Complete aircraft engine containment test method

Abstract

The invention discloses a complete machine containment test method for an aero-engine, which is used for carrying out complete machine containment test on a turboprop engine and comprises the following steps: S100, prefabricating a notch in a membrane disc coupling, designing a part test device to carry out twist-off test on the membrane disc coupling, adjusting the size design of the notch, and carrying out complete machine containment test on the membrane disc coupling; the membrane disc coupling can be broken under the twist-off torque of the rotor shaft; s200, the diaphragm disc coupler with the notch meeting the requirement is installed between the rotor shaft and the speed reducer gear train, complete machine assembly of the turboprop engine is completed, the turboprop engine obtained after assembly is completed is fixed to a test bed, and the turboprop engine is started to conduct a complete machine containing test; and S300, by referring to the execution standard, verifying whether the complete machine containment test of the turboprop engine passes the examination standard or not. According to the invention, a reducer gear train and a propeller can be effectively protected, the test risk is reduced, and the over-rotation protection of the power turbine disc can be verified while a complete machine containment test is carried out; and a test bed does not need to be modified, and the test complexity is low.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengine blade failure containment verification, and in particular, to a method for a turboprop engine blade containment test. Background Art

[0002] When a blade breaks and flies off in an aeroengine, high-energy fragments will be generated to impact the casing, and at the same time, the rotor unbalance will suddenly increase, thereby causing abnormal vibration of the engine, resulting in huge deformation of the casing, posing a great test to the safety of the external mounting joints, mounting edges, bearings, bearing seats and fuel and lubricating oil pipelines of the aeroengine, seriously endangering the flight safety of the aircraft and even threatening the lives of passengers. Therefore, military and civilian gas turbine engine specifications worldwide all have inclusive requirements without exception. Aeroengines need to conduct a whole-engine containment test according to relevant requirements to pass safety verification. The test results require that at least a single blade should be contained after breaking at a cross-section outside the tenon, or for an integral bladed disk, at least 80% of a single blade should be damaged and contained. Any engine damage caused thereby shall not have any dangerous impact on the aircraft.

[0003] Currently, the whole-engine containment test is generally carried out by prefabricating notches or burying explosives at the blade roots of the aeroengine turbine disk. However, these two methods usually only cause a single blade to break away, and the fracture position is fixed at the blade root, which is different from the actual working conditions and affects the accuracy of the test. Moreover, when using the method of prefabricating notches at the blade roots, due to the influence of material dispersion, processing errors and notch sensitivity, the control accuracy of the flying-off speed is relatively low. In actual applications, notches are usually prefabricated conservatively, resulting in multiple times of lifting and lowering the test rig, and it is difficult to guarantee the success rate of the test. When using the blasting method for blade flying-off, since the detonation pressure has no directionality, it will increase the additional kinetic energy of the blade flying outwards and affect the test results.

[0004] To solve the above problems, in the prior art, there is also a method of performing a whole-engine containment test by overspeeding the output shaft of an aeroengine. This method is to set up a power absorption device and a feed mechanism, connect the power absorption mechanism to the output shaft of the aeroengine through a connecting shaft, cut off the connecting shaft through the feed mechanism, so that the output shaft of the aeroengine instantly loses its load, and the rotational speed rapidly rises until overspeed occurs, causing the blades to break and impact the casing, thereby completing the whole-engine containment test of the aeroengine. However, the output shaft of a turboprop engine is a reduction gear propeller drive shaft, and the reduction gear propeller drive shaft is connected to the rotor shaft of the engine through the gear train of the reducer. There are two types of existing turboprop engine test stands. One is the shaft test stand, which connects the reduction gear propeller drive shaft to the power absorption device through a connecting shaft. If the connecting shaft is cut off by the feed mechanism, the gear train of the reducer will rapidly rise along with the rotational speed of the rotor shaft of the engine, resulting in damage to the gear train of the reducer due to overspeed, and the risk of failure of the whole-engine containment test is relatively high, affecting the accuracy of the test. The other is the propeller test stand, which directly connects the reduction gear propeller drive shaft to the propeller. The reduction gear propeller drive shaft is the only fixed constraint method for the propeller. If the connection between the reduction gear propeller drive shaft and the propeller is cut off by the feed mechanism, the propeller will be in a state of no fixed constraint and will be disengaged from the engine, causing serious safety problems. Therefore, it is impossible to complete the whole-engine containment test by cutting with an external feed mechanism on the propeller test stand. In addition, according to the Advisory Circular AC of "Aircraft Engine Airworthiness Certification", in the design of some aeroengine models, when the rotor shaft overspeed occurs, the power turbine disk is protected from flying by detaching the blades to avoid the power turbine disk from bursting, and this requires experimental verification. Summary of the Invention

