Turbine shock wave weakening structure based on oscillating fluidic device

Abstract

The purpose of this invention is to provide a turbine shock wave weakening structure based on a swing jet, belonging to the turbine field. A continuous serpentine cooling channel is arranged inside the blade body and tenon, longitudinally divided into a first segmented chamber to a fourth segmented chamber. The blade body is equipped with blade film cooling holes, leading edge film cooling holes, and a blade swing jet. When gas flows through the first segmented chamber, it is ejected through the leading edge film cooling holes; when gas flows through the second segmented chamber, it is ejected through the blade film cooling holes; and when gas flows through the third and fourth segmented chambers, it is ejected through the blade swing jet. This invention can actively weaken the shock wave intensity without significantly changing the blade geometry, reducing the total pressure loss caused by strong shock waves and improving the overall aerodynamic efficiency of the turbine. The periodic unsteady disturbance generated by the swing jet can break the strong coupling relationship between the shock wave and the boundary layer, weaken separation and vortex structures, improve flow field uniformity, and thus significantly reduce local heat load.

Description

Technical Field

[0001] The present invention relates to a turbine, specifically a turbine blade. Background Technology

[0002] One of the core components of an aero-engine is the high-pressure turbine, whose main function is to extract energy from high-temperature, high-speed exhaust gases to provide driving force for the compressor and other components. With the continuous improvement of engine thrust and efficiency, the operating conditions endured by turbine blades are becoming increasingly stringent. High Mach number flows are prevalent on the blade surface and inside the flow channels, and the occurrence of strong shock waves is unavoidable at transonic and even supersonic speeds. These shock waves not only cause significant total pressure loss but also interact complexly with the boundary layer, inducing flow separation, vortex structures, and localized overheating, thereby leading to decreased aerodynamic efficiency and shortened turbine blade life.

[0003] Current research indicates that blade shock wave losses have become a significant bottleneck restricting further performance improvements in gas turbines. Traditional solutions fall into three main categories: First, reducing shock wave intensity by modifying turbine blade profiles; however, complex designs are difficult and costly to manufacture, and the optimization effect is limited. Second, employing passive flow control structures, such as tip clearance optimization or boundary layer suction, to reduce shock wave and leakage flow interference; however, the effectiveness often depends on specific operating conditions and has limited applicability. Third, relying on traditional cooling technologies to alleviate the heat load problem caused by shock waves; however, the use of cooling air directly affects engine cycle efficiency, making it difficult to balance energy saving and high efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a turbine shock wave weakening structure based on an oscillating jet that effectively weakens the intensity of the shock wave by interfering with the shock wave formation mechanism, while suppressing separation and reducing losses.

[0005] The objective of this invention is achieved as follows: This invention discloses a turbine shock weakening structure based on a swing jet ejector, characterized by comprising a blade body, a rim plate, and a tenon. The blade body is mounted on the rim plate, and the rim plate is mounted on the tenon. A through-type serpentine cooling channel is provided inside the blade body and the tenon. The serpentine cooling channel is longitudinally divided into a first segmented cavity and a fourth segmented cavity. The blade body is provided with blade film gas holes, leading edge film gas holes, and a blade swing jet ejector. When gas flows through the first segmented cavity, it is ejected through the leading edge film gas holes. When gas flows through the second segmented cavity, it is ejected through the blade film gas holes. When gas flows through the third and fourth segmented cavities, it is ejected through the blade swing jet ejector.

[0006] The present invention may also include: 1. The blade swing jet includes a swing jet inlet, a swing jet outlet, a swing jet inner cavity, and a swing jet return cavity. The swing jet inner cavity is located between the swing jet inlet and the swing jet outlet. Swing jet return cavities are arranged on both sides of the swing jet inner cavity. The swing jet return cavities are respectively connected to the swing jet inlet, the swing jet outlet, and the swing jet inner cavity.

[0007] 2. The blade swing jet is positioned upstream of the shock wave, at the point of generation and reflection, or downstream of the shock wave.

[0008] 3. The angle between the tangent direction of the blade body surface and the center line of the blade swing jet is in the range of 25° to 45°.

