A similarity design method of a power turbine rotor simulation tester

Abstract

The application belongs to the technical field of engine test, and particularly relates to a similarity design method of a power turbine rotor simulation tester. The method comprises the following steps: determining a rotor support form, a turbine blade disc position, a rotor critical speed and a strain energy distribution of a real power turbine rotor structure to be simulated; giving an initial structure scheme of the power turbine rotor tester in line with the above structure and dynamics requirements, and adopting a rotor structure with two support points of a cantilever disc; obtaining support point load, rotor critical speed and strain energy distribution of the power turbine rotor tester, and comparing with the real power turbine rotor structure, and when a comparison error exceeds a set value, adjusting the support points, the cantilever disc and the rotor structure; judging whether the elastic support damper meets the processing and assembly requirements, and if not, adjusting the interface of the elastic support damper. The application ensures that the operation environment and load characteristics of the tester are consistent with the real power turbine rotor.

Description

Technical Field

[0001] This application belongs to the field of engine testing technology, specifically relating to a similar design method for a power turbine rotor simulation tester. Background Technology

[0002] Vibration of aircraft engines / derivative gas turbines directly affects their lifespan and safety. Statistics show that over 90% of structural strength failures are caused by or related to vibration. Aircraft / gas turbines have complex structures and operate under harsh conditions; many factors can influence overall vibration. Employing a spring-supported damper structure is the most effective way to reduce engine vibration and improve its stability. A spring-supported damper refers to a structure that supports the rotor shaft through an elastic structure, while simultaneously forming an oil film hole between the elastic structure and the engine casing, injecting oil to provide vibration damping.

[0003] However, when conducting relevant power turbine rotor tests, scaled-down models are usually used. On the one hand, scaled-down models do not achieve similarity in structural size and scale, and the support loads of scaled-down models deviate significantly from the actual loads. The gravitational eccentricity effect of the damper cannot be considered. On the other hand, scaled-down templates cannot be replaced with real spring-supported damper structures. Simulated parts must be fabricated separately to carry out scaled-down theoretical research, which results in a significant deviation in engineering significance.

[0004] The aforementioned power turbine rotor simulation test apparatus is used to study the vibration characteristics of the rotor support system and the vibration suppression effect of the spring support-damper structure. In order to maximize the engineering significance of the test results, it is necessary to establish a similarity design method that includes both structural and dynamic dimensions.

[0005] Existing rotor testing equipment designs generally consider structural similarity to engineering applications superficially, but fail to balance structural and dynamic similarity. From a structural similarity perspective, they typically only employ scaled-down structures, while from a rotor dynamic similarity perspective, they generally only achieve numerical similarity in critical speeds, neglecting strain energy distribution. In summary, existing technologies suffer from technical deficiencies that deviate from engineering applications, necessitating the development of a more refined similarity simulation testing equipment design method. Summary of the Invention

[0006] To address one of the aforementioned problems, this application provides a similar design method for a power turbine rotor simulation test apparatus, mainly comprising:

[0007] Step S1: Perform structural and dynamic analysis on the real power turbine rotor to be simulated to determine the rotor support form, turbine disk position, rotor critical speed and strain energy distribution of the real power turbine rotor structure to be simulated.

[0008] Step S2: Provide an initial structural scheme for a power turbine rotor tester that meets the above structural and dynamic requirements. The initial structural scheme is a rotor structure with two supports and a cantilever disk. The cantilever disk simulates a multi-stage power turbine structure. A spring-loaded damper structure is set at the first support near the cantilever disk to simulate the elastic support of the power turbine rotor. The damping effect is achieved by forming a squeezed oil film between the spring-loaded damper structure and the power turbine rotor through oil supply.

[0009] Step S3: Obtain the fulcrum load, rotor critical speed, and strain energy distribution of the power turbine rotor tester, and compare them with the fulcrum load, rotor critical speed, and strain energy distribution of the actual power turbine rotor structure at the corresponding fulcrum position obtained in Step S1. When the comparison error exceeds the set value, return to Step S2 to adjust the fulcrum, cantilever disk, and rotor structure.

[0010] Step S4: When the comparison error does not exceed the set value, determine whether the spring damper meets the processing and assembly requirements. If it does not meet the processing and assembly requirements, return to step S2 to adjust the interface of the spring damper.

