Method for improving aerodynamic performance of turbine rotor blade

Abstract

The invention relates to a method for improving aerodynamic performance of a turbine rotor blade. The problems existing in a traditional method are solved. Firstly, surface oxides and dirt are removed through low-temperature plasma cleaning, and the roughness of a turbine rotor blade base body is reduced; a blade coating is prepared through vacuum arc plating, and it is guaranteed that the surface of the coating is uniform and consistent; then rough polishing of ceramic particles and precise modification of a composite abrasive are carried out, and the surface roughness is reduced to Ra 0.2 micron; and finally, the surface roughness is measured by adopting a white light interferometer, so that the coating is prevented from being scratched by the probe. According to the method, airflow loss can be reduced, the cooling efficiency is improved, and the work efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine maintenance, and in particular relates to a method for improving the aerodynamic performance of turbine rotor blades. Background Technology

[0002] Turbine rotor blades are critical components of aero-engines, and the surface roughness of their coating directly affects aerodynamic efficiency and fatigue life. Traditional coating processes tend to accumulate on complex surfaces such as blade tips and roots, often resulting in roughness levels of Ra ≥ 1.6 μm. During engine operation, the high roughness of turbine rotor blades leads to airflow separation, increasing drag and friction losses, and reducing aerodynamic efficiency. Furthermore, the roughness of the film cooling hole surface interferes with cooling gas flow, reducing cooling efficiency. Studies have shown that for every 1 μm increase in coating surface roughness, the boundary layer turbulence intensity increases by approximately 10%. For a certain type of high-pressure turbine blade, increasing the coating roughness from Ra 0.4 μm to Ra 1.6 μm can result in a 5%–8% reduction in stage efficiency. In addition, high blade roughness facilitates carbon buildup, increasing blade weight. This carbon buildup further increases surface roughness, leading to a further reduction in aerodynamic and cooling efficiency. Therefore, it is necessary to research a method suitable for improving the working efficiency of turbine rotor blades. This method can address challenges such as reducing airflow losses and improving cooling efficiency, thereby enhancing overall working efficiency. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for improving the aerodynamic performance of turbine rotor blades.

[0004] The objective of this invention is achieved through the following technical solution: A method for improving the aerodynamic performance of turbine rotor blades involves firstly using low-temperature plasma cleaning to remove surface oxides and contaminants, thereby reducing the roughness of the turbine rotor blade substrate; then, using vacuum arc plating to prepare a blade coating, ensuring a uniform coating surface; next, using ceramic particle coarse polishing followed by composite abrasive precision finishing to reduce the surface roughness to Ra0.2μm; and finally, using a white light interferometer to measure the surface roughness, avoiding probe scratches on the coating.

[0005] Specifically, the following steps are included: S1. Coating removal: Remove the surface coating using chemical or mechanical methods or a combination of both.

[0006] S2. Low-temperature plasma cleaning: Removes surface oxides and contaminants, substrate roughness Ra≤0.8μm, power: 100~350W, time: 5~20min.

[0007] S3. Coating preparation: A NiCrAlYSi coating with a thickness of 40~80μm was prepared by vacuum arc plating.

[0008] S4. Vibratory finishing and rough polishing: Install the blades in the vibratory finishing equipment fixture, add abrasive and polishing fluid, and the roughness Ra≤0.6μm; the specific parameters are: abrasive: alumina tetrahedral ceramic abrasive (size 5~10mm), polishing fluid: finishing agent and deionized water volume ratio of 0.5:100, vibration frequency: 35~45Hz, time: 10~30min.

[0009] S5. Vibratory finishing: Install the blades in the vibratory finishing equipment fixture, add abrasive and abrasive fluid, roughness Ra≤0.2μm; specific parameters are: abrasive: polyurethane composite abrasive (2mm spherical size), abrasive fluid: finishing agent and deionized water volume ratio of 0.5:100, vibration frequency: 30~40Hz, time: 60~120min.

[0010] S6. Roughness Measurement: The roughness of the blade after precision finishing is measured using a white light interferometer to avoid damaging the blade.

[0011] The method of this invention can address challenges such as reducing airflow loss and improving cooling efficiency, thereby increasing work efficiency.

[0012] The beneficial effects of this invention are: (1) The method of the present invention adopts a composite process (a process of low temperature plasma cleaning and vibration finishing rough polishing and precision finishing), which breaks through the roughness control limit of a single process. The roughness is reduced from Ra≥1.6μm to Ra0.2μm, which improves the aerodynamic efficiency of the high pressure turbine rotor by more than 8%.

[0013] (2) The method of the present invention uses silicon carbide / alumina ceramic abrasive (size 5~10mm) for rough polishing and polyurethane composite abrasive for precision finishing. After vibration finishing, the area around the blade orifice is smoother, which can improve the cooling efficiency of the orifice.

[0014] (3) The method of the present invention uses a white light interferometer to measure the blade roughness, thus avoiding damage to the blade.

