation of the turbine blade cooling fringe construction system based on level set topology optimization can refer to the implementation of the turbine blade cooling fringe construction method based on level set topology optimization disclosed in the above embodiments, and will not be repeated. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0113] Figure 3 This is a structural block diagram of a turbine blade cooling fringe construction system based on level set topology optimization disclosed in an embodiment of the present invention, as shown below. Figure 3 As shown, the system includes a fluid-structure interaction modeling unit 301, a fluid-structure interaction solution unit 302, an optimization model construction unit 303, a topology evolution driving unit 304, and an iterative control and output unit 305. The structure is described below.

[0114] Specifically, the fluid-structure interaction modeling unit 301 is used to construct a fluid-structure interaction calculation model that includes the cooling channel fluid domain, the blade wall solid domain and their interface, and to define a level set function to implicitly represent the cooling channel fluid domain and the blade wall solid domain.

[0115] The fluid-structure interaction solution unit 302 is used to establish a unified set of control equations covering the entire computational domain based on the horizontal set function, introduce a flow velocity suppression mechanism in the solid domain of the blade wall, perform single-domain coupling solution of fluid flow and solid heat conduction, and obtain fluid-structure interaction physical field solution.

[0116] The optimization model construction unit 303 is used to construct an optimization model with cooling performance as the objective function and the volume fraction of the turbulence ribs as the constraint condition based on the solution of the fluid-structure interaction physical field, and to calculate the current objective function value;

[0117] The topology evolution driving unit 304 is used to calculate the sensitivity of the objective function to the level set function based on the optimization model, and drive the level set function to update in order to evolve the topological boundary of the fringe rib.

[0118] The iterative control and output unit 305 is used to determine whether the convergence condition is met based on the evolved horizontal set field and the current objective function value. If the condition is not met, the evolved horizontal set field is used as the horizontal set function for the next iteration step. If the condition is met, the iteration is terminated and the final rib geometry that satisfies the rib volume fraction constraint and the objective function converges is output.

[0119] This invention also provides a turbine blade cooling spoiler rib configuration. This configuration is an irregular topological structure constructed by the above method, and its shape is either an interlaced oblique rib or an aircraft-shaped spoiler rib. Specifically, this embodiment takes the internal straight cooling channel of an aero-engine high-pressure turbine blade as the research object, and the spoiler rib construction process is as follows:

[0120] Step 1: Cooling Channel Model Construction: The specific parameters of the straight cooling channel include a length of 50mm, a width of 20mm, a height of 10mm, and a channel wall thickness of 0.5mm. The upper wall is the cold air channel wall, and the lower wall is in contact with the gas combustion zone. An equivalent convection boundary is used to replace the gas combustion properties. The boundary conditions of the cooling channel are set as follows: cold air inlet total temperature 500K, total pressure 1000kPa, outlet static pressure 990kPa; gas combustion side heat transfer coefficient 2000W / (m²·K), gas combustion temperature 1500K.

[0121] Step 2: Solving the fluid-structure interaction governing equations: A unified governing equation is used to describe the physical behavior of the fluid and solid regions. The specific equations are as follows:

[0122] Continuity equation: fluid domain solid domain This equation is used to describe the conservation of fluid mass, ensuring the balance between fluid density and velocity during flow.

[0123] Momentum equation: fluid domain solid domain The equation introduces a Brinkman penalty term. ,in In this embodiment ,when When =1, the flow velocity is forced to approach 0, achieving flow suppression in the solid region; when When the value is 0, the penalty term is invalid and does not affect the normal flow of fluid.

[0124] Energy equation: , ( For isobaric specific heat capacity, fluid domain solid domain Effective thermal conductivity ,in , This formula automatically handles the thermal conductivity difference at the solid-liquid interface.

[0125] Step 3: Perform level set topology optimization

[0126] Step 3.1: Initialize the level set function and set the initial level set function. =0, and apply a small perturbation to provide the initial structural basis for the evolution of the perturbation ribs. Initialization expression This ensures that the initial disturbance is small and uniform;

[0127] Step 3.2: Initialize the equations and set the iteration step size. The initial iteration count is 20 times after each round of topology update, until... ;

[0128] Step 3.3: Setting the objective function and constraints. The optimization objective is to reduce the average temperature of the turbine blade's outer wall surface. The objective function expression is as follows: The constraints are that the total volume of the cooling channel remains unchanged, and the volume fraction of the turbulence ribs is no more than 15%.