[0005] The present invention provides a method for aeroengine whole-engine containment test to solve the technical problems that the blade containment of the whole engine and the overspeed protection of the turbine disk cannot be verified under the overspeed state of the existing turboprop engine.

[0006] According to one aspect of the present invention, there is provided a method for aeroengine whole-engine containment test for performing a whole-engine containment test on a turboprop engine. The turboprop engine includes a propeller, a reduction gear train, and a power turbine disk arranged axially in sequence. The power turbine disk is installed on the rotor shaft, the propeller is connected to the output end of the reduction gear train, and the rotor shaft and the reduction gear train are connected through a diaphragm coupling. The aeroengine whole-engine containment test method includes the following steps:

[0007] S100: Pre-make a notch on the diaphragm coupling, design a component test device to perform a torsion break test on the diaphragm coupling, and adjust the notch size design so that the diaphragm coupling can break under the torsion break torque of the rotor shaft;

[0008] S200: Install a membrane disk coupling with a notch meeting the requirements between the rotor shaft and the reducer gear train, complete the overall assembly of the turboprop engine, fix the assembled turboprop engine on the test bench, and start the turboprop engine to conduct an overall containment test;

[0009] S300: Refer to the implementation standard to verify whether the overall containment test of the turboprop engine passes the assessment standard.

[0010] Furthermore, the notch on the membrane disk coupling is designed circumferentially, and the cross-sectional shape of the notch is designed as U-shaped or V-shaped.

[0011] Furthermore, the notch is designed as U-shaped, and the notch is dimensioned according to the calculation formula: where L is the torsional breaking moment of the rotor shaft, σ b is the smooth tensile ultimate strength of the material, h1 is the depth of the notch, D is the outer diameter of the notch prefabrication position of the membrane disk coupling, d is the inner diameter of the notch prefabrication position of the membrane disk coupling, and W t is the torsional section modulus of the notch cross-section;

[0012] And the notch needs to meet where w1 is the width of the notch and r is the chamfer radius on one side of the notch bottom.

[0013] Furthermore, the notch is designed as V-shaped, and the notch is dimensioned according to the calculation formula: where L is the torsional breaking moment of the rotor shaft, σ b is the smooth tensile ultimate strength of the material, D is the outer diameter of the notch prefabrication position of the membrane disk coupling, d is the inner diameter of the notch prefabrication position of the membrane disk coupling, and W t is the torsional section modulus of the notch cross-section, and w2 is the width of the notch;

[0014] And the notch needs to meet α ∈ [60°, 120°], where α is the V-shaped angle of the notch.

[0015] Furthermore, the component test device includes a torque sensor, a rotary oil cylinder, and an angle sensor connected in sequence along the axial direction. The membrane disk coupling prefabricated with a notch is arranged between the torque sensor and the rotary oil cylinder and connected to the output end of the rotary oil cylinder.

[0016] Furthermore, step S200 specifically includes:

[0017] S201: Install a membrane disk coupling with a notch meeting the requirements between the rotor shaft and the reducer gear train, complete the overall assembly of the turboprop engine, and fix the assembled turboprop engine on the test bench;

[0018] S202: Start the turboprop engine and run it at the ground idle speed for a preset time, and then push the turboprop engine up to the in-air idle speed and run it for a preset time;

[0019] S203: Turn on the intake air heating device to simulate a high-temperature environment;

[0020] S204: Slowly and uniformly push up the output power of the rotor shaft of the turboprop engine, control the rotor shaft to maintain a 100% speed, and adjust the output power and stabilization time of the turboprop engine so that the temperature of the turboprop engine's casing reaches a predetermined value;

[0021] S205: Under the condition that the rotor shaft maintains a 100% speed, push up the output power of the turboprop engine to more than 100%, so that the membrane disc coupling breaks under the torsional breaking moment of the rotor shaft, and make the turboprop engine continue to run for 15 s and then make an emergency stop.

