Aero-engine vectoring nozzle deflection control method and device

Abstract

The application belongs to the field of engine control and relates to a method and device for deflection control of an aero-engine vector nozzle. The method comprises the following steps: S1, interpolating a current throat area correction coefficient from a preset throat area correction coefficient table according to a nozzle expansion ratio and a deflection angle under a current engine state; S2, pre-amplifying a non-vector deflection state nozzle geometric throat area according to the current throat area correction coefficient to obtain a corrected throat area; S3, interpolating a current engine total pressure ratio from a preset pressure ratio control table according to a low-pressure rotor conversion speed and a fan inlet temperature of the current engine; and S4, performing closed-loop adjustment on the corrected throat area to ensure that the current engine total pressure ratio is unchanged. The application improves control precision and ensures flight safety during vector deflection.

Description

Technical Field

[0001] This application belongs to the field of engine control, and specifically relates to a method and device for controlling the deflection of a vector nozzle in an aero-engine. Background Technology

[0002] Vectoring nozzles are crucial components for achieving vector thrust in aircraft engines. They not only provide forward thrust and vector thrust for flight control, but also alter the common operating point of the compressor and turbine by adjusting the geometric throat area. For vectoring nozzles, vector deflection not only changes the airflow direction in the expansion section but also causes rapid changes in the nozzle's throat position and effective flow area, leading to fluctuations in engine parameters. Simultaneously, the common operating point of engine components changes accordingly, resulting in a reduced surge margin for the compressor (especially the low-pressure compressor). Under special operating conditions such as high-maneuverability or high-altitude low-airspeed conditions, this may trigger engine surge.

[0003] Currently, the adjustment of the effective throat of the vector nozzle under vector deflection state is based on the relationship between the geometric throat area of ​​the nozzle and the vector deflection angle under non-vector deflection state, as shown in the following formula. This method only considers the influence of the single factor of vector deflection angle and does not consider the changes in parameters such as the flow coefficient of the vector nozzle before and after vector deflection. The adjustment accuracy is limited. Over-adjustment will lead to engine thrust loss, while under-adjustment will lead to insufficient engine surge margin.

[0004] A 8,δ =A8 / cosδ; where: δ is the vector deflection angle, A8 is the nozzle geometric throat area in the non-vector deflection state, A 8,δ The vector deflection state is the geometric throat area of ​​the vector nozzle. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a method and apparatus for controlling the deflection of aero-engine vector nozzles, thereby resolving the problem of inaccurate effective throat adjustment of the nozzle during the vector deflection process of existing aero-engines, and the resulting thrust loss or insufficient surge margin maintenance.

[0006] The first aspect of this application provides a method for controlling the deflection of a vector nozzle in an aero-engine, mainly including:

[0007] Step S1: Based on the nozzle expansion ratio and deflection angle under the current engine condition, interpolate the current throat area correction coefficient from the preset throat area correction coefficient table.

[0008] Step S2: Based on the current throat area correction coefficient, pre-enlarge the geometric throat area of ​​the nozzle in the non-vector deflection state to obtain the corrected throat area.

[0009] Step S3, interpolating the current engine total pressure ratio in a preset pressure ratio control table according to the current engine low-pressure rotor equivalent speed and the fan inlet temperature;

[0010] Step S4, closed-loop regulating the corrected throat area with the control target of keeping the current engine total pressure ratio unchanged.

[0011] Preferably, step S1 further comprises:

[0012] Selecting multiple nozzle expansion ratios and deflection angles, for each combination of nozzle expansion ratio and deflection angle, adjusting the nozzle throat area to make the flow rate of the nozzle before and after adjustment the same, obtaining the ratio of the adjusted nozzle throat area to the adjusted nozzle throat area, and forming a throat area correction coefficient table.

[0013] Preferably, the nozzle expansion ratio and deflection angle are discretized according to a set step size.

[0014] Preferably, step S4 further comprises:

[0015] The engine total pressure ratio in the closed-loop regulation process is calculated by the total pressure of the engine internal exhaust gas and the total pressure of the fan inlet;

[0016] According to the difference between the calculated engine total pressure ratio and the interpolated current engine total pressure ratio, the adjusted nozzle throat area is given by a PID algorithm.