[0129] Step 3.4: Accompanied sensitivity analysis, constructing the Lagrange functional. Differentiating the Lagrange function, we establish the adjoint continuity equation, adjoint momentum equation, and adjoint energy equation, and solve for the adjoint velocity field. and accompanying temperature field Thus, the sensitivity expression is obtained: .

[0130] Step 3.5: Level set function update and mesh processing, using the level set evolution equation. Update function, where Adaptive local mesh refinement technology is employed during the iteration process. Mesh refinement is performed near 0 and in areas with large temperature and velocity gradients, with a maximum refinement level of 3 layers to ensure the capture of complex structural features.

[0131] Step 4: Iterative Convergence and Result Optimization

[0132] Following the iterative process of "solving the original fluid-structure interaction equation → solving the adjoint equation → calculating sensitivity → updating the level set function → adaptive mesh generation", convergence is determined when the rate of change of the objective function is <1%. In this embodiment, the convergence condition is reached after 42 iterations, and two types of efficient flow-disrupting rib structures are automatically generated.

[0133] The staggered oblique rib shape is as follows: Figure 4 As shown, it includes multiple sets of inclined ribs arranged alternately along the fluid flow direction. The inclined directions of adjacent inclined ribs are opposite, and the angle between the long axis of the inclined rib and the flow direction is 30°~60°. This structure forms two large-scale counter-rotating vortices in the flow direction, which can effectively disturb the fluid boundary layer and is suitable for low Reynolds number conditions.

[0134] The aircraft-shaped spoiler rib is shaped as follows: Figure 5 As shown, the device comprises multiple streamlined cross-section ribs with smooth leading edges and sharp trailing edges. These ribs are arranged in an array within the cooling channel to induce longitudinal vortices. This type of rib, with its sharp leading edge and airfoil structure at the rear, reduces fluid resistance, maintains a large Nusselt number ratio under high Reynolds number conditions, exhibits uniform temperature distribution, and achieves optimal overall cooling efficiency.

[0135] Step 4: Performance Comparison and Verification

[0136] Under the same operating conditions, the performance of the two types of rib structures generated by this invention was compared with that of traditional rectangular ribs, wavy ribs, and W-shaped ribs. The results are shown in Table 1 below:

[0137] Table 1: Performance comparison results of the baffles constructed by the method of the present invention and the traditional method

[0138]

[0139] As shown in Table 1 above, the staggered oblique ribs and aircraft-shaped spoiler ribs generated by the present invention are significantly superior to the traditional structure in terms of Nusselt number ratio and overall cooling efficiency. Among them, the overall cooling efficiency of the aircraft-shaped spoiler ribs is improved by about 46.4% compared with the traditional rectangular ribs, which verifies the effectiveness and superiority of the method of the present invention.

[0140] This invention also provides an aero-engine turbine blade, including a blade body and the aforementioned friction rib configuration disposed in its internal cooling channel.

[0141] This invention integrates fluid-structure interaction (FSI) solution, adjoint sensitivity analysis, and level set topology optimization to construct a unified single-domain governing equation model. This model implicitly represents both solid and fluid regions and dynamically drives the evolution of the fringe boundary using level set functions, thereby automatically generating irregular, high-efficiency cooling structures. While significantly improving the Nusselt number ratio and overall cooling efficiency of cooling channels, it drastically reduces the computational cost of the optimization process, providing an efficient and reliable solution for the cooling design of high-performance aero-engine turbine blades.

[0142] Compared with the prior art, the beneficial effects that the at least one technical solution adopted in the embodiments of the present invention can achieve include at least:

[0143] 1. Compared to traditional methods that rely on pre-defined parametric rib shapes such as rectangles and W-shapes, which can only be adjusted within a local parameter space, this invention overcomes geometric limitations by automatically evolving boundaries through level set topology optimization. It requires no pre-defined shape and can generate complex and efficient structures such as staggered oblique ribs and aircraft-shaped spoiler ribs, achieving global synergistic optimization of heat transfer and flow performance within the cooling channel.