[0011] Preferably, the adjustments to the fulcrum, cantilever disk, and rotor structure include:

[0012] Change the fulcrum position, turntable weight, turntable position, and shaft diameter.

[0013] Preferably, the interface adjustment of the spring-loaded damper includes:

[0014] Adjust the connecting flange, bearings, oil supply and drainage lines, and oil film gap used to form the squeeze oil film of the spring damper.

[0015] Preferably, the comparison error is (simulator parameters - actual parameters) / actual parameters, the set value is 5%, the simulator parameters include the fulcrum load of the power turbine rotor tester, the rotor critical speed and the strain energy at multiple positions, and the actual parameters are the fulcrum load, rotor critical speed and the strain energy at multiple positions of the corresponding real power turbine rotor structure.

[0016] Preferably, the strain energy at the plurality of locations includes at least the rotor strain energy and the strain energy at the first fulcrum near the end of the cantilever disk.

[0017] The advantages of this application are:

[0018] (1) It solves the problem of similar size in structural similarity, especially realizing the ability to analyze the influence of support load on damper oil film eccentricity;

[0019] (2) The interface problem with the actual spring-supported damper structure of the power turbine was solved, and the ability to conduct tests on the actual structure was realized on the test equipment;

[0020] (3) Dynamic similarity ensures the similarity of critical speed and strain energy in two dimensions, ensuring that the operating environment and load characteristics of the rotor-support system of the tester are consistent with those of the power turbine. Attached Figure Description

[0021] Figure 1 This is a flowchart of a preferred embodiment of a similar design method for the power turbine rotor simulator of this application.

[0022] Figure 2 For this application Figure 1 A simplified structural diagram of the experimental apparatus in the illustrated embodiment.

[0023] Figure 3 This is a schematic diagram of the overall apparatus of a preferred embodiment of a similar design method for the power turbine rotor simulator of this application.

[0024] Figure 4 For this application Figure 3 A schematic diagram of the internal structure of the embodiment shown.

[0025] Figure 5 For this application Figure 3 A schematic diagram showing the formation of an oil film cavity between the elastic support and the first support in the embodiment shown.

[0026] Wherein, 1-first tapered sleeve, 2-first cantilever disc, 3-second tapered sleeve, 4-second cantilever disc, 5-first deep groove ball bearing, 6-elastic support, 61-ring plate, 62-support arm, 63-oil film cavity, 7-rotor shaft, 8-bearing housing, 9-second deep groove ball bearing, 10-coupling, 11-first support, 12-second support, 13-third support. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0028] This application provides a similar design method for a power turbine rotor simulation test apparatus, such as... Figure 1 As shown, it mainly includes:

[0029] Step S1: Perform structural and dynamic analysis on the real power turbine rotor to be simulated to determine the rotor support form, turbine disk position, rotor critical speed and strain energy distribution of the real power turbine rotor structure to be simulated.

[0030] Step S2: Provide an initial structural scheme for a power turbine rotor tester that meets the above structural and dynamic requirements. The initial structural scheme is a rotor structure with two supports and a cantilever disk. The cantilever disk simulates a multi-stage power turbine structure. A spring-loaded damper structure is set at the first support near the cantilever disk to simulate the elastic support of the power turbine rotor. The damping effect is achieved by forming a squeezed oil film between the spring-loaded damper structure and the power turbine rotor through oil supply.

[0031] Step S3: Obtain the fulcrum load, rotor critical speed, and strain energy distribution of the power turbine rotor tester, and compare them with the fulcrum load, rotor critical speed, and strain energy distribution of the actual power turbine rotor structure at the corresponding fulcrum position obtained in Step S1. When the comparison error exceeds the set value, return to Step S2 to adjust the fulcrum, cantilever disk, and rotor structure.

[0032] Step S4: When the comparison error does not exceed the set value, determine whether the spring damper meets the processing and assembly requirements. If it does not meet the processing and assembly requirements, return to step S2 to adjust the interface of the spring damper.