[0017] The second aspect of the present application provides an aircraft engine vectoring nozzle deflection control device, mainly comprising:

[0018] A current throat area correction coefficient interpolation module is configured to interpolate the current throat area correction coefficient in a preset throat area correction coefficient table according to the nozzle expansion ratio and the deflection angle under the current engine state;

[0019] A throat area correction module is configured to pre-amplify the non-vectoring deflection state nozzle geometric throat area according to the current throat area correction coefficient to obtain a corrected throat area;

[0020] A current engine total pressure ratio interpolation module is configured to interpolate the current engine total pressure ratio in a preset pressure ratio control table according to the current engine low-pressure rotor equivalent speed and the fan inlet temperature;

[0021] A closed-loop regulation module is configured to closed-loop regulate the corrected throat area with the control target of keeping the current engine total pressure ratio unchanged.

[0022] Preferably, the closed-loop regulation module comprises:

[0023] engine total pressure ratio calculation unit, for calculating the engine total pressure ratio in the closed-loop regulation process by the total pressure of the exhaust gas in the engine and the total pressure at the fan inlet;

[0024] a nozzle throat area calculation unit, for giving the adjusted nozzle throat area by the PID algorithm according to the difference between the calculated engine total pressure ratio and the interpolated current engine total pressure ratio.

[0025] The application effectively improves the control precision while ensuring the vector deflection control speed, realizes small parameter fluctuation in the vector deflection process of the aero-engine, does not reduce the surge margin, and does not lose the thrust, thereby ensuring the flight safety in the vector deflection process. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a flow chart of a preferred embodiment of the vectoring control method of the aero-engine vectoring nozzle of the application.

[0027] Figure 2 is a schematic diagram of the engine air path cross section numbering.

[0028] Figure 3 is a schematic diagram of the open-loop regulation of the nozzle throat area.

[0029] Figure 4 is a schematic diagram of the closed-loop regulation of the nozzle throat area. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme in the embodiment of the application will be described in more detail below in combination with the drawings in the embodiment of the application. In the drawings, the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the application, not all of the embodiments of the application. The embodiments described below by referring to the drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application. The embodiments of the application will be described in detail below in combination with the drawings.

[0031] The first aspect of the application provides a vectoring nozzle deflection control method of an aero-engine, as shown in Figure 1 mainly includes:

[0032] Step S1, according to the nozzle expansion ratio and the deflection angle under the current engine state, interpolating the current throat area correction coefficient in the preset throat area correction coefficient table;

[0033] Step S2: Based on the current throat area correction coefficient, pre-enlarge the geometric throat area of ​​the nozzle in the non-vector deflection state to obtain the corrected throat area.

[0034] Step S3: Based on the current low-pressure rotor speed and fan inlet temperature of the engine, interpolate the current total boost ratio of the engine in the preset boost ratio control table.

[0035] Step S4: With the goal of ensuring that the current total boost ratio of the engine remains unchanged, the area of ​​the corrected throat is adjusted in a closed loop.

[0036] This application performs open-loop adjustment of the nozzle throat area through steps S1 and S2, such as... Figure 3 As shown, the nozzle throat area is then adjusted in a closed loop through steps S3 and S4, as follows. Figure 4 As shown, the above-described aero-engine vector deflection process, which combines open-loop and closed-loop control, adjusts the nozzle throat area, effectively reducing parameter fluctuations and compressor surge margin losses during the vector deflection process. Upon receiving a vector deflection command, the nozzle throat area is first pre-amplified through open-loop control for rapid adjustment; then, closed-loop control ensures the engine main unit's state remains unchanged, achieving accurate adjustment, i.e., maintaining constant compressor surge margin.

[0037] For open-loop regulation, under vector deflection, the effective throat position of the vector nozzle shifts, the effective throat area decreases, and the vector nozzle flow coefficient decreases. The amount of flow coefficient reduction differs for the same deflection angle but different nozzle expansion ratios. Therefore, a method based on the nozzle expansion ratio π is proposed. n The vector nozzle throat adjustment method, with the vector deflection angle δ as the input parameter, enables rapid adjustment of the nozzle throat area A8 during the vector deflection process, while providing more accurate input for closed-loop regulation.

