Method and device for determining warm-up speed of a dual-shaft turbofan engine

Abstract

The present application belongs to the field of engine control technology, and specifically relates to a method and device for determining the warm-up speed of a dual-shaft turbofan engine. The method includes step S1, determining the first maximum distortion index at each low-pressure conversion speed that can ensure the stable operation of the engine fan; step S2, determining the second maximum distortion index at each low-pressure conversion speed that can ensure the stable operation of the compressor; step S3, determining the maximum low-pressure conversion speed based on the inlet distortion index and the first and second maximum distortion indices; step S4, determining the maximum high-pressure conversion speed corresponding to the maximum low-pressure conversion speed; step S5, calculating the maximum high-pressure physical speed corresponding to the maximum high-pressure conversion speed; step S6, using the area between the warm-up minimum speed and the maximum high-pressure physical speed as the warm-up speed area. While ensuring the warm-up effect, the present application can ensure that the engine will not experience surge problems due to excessive warm-up state and excessive inlet air flow.

Description

Technical Field

[0001] The present application belongs to the field of engine control technology, and specifically relates to a method and device for determining the warm-up speed of a dual-shaft turbofan engine. Background Art

[0002] Typically, to improve engine stability margin and thrust and reduce the likelihood of excessive engine vibration, the engine must be warmed up before normal operation. To facilitate user memorization and usage, aircraft engine warm-up speeds are all given in the same physical speed range.

[0003] Typically, aircraft engine warm-up speeds are assigned within a specific physical range. This warm-up speed range is suitable for most operating conditions, but it doesn't fully account for low-temperature engine operation. When operating at low temperatures, the engine's conversion state is high, resulting in excessive airflow and significant inlet distortion. This can lead to surge issues for some engines with insufficient surge margin. Summary of the Invention

[0004] In order to solve one of the above problems, the present application provides a method and device for determining the warm-up speed of a dual-shaft turbofan engine, which can not only ensure stable operation of the engine (no surge) but also achieve a warm-up speed with a warm-up effect.

[0005] The first aspect of the present application provides a method for determining the warm-up speed of a dual-shaft turbofan engine, mainly comprising:

[0006] Step S1: determining a first maximum distortion index that can ensure stable operation of the engine fan at each low-pressure converted speed;

[0007] Step S2: determining a second maximum distortion index at each low-pressure converted speed that can ensure stable operation of the compressor;

[0008] Step S3: As the low-pressure converted speed increases, the low-pressure converted speed when the intake duct distortion index first becomes equal to the first maximum distortion index or equal to the second maximum distortion index is obtained, and the low-pressure converted speed is the maximum low-pressure converted speed;

[0009] Step S4: determining the maximum high-pressure converted speed corresponding to the maximum low-pressure converted speed according to the upper limit of the engine slip;

[0010] Step S5, calculating the maximum high-pressure physical speed corresponding to the maximum high-pressure converted speed;

[0011] Step S6: The area between the warm-up minimum speed and the maximum high-pressure physical speed is used as the warm-up speed area.

[0012] Preferably, step S1 further comprises:

[0013] Step S11, obtaining the fan surge margin, the allowable fan residual margin, and the fan distortion sensitivity coefficient corresponding to each low-pressure converted speed;

[0014] Step S12: Calculate the first maximum distortion index corresponding to each low-pressure converted speed.

[0015] Preferably, step S2 further comprises:

[0016] Step S21: obtaining the minimum surge margin, allowable compressor residual margin, compressor distortion sensitivity coefficient, and fan distortion attenuation coefficient of the engine compressor corresponding to each low-pressure converted speed;

[0017] Step S22: Calculate the second maximum distortion index corresponding to each low-pressure converted speed.

[0018] Preferably, step S3 further comprises:

[0019] Step S31, determining a first relationship curve between a low-pressure converted rotational speed and a first maximum distortion index, and a second relationship curve between a low-pressure converted rotational speed and a second maximum distortion index;

[0020] Step S32: placing the third relationship curve between the low-pressure converted speed and the intake duct distortion index, the first relationship curve, and the second relationship curve in the same coordinate system;

[0021] Step S33: determine the intersection points of the third relationship curve and the first relationship curve, and the intersection points of the third relationship curve and the second relationship curve, and take the minimum value of the low-pressure converted speed among all the intersection points as the maximum low-pressure converted speed.