[0015] (4) The method of the present invention designs tenon protection fixtures to avoid damage to the tenon part of the blade during the finishing process. At the same time, positioning bolts and electromagnetic adsorption are used for fixation, which is accurate and convenient to operate. Attached Figure Description

[0016] Figure 1 A schematic diagram of a high-pressure turbine rotor blade; Figure 2 This is a schematic diagram of the blade installation and tenon protection fixture. Detailed Implementation

[0017] The following is in conjunction with the appendix Figure 1 , 2The technical solution of the present invention will be described in further detail below, but the scope of protection of the present invention is not limited to the following description.

[0018] S1. Coating Removal: The surface coating is removed using chemical or mechanical methods, or a combination of both. Figure 1 As shown.

[0019] S2. Low-temperature plasma cleaning: Removes surface oxides and contaminants, substrate roughness Ra≤0.8μm, power: (100~350)W, time: (5~20)min.

[0020] S3. Coating preparation: NiCrAlYSi coating with a thickness of (40~80) μm was prepared by vacuum arc plating.

[0021] S4. Blade Installation: Install the blade tenon onto the fixture along the tenon direction (inside the fir-tree-shaped mortise that mates with the tenon), tighten the side, and ensure the lower surface of the blade edge plate is flush with the fixture to prevent abrasive and polishing fluid from entering and damaging the tenon during finishing. Next, install the fixture with the blade onto the positioning bolts that mate with the equipment (blade tip facing down), rotate 90°, and then fix it using electromagnetic adsorption, with 8 points evenly distributed around the circumference, such as... Figure 2 As shown.

[0022] S5. Vibratory finishing and rough polishing: Add abrasive and polishing fluid, roughness Ra≤0.6μm. Specific parameters are: abrasive: alumina tetrahedral ceramic abrasive (size 5~10mm), polishing fluid: polishing agent and deionized water volume ratio of 0.5:100, vibration frequency: (30~50)Hz, time: (10~30)min, rotation speed: (200~400)r / min.

[0023] S6. Vibratory finishing: Install the blades in the vibratory finishing equipment fixture, add abrasive and abrasive fluid, and ensure the surface roughness Ra ≤ 0.2 μm. Specific parameters are as follows: abrasive: polyurethane composite abrasive (2 mm spherical size), abrasive fluid: finishing agent and deionized water in a volume ratio of 0.5:100, vibration frequency: (20~40) Hz, time: (60~120) min, rotation speed: (300~700) r / min.

[0024] S7. Blade Removal: Remove the tooling from the equipment and remove the blade from the tooling.

[0025] S8. Roughness Measurement: The roughness of the blade after precision finishing is measured using a white light interferometer to avoid damaging the blade.

[0026] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method of improving the aerodynamic performance of a turbine rotor blade, characterized by: Firstly, low temperature plasma cleaning is used to remove surface oxide and dirt, and reduce the roughness of turbine rotor blade substrate; then vacuum arc plating is used to prepare blade coating, to ensure the uniformity of the coating surface; then ceramic particle rough polishing + composite abrasive precision modification is used to reduce the surface roughness to Ra0.2μm; finally, white light interferometer is used to measure the surface roughness to avoid scratching the coating by the probe.

2. The method of claim 1, wherein the method further comprises: Specifically comprising the following steps: S1. Coating removal: chemical or mechanical method or both are used to remove the surface coating. S2. Low temperature plasma cleaning: remove surface oxide and contaminants, substrate roughness Ra≤0.8μm, power: 100~350W, time: 5~20min. S3. Coating preparation: vacuum arc plating is used to prepare NiCrAlYSi coating, thickness 40~80μm. S4. Vibration polishing rough polishing: install the blade in the vibration polishing equipment tooling, add abrasive and grinding fluid, roughness Ra≤0.6μm; the specific parameters are: abrasive: alumina tetrahedral ceramic abrasive, grinding fluid: polishing agent and deionized water volume ratio 0.5:100, vibration frequency: 35~45Hz, time: 10~30min. S5. Vibration polishing precision modification: install the blade in the vibration polishing equipment tooling, add abrasive and grinding fluid, roughness Ra≤0.2μm; the specific parameters are: abrasive: polyurethane composite abrasive, grinding fluid: polishing agent and deionized water volume ratio 0.5:100, vibration frequency: 30~40Hz, time: 60~120min. S6. Roughness measurement: white light interferometer is used to measure the roughness of the blade after precision modification to avoid damaging the blade.

3. The method of improving the aerodynamic performance of a turbine rotor blade according to claim 2, wherein: In step S4, the size of alumina tetrahedral ceramic abrasive is 5~10mm.

4. The method of improving the aerodynamic performance of a turbine rotor blade according to claim 2, wherein: In step S5, the polyurethane composite abrasive is spherical with a size of 2mm.

5. The method of improving the aerodynamic performance of a turbine rotor blade according to claim 2, wherein: In steps S4 and S, when installing the blade, install the blade tenon along the tenon direction into the fir-shaped mortise inside the tooling matched with the tenon, tighten the side surface, at the same time, the lower surface of the blade rim plate is attached to the tooling to avoid the grinding fluid and abrasive entering and damaging the tenon during polishing, then install the tooling with the blade on the positioning bolt matched with the equipment, the blade tip is downward, rotate 90°, then use electromagnetic adsorption to fix, and evenly distribute 8 points around the circumference.

Images