[0022] Further, a monitoring system is installed in the turboprop engine to record and detect the whole process of the turboprop engine's full-machine test.

[0023] Further, step S205 includes making all the blades of the power turbine disc fall off in a full circle.

[0024] Further, the assessment criteria for step S300 include: the blades can fall off within the predetermined overspeed range of the rotor shaft;

[0025] The fallen blades can be contained by the casing and will not cause harmful consequences;

[0026] No uncontrollable fire breaks out during the test process;

[0027] The ability to stop the aeroengine during the test process is available.

[0028] Further, step S200 also includes designing a safety protection plan to provide safety protection for the possible hazards during the test process. The hazards include unacceptable events and non-unacceptable events. Among them, the unacceptable events include:

[0029] After the rotor shaft reaches the predetermined overspeed range, the blades do not fly off and the power turbine disc is damaged;

[0030] After the blades fly off, the debris is not fully contained by the casing and penetrates through the casing and flies out;

[0031] An uncontrollable fire breaks out during the test process;

[0032] The non-unacceptable events include:

[0033] The vibration of the aeroengine is too large, resulting in the instability and shaking of the test bench, the fracture of the leaf spring steel plate and the detachment of the installation structure of the test bench frame;

[0034] The engine vibrates excessively, causing the air intake duct to shake or fall off;

[0035] After a non - unacceptable event occurs, it does not affect the evaluation of the test results. The protection design is carried out based on the actual conditions according to the requirements.

[0036] The present invention has the following beneficial effects:

[0037] 1. By adopting the present invention, the verification of the overall machine containment of a turboprop engine under over - speed conditions can be realized. Compared with the prior art, it does not need to rely on a power absorption device, does not need to add a feed mechanism, reduces the cutting operation of the feed during the test process, reduces the complexity of the test, and improves the safety of the test; the overall machine containment test can be completed on both the shaft platform and the propeller platform of the turboprop engine, with a wide range of operability, and does not require the modification of the test bench, simplifies the test bench, and effectively reduces the test cost.

[0038] 2. By pre - fabricating a notch on the diaphragm coupling between the reducer gear train and the rotor shaft, its torque - bearing capacity is reduced, so that it can be torsionally broken at a specific torque to disconnect the connection between the rotor shaft and the reducer gear train, and the reducer gear train stops rotating after losing the power connection, avoiding damage to the reducer gear train due to over - speed and effectively protecting the reducer gear train.

[0039] 3. By the way of pre - fabricating a notch on the diaphragm coupling to break the diaphragm coupling, the over - speed state of the rotor shaft can be simulated. On the one hand, it can verify whether the over - speed protection of the power turbine disk is effective, that is: when the rotational speed of the rotor shaft reaches the maximum value of the predetermined over - speed rotational speed, the blades fall off to protect the power turbine disk from cracking due to over - speed, which means the over - speed protection function is effective; on the other hand, it can verify whether the blades can be contained by the engine structure after detaching from the power turbine disk without causing consequences harmful to the engine, realizing the verification of the overall machine containment of the turboprop engine.

[0040] 4. By adopting the method of pre - fabricating a notch on the diaphragm coupling for the overall machine containment test of the turboprop engine, the blades can fall off due to the over - speed of the rotor shaft. Compared with the prior art methods of pre - fabricating a notch at the blade root and burying explosives at the blade root, the fracture position of the blades in the present invention is not fixed and the falling - off trajectory has a certain direction, meeting the design requirements of the vast majority of turboprop engines. The blades can fracture from the blade body or from the disk tenon groove, and the test results are more reliable.

