Self-adaptive flat plate double-wall cooling structure based on impact slits

Abstract

The invention discloses a self-adaptive flat plate double-wall cooling structure based on impact slits, and belongs to the field of aero-engines. Comprising a target surface; an impact plate; a gas film hole; one or more impact slits are formed in the impact plate and are used for spraying cooling gas to a cold air impact wall surface of the target surface in a long and narrow jet flow form; moreover, the wall surface part, forming the impact slit, on the impact plate is made of an elastic deformable material and forms a deformable wall; the deformable wall is configured to elastically deform in response to changes of thermal parameters acting on the deformable wall, so that the effective flow area of the impact slit is automatically adjusted, and self-adaptive control over the cooling flow is achieved. Passive self-adaptive cooling distributed according to needs is achieved through the variable geometric design, and therefore the cooling efficiency and the overall cycle efficiency of the engine are cooperatively improved.

Description

Technical Field

[0001] This invention belongs to the field of aero-engines, specifically relating to an adaptive flat double-wall cooling structure based on an impact slit. Background Technology

[0002] In pursuit of higher thermal efficiency, modern aero engines have continuously increased turbine inlet temperatures, far exceeding the melting point limits of existing metallic materials. Therefore, to maintain the structural integrity and long-term service life of metal components in such extreme thermal environments, efficient and reliable cooling technology has become a key technological path parallel to the development of high-temperature materials.

[0003] The evolution of cooling technology reflects a relentless pursuit of cooling efficiency: from the initial simple internal convection cooling to highly efficient impingement cooling, then to heat-insulating film cooling, and finally to composite cooling integrating multiple cooling mechanisms. Among these, the double-wall cooling structure is currently the most advanced composite cooling solution. It combines impingement cooling and film cooling—two of the most efficient cooling methods—to achieve effective thermal protection of the combustion gas side of the blades, and is widely used in hot-end components such as high-pressure turbine blades and guide vanes in modern aero-engines. The double-wall cooling structure is one of the most advanced cooling technologies currently available, typically consisting of a load-bearing outer wall and an inner impingement plate. Cool air first impinges on the chamber through holes in the impingement plate, then deflects back into the film cooling holes on the outer wall, forming a film insulation layer.

[0004] While double-walled cooling structures represent the cutting edge of current technology, their traditional implementation methods are gradually facing bottlenecks. With further improvements in engine performance, increasingly stringent requirements are being placed on the efficiency, uniformity, reliability, and adaptability of cooling systems. Traditional double-walled structures, due to their fixed diameter, shape, and arrangement of the impact holes, cannot adjust the cooling gas flow coefficient in real time according to changes in engine operating conditions. This leads to localized overheating and erosion of the high-temperature combustion gas walls.

[0005] In summary, the common limitation of existing technologies lies in the "rigidity" and "static" characteristics of their cooling structures. The size, shape, and layout of the impact holes are fixed after manufacturing, preventing their cooling characteristics from dynamically adjusting to changes in the surface heat load of components under actual engine operating conditions (such as takeoff, cruise, and idling). This "one-size-fits-all" design leads to a significant decrease in cooling efficiency under non-design conditions, manifesting as insufficient cooling in high-heat-load areas, posing a risk of localized overheating and ablation; while low-heat-load areas are over-cooled, wasting valuable coolant and increasing parasitic losses in the engine.

[0006] Therefore, the present invention provides an adaptive flat double-wall cooling structure based on an impact slit. Summary of the Invention

[0007] The technical problem to be solved: To avoid the shortcomings of existing technologies, this invention provides an adaptive flat double-wall cooling structure based on an impact slit. By replacing the impact hole structure with an impact slit, which is made of a material with a special elastic modulus, passive and on-demand adaptive cooling is achieved through variable geometry design, thereby realizing a synergistic improvement in cooling efficiency and overall engine cycle efficiency.

[0008] The technical solution of this invention is: an adaptive flat double-wall cooling structure based on an impact slit, comprising: Target surface 1 has one side being a high-temperature wall surface subjected to high-temperature combustion gas, and the other side being a wall surface impacted by cold gas. The impact plate 2 is positioned opposite to the cold air impact wall of the target surface 1, and a cooling chamber 3 is formed between the two. The air film hole 4 penetrates the target surface 1 and is used to draw the cooling gas in the cooling chamber 3 to the high-temperature wall to form a heat insulation air film. The impact plate 2 is provided with one or more impact slits 5 for spraying cooling gas into the cold gas impact wall of the target surface 1 in the form of a narrow jet. Furthermore, the wall portion of the impact plate 2 that forms the impact slit 5 is made of an elastic deformable material, forming a deformable wall; The deformable wall is configured to elastically deform in response to changes in thermal parameters acting on it, thereby automatically adjusting the effective flow area of ​​the impact slit 5 and achieving adaptive control of the cooling flow rate.

