Maximum power state control method for the right boundary of the flight envelope of aerospace turbofan engines

Abstract

The present application belongs to the technical field of aviation turbofan engine control design, and specifically relates to a maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine, comprising: step one, obtaining the design state slip of each operating point at the right boundary of the envelope according to the engine flight envelope; step two, when the engine flight envelope enters the right boundary and reaches the maximum power state, based on the design state slip of the corresponding operating point, the slip is closed-loop controlled by adjusting the nozzle throat area; if one of the engine's high-pressure speed n2, low-pressure speed n1, and exhaust temperature T6 reaches the limit value, it is judged that the engine has reached the maximum power state.

Description

Technical Field

[0001] The present application belongs to the technical field of aviation turbofan engine control design, and specifically relates to a method for controlling the maximum power state of the right boundary of the flight envelope of an aviation turbofan engine. Background Art

[0002] The right boundary of the flight envelope of an aviation turbofan engine, such as Figure 1 As shown, the inlet temperature and pressure are relatively high. The thrust of the whole machine is usually increased by increasing the engine speed and expanding the nozzle throat area. The high speed and low pressure speed of the engine are usually taken as the design limit value of the engine's full envelope.

[0003] For aviation turbofan engines with adjustable nozzle throat area, such as twin-rotor turbofan engines, when the engine is running at maximum power, the nozzle throat area is usually closed-loop controlled according to the engine pressure ratio or turbine expansion ratio being equal to a constant value. This control mode takes into account the influence of high and low pressure speeds when designing the engine. However, in actual use, due to the influence of individual differences in the engine, test errors, etc., the slip of the engine high-pressure speed and low-pressure speed is difficult to reach the optimal design state.

[0004] At the right boundary of the flight envelope of an aviation turbofan engine, when the engine runs to the maximum power state, there is usually a situation where the high-pressure speed reaches the design limit but the low-pressure speed does not reach the corresponding design optimal value. In this case, the engine inlet air flow will be small and the overall thrust will be low. Alternatively, the low-pressure speed reaches the design limit but the high-pressure speed does not reach the design optimal value. In this case, the engine core flow will be low, the air flow participating in combustion will be low, and the overall thrust will be low.

[0005] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0006] The purpose of the present application is to provide a method for controlling the maximum power state at the right boundary of the flight envelope of an aviation turbofan engine, so as to overcome or alleviate at least one aspect of the known technical defects.

[0007] The technical solution of this application is:

[0008] A method for controlling a maximum power state at the right boundary of a flight envelope of an aviation turbofan engine, comprising:

[0009] Step 1: According to the engine flight envelope, the design state deviation of each operating point on the right boundary of the envelope is obtained;

[0010] Step 2: When the engine flight envelope enters the right boundary and reaches the maximum power state, based on the design state slip of the corresponding operating point, the slip is closed-loop controlled by adjusting the nozzle throat area;

[0011] If one of the high-pressure speed n2, low-pressure speed n1, and exhaust temperature T6 of the engine reaches a limit value, it is determined that the engine has reached the maximum power state.

[0012] Optionally, in the above-mentioned maximum power state control method for the right boundary of the aviation turbofan engine flight envelope, in step one, the engine design state slip is expressed as a relationship curve between the high-pressure speed n2 and the low-pressure speed n1 from slow speed to maximum power state under the design state.

[0013] Optionally, in the above-mentioned maximum power state control method for the right boundary of the aviation turbofan engine flight envelope, in step two, when the engine flight envelope enters the right boundary and the high-pressure speed n2 of the engine reaches the limit value, the nozzle throat area is expanded to keep the slip at the design state slip.

[0014] Optionally, in the above-mentioned maximum power state control method for the right boundary of the aviation turbofan engine flight envelope, in step two, when the engine flight envelope enters the right boundary and the low-pressure speed n1 of the engine reaches the limit value, the nozzle throat area is reduced to keep the slip at the design state slip.

[0015] Optionally, in the above-mentioned maximum power state control method for the right boundary of the aviation turbofan engine flight envelope, in step two, when the engine flight envelope enters the right boundary and the exhaust temperature T6 of the engine reaches the limit value, the nozzle throat area is adjusted to keep the slip at the design state slip, and the high-pressure speed n2 and the low-pressure speed n1 are adjusted according to the relationship curve between the high-pressure speed n2 and the low-pressure speed n1 from slow speed to the maximum power state under the design state.

[0016] This application has at least the following beneficial technical effects:

[0017] A maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine is provided. When the flight envelope of the engine enters the right boundary and reaches the maximum power state, the slip is controlled in a closed loop by adjusting the nozzle throat area based on the design state slip of the corresponding operating point, and the slip is kept in the design state slip to achieve the optimal design state, thereby improving the thrust of the whole machine and optimizing the engine performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the right boundary of the flight envelope of existing aviation turbofan engines;

[0019] Figure 2 It is a schematic diagram of a maximum power state control method for a right boundary of a flight envelope of an aviation turbofan engine provided by an embodiment of the present application;

[0020] Figure 3It is a schematic diagram of the limiting values ​​of the high pressure speed, low pressure speed, and exhaust temperature of the engine provided in the embodiment of the present application;

[0021] Figure 4 It is a schematic diagram of closed-loop control of the slip by adjusting the nozzle throat area based on the design state slip of the corresponding operating point when the engine flight envelope enters the right boundary and reaches the maximum power state, as provided in an embodiment of the present application.