[0041] 5. Through the component test device, the notch design on the diaphragm coupling is verified to ensure that the torque - bearing capacity of the diaphragm coupling after pre - fabricating the notch meets the requirements. After successful verification, the same batch of diaphragm couplings are used for pre - fabricating notches of the same specification for the overall machine containment test, improving the accuracy and efficiency of the test and avoiding repeated operations.

[0042] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0044] Figure 1 is a schematic diagram of the method for the whole - engine containment test of an aero - engine according to a preferred embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of the structure of a turboprop engine according to a preferred embodiment of the present invention;

[0046] Figure 3 is a schematic diagram of the structure of pre - forming a U - shaped notch on a diaphragm coupling according to a preferred embodiment of the present invention;

[0047] Figure 4 is a schematic diagram of the structure of pre - forming a V - shaped notch on a diaphragm coupling according to a preferred embodiment of the present invention.

[0048] Figure 5 is a schematic diagram of the structure of a component test according to a preferred embodiment of the present invention.

[0049] LEGEND DESCRIPTION:

[0050] 100, turboprop engine; 101, propeller; 102, reduction gear train; 103, diaphragm coupling; 1031, notch; 104, power turbine disk; 105, rotor shaft; 200, component test device; 201, torque sensor; 202, rotary oil cylinder; 203, angle sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] The following will describe the embodiments of the present invention in detail with reference to the drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0052] As Figure 1 and Figure 2 shown, the method for the whole - engine containment test of the aero - engine in this embodiment is used to conduct a whole - engine containment test on the turboprop engine 100. The turboprop engine 100 includes a propeller 101, a reduction gear train 102, a diaphragm coupling 103 and a power turbine disk 104 that are connected in sequence along the axial direction. The power turbine disk 104 is installed on the rotor shaft 105. The propeller 101 and the reduction gear train 102 are connected by a propeller 101 reduction gear drive shaft. The diaphragm coupling 103 connects the propeller 101 reduction gear drive shaft and the rotor shaft 105. The method for the whole - engine containment test of the aero - engine includes the following steps:

[0053] S100: Pre - fabricate a notch 1031 on the membrane disk coupling 103. Design a component test device 200 to conduct a torsional fracture test on the membrane disk coupling 103, and adjust the dimension design of the notch 1031 so that the membrane disk coupling 103 can fracture under the torsional fracture torque of the rotor shaft 105. Specifically, measure the torsional fracture torque of the rotor shaft 105, and design the dimension of the notch 1031 on the membrane disk coupling 103 according to the torsional fracture torque. Specifically, the working torque of the rotor shaft 105 = 9549 * power of the rotor shaft 105 / rotational speed of the rotor shaft 105. When the rotational speed of the rotor shaft 105 reaches 100% and the power of the rotor shaft 105 exceeds 100%, it reaches the torsional fracture torque of the rotor shaft 105. Design the dimension of the notch 1031 on the membrane disk coupling 103 according to the torsional fracture torque of the rotor shaft 105, so that the dimension design of the notch 1031 meets the requirement of ensuring that the membrane disk coupling 103 can fracture under the torsional fracture torque of the rotor shaft 105. Then conduct a torsional load verification on the membrane disk coupling 103 after the notch 1031 is pre - fabricated, ensure that the torsional load - bearing capacity of the membrane disk coupling 103 after the notch 1031 is pre - fabricated meets the requirements. After the verification is successful, use the same batch of membrane disk couplings 103 to pre - fabricate notches 1031 of the same specification for the whole - machine containment test, which improves the accuracy and efficiency of the test and avoids repeated operations.