[0009] A further technical solution of the present invention is that the impact slit 5 is a long strip-shaped slit, the length of which is much greater than the width, and the width of which can dynamically change with the deformation of the deformable wall. A further technical solution of the present invention is that the elastic modulus of the elastic deformable material is in the range of 50 GPa to 70 GPa.

[0010] A further technical solution of the present invention is that the impact slits 5 are arranged in an array on the impact plate 2, and one impact slit 5 replaces a whole row of traditional discrete circular impact holes in the cooling coverage area.

[0011] A further technical solution of the present invention is that the air film holes 4 on the target surface 1 and the impact slits 5 on the impact plate 2 are arranged alternately in projection.

[0012] A further technical solution of the present invention is: the thermodynamic parameters include the pressure load and temperature load on the impact plate 2; under high load conditions, the increased pressure load and temperature load jointly drive the deformable wall to deform away from the opposite wall surface, thereby increasing the width of the impact slit 5; under low load conditions, the reduced load causes the deformable wall to reset under its own elastic restoring force, thereby reducing the width of the impact slit 5.

[0013] A design method for an adaptive flat double-walled cooling structure based on an impact slit, the specific steps of which are as follows: S1: Determine the adaptive target: Based on the engine's varying operating conditions, determine the target deformation that the impact slit of the cooling structure needs to achieve between the target high-load condition and the target low-load condition. and the corresponding change in target circulation area; S2: Establish a parametric design model: Establish a parametric model of the impact plate, in which the wall portion constituting the impact slit is abstracted as having a specific length. An elastic microbeam structure with cross-sectional moment of inertia I and torsional moment of inertia J is given initial material parameters, including elastic modulus E and shear modulus G. S3: Constructing the mechanical response relationship: Based on the theory of elasticity, establish the mechanical response relationship of the elastic microbeam structure under the action of cooling airflow, including its deformation perpendicular to the wall surface. Dominated by the following formula:

[0014] At the same time, its deformation in the direction parallel to the wall surface Dominated by the following formula:

[0015] in, ; The effective uniformly distributed load acting on the elastic microbeam is T, where T is the torque distributed per unit length; It includes the layout P, ​​number N, width W of the impact slits, and the total pressure at the main inlet. and total temperature The function, ; S4: Perform numerical simulation and parameter matching of fluid-structure-thermal coupling. Embed the parameterized model described in S2 and the mechanical response relationship described in S3 into numerical analysis software; Apply pressure and temperature load boundary conditions corresponding to the target high-load and low-load conditions; By iteratively adjusting the combination of the material and geometric parameters, a fluid-structure-thermal coupling simulation is performed until the deformation calculated by the simulation matches the target deformation determined by S1. The matching parameters determine a set of final design parameters. S5: Output and Manufacturing: Based on the final design parameters obtained in S4, complete the design of the adaptive flat double-wall cooling structure.

[0016] An adaptive flat plate double-wall cooling method based on impact slits, the specific steps of which are as follows: S1: Cooling gas flows into the gas collection chamber outside the impact plate 2; S2: Cooling gas passes through the impact slit 5 on the impact plate 2, forming a narrow jet that impacts the inner surface of the target surface 1, performing impact heat exchange; wherein, the adaptive adjustment steps of the impact slit 5 are as follows: S2.1: The deformable wall of the impact plate 2 senses the changes in thermodynamic parameters caused by changes in engine operating conditions in real time; S2.2: When the heat load and pressure increase, the deformable wall undergoes elastic deformation, increasing the effective flow area of ​​the impact slit 5 and automatically increasing the impact cooling air flow rate. S2.3: When the heat load and pressure decrease, the deformable wall elastically recovers, reducing the effective flow area of ​​the impact slit 5 and automatically saving cooling air flow. S3: The airflow that has completed the impact heat exchange is turned back in the cooling chamber 3 and flows out through the air film hole 4 on the target surface 1, forming a covering air film outside the high temperature wall.