[0009] 4. The radial distribution number N of the blade-mounted jet ejector is: N=round((H-2d) / 3d) Where H is the overall radial height of the blade body, and d is the outlet radial dimension of the blade swing jet.

[0010] 5. The blade oscillating jets are arranged in a radially staggered manner, so that the high-frequency oscillating cold air ejected by the blade oscillating jets near the leading edge of the blade can cover the radial gap area between the blade oscillating jets near the trailing edge.

[0011] 6. Increase the number of blade-mounted jet jets in the third and fourth segmented chambers, with 1-3 rows of blade-mounted jet jets arranged in each segmented chamber.

[0012] 7. In locations where the shock wave is relatively weak in the flow channel, the width of the blade-mounted jet jet is the same as the conventional film cooling orifice size; in locations where the shock wave is relatively strong in the flow channel, the width of the blade-mounted jet jet is 2-3 times the conventional film cooling orifice size.

[0013] 8. A grooved blade tip is provided at the top of the blade body, and a blade tip air film hole is provided on the middle arc line of the grooved blade tip.

[0014] 9. Trailing edge turbulence columns are arranged in the internal flow channel of the trailing edge of the blade body, and trailing edge cooling gas slots are set at the trailing edge of the blade body. Gas is discharged through the trailing edge cooling gas slots after passing through the trailing edge turbulence columns.

[0015] The advantages of this invention are as follows: By arranging oscillating jets in key areas of the turbine blades, active reduction of shock wave intensity can be achieved without significantly altering the blade geometry, reducing the total pressure loss caused by strong shock waves and improving the overall aerodynamic efficiency of the turbine. The periodic unsteady disturbances generated by the oscillating jets can effectively break the strong coupling between the shock wave and the boundary layer, weaken separation and vortex structures, improve flow field uniformity, and thus significantly reduce local thermal load. Compared with traditional geometry optimization and passive control methods, this structure has the characteristics of strong controllability and a wide range of applicable operating conditions, maintaining stable control effects under different operating conditions and improving the adaptability of the turbine blades. The introduction of oscillating jets balances aerodynamic performance and cooling efficiency, reducing cooling air consumption and energy consumption, thereby further improving engine cycle efficiency while ensuring blade strength and lifespan. Attached Figure Description

[0016] Figure 1 The complex shock wave structure in a supersonic turbine; Figure 2 This is a schematic diagram of the turbine blade structure of the jet ejector with blade body oscillation according to the present invention; Figure 3 This is a schematic diagram of the internal structure of a turbine blade; Figure 4 This is a schematic diagram of the structure of the blade-oscillating jet ejector inside the blade wall. Figure 5 Flow diagram of a blade-oscillating jet ejector; Figure 6 A schematic diagram of the blade-mounted jet ejector and shock wave structure; Figure 7 A schematic diagram showing the angle between the tangent direction on the blade body surface and the centerline of the blade swing jet; Figure 8 Schematic diagram to increase the radial distribution density of the blade swing jet on the blade body; Figure 9 A diagram showing the radially staggered arrangement of the blade-swinging jet ejector; Figure 10 A schematic diagram showing the addition of multi-row blade swing jets to the third and fourth segmented chambers; Figure 11 Schematic diagram of jet ejectors with blades of different shapes. Detailed Implementation