[0054] S200: Install the membrane disk coupling 103 with the notch 1031 meeting the requirements between the rotor shaft 105 and the reduction gear train 102 of the reducer, and complete the overall assembly of the turboprop engine 100. Fix the assembled turboprop engine 100 on the test bench and start the turboprop engine 100 to conduct the whole - machine containment test. Specifically, for the design of the notch 1031 of the membrane disk coupling 103 that has passed the torsional load verification of the component test, use the same batch of membrane disk couplings 103 to pre - fabricate and process notches 1031 of the same specification. Then assemble this membrane disk coupling 103 onto the turboprop engine 100, and further conduct the whole - machine containment test on the assembled turboprop engine 100 on the test bench. Thus, by pre - fabricating a notch 1031 on the membrane disk coupling 103 between the rotor shaft 105 and the reduction gear train 102 of the reducer, its torsional load - bearing capacity is reduced, so that it can achieve torsional fracture under a specific torque, disconnect the connection between the rotor shaft 105 and the reduction gear train 102, make the reduction gear train 102 stop rotating after losing the power connection, avoid the reduction gear train 102 from being damaged due to over - rotation, effectively protect the reduction gear train 102, and at the same time, the disconnected rotor shaft 105 undergoes over - rotation, causing the blades to fall off under the action of over - rotation.

[0055] S300: Refer to the implementation standards to verify whether the whole - engine containment test of the turboprop engine 100 passes the assessment criteria. Specifically, the implementation standards referred to include the Advisory Circular AC - 33 on "Airworthiness Certification of Aero - engines" and the Airworthiness Regulation CCAR - 33R2. Specifically, the assessment criteria include: the blades can fall off within the predetermined overspeed range of the rotor shaft 105; the fallen blades can be contained by the casing without causing harmful consequences; no uncontrollable fire occurs during the test; the ability to stop the aero - engine is available during the test.

[0056] As Figure 3 and Figure 4 shown, the notch 1031 on the diaphragm coupling 103 is designed circumferentially, and the cross - sectional shape of the notch 1031 is designed as U - shaped or V - shaped. Specifically, in one embodiment, the notch 1031 is designed as U - shaped, and the notch 1031 is dimensioned according to the formula: where L is the torsional breaking moment of the rotor shaft 105, σ b is the smooth tensile ultimate strength of the material, h1 is the depth of the notch 1031, D is the outer diameter at the pre - formed position of the notch 1031 of the diaphragm coupling 103, d is the inner diameter at the pre - formed position of the notch 1031 of the diaphragm coupling 103, W t is the torsional section modulus of the cross - section of the notch 1031, and the notch 1031 needs to satisfy where w1 is the width of the notch 1031 and r is the chamfer radius on one side of the bottom of the notch 1031.

[0057] In another embodiment, the notch 1031 is designed as V - shaped, and the notch 1031 is dimensioned according to the formula: where L is the torsional breaking moment of the rotor shaft 105, σ b is the smooth tensile ultimate strength of the material, D is the outer diameter at the pre - formed position of the notch 1031 of the diaphragm coupling 103, d is the inner diameter at the pre - formed position of the notch 1031 of the diaphragm coupling 103, W t is the torsional section modulus of the cross - section of the notch 1031, w2 is the width of the notch 1031, and the notch 1031 needs to satisfy α ∈ [60°, 120°], where α is the V - shaped angle of the notch 1031.

[0058] As Figure 5As shown, the component test device 200 includes a torque sensor 201, a rotary oil cylinder 202, and an angle sensor 203 that are sequentially connected along the axial direction. A membrane disk coupling 103 prefabricated with a notch 1031 is disposed between the torque sensor 201 and the rotary oil cylinder 202 and connected to the output end of the rotary oil cylinder 202. Specifically, first, each component is installed and calibrated. Second, test parameters such as the rotational speed and torque loading range of the rotary oil cylinder 202 are set, and the rotary oil cylinder 202 is started to operate at the rotational speed simulating the rotor shaft 105 of the turboprop engine 100. The torque is gradually loaded until the torque range of the torsional breakage moment of the membrane disk coupling 103 is reached. During the test process, the torque sensor 201 and the angle sensor 203 are used to monitor the torque and rotational angle borne by the membrane disk coupling 103 in real time. The measurement data of the torque sensor 201 and the angle sensor 203 are collected and recorded and analyzed, so as to obtain the torque-bearing capacity of the membrane disk coupling. If the membrane disk coupling 103 does not break after reaching the torsional breakage moment, it is necessary to redesign the notch 1031 on the membrane disk coupling 103. By verifying the torque-bearing capacity of the membrane disk coupling 103 after the notch 1031 is prefabricated, it can be ensured that the torque-bearing capacity of the membrane disk coupling 103 after the notch 1031 is prefabricated meets the requirements. After the verification is successful, the membrane disk couplings 103 of the same batch are used to prefabricate the notches 1031 of the same specification for the whole machine containment test, which improves the test accuracy and test efficiency and avoids repeated operations.