[0022] A second aspect of the present application provides a device for determining a warm-up speed of a dual-shaft turbofan engine, mainly comprising:

[0023] A first maximum distortion index determination module is used to determine a first maximum distortion index that can ensure stable operation of the engine fan at each low-pressure converted speed;

[0024] A second maximum distortion index determination module is used to determine the second maximum distortion index that can ensure stable operation of the compressor at each low-pressure converted speed;

[0025] a maximum low-pressure converted speed determining module, configured to determine, as the low-pressure converted speed continuously increases, the low-pressure converted speed when the intake duct distortion index first becomes equal to the first maximum distortion index or the second maximum distortion index, and the low-pressure converted speed being the maximum low-pressure converted speed;

[0026] a maximum high-pressure converted speed determining module, configured to determine a maximum high-pressure converted speed corresponding to the maximum low-pressure converted speed according to an upper limit of engine slip;

[0027] a maximum high-pressure physical speed determination module, configured to calculate the maximum high-pressure physical speed corresponding to the maximum high-pressure converted speed;

[0028] The warm-up speed region determining module is configured to determine a region between the warm-up minimum speed and the maximum high-pressure physical speed as the warm-up speed region.

[0029] Preferably, the first maximum distortion index determining module includes:

[0030] A fan parameter acquisition unit is used to obtain the fan surge margin, the allowable fan residual margin and the fan distortion sensitivity coefficient corresponding to each low-pressure converted speed;

[0031] The first maximum distortion index calculation unit is used to calculate the first maximum distortion index corresponding to each low-pressure converted speed.

[0032] Preferably, the second maximum distortion index determining module includes:

[0033] A compressor parameter acquisition unit is used to obtain the minimum surge margin, allowable compressor residual margin, compressor distortion sensitivity coefficient and fan distortion attenuation coefficient of the engine compressor corresponding to each low-pressure converted speed;

[0034] The second maximum distortion index calculation unit is used to calculate the second maximum distortion index corresponding to each low-pressure converted speed.

[0035] Preferably, the maximum low-pressure converted speed determination module includes:

[0036] a relationship curve determining unit, configured to determine a first relationship curve between a low-pressure converted rotational speed and a first maximum distortion index, and a second relationship curve between a low-pressure converted rotational speed and a second maximum distortion index;

[0037] a curve intersection calculation unit, configured to place a third relationship curve between the low-pressure converted speed and the intake duct distortion index, the first relationship curve, and the second relationship curve in the same coordinate system;

[0038] The maximum low-pressure conversion speed selection unit is used to determine the intersection point of the third relationship curve and the first relationship curve, and the intersection point of the third relationship curve and the second relationship curve, and take the minimum low-pressure conversion speed among all the intersection points as the maximum low-pressure conversion speed.

[0039] The warm-up speed designed in this application can ensure the warm-up effect while ensuring that the engine will not experience surge problems due to excessive warm-up state and excessive air flow in the intake duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1This is a flow chart of a preferred embodiment of the method for determining the warm-up speed of a dual-shaft turbofan engine of the present application. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the implementation of this application will be described in more detail below in conjunction with the drawings in the implementation of this application. In the drawings, the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and should not be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in conjunction with the drawings.

[0042] The first aspect of the present application provides a method for determining the warm-up speed of a dual-shaft turbofan engine, mainly comprising:

[0043] Step S1: determining a first maximum distortion index that can ensure stable operation of the engine fan at each low-pressure converted speed;

[0044] Step S2: determining a second maximum distortion index at each low-pressure converted speed that can ensure stable operation of the compressor;

[0045] Step S3: As the low-pressure converted speed increases, the low-pressure converted speed when the intake duct distortion index first becomes equal to the first maximum distortion index or equal to the second maximum distortion index is obtained, and the low-pressure converted speed is the maximum low-pressure converted speed;

[0046] Step S4: determining the maximum high-pressure converted speed corresponding to the maximum low-pressure converted speed according to the upper limit of the engine slip;

[0047] Step S5, calculating the maximum high-pressure physical speed corresponding to the maximum high-pressure converted speed;

[0048] Step S6: The area between the warm-up minimum speed and the maximum high-pressure physical speed is used as the warm-up speed area.