[0017] The invention will now be described in more detail with reference to the accompanying drawings: Combination Figure 1-11This invention provides a turbine shock weakening structure based on a swing jet, comprising a blade body 2, a grooved blade tip 8, a blade tip film film aperture 7, a blade body film film aperture 9, a leading edge film film aperture 10, a rim plate 5, a tenon 6, an internal serpentine channel 16, a trailing edge baffle column 14, and a blade body swing jet 11. The blade tip film film aperture 7 is located on the mid-arc line at the bottom of the grooved blade tip 8. The blade body film film aperture 9, the leading edge film film aperture 10, and the blade body swing jet 11 are all disposed on the blade body 2 and penetrate the outer wall of the blade. Their inner sides communicate with the internal serpentine channel 16, and their outer sides open onto the blade pressure surface 4 and the blade suction surface 3, respectively. The trailing edge baffle column 14 is arranged in the internal flow channel of the blade trailing edge for cooling the trailing edge region. The cooled air passes through the trailing edge baffle column 14 and is finally discharged through the trailing edge cooling air slot 15. The blade body 2 is located above the rim plate 5, and the tenon 6 is connected below it for fixing the blade to the turbine disk. The blade body 2 and tenon 6 are integrally equipped with a through-type serpentine cooling channel 16. Cool air enters from the inlet at the bottom of tenon 6 and flows through the serpentine channel multiple times, filling the entire interior of the blade. The serpentine channel 16 is longitudinally divided into a first segmented cavity 17, a second segmented cavity 18, a third segmented cavity 19, and a fourth segmented cavity 20. When the cool air flows through the first segmented cavity 17, it is ejected through the leading edge film gas hole 10 due to the pressure difference between the inside and outside of the blade; when the cool air flows through the second segmented cavity 18, it is ejected through the blade film gas hole 9; and when the cool air continues to flow through the third segmented cavity 19 and the fourth segmented cavity 20, it is ejected through the blade swing jet 11.

[0018] like Figure 1 , Figure 2 and Figure 5As shown, when the turbine operates in transonic or supersonic flow conditions, the blade-mounted oscillating jet 11 is positioned near the shock wave generation or reflection location in the turbine flow channel. Cool air is delivered to the blade-mounted oscillating jet 11 through the internal serpentine channel 16 and enters the jet interior via the oscillating jet inlet 21. During the flow, influenced by the Coanda effect, the fluid tends to flow along the wall. At flow moment 1, the cool air flow within the blade-mounted oscillating jet 11 is deflected to the left side of the inner cavity, forming a backflow 24 as it flows through the oscillating jet return cavity 23. This backflow, after undergoing a significant rotation, impacts the main flow 25 of the oscillating jet, causing the main flow 25 to deflect to the right side of the inner cavity 26, thus forming the flow structure shown at flow moment 2. Consequently, the cool air alternately approaches both sides of the oscillating jet's inner cavity at different time intervals, resulting in a high-frequency, double-sided oscillating jet at the outlet. The aforementioned high-frequency oscillating cold gas injection can generate unsteady disturbances in the flow field, significantly altering the pressure gradient distribution around the oscillating jet, effectively weakening the cumulative effect of pressure rise, and thus reducing shock wave intensity. From a cooling perspective, this high-frequency double-sided oscillating injection expands the cold gas coverage area, transforming the traditional strip-shaped film cooling into a planar distribution (within the swept edge 13, specifically in swept shape 12), significantly improving cold gas utilization. From a heat transfer perspective, the weakening of shock wave intensity reduces shock wave-boundary layer interaction, while the more uniform cold gas coverage improves the wall thermal protection effect and reduces the heat transfer intensity between the mainstream high-temperature gas and the turbine wall. Therefore, this embodiment can synergistically weaken shock waves and improve cooling effect, significantly optimizing the heat load distribution of the blades.

[0019] like Figure 6As shown, one of the main functions of the blade oscillating jet 11 is to weaken the shock wave 1 in the turbine flow channel. Therefore, the arrangement position of the blade oscillating jet 11 on the blade can be adjusted according to the generation or reflection position of the shock wave 1. Specifically, the blade oscillating jet 11 can be preset in the following three types of positions: (1) upstream position of the shock wave 1: When the oscillating jet is arranged in the upstream region of the generation or reflection position of the shock wave 1, the pressure accumulation effect can be suppressed by disturbing and adjusting the local flow field pressure distribution in advance, thereby effectively reducing the possibility of shock wave 1 formation and playing the role of preventing shock wave generation. (2) generation or reflection position of the shock wave 1: When the oscillating jet is arranged in the generation or reflection position of the shock wave 1, the high-frequency oscillating jet of the cold air can directly act on this region, thereby weakening the local shock wave intensity, reducing the strong heat transfer phenomenon at the blade wall in this region, and improving the heat load distribution. (3) Downstream position of shock wave 1: When the oscillating jet is arranged in the downstream region of shock wave 1, the adverse effects of the formed shock wave on the downstream flow field can be controlled by periodic cold air disturbance, thereby correcting and reconstructing the flow field structure and improving the overall aerodynamic performance of the blade. In the practical application of this invention, it is recommended to simultaneously set the blade oscillating jet 11 at the location where shock wave 1 is generated or reflected, upstream and downstream, to achieve a better shock wave control effect.