[0059] In the present invention, step S200 specifically includes:

[0060] S201: Install the membrane disk coupling 103 with the notch 1031 meeting the requirements between the rotor shaft 105 and the reduction gear train 102, and complete the overall assembly of the turboprop engine 100. Fix the assembled turboprop engine 100 on the test bench;

[0061] S202: Start the turboprop engine 100 to the ground idle state and operate for 2 minutes, and then push the turboprop engine 100 up to the air idle state and operate for 3 minutes;

[0062] S203: Turn on the intake air heating device to simulate a high-temperature environment;

[0063] S204: Slowly and uniformly push up the output power of the rotor shaft 105 of the turboprop engine 100, control the rotor shaft 105 to maintain a 100% rotational speed, and adjust the output power and stabilization time of the turboprop engine 100 so that the casing temperature of the turboprop engine 100 reaches a predetermined value;

[0064] S205: Under the condition that the rotor shaft 105 maintains a speed of 100%, increase the output power of the turboprop engine 100 to more than 100%, so that the diaphragm coupling 103 breaks under the torsional breaking moment of the rotor shaft 105, and make the turboprop engine 100 continue to run for 15 s and then make an emergency stop.

[0065] Finally, according to step S300, verify the turboprop engine 100 against the assessment criteria to complete the whole-engine containment test of the turboprop engine 100.

[0066] A monitoring system is installed on the turboprop engine 100. The monitoring system includes transient image acquisition devices installed at different parts of the test piece to acquire transient images during the test. The transient images include the damage condition of the power turbine disk 104, the process of the blade flying out instantaneously at the moment of fracture, the collision process between the blade and the casing, as well as the trajectory, speed and complete record of the debris that may be released from the aeroengine fan inlet, turbine outlet or through the casing, providing key data for the analysis of blade fracture, component damage and the whole test process. The transient image acquisition device is designed with a protection structure. Preferably, the protection structure adopts a bulletproof glass cover, a protection gantry or protection sandbags to prevent the transient image acquisition device from being damaged by the flying high-energy debris. Moreover, the transient image acquisition device is connected to a power supply system to ensure normal use during the experiment. The power supply system does not cross the axis of the aeroengine to reduce the possibility of being interrupted.

[0067] A speed measurement device is installed on the rotor shaft 105 to measure and record the speed of the rotor shaft 105 during the test, so as to facilitate the combination with the data acquired by the transient image acquisition device to analyze whether the blade falls off within the predetermined overspeed range of the rotor shaft 105. If the blade falls off within the predetermined overspeed range of the rotor shaft 105 and the fallen blade is contained by the casing, it indicates that the turboprop engine 100 has passed the whole-engine containment test, and at the same time indicates that the power turbine disk 104 can achieve overspeed protection.

[0068] Specifically, step 205 includes all the blades of the power turbine disk 104 falling off in a full circle to verify that when the rotor shaft 105 overspeed rotates, the active shedding of all the blades of the power turbine disk 104 in a full circle can avoid the runaway rotation of the power turbine disk 104, thereby protecting the power turbine disk 104 from cracking. The whole-engine containment test of the turboprop engine 100 carried out by using the method of the present invention is a more stringent test than the single blade shedding test, and is suitable for the regulations in Advisory Circular AC-33 of "Airworthiness Certification of Aeroengines", that is: in the design of some engine models, when the rotor shaft 105 overspeed rotates, the active shedding of the blades can avoid the runaway rotation of the power turbine disk 104, thereby protecting the power turbine disk 104 from cracking. The turboprop engine 100 is an engine with the above design features, and should show through the whole-engine containment test that: the blades can fall off within the predetermined speed range of the rotor shaft 105, and the fallen blades can be contained by the engine structure without causing consequences that endanger the engine. Therefore, for the whole-engine containment test of the turboprop engine 100 carried out by using the method of the present invention, if the fallen blade is a critical blade defined according to Article 33.94 of CCAR-33R2 "Airworthiness Requirements for Aeroengines", and the blade shedding test successfully proves the structural integrity of the aeroengine, then the blade penetration energy and unbalanced load at this time have exceeded the requirements of Article 33.94 of CCAR-33R2 "Airworthiness Requirements for Aeroengines", and there is no need to conduct the whole-engine test according to the requirements of CCAR-33R2 "Airworthiness Requirements for Aeroengines".