[0017] A turbine blade, wherein at least a portion of the turbine blade wall is provided with the aforementioned adaptive flat double-wall cooling structure based on an impact slit.

[0018] Beneficial effects The beneficial effects of this invention are as follows: This invention designs an adaptive flat double-walled cooling structure based on an impact slit, which can change the effective width of the impact slit in real time according to changes in pressure and temperature loads, thereby achieving a balance in the cooling airflow. Compared with the prior art, the advantages and positive effects of this invention are: (1) Adaptive cooling capability: By designing the relevant material parameters of the impact slit, the width of the impact slit can be passively adjusted according to the operating conditions, realizing the "on-demand distribution" of cooling airflow, i.e., adaptive cooling. Under high load conditions, the slit opening increases, delivering more cooling gas to enhance cooling; under low load conditions, the slit opening decreases, automatically saving cooling air. This "on-demand distribution" intelligent cooling mechanism overcomes the inherent defect of low cooling efficiency of traditional fixed hole structures under non-design point operating conditions, enabling components to obtain stable and efficient thermal protection throughout the entire engine operating envelope.

[0019] (2) Excellent anti-clogging performance: Compared with small-diameter round holes, the equivalent hydraulic diameter of the slit is larger and it is not easily completely blocked by particles, which improves the reliability and service life of the cooling system. Compared with circular jets, the elongated impact jet can form a more continuous and uniform cooling coverage on the target wall, reducing the "cooling stagnation zone" that exists between traditional round hole jets.

[0020] (3) Simplified structure and weight reduction potential: A single slit can replace an entire row of impact holes, reducing the amount of processing, simplifying the structure, and having the potential to reduce weight. Attached Figure Description

[0021] Figure 1 Schematic diagram of a typical flat plate impact cooling structure; Figure 2 The embodiment of this invention features an adaptive flat double-wall cooling structure. Figure 3 : Top view of the impact slit in an embodiment of the present invention; Figure 4 : A cloud map showing the distribution of the deformation of the impact plate in an embodiment of the present invention; Figure 5 The following are cloud diagrams of the overall cooling effect distribution before and after deformation in the embodiments of the present invention: (a) cloud diagram of the overall cooling effect distribution of the cooling structure before deformation, (b) cloud diagram of the overall cooling effect distribution of the cooling structure after deformation. Explanation of reference numerals in the attached diagram: 1. Target surface, 2. Impact plate, 3. Cooling chamber, 4. Film gas hole, 5. Impact slit. Detailed Implementation The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] like Figure 1As shown, existing technologies employ a traditional double-wall cooling structure using a discrete circular impact hole array. In this scheme, a large number of small circular holes are machined on the impact plate according to a certain rule (such as in a straight line or a staggered arrangement). The cooling airflow passes through these holes, forming a series of discrete, high-speed circular air jet columns that vertically impact the inner surface of the target surface. Each jet creates a highly efficient cooling region around its impact point. This scheme consists of three core parts: (1) Target surface (outer wall): It forms part of the double wall and is subjected to high-temperature gas scouring. It has gas film pores distributed on it.

[0024] (2) Impact plate (inner wall): It is placed parallel to the target surface and forms a closed cooling chamber by welding or casting. The impact plate is machined with a large number of small circular holes arranged in a straight or staggered pattern, which are called impact holes.

[0025] (3) Cooling chamber: The cavity located between the two walls mentioned above.

[0026] The detailed cooling process is as follows: High-pressure cooling gas enters the gas collection chamber outside the impact plate, passes through numerous circular impact holes, and forms multiple discrete high-speed circular air jets. These jets vertically impact the inner surface (cold side) of the target surface. After completing the impact cooling, the airflow is reversed in the chamber and finally flows out through the air film holes on the target surface, forming a heat-insulating air film.

[0027] The existing technical solution has the following main drawbacks, which can be analyzed from three dimensions: technology, cost, and efficiency. (a) Technical shortcomings (1) Low anti-clogging and reliability: Micrometer-diameter orifices are easily clogged, either partially or completely, by tiny impurities such as dust, oil, and burning carbon particles carried by the cooling air. Once clogged, the corresponding target area will instantly lose impact cooling, leading to localized overheating, ablation, or even structural failure, posing a serious threat to engine operating safety. Maintaining and inspecting the blockage of these orifices is also extremely difficult.