[0038] Nozzle expansion ratio π n π can be calculated in the following way: n =P6*σ / P1. Where σ is the total pressure recovery coefficient of the afterburner, P6 is the total exhaust pressure inside the engine, and P1 is the total inlet pressure of the engine. Figure 2 The numbering of each air passage section in the engine is given. For example, the leftmost section of the entire engine is numbered 1, indicating an engine inlet temperature of T1 and a total engine inlet pressure of P1. The section before the compressor is numbered 25, indicating a compressor inlet temperature of T. 25 The compressor inlet pressure is P 25 .

[0039] In some alternative implementations, step S1 is further preceded by:

[0040] Select multiple nozzle expansion ratio and deflection angle, for each nozzle expansion ratio and deflection angle combination, by adjusting the nozzle throat area, the same flow before and after adjusting the nozzle, get the ratio of the adjusted nozzle throat area and the nozzle throat area before adjustment, form the throat area correction coefficient table.

[0041] In some alternative embodiments, according to the set step, discrete multiple nozzle expansion ratio and deflection angle.

[0042] In this embodiment, according to the characteristics of the engine, according to a certain step, the vector nozzle pressure ratio is selected n1 ,π n2 ……π nn And the vector deflection angle δ1, δ2… δ n , through three-dimensional calculation, adjust the geometric throat area of the vector nozzle under different expansion ratio and vector deflection angle one by one, until the effective throat area of the vector nozzle before and after the vector deflection is equal, that is, the flow remains unchanged, obtain the ratio K of the geometric throat area A 8,δ After the vector deflection and the geometric throat area A8 before the deflection under different expansion ratio and vector deflection angle, as the correction coefficient, finally form the throat area correction coefficient table shown in table 1 below.

[0043] Table 1 Throat area correction coefficient table

[0044] Nozzle expansion ratio vector angle δ1 vector angle δ2 … Vector angle δ n ]]> n1 ]]> ​ 1.03 1.04 … 1.1 n2 ]]> ​ 1.02 1.03 … 1.06 … … … … … nn ]]> ​ 1.003 1.006 … 1.01

[0045] After that, according to the nozzle expansion ratio and deflection angle under the current engine state, interpolation calculation can be carried out according to the above table 1 to obtain the current throat area correction coefficient K1. Then in step S2, as Figure 3 Shown, on the basis of the nozzle throat area A8 under the current state of non vector deflection state, according to the correction coefficient K1, the nozzle throat area A8 is pre amplified.

[0046] For closed loop regulation, mainly according to the engine total pressure ratio as the control target, the nozzle throat area A8 is closed loop controlled to ensure that the engine main machine state is unchanged during the vector deflection process.

[0047] In some alternative embodiments, step S4 further comprises:

[0048] The engine total pressure ratio in the closed loop regulation process is calculated by the total pressure P6 in the engine and the total pressure P2 at the fan inlet;

[0049] According to the difference between the calculated engine total pressure ratio and the current engine total pressure ratio, the adjusted nozzle throat area is given by PID algorithm.

[0050] As Figure 4 Shown, according to the engine low pressure rotor conversion speed n1r and import temperature T2, according to the boost ratio control table shown in Table 2, the required EPR of the current state is obtained by interpolation, the vector deflection process is adjusted by the engine controller to ensure that the EPR is unchanged, and in this embodiment, ERP=P6 / P2.

[0051] Table 2 Boost ratio control table / EPR control law

[0052]

[0053] The application provides a control scheme combining open-loop control and closed-loop control of the nozzle throat area through the vector deflection process, which effectively reduces parameter fluctuation and surge margin loss during vector deflection, effectively improves control accuracy while ensuring vector deflection control speed, realizes small parameter fluctuation, non-reduced surge margin, and non-loss thrust during vector deflection of the aircraft engine, and ensures flight safety during the vector deflection process.