[0069] Step S200 of the present invention further includes designing a safety protection plan. When designing the safety protection plan, the possible hazards during the test are listed, including unacceptable events and non-unacceptable events. Among them, the unacceptable events include: after the rotor shaft 105 reaches the predetermined overspeed range, the blades do not fly off and the power turbine disk 104 is damaged; after the blades fly off, the fragments are not fully contained by the casing and penetrate the casing and fly out; an uncontrollable fire breaks out during the test.

[0070] The non-unacceptable events include: the excessive vibration of the aeroengine causes the test bench to become unstable and shake, the spring steel plate to break, and the installation structure of the test bench to fall off; the excessive vibration of the engine causes the air intake duct to shake or fall off. After the non-unacceptable events occur, they do not affect the evaluation of the test results, and the protection design is carried out based on the actual conditions as required.

[0071] In response to the possible hazards during the test described above, a protective ring is arranged outside the turboprop engine 100 before the test to prevent the blade fragments or the power turbine disk 104 that penetrate out of the casing from causing harm to the test bench or personnel, and at the same time, prevent and control the possible fire in case of test failure to ensure the safety of the test. The material selection and thickness design of the protective ring are obtained according to the energy of the flying fragments analyzed by the strength of the aeroengine.

[0072] Preferably, the test object of the present invention is not limited to the turboprop engine 100, and may also be other shaft parts having a connection structure between the rotor shaft 105 and the reduction gear train 102.

[0073] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An overall containment test method for an aero-engine, which is used to conduct an overall containment test on a turboprop engine (100). The turboprop engine (100) includes a propeller (101), a reduction gear train (102), and a power turbine disk (104) arranged in sequence along the axial direction. The power turbine disk (104) is installed on a rotor shaft (105). The propeller (101) is connected to the output end of the reduction gear train (102). A membrane disk coupling (103) is used to connect the rotor shaft (105) and the reduction gear train (102). It is characterized in that, The method for the whole - engine containment test of an aero - engine includes the following steps: S100: Pre - fabricate a notch (1031) on the membrane disk coupling (103), design a component test device (200) to conduct a torsional fracture test on the membrane disk coupling (103), and adjust the dimension design of the notch (1031) so that the membrane disk coupling (103) can break under the torsional fracture moment of the rotor shaft (105); S200: Install the membrane disk coupling (103) with the notch (1031) meeting the requirements between the rotor shaft (105) and the reduction gear train (102), complete the whole - engine assembly of the turboprop engine (100), fix the assembled turboprop engine (100) on a test bench, and start the turboprop engine (100) to conduct the whole - engine containment test; S300: Refer to the execution standard to verify whether the whole - engine containment test of the turboprop engine (100) passes the assessment standard.

2. The method for the whole - engine containment test of an aero - engine according to claim 1, wherein the notch (1031) on the membrane disk coupling (103) is designed circumferentially, and the cross - sectional shape of the notch (1031) is designed as a U - shape or a V - shape.

3. The method for the whole - engine containment test of an aero - engine according to claim 2, wherein The notch (1031) is designed to be U-shaped, and the notch (1031) is dimensioned according to the calculation formula: where L is the torsional breaking moment of the rotor shaft (105), σ b is the smooth tensile ultimate strength of the material, h1 is the depth of the notch (1031), D is the outer diameter of the prefabricated position of the notch (1031) of the diaphragm coupling (103), d is the inner diameter of the prefabricated position of the notch (1031) of the diaphragm coupling (103), and W t is the torsional section modulus of the notch cross-section; and the notch (1031) needs to satisfy wherein, w1 is the width of the notch (1031), and r is the chamfer radius on one side of the bottom of the notch (1031).