[0028] (2) Lack of adaptive ability: The size, shape, and layout of the impact holes are fixed after manufacturing. Their cooling characteristics cannot be self-adjusted according to the actual operating conditions of the engine (such as changes in heat load distribution under different power levels). They may perform well at the design point, but their cooling efficiency will decrease under non-design conditions (such as takeoff, cruise, and idling), resulting in poor adaptability.

[0029] (ii) Cost disadvantages (1) High manufacturing cost: Machining thousands of micro-holes with extremely small diameters and large aspect ratios on high-temperature alloy impact plates requires highly sophisticated processing techniques (such as laser drilling and electrical discharge machining), resulting in long processing cycles and significant wear and tear on tools and equipment. Furthermore, issues such as hole deviations, burrs, and micro-cracks are prone to occur during processing, leading to a high scrap rate and increasing the cost per unit.

[0030] (2) High maintenance and potential life-cycle costs: Blockages during use are difficult to detect online, usually requiring engine disassembly and complex non-destructive testing (such as endoscopic inspection), resulting in high maintenance costs. Once cooling failure occurs due to blockage or thermal fatigue, the entire hot-end component (such as turbine blades) must be scrapped and replaced, which is very expensive.

[0031] (III) Disadvantages in terms of efficiency (1) Regarding overall efficiency, due to the existence of a cooling stagnation zone, the utilization efficiency of the cooling working fluid is not high overall. Some of the cooling gas is not effectively used for heat exchange, but participates in the inefficient mixing process in the chamber. In order to meet the overall cooling requirements, more cooling air is often required.

[0032] (2) Due to unstable airflow pressure and uneven flow rate at the gas film vents, the resulting gas film coverage and stability are poor, leading to reduced insulation efficiency. Fluid resistance and power consumption: (3) When the cooling airflow passes through a large number of small holes, it will generate significant throttling losses and frictional resistance. In order to maintain the required cooling flow, higher pressure air needs to be drawn from the compressor, which will increase engine losses and have a negative impact on overall engine efficiency.

[0033] Based on the above problems, existing technologies have been further optimized, for example: Existing technologies (such as CN202411621167.X) optimize airflow distribution within the cooling chamber and improve the uniformity of flow distribution in the film cooling holes by setting narrow walls and baffles. However, the impact holes are still fixed circular holes, which cannot adjust the flow rate according to changes in operating conditions, and the inherent risk of clogging in micron-sized circular holes is not resolved.

[0034] Existing technologies (such as CN202510956002.6) set fixed protrusions and guide ribs on the target surface to redirect the impinging jet and improve local heat transfer intensity. However, this is also a passive and fixed geometric optimization, which does not have the ability to respond to changes in global heat load.

[0035] Existing technologies (such as CN202111606243.6) introduce fixed contraction / expansion slits on the fins of the inner wall of the film cooling plate. Their main purpose is to improve heat transfer uniformity, rather than to regulate cooling flow. These slits are static structures machined onto fixed fins, and their geometry cannot be changed once manufactured.

[0036] In summary, existing technical solutions suffer from inherent defects such as low reliability and poor adaptability. Furthermore, they are costly due to manufacturing and maintenance issues, leading to reduced economic efficiency. Finally, neither the cooling medium nor the overall energy utilization efficiency of the engine is optimal. This invention aims to fundamentally and systematically address these shortcomings. The specific solution is as follows: This invention proposes an adaptive flat double-wall cooling structure based on an impact slit, comprising: Target surface 1 has one side being a high-temperature wall surface subjected to high-temperature combustion gas, and the other side being a wall surface impacted by cold gas. The impact plate 2 is positioned opposite to the cold air impact wall of the target surface 1, and a cooling chamber 3 is formed between the two. The air film hole 4 penetrates the target surface 1 and is used to draw the cooling gas in the cooling chamber 3 to the high-temperature wall to form a heat insulation air film. The impact plate 2 is provided with one or more impact slits 5 for spraying cooling gas into the cold gas impact wall of the target surface 1 in the form of a narrow jet. Furthermore, the wall portion of the impact plate 2 that forms the impact slit 5 is made of an elastic deformable material, forming a deformable wall; The deformable wall is configured to elastically deform in response to changes in thermal parameters acting on it, thereby automatically adjusting the effective flow area of ​​the impact slit 5 and achieving adaptive control of the cooling flow rate.