[0049] In some optional embodiments, step S1 further includes:

[0050] Step S11, obtaining the fan surge margin, the allowable fan residual margin, and the fan distortion sensitivity coefficient corresponding to each low-pressure converted speed;

[0051] Step S12: Calculate the first maximum distortion index corresponding to each low-pressure converted speed.

[0052] Specifically, according to the low pressure conversion speed (n 1R ) fan surge margin SM under F , allowable residual margin △SM F (given based on experience) and the distortion sensitivity coefficient α F , the maximum distortion index W at which the engine fan can operate stably at each speed can be determined F,max (with n 1R Related functions):

[0053]

[0054] In some optional embodiments, step S2 further includes:

[0055] Step S21: obtaining the minimum surge margin, allowable compressor residual margin, compressor distortion sensitivity coefficient, and fan distortion attenuation coefficient of the engine compressor corresponding to each low-pressure converted speed;

[0056] Step S22: Calculate the second maximum distortion index corresponding to each low-pressure converted speed.

[0057] Specifically, according to the minimum surge margin SM of the engine compressor at all converted speeds C,min , allowable residual margin △SM C (given based on experience), distortion sensitivity coefficient α C and fan distortion attenuation coefficient β F , the maximum distortion index W of the fan inlet that can ensure stable operation at all engine compressor speeds can be determined C,max (with n 1R Related functions):

[0058]

[0059] It should be noted that the maximum distortion index W at the fan inlet is calculated C,max When, SM C,min is a fixed value, which is the minimum surge margin of the engine compressor at all low-pressure converted speeds, and the allowed remaining margin △SM C , distortion sensitivity coefficient α C and fan distortion attenuation coefficient β F There are multiple values, each corresponding to a low-pressure conversion speed. Therefore, the calculated maximum distortion index W of the fan inlet is C,max It is a function related to the low-pressure conversion speed. In addition, it should be noted that the distortion of the compressor is mapped to the distortion at the fan inlet through the fan distortion attenuation coefficient. Therefore, the second maximum distortion index here refers to the maximum distortion index W at the fan inlet. C,max .

[0060] In some optional embodiments, step S3 further includes:

[0061] Step S31, determining a first relationship curve between a low-pressure converted rotational speed and a first maximum distortion index, and a second relationship curve between a low-pressure converted rotational speed and a second maximum distortion index;

[0062] Step S32: placing the third relationship curve between the low-pressure converted speed and the intake duct distortion index, the first relationship curve, and the second relationship curve in the same coordinate system;

[0063] Step S33: determine the intersection points of the third relationship curve and the first relationship curve, and the intersection points of the third relationship curve and the second relationship curve, and take the minimum value of the low-pressure converted speed among all the intersection points as the maximum low-pressure converted speed.

[0064] It should be noted that, under normal design conditions, W F,max and W C,max In the low speed section, it will be higher than the intake duct distortion index W. Therefore, as the low-pressure converted speed increases, the third relationship curve will intersect with the first relationship curve and the second relationship curve.

[0065] In step S4, according to the upper limit of engine slip (characterizing the relationship between low pressure conversion speed and high pressure conversion speed: n 1R -n 2R ) and the maximum low-pressure conversion speed n determined above 1R_max , determine the maximum high-pressure conversion speed n that ensures the engine does not surge during warm-up 2R暖机_max ;

[0066] In step S5, the speed n is converted according to the maximum high pressure. 2R暖机_max Determine the maximum high-pressure physical speed n 2max (The engine may surge if this value is exceeded):

[0067]

[0068] In step S6, take the value above the “minimum warm-up speed” and n 2max The area below is the warm-up speed area, which can ensure that the warm-up effect is achieved and that surge does not occur during warm-up.