4. The method for the whole - engine containment test of an aero - engine according to claim 2, wherein The notch (1031) is designed as a V shape and is dimensioned according to the calculation formula: where L is the torsional breaking moment of the rotor shaft (105), σ b is the smooth tensile ultimate strength of the material, D is the outer diameter of the prefabricated position of the notch (1031) of the membrane disk coupling (103), d is the inner diameter of the prefabricated position of the notch (1031) of the membrane disk coupling (103), W t is the torsional section modulus of the notch section, w2 is the width of the notch (1031), and the notch (1031) needs to satisfy α ∈ [60°, 120°], where α is the V-shaped angle of the notch (1031).

5. The method for the whole - engine containment test of an aero - engine according to claim 1, wherein the component test device (200) includes a torque sensor (201), a rotary oil cylinder (202), and an angle sensor (203) connected in sequence along the axial direction. The membrane disk coupling (103) pre - fabricated with the notch (1031) is arranged between the torque sensor (201) and the rotary oil cylinder (202) and is connected to the output end of the rotary oil cylinder (202).

6. The method for the whole - engine containment test of an aero - engine according to claim 1, wherein Step S200 specifically includes: S201: Install the membrane disk coupling (103) with the notch (1031) meeting the requirements between the rotor shaft (105) and the reduction gear train (102), complete the whole - engine assembly of the turboprop engine (100), and fix the assembled turboprop engine (100) on a test bench; S202: Start the turboprop engine (100) to run at the ground idle state for a preset time, and then push the turboprop engine (100) up to the air idle state to run for a preset time; S203: Turn on the intake air heating device to simulate a high - temperature environment; S204: Slowly and uniformly push up the output power of the rotor shaft (105) of the turboprop engine (100), control the rotor shaft (105) to maintain a 100% speed, and adjust the output power and stabilization time of the turboprop engine (100) so that the casing temperature of the turboprop engine (100) reaches a predetermined value. S205: Under the condition that the rotor shaft (105) maintains a speed of 100%, increase the output power of the turboprop engine (100) to more than 100% so that the membrane disk coupling (103) breaks under the torsional breaking moment of the rotor shaft (105), and make the turboprop engine (100) continue to run for 15 s and then make an emergency stop.

7. The method for the whole - engine containment test of an aero - engine according to claim 1, characterized in that A monitoring system is installed in the turboprop engine (100) to record and detect the whole process of the whole - engine test of the turboprop engine (100).

8. The method for the whole - engine containment test of an aero - engine according to claim 6, characterized in that Step S205 includes making all the blades of the power turbine disk (104) fall off in a full circle.

9. The method for the whole - engine containment test of an aero - engine according to claim 1, characterized in that The assessment criteria for step S300 include: the blades can fall off within the predetermined overspeed range of the rotor shaft (105); The fallen blades can be contained by the casing without causing harmful consequences; No uncontrollable fire occurs during the test; The aero - engine has the ability to stop during the test.

10. The method for the whole - engine containment test of an aero - engine according to claim 1, characterized in that Step S200 further includes designing a safety protection plan to protect against the hazards that may occur during the test. The hazards include unacceptable events and non - unacceptable events. Among them, unacceptable events include: After the rotor shaft (105) reaches the predetermined overspeed range, the blades do not fly off and the power turbine disk (104) is damaged; After the blades fly off, the fragments are not fully contained by the casing and penetrate the casing and fly out; An uncontrollable fire occurs during the test; Non - unacceptable events include: The vibration of the aero - engine is too large, resulting in the instability and shaking of the test bench, the fracture of the leaf spring steel plate and the detachment of the installation structure of the test bench frame; The vibration of the engine is too large, resulting in the shaking or detachment of the air intake duct; After a non - unacceptable event occurs, it does not affect the assessment of the test results, and the protection design is carried out based on the actual conditions as required.

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