[0144] 2. Compared to existing optimization processes that often neglect solid heat conduction or use simplified thermal boundary conditions, leading to design results that deviate from reality, this invention solves for fluid flow and solid heat conduction simultaneously in a unified equation set, performing high-precision fluid-structure interaction modeling to accurately describe the heat transfer behavior at the solid-liquid interface and in high-gradient regions, ensuring that the optimization results reflect the real heat transfer process.

[0145] 3. To address the high cost of sensitivity calculation in traditional topology optimization, this invention employs the adjoint method to analytically solve the gradient of the objective function, avoiding numerous numerical differential trial calculations and significantly improving computational efficiency. Simultaneously, by introducing the Brinkman penalty term, the complexity of explicit interface processing is eliminated, and convergence is achieved in only 30–50 iterations under typical operating conditions, greatly shortening the design cycle while ensuring accuracy.

[0146] 4. Under the same constraint of turbulence rib volume fraction, the irregular structure generated by the present invention can effectively enhance fluid disturbance and suppress flow separation. Compared with traditional rectangular ribs, W-shaped ribs or wave-shaped ribs, the Nusselt number ratio is increased by 1% to 296%, the overall cooling efficiency is increased by 4.6% to 46.4%, and the average wall temperature is significantly reduced.

[0147] 5. The method of the present invention does not rely on specific geometric priors or empirical rules, and is applicable to various internal heat transfer scenarios. It can be extended to engineering scenarios involving efficient heat transfer such as gas turbine blades, high-temperature heat exchangers, and microchannel heat dissipation of electronic devices, and has good universality and scalability.

[0148] In this embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the above-described methods for constructing turbine blade cooling fringe based on level set topology optimization.

[0149] Specifically, the computer device can be a computer terminal, a server, or a similar computing device.

[0150] In this embodiment, a computer-readable storage medium is provided, which stores a computer program that executes any of the above-described methods for constructing turbine blade cooling fringe based on level set topology optimization.

[0151] Specifically, computer-readable storage media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable storage media does not include transient media, such as modulated data signals and carrier waves.

[0152] Obviously, those skilled in the art should understand that the modules or steps of the above-described embodiments of the present invention can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the embodiments of the present invention are not limited to any particular hardware and software combination.

[0153] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of 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 method for constructing cooling fringe ribs for turbine blades based on level set topology optimization, characterized in that, The method includes: A fluid-structure interaction computational model is constructed, which includes the fluid domain of the cooling channel, the solid domain of the blade wall, and their interface. A level set function is defined to implicitly represent the fluid domain of the cooling channel and the solid domain of the blade wall. Based on the aforementioned level set function, a unified set of governing equations covering the entire computational domain is established. A velocity suppression mechanism is introduced within the solid domain of the blade wall to perform a single-domain coupled solution of fluid flow and solid heat conduction, obtaining the fluid-structure interaction physical field solution. The unified set of governing equations includes a continuity equation describing mass conservation, a momentum equation describing momentum conservation, and an energy equation describing energy conservation. When establishing the momentum equation, a Brinkman penalty term is introduced as the velocity suppression mechanism. The expression for the Brinkman penalty term is: ;in, For level set functions, For fluid velocity vector, , The maximum penalty coefficient is preset. Based on the fluid-structure interaction physical field solution, an optimization model is constructed with cooling performance as the objective function and the volume fraction of the turbulence ribs as the constraint condition, and the current objective function value is calculated; Based on the optimization model, the sensitivity of the objective function to the level set function is calculated, and the level set function is updated to evolve the topological boundary of the rib; the sensitivity is calculated using the adjoint method, including: constructing the Lagrangian function L, wherein the expression for the Lagrangian function L using the adjoint method is: ;in, The average temperature of the wall surface. The accompanying velocity vector, As an accompanying temperature scalar, For the residuals of the continuous equation, This is the residual of the momentum equation. The residual of the energy equation, Let Ω be the infinitesimal volume within the physical domain. Represents the Hamiltonian operator. The density of the cooling fluid, The velocity vector of the fluid. The static pressure of the fluid within the cooling channel. The molecular dynamic viscosity of the cooling fluid. The volume force source term vector, For enthalpy, The effective thermal conductivity of the cooling fluid, The fluid temperature in the cooling channel is used; by taking the variation of the Lagrangian function with respect to the state variables and setting it to zero, the adjoint equations are obtained; by solving the adjoint equations, the gradient of the objective function with respect to the level set function is obtained, and the sensitivity is obtained. The convergence condition is determined based on the current objective function value. If the convergence condition is met, the final rib geometry is output. If not, the fluid-structure interaction solution, optimization model construction, and level set function update are re-executed based on the updated level set function until the convergence condition is met and the final rib geometry is output.