[0020] like Figure 7 As shown, the angle of the cold air injection channel can be adjusted by setting the angle α between the tangent direction of the blade body 2 surface and the centerline of the blade oscillating jet 11. The change in angle α directly affects the penetration depth of the high-frequency oscillating cold air in the blade's normal direction. When α increases, the spatial control range of the shock wave by the blade oscillating jet 11 expands, but the re-adsorption effect of the cold air on the blade surface weakens. To achieve the best balance between cooling efficiency and shock wave intensity reduction, this invention recommends an angle α range of 25° to 45°.

[0021] like Figure 8 As shown, the cooling gas coverage and shock wave control effect can be improved by increasing the radial distribution density of the blade oscillating jet 11 on the blade body 2. At a higher distribution density, the cooling gas ejected from the blade oscillating jet 11 sweeps the edge 13 in a continuous radial connection, thus ensuring more thorough coverage of the blade surface. Simultaneously, the effect of the high-frequency cooling gas flow on the shock wave 1 is more continuous and uniform in the radial direction. Therefore, the blade oscillating jet 11 scheme with a high-density distribution arrangement can achieve better aerodynamic control and cooling effects. The formula for calculating the radial distribution number N of a single row of oscillating jets recommended by this invention is as follows: N=round((H-2d) / 3d) Where H is the overall radial height of the blade body 2, and d is the outlet radial dimension of the oscillating jet 11.

[0022] like Figure 9As shown, in the design with double-row blade oscillating jets 11, the blade oscillating jets 11 can be arranged in a radially staggered configuration. The high-frequency oscillating cold air ejected from the oscillating jets 11 near the leading edge of the blade can effectively cover the radial gap area between the oscillating jets 11 near the trailing edge. This staggered arrangement achieves more efficient and continuous cold air coverage, thus optimizing both cooling effect and equipment cost.

[0023] like Figure 10 As shown, based on the double-row blade oscillating jet 11 scheme, multiple rows of blade oscillating jets 11 are further added to the third segmented cavity 19 or the fourth segmented cavity 20 to achieve more efficient shock wave control and cooling gas coverage. Considering the limitation of the segmented cavity size, this invention recommends arranging 1 to 3 rows of blade oscillating jets 11 in each segmented cavity to balance shock wave control efficiency, cooling coverage intensity, and the feasibility of structural arrangement.

[0024] like Figure 11 As shown, different jet flow rates can be achieved by adjusting the width of the blade-mounted jet ejector 11. Under the condition of a fixed cold air inlet pressure, increasing the width of the jet ejector 11 can proportionally increase the cold air flow rate, thereby enhancing the cold air sweep momentum, strengthening the control intensity of the shock wave, and achieving a more efficient aerodynamic control effect. Generally, the width of the jet ejector 11 can be set to be similar to the size of a conventional film gas orifice (characteristic dimension of 0.5-1mm). However, when there is a strong shock wave in the flow channel, it is recommended that the width of the jet ejector 11 be set to 2-3 times the conventional size to achieve a better shock wave control effect.

[0025] This invention introduces a penetrating jet jet near the shock wave generation region of a supersonic blade. This allows the airflow in the internal cooling channel to enter the mainstream flow field in the form of high-frequency, periodic oscillating jets, creating unsteady disturbances that effectively weaken the shock wave intensity, suppress flow separation, and reduce losses. Regarding flow resistance control, traditional prototype film cooling orifices typically have low flow resistance. Therefore, under certain cooling gas inlet pressure conditions, their blowing ratio is often difficult to precisely adjust, resulting in limited adhesion of cooling gas to the blade surface. In contrast, the oscillating jet jet used in this invention has both a return channel and a main channel structure. By rationally designing and adjusting the flow distribution area of ​​the return channel and the main channel, precise control of the blowing ratio can be achieved under a fixed cooling gas inlet pressure. This not only improves the flow adhesion of cooling gas to the blade surface but also significantly enhances cooling efficiency and the stability of control performance.