[0037] Preferably, the impact slit 5 is a long strip-shaped slit, the length of which is much greater than its width, and its width can dynamically change with the deformation of the deformable wall. Preferably, the impact slits 5 are arranged in an array on the impact plate 2, and one impact slit 5 replaces a whole row of traditional discrete circular impact holes in the cooling coverage area.

[0038] Preferably, the air film holes 4 on the target surface 1 and the impact slits 5 on the impact plate 2 are arranged alternately in projection.

[0039] The thermodynamic parameters include the pressure load and temperature load on the impact plate 2. Under high load conditions, the increased pressure load and temperature load together drive the deformable wall to deform away from the opposite wall surface, thereby increasing the width of the impact slit 5. Under low load conditions, the reduced load causes the deformable wall to reset under its own elastic restoring force, thereby reducing the width of the impact slit 5.

[0040] This invention also proposes a design method for an adaptive flat double-wall cooling structure based on an impact slit, the specific steps of which are as follows: S1: Determine the adaptive target: Based on the engine's varying operating conditions, determine the target deformation that the impact slit of the cooling structure needs to achieve between the target high-load condition and the target low-load condition. and the corresponding change in target circulation area; S2: Establish a parametric design model: Establish a parametric model of the impact plate, in which the wall portion constituting the impact slit is abstracted as having a specific length. An elastic microbeam structure with cross-sectional moment of inertia I and torsional moment of inertia J is given initial material parameters, including elastic modulus E and shear modulus G. S3: Constructing the mechanical response relationship: Based on the theory of elasticity, establish the mechanical response relationship of the elastic microbeam structure under the action of cooling airflow, including its deformation perpendicular to the wall surface. Dominated by the following formula:

[0041] At the same time, its deformation in the direction parallel to the wall surface Dominated by the following formula:

[0042] in, ; The effective uniformly distributed load acting on the elastic microbeam is T, where T is the torque distributed per unit length; It includes the layout P, ​​number N, width W of the impact slits, and the total pressure at the main inlet. and total temperature The function, ; S4: Perform numerical simulation and parameter matching of fluid-structure-thermal coupling. Embed the parameterized model described in S2 and the mechanical response relationship described in S3 into numerical analysis software; Apply pressure and temperature load boundary conditions corresponding to the target high-load and low-load conditions; By iteratively adjusting the combination of the material and geometric parameters, a fluid-structure-thermal coupling simulation is performed until the deformation calculated by the simulation matches the target deformation determined by S1. The matching parameters determine a set of final design parameters. S5: Output and Manufacturing: Based on the final design parameters obtained in S4, complete the design of the adaptive flat double-wall cooling structure.

[0043] This invention also proposes an adaptive flat plate double-wall cooling method based on impact slits, the specific steps of which are as follows: S1: Cooling gas flows into the gas collection chamber outside the impact plate 2; S2: Cooling gas passes through the impact slit 5 on the impact plate 2, forming a narrow jet that impacts the inner surface of the target surface 1, performing impact heat exchange; wherein, the adaptive adjustment steps of the impact slit 5 are as follows: S2.1: The deformable wall of the impact plate 2 senses the changes in thermodynamic parameters caused by changes in engine operating conditions in real time; S2.2: When the heat load and pressure increase, the deformable wall undergoes elastic deformation, increasing the effective flow area of ​​the impact slit 5 and automatically increasing the impact cooling air flow rate. S2.3: When the heat load and pressure decrease, the deformable wall elastically recovers, reducing the effective flow area of ​​the impact slit 5 and automatically saving cooling air flow. S3: The airflow that has completed the impact heat exchange is turned back in the cooling chamber 3 and flows out through the air film hole 4 on the target surface 1, forming a covering air film outside the high temperature wall.

[0044] The present invention also proposes a turbine blade, wherein at least a portion of the wall surface of the turbine blade adopts the aforementioned adaptive flat double-wall cooling structure based on impact slits.

[0045] The above technical solution will be further explained below with reference to the accompanying drawings: In one embodiment, refer to Figure 2 As shown, one of the core features of this invention is that the impact slit is designed not only as a fluid channel but also as a structurally and functionally integrated design. By creating the slit, the originally continuous impact plate is transformed into an array of one or more micro cantilever beams with specific aspect ratios. These micro-beam structures have a natural mechanical amplification effect on the pressure and thermal loads acting on their surfaces. Unlike simple material thermal expansion, this beam structure can convert distributed pressure and thermal stress into significant, usable macroscopic displacements at the beam ends (i.e., the slit edges), thereby achieving effective control over the slit width.