2. The method for constructing turbine blade cooling fringe based on level set topology optimization according to claim 1, characterized in that, The positive value of the horizontal set function corresponds to the fluid domain of the cooling channel, the negative value corresponds to the solid domain of the blade wall, and its zero isovalue corresponds to the interface between the two.

3. The method for constructing turbine blade cooling fringe based on level set topology optimization according to claim 1, characterized in that, The objective function is the average temperature of the outer wall surface on the combustion side of the blade or the Nusselt number ratio of the cooling channels.

4. The method for constructing turbine blade cooling fringe based on level set topology optimization according to claim 1, characterized in that, The volume fraction of the baffle ribs is the ratio of the volume occupied by the baffle ribs to the total volume of the cooling channel, and its value ranges from 10% to 30%.

5. The method for constructing turbine blade cooling fringe based on level set topology optimization according to claim 1, characterized in that, The level set function is updated by solving Hamilton-Jacobi type evolution equations, the expressions of which are: ； in, Normal velocity, Let t be the level set function, and t be the pseudo-time of the level set evolution.

6. A turbine blade cooling fin structure system based on level set topology optimization, characterized in that, To implement the method as described in any one of claims 1 to 5, comprising: The fluid-structure interaction modeling unit is used to construct a fluid-structure interaction calculation model that includes the fluid domain of the cooling channel, the solid domain of the blade wall, and their interface, and defines a level set function to implicitly represent the fluid domain of the cooling channel and the solid domain of the blade wall. The fluid-structure interaction solution unit is used to establish a unified set of governing equations covering the entire computational domain based on the horizontal set function, introduce a flow velocity suppression mechanism in the solid domain of the blade wall, perform single-domain coupling solution of fluid flow and solid heat conduction, and obtain the fluid-structure interaction physical field solution. The optimization model building unit is used to construct an optimization model with cooling performance as the objective function and the volume fraction of the turbulence ribs as the constraint condition based on the solution of the fluid-structure interaction physical field, and to calculate the current objective function value. The topology evolution driving unit is used to calculate the sensitivity of the objective function to the level set function based on the optimization model, and drive the level set function to update in order to evolve the topological boundary of the fringe rib. The iterative control and output unit is used to determine whether the convergence condition is met based on the evolved horizontal set field and the current objective function value. If the condition is not met, the evolved horizontal set field is used as the horizontal set function for the next iteration step. If the condition is met, the iteration is terminated, and the final spoiler rib geometry that satisfies the spoiler rib volume fraction constraint and the objective function converges is output.

7. A turbine blade cooling friction rib configuration device, characterized in that, The irregular topological structure obtained by the method described in any one of claims 1 to 5 is a staggered oblique rib or an aircraft-shaped spoiler rib. The staggered rib configuration includes multiple sets of inclined ribs arranged alternately along the fluid flow direction, with adjacent inclined ribs having opposite inclination directions, and the angle between the major axis of the inclined ribs and the flow direction being 30°~60°. The aircraft-shaped spoiler rib includes multiple streamlined cross-section ribs, which have smooth leading edges and sharp trailing edges, and are arranged in an array within the cooling channel to induce longitudinal vortices.

8. A turbine blade assembly for an aero-engine, characterized in that, It includes the blade body and the friction rib configuration device as described in claim 7, which is disposed in the internal cooling channel therein.

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