[0022] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0023] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0024] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0025] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0026] A maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine is provided. A closed-loop control is performed based on the slip to keep the slip in the designed state, such as Figure 2 shown.

[0027] Step 1: Based on the engine flight envelope, obtain the design state deviation of each operating point on the right boundary of the envelope.

[0028] Each operating point of the engine corresponds to a different altitude and Mach number.

[0029] The engine design state slip can be expressed as a relationship curve between the high-pressure speed n2 and the low-pressure speed n1 from slow speed to maximum power state in the design state.

[0030] Step 2: When the engine flight envelope enters the right boundary and reaches the maximum power state, based on the design state slip of the corresponding operating point, the slip is closed-loop controlled by adjusting the nozzle throat area.

[0031] When one of the high pressure speed n2, low pressure speed n1, and exhaust temperature T6 of the engine reaches the limit value, the engine is considered to have reached the maximum power state. The limit values ​​of the high pressure speed n2, low pressure speed n1, and exhaust temperature T6 of the engine are as follows: Figure 3 shown.

[0032] When the high-pressure speed n2 of the engine reaches the limit value, the nozzle throat area is expanded to increase the low-pressure turbine work, thereby increasing the low-pressure speed n1, keeping the slip at the design state slip, increasing the inlet air flow, and improving the thrust of the whole machine.

[0033] When the low-pressure speed n1 of the engine reaches the limit value, the nozzle throat area is reduced to reduce the low-pressure turbine work, thereby increasing the high-pressure speed n2, keeping the slip at the design state slip, increasing the core engine air flow, and improving the thrust of the whole machine. It should be noted that this adjustment process does not allow the exhaust temperature T6 to exceed the limit value.

[0034] When the exhaust temperature T6 of the engine reaches the limit value, the nozzle throat area is adjusted to keep the slip at the design state, and the high-pressure speed n2 and low-pressure speed n1 are adjusted according to the relationship curve between the high-pressure speed n2 and the low-pressure speed n1 from slow speed to maximum power state in the design state.

[0035] The design state slip of each operating point at the right boundary of the engine flight envelope can be saved in the engine controller. When the engine flight envelope enters the right boundary and reaches the maximum power state, the slip is closed-loop controlled by adjusting the nozzle throat area based on the design state slip of the corresponding operating point, such as Figure 4 As shown, the specific process is as follows:

[0036] S1. Calculate the deviation between the engine slip and the design state slip ,in, The design status of the engine deteriorates; is the engine slip, .

[0037] S2. Calculate the control current of the electro-hydraulic servo valve of the nozzle actuator using the PI control algorithm ,in, is the proportional control parameter, which is a constant; The balance current of the electro-hydraulic servo valve of the nozzle actuator is a constant; is the integral control parameter, which is a constant; Indicates the integration phase.

[0038] S3, the nozzle actuator electro-hydraulic servo valve control current , which is transmitted to the electro-hydraulic servo valve of the nozzle actuator to drive the nozzle actuator and adjust the nozzle throat area to reduce the deviation of the engine slip from the design state slip. Tends to zero.

[0039] The maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine disclosed in the above-mentioned embodiment is designed to control the slip in a closed loop by adjusting the nozzle throat area based on the design state slip of the corresponding operating point when the engine flight envelope enters the right boundary and reaches the maximum power state, so as to maintain the slip at the design state slip and achieve the optimal design state, thereby improving the thrust of the entire machine and optimizing the engine performance.

[0040] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for controlling the maximum power state of the right boundary of the flight envelope of an aviation turbofan engine, characterized in that: include: Step 1: According to the engine flight envelope, the design state deviation of each operating point on the right boundary of the envelope is obtained; Step 2: When the engine flight envelope enters the right boundary and reaches the maximum power state, based on the design state slip of the corresponding operating point, the slip is closed-loop controlled by adjusting the nozzle throat area; If one of the high-pressure speed n2, low-pressure speed n1, and exhaust temperature T6 of the engine reaches a limit value, it is determined that the engine has reached the maximum power state.

2. The maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine according to claim 1, characterized in that: In step 1, the engine design state slip is represented by a relationship curve between the high-pressure speed n2 and the low-pressure speed n1 from slow speed to maximum power state under the design state.

3. The maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine according to claim 2, characterized in that: In step 2, when the engine flight envelope enters the right boundary and the high pressure speed n2 of the engine reaches the limit value, the nozzle throat area is expanded to keep the slip at the design state slip.

4. The maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine according to claim 3, characterized in that: In step 2, when the engine flight envelope enters the right boundary and the low-pressure speed n1 of the engine reaches the limit value, the nozzle throat area is reduced to keep the slip at the design state slip.

5. The maximum power state control method for the right boundary of the flight envelope of an aviation turbofan engine according to claim 4, characterized in that: In step 2, when the engine flight envelope enters the right boundary and the engine exhaust temperature T6 reaches the limit value, the nozzle throat area is adjusted to keep the slip at the design state, and the high-pressure speed n2 and low-pressure speed n1 are adjusted according to the relationship curve between the high-pressure speed n2 and the low-pressure speed n1 from slow speed to the maximum power state in the design state.

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