[0046] Another key feature of this invention is that the impact plate is not made of any arbitrary elastic material, but rather the elastic modulus (E) of the material is combined with the geometric dimensions of the microbeam (such as length). Precise parametric matching is performed on the thickness (t). The end deformation (w) of the impact support plate is related to the load it receives and its own length. The elastic modulus E of a material is related to the moment of inertia I of its cross section. That is: (1) “ "For an effective uniformly distributed load, although the actual pressure distribution generated by the slit jet airflow is complex, the resulting end deformation can be equivalent to the deformation produced by an ideal uniformly distributed load. We call this equivalent ideal load the 'effective uniformly distributed load'." )". "The layout P, ​​number N, width W, and total pressure of the main inlet of the impact slits" and mainstream entrance total temperature Related. The function expression is:

[0047] Therefore, the deformation perpendicular to the support plate direction is " "It can be calculated from equation (2):" (2) In the formula, For an effective uniformly distributed load, i.e., gas pressure; E is the length of the impact support plate; E is the elastic modulus (Young's modulus) of the support plate material; I is the moment of inertia of the cross section.

[0048] The gas impact not only generated forces that caused the beam to bend. This also generates a moment T that causes the beam to twist, resulting in an end twist angle along the direction parallel to the support plate: (3) Where T is the torque distributed per unit length, G is the shear modulus of the material, and J is the torsional moment of inertia of the cross section.

[0049] The deformation along the direction parallel to the support plate can then be approximately calculated using equation (4): (4) Therefore, the change in the cross-sectional area of ​​the impact slit is related to " "Positive correlation can complete the adaptive flow adjustment process."

[0050] The method for determining the functional relationship of equation (1) is through numerical simulation, using numerical analysis software to perform fluid-structure-thermal coupling simulation. By establishing a parameterized geometric model in the software and applying different pressure and temperature loads, the functional relationship under different parameter combinations can be accurately calculated. , , Deformation amount under ) By fitting these simulation data, we can obtain the accurate numerical solution or empirical formula of the functional relationship f within a specific operating range.

[0051] In one embodiment, an adaptive flat double-wall cooling structure based on an impact slit mainly includes a target wall 1, an impact plate 2, a cooling chamber 3, and a film cooling hole 4, such as... Figure 2 As shown; (1) Target wall: One side is a high-temperature wall surface that is scoured by high-temperature gas, and the other side is a wall surface impacted by cold air; (2) Two impact plates: They are arranged opposite to the cold air impact wall of the target wall, forming a cooling chamber between them; (3) Gas film holes: penetrating the target wall surface, used to draw the cooling gas in the cooling chamber to the high-temperature wall surface to form a gas film; (4) Impact slit: Two impact plates are spaced 0.5 mm apart to form an impact slit. Figure 3 A top view of the impact slit; The impact plate has one or more impact slits for injecting cooling gas from a cold gas source into the target wall surface in the form of a narrow jet. Its adaptive adjustment mechanism is based on the pressure difference between the inside and outside of the double-wall structure under different operating conditions, driving the impact plate to deform.

[0052] After simulating the aforementioned adaptive flat double-walled cooling structure using CFD software, its pressure and temperature loads were extracted and imported into the static structure module via the external data module of Ansys Workbench. Relevant material properties were then set, and the maximum stress and maximum deformation were analyzed. For example... Figure 4 As shown, when the elastic modulus of the material is set to 50 GPa, the maximum deformation of the impact plate can reach approximately 0.106 mm.

[0053] Figure 5 (a) and Figure 5 Figure (b) shows the surface cooling efficiency distribution cloud maps of the double-walled cooling structure before and after deformation of the impact slit, under the same boundary conditions, on the high-temperature gas side of the flat plate. It can be observed that the cooling efficiency of the deformed impact structure is more uniform, and the average value of the gas film cooling efficiency before deformation is 0.65198, while the average value of the gas film cooling efficiency after deformation is 0.66771, which is 2.41% higher than before deformation.

[0054] Explanation of the relationship between principle and action: Adaptive impact slit design: The impact plate is not a simple flat plate, but a flat plate designed with a material whose elastic modulus is between 50 GPa and 70 GPa (e.g., made of gold foil with a low elastic modulus but high yield strength). Its core characteristic is that the impact plate can deform upward according to the pressure and temperature loads acting on it, thereby increasing the width of the impact slit, increasing its impact effect, thereby enhancing heat transfer and reducing the temperature of the target surface.