[0033] In step S2, this application provides an initial structural scheme for a power turbine rotor test device that meets the above-mentioned structural and dynamic requirements, including three aspects: First, it adopts a spring-supported damper structure interface matching, which is an important similarity design step proposed to enable the use of a real gas turbine structure. The interface items include connecting flanges, bearings, oil supply and discharge, and oil film clearance adjustment. It is necessary to ensure that these interface items can meet the requirements and are basically consistent with the gas turbine state. Second, it designs the rotor support form, which includes the rotor's support point position, span, and turntable position parameters. This application mainly designs a two-support rotor structure with a cantilevered disc, and the structural diagram is as follows. Figure 2 As shown, the third step is to determine the support load and obtain the support load of the test instrument to ensure that the support load of the test instrument is similar to that of the power turbine rotor support system. The eccentricity of the damper structure directly affects the vibration reduction effect. Ensuring that the support load is consistent with that of the actual structure ensures the initial eccentric environment of the damper.

[0034] In one specific embodiment, the structure of the power turbine rotor tester obtained in step S2 is as follows: Figures 3-5 As shown, it mainly includes:

[0035] The rotor shaft 7 includes a first end and a second end. The first end is rotatably supported by a first support 11 and a second support 12, and the second end is rotatably supported by a third support 13. The second end is connected to a power input device through a coupling 10.

[0036] A cantilevered disk, fixed to the first end of the rotor shaft 7, is used to simulate a power turbine disk;

[0037] The elastic support 6 includes a ring plate 61 and a plurality of support arms 62 distributed circumferentially along the ring plate 61. The inner end of the ring plate 61 is rotatably connected to the rotor shaft 7. An oil film cavity 63 is formed between the outer end of the ring plate 61 and the first support 11. The support arms 62 extend in a direction parallel to the axial direction of the ring plate 61, with one end connected to the outer end of the ring plate 61 and the other end connected to the second support 12.

[0038] The first support 11 is a height-adjustable support, and the first support 11 has a through hole that penetrates the oil film cavity 63. The oil film cavity 63 is connected to the oil supply system through the through hole.

[0039] refer to Figure 5 By injecting oil into the oil film cavity 63 through the through-hole, the influence of the damper's oil supply and discharge pressure on the vibration reduction effect can be studied. Specifically, this can be achieved by adjusting the oil supply and discharge pressure of the oil supply system, and the influence law of vibration suppression effect can be obtained through vibration measurement. In addition, by injecting oil into the oil film cavity 63 through the through-hole, the influence of lubricating oil viscosity can also be studied, which can be achieved by adjusting the oil temperature or replacing the lubricating oil.

[0040] Typically, the cantilever disc has multiple bolt holes arranged circumferentially. The imbalance of the cantilever disc is adjusted by installing counterweight bolts of appropriate number or weight. The rotor imbalance is loaded and adjusted by installing counterweight bolts of different numbers or weights through the pre-reserved balance bolt holes on the first cantilever disc 2 and the second cantilever disc 4.

[0041] refer to Figure 1For the initial design of the rotor tester structure, the main analysis focuses on structural similarity and dynamic similarity design. Structural similarity, as described above, includes matching of the spring-supported damper structure interface, rotor support form, and fulcrum load requirements with the actual power turbine rotor structure. Dynamic similarity mainly includes rotor critical speed and strain energy distribution. Dynamic similarity requires the rotor critical speed to be similar to that of the power turbine, and crucially, the strain energy distribution must be consistent with that of the power turbine. In some optional implementations, the comparison error is set as (simulator parameters - actual parameters) / actual parameters, with a set value of 5%. The simulator parameters include the fulcrum load, rotor critical speed, and strain energy at multiple locations of the power turbine rotor tester. The actual parameters are the fulcrum load, rotor critical speed, and strain energy at multiple locations of the corresponding actual power turbine rotor structure. Through the similarity design of strain energy, the rotor-support system operating state is ensured to be consistent with that of the gas turbine to the greatest extent, as shown in Table 1 below.

[0042] Table 1 Comparison of Dynamic Parameters of Real-Powered Turbine Rotor and Dynamic Parameters of Test Instrument

[0043]

[0044] In some alternative implementations, the strain energy at the plurality of locations includes at least the rotor strain energy and the strain energy at the first fulcrum near the cantilever disk end. In this embodiment, the first critical speed shown in Table 1 is represented by the pitch mode of the turntable position, i.e., the strain energy is mainly distributed at fulcrum 1, therefore the error analysis is usually based on fulcrum 1.

