Aerial turbofan engine flight envelope right boundary maximum power state control method

Abstract

The invention belongs to the technical field of aviation turbofan engine control design, and particularly relates to an aviation turbofan engine flight envelope right boundary maximum power state control method which comprises the steps that firstly, according to an engine flight envelope, the design state slip of all working condition points of the envelope right boundary is obtained; step 2, when the flight envelope of the engine enters the right boundary and reaches the maximum power state, performing closed-loop control on the slip by adjusting the throat area of the spray pipe based on the design state slip of the corresponding working condition point; and if one of the high-pressure rotating speed n2, the low-pressure rotating speed n1 and the exhaust temperature T6 of the engine reaches the limiting value, it is judged that the engine reaches the maximum power state.

Description

Technical Field

[0001] The present application belongs to the field of aviation turbofan engine control design technology, 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, and 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 full envelope.

[0003] In aviation turbofan engines with adjustable nozzle throat area, such as twin-spool turbofan engines, 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 when the engine is running at maximum power. This control mode takes into account the influence of high and low pressure speeds during engine design. However, in actual use, due to the influence of individual engine differences, test errors, etc., the slip between the engine high-pressure speed and the 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 is running at maximum power, 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 this 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 of the known technical defects.

[0007] The technical solution of this application is: A method for controlling a maximum power state at the right boundary of a flight envelope of an aviation turbofan engine, comprising: Step 1: Based on the engine flight envelope, obtain the design state deviation of each operating point on the right boundary of the envelope; 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 nozzle throat area is adjusted to perform closed-loop control of the slip; If any 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.

[0008] 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.

[0009] 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.

[0010] 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.

[0011] Optionally, in the above-mentioned maximum power state control method for the right boundary of the aviation turbofan engine flight envelope, 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 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 in the design state to the maximum power state.

[0012] This application has at least the following beneficial technical effects: A method for controlling the maximum power state at the right boundary of the flight envelope of an aviation turbofan engine is provided. When the engine flight envelope enters the right boundary and reaches the maximum power state, the method performs closed-loop control of the slip by adjusting the nozzle throat area based on the design state slip of the corresponding operating point. The slip is maintained at the design state slip and reaches the optimal design state, thereby improving the overall thrust and optimizing the engine performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the right boundary of the flight envelope of existing aviation turbofan engines; Figure 2 Schematic diagram of a method for controlling a maximum power state at the right boundary of a flight envelope of an aviation turbofan engine provided by an embodiment of the present application; Figure 3 Schematic diagram of the limit values ​​of high-pressure speed, low-pressure speed, and exhaust temperature of the engine provided in the embodiment of the present application; Figure 4It 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, provided by an embodiment of the present application.

[0014] In order to better illustrate this 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 understood as limiting this application. DETAILED DESCRIPTION

[0015] To make the technical solution and its advantages of this application more clear, the technical solution of this application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only some of the embodiments of this application and are only used to explain this application, not to limit this application. It should be noted that for ease of description, only the parts relevant to this application are shown in the accompanying drawings, and other relevant parts can refer to the general design.

[0016] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application should have the usual meanings understood by those skilled in the art in the field to which this application belongs. The words indicating orientation used in the description of this application 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 means 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.

[0017] In addition, it should be noted that, unless otherwise clearly stipulated 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.

[0018] A method for controlling the maximum power state of an aviation turbofan engine at the right boundary of the flight envelope is provided. The closed-loop control is performed based on the slip to keep the slip at the designed state. Figure 2 shown.

[0019] Step 1: Based on the engine flight envelope, obtain the design state deviation of each operating point on the right boundary of the envelope.

[0020] Each engine operating point corresponds to a different altitude and Mach number.

[0021] The engine design state slip can be expressed as a curve showing the relationship between the high-pressure speed n2 and the low-pressure speed n1 from idling to maximum power state in the design state.

[0022] Step 2: When the engine flight envelope 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.

[0023] When one of the engine's high-pressure speed n2, low-pressure speed n1, and exhaust temperature T6 reaches the limit value, the engine is considered to have reached the maximum power state. The limit values ​​of the engine's high-pressure speed n2, low-pressure speed n1, and exhaust temperature T6 are as follows: Figure 3 shown.

[0024] 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 entire machine.

[0025] When the engine's low-pressure speed n1 reaches its limit, the nozzle throat area is reduced to reduce the low-pressure turbine work, thereby increasing the high-pressure speed n2, maintaining the slip at the design level, increasing the core engine air flow, and improving the overall thrust. It is important to note that this adjustment process does not allow the exhaust temperature T6 to exceed the limit.

[0026] 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 in the design state to the maximum power state.

[0027] 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: 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, .

[0028] 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 link.

[0029] S3, control the current of the electro-hydraulic servo valve of the nozzle actuator , which is delivered 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.

[0030] The above-mentioned embodiment discloses a method for controlling the maximum power state at the right boundary of the flight envelope of an aviation turbofan engine. When the engine flight envelope enters the right boundary and reaches the maximum power state, the method is designed to perform closed-loop control on the slip based on the design state slip of the corresponding operating point by adjusting the nozzle throat area, 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.

[0031] 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 replacements to the relevant technical features, and the technical solutions after these changes or replacements 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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