[0055] Adaptive working mechanism (passive feedback): The pressure and temperature ratios of the main and secondary flows are typically maintained within a certain range. When the main flow is at high temperature and high pressure, the temperature and pressure of the secondary flow will also increase, leading to increased pressure and temperature loads on the plate and consequently, increased deformation. The specific deformation follows the mechanical behavior of a cantilever beam.

[0056] High-load operating conditions (such as high engine power conditions): High temperature causes significant thermal expansion and deformation of the upper impact plate. High pressure: The cooling air source provided by the compressor also has a higher pressure, resulting in a greater pressure difference between the upper and lower surfaces of the impact plate.

[0057] Dual drive: The combined effect of thermal stress and pressure load strongly drives the upper impact plate to produce significant deformation, maximizing the effective width of the impact slit.

[0058] Result: More cooling airflow is drawn in and impacts the walls of the high-temperature areas that require enhanced cooling, achieving efficient cooling.

[0059] Low-load operating conditions (such as engine idling): Lower temperatures result in less thermal deformation of the upper impact plate. Lower pressure reduces the pressure of the cooling air source, leading to a corresponding decrease in the pressure difference between the upper and lower surfaces of the impact plate.

[0060] State recovery: The force driving the deformation weakens, and the upper impact plate returns to a state of close contact with the lower impact plate under its own elastic restoring force, keeping the slit width to a minimum.

[0061] Result: The cooling air flow rate was automatically reduced, which greatly saved cooling gas consumption and improved circulation efficiency.

[0062] This embodiment verifies, through a specific and repeatable engineering simulation process, that... This functional relationship objectively exists and can be quantified using standard technical means. It indicates that once the structural and material parameters (E, , The deformation response of a material under a specific thermodynamic load is determined by the design. It is unique and predictable. This not only proves the feasibility of the technical solution of the present invention, but also strongly supports the core inventive point of the present invention: that is, to obtain the expected and controllable adaptive cooling performance by actively and collaboratively designing these input parameters.

[0063] Based on the inherent defects of the traditional circular impact hole double-wall cooling structure described in the background art, the present invention aims to solve the following two key technical problems.

[0064] 1. Solve the problems of poor anti-clogging performance and low reliability. Traditional small-diameter circular holes are easily clogged by foreign objects, leading to complete failure of localized cooling and posing a serious safety hazard. The technical problem this invention aims to solve is: how to improve the anti-clogging ability of impact cooling structures, ensuring their long-term and reliable operation even in working environments containing impurities, thereby enhancing the robustness and safety of the cooling system.

[0065] 2. Solve the problem of the structure lacking adaptive cooling capability. Traditional circular orifices have fixed geometry and flow coefficients, making them unable to self-adjust according to changes in the actual heat load on the component surface. The technical problem this invention aims to solve is: how to enable a cooling structure to possess a passive adaptive capability, automatically guiding more cooling airflow to areas with higher heat loads, achieving "on-demand allocation" of cooling resources, and thus maintaining excellent cooling performance under varying operating conditions.

[0066] In summary, the overall goal of this invention is to overcome the challenges of clogging and rigidity in traditional technologies through an innovative structural design, ultimately providing an efficient, reliable, uniform, and intelligent adaptive cooling solution.

[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An adaptive flat double-walled cooling structure based on an impact slit, comprising: The target surface (1) has one side as a high-temperature wall surface that withstands high-temperature gas, and the other side as a cold gas impact wall surface. The impact plate (2) is set opposite to the cold air impact wall of the target surface (1), and a cooling chamber (3) is formed between the two. The air film hole (4) penetrates the target surface (1) and is used to draw the cooling gas in the cooling chamber (3) out to the high temperature wall to form a heat insulation air film; Its features are: The impact plate (2) is provided with one or more impact slits (5) for spraying cooling gas into the cold gas impact wall of the target surface (1) in the form of a narrow jet. Furthermore, the wall portion of the impact plate (2) that forms the impact slit (5) is made of an elastic deformable material, forming a deformable wall; The deformable wall is configured to elastically deform in response to changes in the thermal parameters acting on it, thereby automatically adjusting the effective flow area of ​​the impact slit (5) to achieve adaptive control of the cooling flow rate.