[0069] A second aspect of the present application provides a device for determining a warm-up speed of a dual-shaft turbofan engine corresponding to the above method, mainly comprising:

[0070] A first maximum distortion index determination module is used to determine a first maximum distortion index that can ensure stable operation of the engine fan at each low-pressure converted speed;

[0071] A second maximum distortion index determination module is used to determine the second maximum distortion index that can ensure stable operation of the compressor at each low-pressure converted speed;

[0072] a maximum low-pressure converted speed determining module, configured to determine, as the low-pressure converted speed continuously increases, the low-pressure converted speed when the intake duct distortion index first becomes equal to the first maximum distortion index or the second maximum distortion index, and the low-pressure converted speed being the maximum low-pressure converted speed;

[0073] a maximum high-pressure converted speed determining module, configured to determine a maximum high-pressure converted speed corresponding to the maximum low-pressure converted speed according to an upper limit of engine slip;

[0074] a maximum high-pressure physical speed determination module, configured to calculate the maximum high-pressure physical speed corresponding to the maximum high-pressure converted speed;

[0075] The warm-up speed region determining module is configured to determine a region between the warm-up minimum speed and the maximum high-pressure physical speed as the warm-up speed region.

[0076] In some optional implementations, the first maximum distortion index determination module includes:

[0077] A fan parameter acquisition unit is used to obtain the fan surge margin, the allowable fan residual margin and the fan distortion sensitivity coefficient corresponding to each low-pressure converted speed;

[0078] The first maximum distortion index calculation unit is used to calculate the first maximum distortion index corresponding to each low-pressure converted speed.

[0079] In some optional implementations, the second maximum distortion index determination module includes:

[0080] A compressor parameter acquisition unit is used to obtain the minimum surge margin, allowable compressor residual margin, compressor distortion sensitivity coefficient and fan distortion attenuation coefficient of the engine compressor corresponding to each low-pressure converted speed;

[0081] The second maximum distortion index calculation unit is used to calculate the second maximum distortion index corresponding to each low-pressure converted speed.

[0082] In some optional implementations, the maximum low-pressure converted speed determination module includes:

[0083] a relationship curve determining unit, configured to determine a first relationship curve between a low-pressure converted rotational speed and a first maximum distortion index, and a second relationship curve between a low-pressure converted rotational speed and a second maximum distortion index;

[0084] a curve intersection calculation unit, configured to place a third relationship curve between the low-pressure converted speed and the intake duct distortion index, the first relationship curve, and the second relationship curve in the same coordinate system;

[0085] The maximum low-pressure conversion speed selection unit is used to determine the intersection point of the third relationship curve and the first relationship curve, and the intersection point of the third relationship curve and the second relationship curve, and take the minimum low-pressure conversion speed among all the intersection points as the maximum low-pressure conversion speed.

[0086] The key point of this application is that the surge margin of the engine fan and compressor cannot be too low (relative to the distortion index of the actual use of the intake duct). Otherwise, under some state points, the "minimum warm-up speed" will be higher than the warm-up speed required for no surge, resulting in the inability to design the warm-up speed.

[0087] The warm-up speed designed in this application can ensure the warm-up effect while ensuring that the engine will not experience surge problems due to excessive warm-up state and excessive air flow in the intake duct.

[0088] Although the present application has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications or improvements may be made based on the present application. Therefore, such modifications or improvements, which do not depart from the spirit of the present application, are within the scope of protection claimed in the present application.

Claims

1. A method for determining the warm-up speed of a dual-shaft turbofan engine, characterized in that: include: Step S1: determining a first maximum distortion index that can ensure stable operation of the engine fan at each low-pressure converted speed; Step S2: determining a second maximum distortion index at each low-pressure converted speed that can ensure stable operation of the compressor; Step S3: As the low-pressure converted speed increases, the low-pressure converted speed when the intake duct distortion index first becomes equal to the first maximum distortion index or equal to the second maximum distortion index is obtained, and the low-pressure converted speed is the maximum low-pressure converted speed; Step S4: determining the maximum high-pressure converted speed corresponding to the maximum low-pressure converted speed according to the upper limit of the engine slip; Step S5, calculating the maximum high-pressure physical speed corresponding to the maximum high-pressure converted speed; Step S6: The area between the minimum warm-up speed and the maximum high-pressure physical speed is used as the warm-up speed area; Wherein, step S1 further comprises: Step S11: Obtain the fan surge margin SM corresponding to each low-pressure converted speed F , Allowable fan residual margin △SM F And fan distortion sensitivity coefficient α F ; Step S12: Calculate the first maximum distortion index W corresponding to each low-pressure converted speed F,max : Step S2 further comprises: Step S21: Obtain the minimum surge margin SM of the engine compressor corresponding to each low-pressure converted speed. C,min , allowable compressor residual margin △SM C , compressor distortion sensitivity coefficient α C and fan distortion attenuation coefficient β F ; Step S22: Calculate the second maximum distortion index corresponding to each low-pressure converted speed:

2. The method for determining the warm-up speed of a twin-shaft turbofan engine according to claim 1, wherein: Step S3 further comprises: Step S31, determining a first relationship curve between a low-pressure converted rotational speed and a first maximum distortion index, and a second relationship curve between a low-pressure converted rotational speed and a second maximum distortion index; Step S32: placing the third relationship curve between the low-pressure converted speed and the intake duct distortion index, the first relationship curve, and the second relationship curve in the same coordinate system; Step S33: determine the intersection points of the third relationship curve and the first relationship curve, and the intersection points of the third relationship curve and the second relationship curve, and take the minimum value of the low-pressure converted speed among all the intersection points as the maximum low-pressure converted speed.

3. A device for determining the warm-up speed of a dual-shaft turbofan engine, characterized in that: include: A first maximum distortion index determination module is used to determine a first maximum distortion index that can ensure stable operation of the engine fan at each low-pressure converted speed; A second maximum distortion index determination module is used to determine the second maximum distortion index that can ensure stable operation of the compressor at each low-pressure converted speed; a maximum low-pressure converted speed determining module, configured to determine, as the low-pressure converted speed continuously increases, the low-pressure converted speed when the intake duct distortion index first becomes equal to the first maximum distortion index or the second maximum distortion index, and the low-pressure converted speed being the maximum low-pressure converted speed; a maximum high-pressure converted speed determining module, configured to determine a maximum high-pressure converted speed corresponding to the maximum low-pressure converted speed according to an upper limit of engine slip; a maximum high-pressure physical speed determination module, configured to calculate the maximum high-pressure physical speed corresponding to the maximum high-pressure converted speed; a warm-up speed region determining module, configured to determine a region between the warm-up minimum speed and the maximum high-pressure physical speed as the warm-up speed region; The first maximum distortion index determination module includes: The fan parameter acquisition unit is used to obtain the fan surge margin SM corresponding to each low-pressure converted speed. F , Allowable fan residual margin △SM F And fan distortion sensitivity coefficient α F ; The first maximum distortion index calculation unit is used to calculate the first maximum distortion index W corresponding to each low-pressure converted speed. F,max : The second maximum distortion index determination module includes: The compressor parameter acquisition unit is used to obtain the minimum surge margin SM of the engine compressor corresponding to each low-pressure converted speed C,min , allowable compressor residual margin △SM C , compressor distortion sensitivity coefficient α C and fan distortion attenuation coefficient β F ; The second maximum distortion index calculation unit is used to calculate the second maximum distortion index corresponding to each low-pressure converted speed:

4. The device for determining the warm-up speed of a twin-shaft turbofan engine according to claim 3, wherein: The maximum low-pressure converted speed determination module includes: a relationship curve determining unit, configured to determine a first relationship curve between a low-pressure converted rotational speed and a first maximum distortion index, and a second relationship curve between a low-pressure converted rotational speed and a second maximum distortion index; a curve intersection calculation unit, configured to place a third relationship curve between the low-pressure converted speed and the intake duct distortion index, the first relationship curve, and the second relationship curve in the same coordinate system; The maximum low-pressure conversion speed selection unit is used to determine the intersection point of the third relationship curve and the first relationship curve, and the intersection point of the third relationship curve and the second relationship curve, and take the minimum low-pressure conversion speed among all the intersection points as the maximum low-pressure conversion speed.

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