[0045] refer to Figure 1 For parameters such as rotor support form, fulcrum load, rotor critical speed and strain energy distribution, similarity analysis or calculation can be used to determine whether the designed test instrument meets the similarity requirements with the actual power turbine rotor structure. If the requirements are not met, the scheme is optimized based on the differences. This mainly involves adjusting the fulcrum, cantilever disk and rotor structure. In some optional embodiments, the adjustment of the fulcrum, cantilever disk and rotor structure includes changing the fulcrum position, turntable weight, turntable position and shaft diameter.

[0046] If the similarity requirement is met, processing and assembly proceed. Here, it's necessary to further assess whether the processing and assembly of the spring-loaded damper can be achieved. If the processing and assembly department finds it impossible to process or difficult to assemble, the structure of the spring-loaded damper needs appropriate adjustments, with improvements made to the details. Typically, the overall framework of the solution will not be altered. For example, in some alternative implementations, adjusting the interface of the spring-loaded damper includes adjusting the connecting flange, bearings, oil supply and drainage lines, and the oil film gap used to form the squeezed oil film.

[0047] This application addresses the issue of dimensional similarity in structural similarity design by dividing the considerations into multiple aspects, such as interface matching of the test instrument, support form, fulcrum load, critical speed, and strain energy distribution. For each aspect, a similarity design is performed, resolving the problem of dimensional similarity in structural similarity. In particular, it enables the analysis of the influence of fulcrum load on the damper oil film eccentricity. It also solves the interface problem with the actual spring-support-damper structure of the power turbine, enabling the testing of the actual structure on the test instrument. Dynamic similarity ensures similarity in both critical speed and strain energy dimensions, guaranteeing that the operating environment and load characteristics of the test instrument's rotor-support system are consistent with those of the power turbine.

[0048] Although this application has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A similarity design method for a power turbine rotor simulation test apparatus, characterized in that, include: Step S1: Perform structural and dynamic analysis on the real power turbine rotor to be simulated to determine the rotor support form, turbine disk position, rotor critical speed and strain energy distribution of the real power turbine rotor structure to be simulated. Step S2: Provide an initial structural scheme for a power turbine rotor tester that meets the above structural and dynamic requirements. The initial structural scheme is a rotor structure with two supports and a cantilever disk. The cantilever disk simulates a multi-stage power turbine structure. A spring-loaded damper structure is set at the first support near the cantilever disk to simulate the elastic support of the power turbine rotor. The damping effect is achieved by forming a squeezed oil film between the spring-loaded damper structure and the power turbine rotor through oil supply. Step S3: Obtain the fulcrum load, rotor critical speed, and strain energy distribution of the power turbine rotor tester, and compare them with the fulcrum load, rotor critical speed, and strain energy distribution of the actual power turbine rotor structure at the corresponding fulcrum position obtained in Step S1. When the comparison error exceeds the set value, return to Step S2 to adjust the fulcrum, cantilever disk, and rotor structure. Step S4: When the comparison error does not exceed the set value, determine whether the spring damper meets the processing and assembly requirements. If it does not meet the processing and assembly requirements, return to step S2 to adjust the interface of the spring damper.

2. The similar design method for the power turbine rotor simulator as described in claim 1, characterized in that, Adjustments to the fulcrum, cantilever disc, and rotor structure include: Change the fulcrum position, turntable weight, turntable position, and shaft diameter.

3. The similar design method for the power turbine rotor simulator as described in claim 1, characterized in that, Adjusting the interface of the spring-loaded damper includes: Adjust the connecting flange, bearings, oil supply and drainage lines, and oil film gap used to form the squeeze oil film of the spring damper.

4. The similar design method for the power turbine rotor simulator as described in claim 1, characterized in that, The comparison error is calculated as (simulator parameters - actual parameters) / actual parameters, with a set value of 5%. The simulator parameters include the fulcrum load, rotor critical speed, and strain energy at multiple locations of the power turbine rotor tester. The actual parameters are the fulcrum load, rotor critical speed, and strain energy at multiple locations of the corresponding real power turbine rotor structure.

5. The similar design method for the power turbine rotor simulator as described in claim 4, characterized in that, The strain energy at the plurality of locations includes at least the rotor strain energy and the strain energy at the first fulcrum near the end of the cantilever disk.

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