2. The adaptive flat double-wall cooling structure based on an impact slit according to claim 1, characterized in that: The impact slit (5) is a long strip-shaped slit, the length of which is much greater than its width, and its width can dynamically change with the deformation of the deformable wall.

3. The adaptive flat double-wall cooling structure based on an impact slit according to claim 1, characterized in that: The elastic modulus of the elastic deformable material is in the range of 50 GPa to 70 GPa.

4. The adaptive flat double-wall cooling structure based on an impact slit according to claim 1, characterized in that: The impact slits (5) are arranged in an array on the impact plate (2), and one impact slit (5) replaces a whole row of traditional discrete circular impact holes in the cooling coverage area.

5. The adaptive flat double-wall cooling structure based on an impact slit according to claim 1, characterized in that: The air film holes (4) on the target surface (1) and the impact slits (5) on the impact plate (2) are arranged alternately in the projection.

6. The adaptive flat double-wall cooling structure based on an impact slit according to claim 1, characterized in that: The thermodynamic parameters include the pressure load and temperature load on the impact plate (2); under high load conditions, the increased pressure load and temperature load together drive the deformable wall to deform away from the opposite wall surface, thereby increasing the width of the impact slit (5); under low load conditions, the reduced load causes the deformable wall to reset under its own elastic restoring force, thereby reducing the width of the impact slit (5).

7. A design method for an adaptive flat double-walled cooling structure based on the impact slit described in any one of claims 1-6, characterized in that... The specific steps are as follows: S1: Determine the adaptive target: Based on the engine's varying operating conditions, determine the target deformation that the impact slit of the cooling structure needs to achieve between the target high-load condition and the target low-load condition. and the corresponding change in target circulation area; S2: Establish a parametric design model: Establish a parametric model of the impact plate, in which the wall portion constituting the impact slit is abstracted as having a specific length. An elastic microbeam structure with cross-sectional moment of inertia I and torsional moment of inertia J is given initial material parameters, including elastic modulus E and shear modulus G. S3: Constructing the mechanical response relationship: Based on the theory of elasticity, establish the mechanical response relationship of the elastic microbeam structure under the action of cooling airflow, including its deformation perpendicular to the wall surface. Dominated by the following formula: At the same time, its deformation in the direction parallel to the wall surface Dominated by the following formula: in, ; The effective uniformly distributed load acting on the elastic microbeam is T, where T is the torque distributed per unit length; It includes the layout P, ​​number N, width W of the impact slits, and the total pressure at the main inlet. and total temperature The function, ; S4: Perform numerical simulation and parameter matching of fluid-structure-thermal coupling. Embed the parameterized model described in S2 and the mechanical response relationship described in S3 into numerical analysis software; Apply pressure and temperature load boundary conditions corresponding to the target high-load and low-load conditions; By iteratively adjusting the combination of the material and geometric parameters, a fluid-structure-thermal coupling simulation is performed until the deformation calculated by the simulation matches the target deformation determined by S1. The matching parameters determine a set of final design parameters. S5: Output and Manufacturing: Based on the final design parameters obtained in S4, complete the design of the adaptive flat double-wall cooling structure.

8. A cooling method based on the adaptive flat double-walled cooling structure based on an impact slit as described in any one of claims 1-6, characterized in that... The specific steps are as follows: S1: Cooling gas flows into the gas collection chamber outside the impact plate (2); S2: Cooling gas passes through the impact slit (5) on the impact plate (2) to form a narrow jet that impacts the inner surface of the target surface (1) for impact heat exchange; wherein, the adaptive adjustment steps of the impact slit (5) are as follows: S2.1: The deformable wall of the impact plate (2) senses the changes in thermal parameters caused by changes in engine operating conditions in real time; S2.2: When the heat load and pressure increase, the deformable wall undergoes elastic deformation, increasing the effective flow area of ​​the impact slit (5) and automatically increasing the flow rate of the impact cooling gas. S2.3: When the heat load and pressure decrease, the deformable wall elastically recovers, reducing the effective flow area of ​​the impact slit (5) and automatically saving the cooling air flow. S3: The airflow that has completed the impact heat exchange is turned back in the cooling chamber (3) and flows out through the air film hole (4) on the target surface (1) to form a covering air film outside the high temperature wall.

9. A turbine blade, characterized in that, At least a portion of the turbine blade wall surface employs the adaptive flat double-wall cooling structure based on impact slits as described in any one of claims 1-6.

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