[0054] The second aspect of the application provides an aircraft engine vector nozzle deflection control device corresponding to the above method, mainly comprising:

[0055] A current throat area correction coefficient interpolation module is configured to interpolate a current throat area correction coefficient from a preset throat area correction coefficient table according to a nozzle expansion ratio and a deflection angle of the current engine state.

[0056] A throat area correction module is configured to pre-amplify a non-vector deflection state nozzle geometric throat area according to the current throat area correction coefficient to obtain a corrected throat area.

[0057] A current engine total boost ratio interpolation module is configured to interpolate a current engine total boost ratio from a preset boost ratio control table according to a low-pressure rotor converted speed and a fan import temperature of the current engine.

[0058] A closed-loop adjustment module is configured to perform closed-loop adjustment on the corrected throat area to ensure that the current engine total boost ratio is unchanged.

[0059] In some optional embodiments, the closed-loop adjustment module comprises:

[0060] An engine total boost ratio calculation unit is configured to calculate the engine total boost ratio in the closed-loop adjustment process by the total pressure of the engine internal exhaust gas and the fan import total pressure.

[0061] A nozzle throat area calculation unit is configured to give the adjusted nozzle throat area by a PID algorithm according to a difference between the calculated engine total boost ratio and the interpolated current engine total boost ratio.

[0062] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for deflection control of an aircraft engine vectoring nozzle, characterized in that, The method comprises the following steps: Step S1, according to the nozzle expansion ratio and the deflection angle under the current engine state, interpolating the current throat area correction coefficient from a preset throat area correction coefficient table; Step S2, according to the current throat area correction coefficient, pre-amplifying the non-vector deflection state nozzle geometric throat area to obtain a corrected throat area; Step S3, according to the low-pressure rotor equivalent speed and the fan inlet temperature of the current engine, interpolating the current engine total pressure ratio from a preset pressure ratio control table; Step S4, taking the invariability of the current engine total pressure ratio as a control target, performing closed-loop regulation on the corrected throat area; Before step S1, the method further comprises the following steps: Selecting a plurality of nozzle expansion ratios and deflection angles, for each combination of the nozzle expansion ratio and the deflection angle, adjusting the nozzle throat area to make the flow rate of the nozzle before and after the adjustment the same, obtaining the ratio of the adjusted nozzle throat area to the unadjusted nozzle throat area, and forming a throat area correction coefficient table; Discretizing a plurality of nozzle expansion ratios and deflection angles according to a set step; Step S4 further comprises the following steps: Calculating the engine total pressure ratio in the closed-loop regulation process by the total pressure of the engine internal exhaust gas and the total pressure of the fan inlet; According to the difference between the calculated engine total pressure ratio and the interpolated current engine total pressure ratio, giving the adjusted nozzle throat area by a PID algorithm.

2. An aircraft engine vectoring nozzle deflection control apparatus, characterized by, The device for implementing the method for controlling the deflection of the vector nozzle of the aero-engine according to claim 1 comprises: A current throat area correction coefficient interpolation module, configured to interpolate the current throat area correction coefficient from a preset throat area correction coefficient table according to the nozzle expansion ratio and the deflection angle under the current engine state; A throat area correction module, configured to pre-amplify the non-vector deflection state nozzle geometric throat area according to the current throat area correction coefficient to obtain a corrected throat area; A current engine total pressure ratio interpolation module, configured to interpolate the current engine total pressure ratio from a preset pressure ratio control table according to the low-pressure rotor equivalent speed and the fan inlet temperature of the current engine; A closed-loop regulation module, configured to take the invariability of the current engine total pressure ratio as a control target and perform closed-loop regulation on the corrected throat area.

3. The gas turbine engine vectoring nozzle deflection control apparatus as in claim 2, wherein, The closed-loop regulation module comprises: An engine total pressure ratio calculation unit, configured to calculate the engine total pressure ratio in the closed-loop regulation process by the total pressure of the engine internal exhaust gas and the total pressure of the fan inlet; A nozzle throat area calculation unit, configured to give the adjusted nozzle throat area by a PID algorithm according to the difference between the calculated engine total pressure ratio and the interpolated current engine total pressure ratio.

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