[0026] This invention achieves synergistic control of shock wave intensity reduction and blade surface cooling enhancement by placing a penetrating oscillating jet near the shock wave generation region of the turbine blade. This technology overcomes the limitations of traditional methods that rely on blade profile optimization or large-volume cooling gas supply to improve blade aerodynamic and cooling performance. It can improve turbine aerodynamic efficiency and thermal protection capabilities while maintaining relatively low energy consumption. Therefore, this invention not only has significant engineering value in supersonic turbine applications but also demonstrates broad prospects for promotion and application.

Claims

1. A turbine shock wave weakening structure based on a swing jet injector, characterized in that: The blade body includes a blade body, a rim plate, and a tenon. The blade body is mounted on the rim plate, and the rim plate is mounted on the tenon. A through-type serpentine cooling channel is set inside the blade body and the tenon. The serpentine cooling channel is divided into a first segmented cavity to a fourth segmented cavity in the longitudinal direction. The blade body is provided with blade film gas holes, leading edge film gas holes, and blade swing jet nozzles. When the gas flows through the first segmented cavity, it is ejected through the leading edge film gas holes. When the gas flows through the second segmented cavity, it is ejected through the blade film gas holes. When the gas flows through the third and fourth segmented cavities, it is ejected through the blade swing jet nozzles.

2. The turbine shock wave weakening structure based on a swing jet generator according to claim 1, characterized in that: The blade oscillating jet includes an oscillating jet inlet, an oscillating jet outlet, an oscillating jet inner cavity, and an oscillating jet return cavity. The oscillating jet inner cavity is located between the oscillating jet inlet and the oscillating jet outlet. Oscillating jet return cavities are arranged on both sides of the oscillating jet inner cavity, and the oscillating jet return cavities are respectively connected to the oscillating jet inlet, the oscillating jet outlet, and the oscillating jet inner cavity.

3. The turbine shock wave weakening structure based on a swing jet according to claim 2, characterized in that: The blade-mounted jet jet is positioned upstream of the shock wave, at the point of generation and reflection, or downstream of the shock wave.

4. The turbine shock wave weakening structure based on a swing jet according to claim 2, characterized in that: The angle between the tangent direction of the blade body surface and the center line of the blade swing jet is in the range of 25° to 45°.

5. A turbine shock wave weakening structure based on a swing jet according to claim 2, characterized in that: The radial distribution number N of the blade-mounted jet ejector is: N=round((H-2d) / 3d) Where H is the overall radial height of the blade body, and d is the outlet radial dimension of the blade swing jet.

6. The turbine shock wave weakening structure based on a swing jet according to claim 2, characterized in that: The blade oscillating jets are arranged in a radially staggered manner, which allows the high-frequency oscillating cold air ejected from the blade oscillating jets near the leading edge of the blade to cover the radial gap area between the blade oscillating jets near the trailing edge.

7. A turbine shock wave weakening structure based on a swing jet according to claim 2, characterized in that: in The number of blade-mounted jet jets is increased in the third and fourth segmented chambers, with 1-3 rows of blade-mounted jet jets arranged in each segmented chamber.

8. A turbine shock weakening structure based on a swing jet according to claim 2, characterized in that: In locations where the shock wave is relatively weak in the flow channel, the width of the blade-mounted jet is the same as the conventional film cooling orifice size; in locations where the shock wave is relatively strong in the flow channel, the width of the blade-mounted jet is 2-3 times the conventional film cooling orifice size.

9. A turbine shock weakening structure based on a swing jet according to claim 1, characterized in that: The blade body has a grooved blade tip, and the blade tip air film hole is set on the middle arc line of the grooved blade tip.

10. A turbine shock weakening structure based on a swing jet according to claim 1, characterized in that: Trailing edge turbulence columns are arranged in the internal flow channel of the trailing edge of the blade body, and trailing edge cooling gas slots are set at the trailing edge of the blade body. Gas is discharged through the trailing edge cooling gas slots after passing through the trailing edge turbulence columns.

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