Method for determining sideslip angle correction of pitch moment coefficient of propeller-driven aircraft

Abstract

The invention belongs to the technical field of propeller aircraft control, and particularly relates to a method for determining sideslip angle correction of a pitch moment coefficient of a propeller aircraft, which comprises the following steps of: 1, calculating a propeller parameter beta0; step 2, based on a propeller parameter beta0, calculating a derivative CYbeta'of a lateral force coefficient defined based on the rotating speed and the diameter of the propeller to a sideslip angle; step 3, based on a propeller parameter beta0, and a derivative CYbeta'of a lateral force coefficient to a sideslip angle defined based on the rotating speed and the diameter of the propeller, 4, calculating the sideslip angle correction delta Cm of the pitching moment coefficient according to the pitching moment coefficient derivative # imgabs1 # based on the incoming flow velocity pressure and the wing reference area. The invention also discloses a method for calculating the sideslip angle correction delta Cm of the wing wing according to the sideslip angle correction delta Cm of the wing wing according to the pitching moment coefficient derivative # imgabs1 # based on the incoming flow velocity pressure and the wing reference area.

Description

Technical Field

[0001] The present application belongs to the technical field of propeller aircraft control, and in particular relates to a method for determining a sideslip angle correction value of a pitch moment coefficient of a propeller aircraft. Background Art

[0002] The pitching moment of a propeller aircraft is not only affected by the propeller slipstream and the normal force of the propeller disc, but the propeller lateral force also has a significant impact on the pitching moment.

[0003] When landing in a strong crosswind, the pitch moment of a propeller aircraft will change significantly. In order to correctly control the pitch attitude angle of the aircraft and ensure landing safety, the sideslip angle correction of the aircraft's pitch moment coefficient must be accurately determined.

[0004] Currently, there is a lack of a method for quickly and accurately determining the sideslip angle correction value of the aircraft pitch moment coefficient to support the safe operation of propeller aircraft in heavy crosswind landing. In view of this, the present application is proposed. Summary of the invention

[0005] The purpose of the present application is to provide a method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft, which is used to calculate the change in the pitch moment of the propeller aircraft in the case of heavy crosswind landing and go-around.

[0006] The technical solution of this application is:

[0007] A method for determining a sideslip angle correction value of a pitch moment coefficient of a propeller aircraft comprises:

[0008] Step 1: Calculate propeller parameter β0;

[0009] Step 2: Based on the propeller parameter β0, calculate the derivative C of the side force coefficient defined by the propeller speed and diameter to the sideslip angle Yβ ';

[0010] Step 3: Derivative C of the side force coefficient to the sideslip angle based on propeller parameter β0, propeller speed, and diameter Yβ ', calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area

[0011] Step 4: Derivative of the pitch moment coefficient based on the incoming flow pressure and the wing reference area Calculate the sideslip angle correction ΔC of the pitching moment coefficient m .

[0012] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 1, the propeller parameter β0 is calculated, specifically:

[0013]

[0014] in,

[0015] C' T is the propeller thrust coefficient defined based on engine thrust, propeller speed and propeller disk diameter;

[0016] σ e is the inherent effectiveness factor of the blade;

[0017] J is the advance ratio of the propeller aircraft;

[0018] B is the number of blades.

[0019] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 1,

[0020] in,

[0021] p e is the pulling force of the engine;

[0022] ρ is the air density;

[0023] n is the propeller speed;

[0024] d is the propeller disc diameter.

[0025] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 1,

[0026] in,

[0027] V0 is the incoming flow velocity.

[0028] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 1, σ e = = 0.0003B × AF;

[0029] in,

[0030] AF is the active factor of the blade.

[0031] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 1,

[0032] in,

[0033] c b is the chord length of the blade spanwise station section;

[0034] r is the spanwise position of the blade section;

[0035] R is the radius of the propeller disc.

[0036] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 2, based on the propeller parameter β0, the derivative C of the side force coefficient defined based on the propeller speed and diameter to the sideslip angle is calculated. Yβ ', for propellers rotating in the same direction:

[0037]

[0038] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 2, based on the propeller parameter β0, the derivative C of the side force coefficient defined based on the propeller speed and diameter to the sideslip angle is calculated. Yβ ', for the propellers rotating in opposite directions:

[0039]

[0040] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 3, the derivative C of the side force coefficient defined based on the propeller parameter β0, the propeller speed, and the diameter of the sideslip angle is Yβ ', calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area For propellers rotating in the same direction:

[0041]

[0042] in,

[0043] is the derivative of the pitching moment coefficient based on the propeller speed and diameter to the sideslip angle, and is the derivative of the side force coefficient based on the propeller speed and diameter to the sideslip angle based on the propeller parameter β0. Yβ 'calculate;

[0044] S p is the paddle disc area;

[0045] S ref is the wing reference area;

[0046] C a is the average aerodynamic chord length.

[0047] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step three,

[0048] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 3, the derivative C of the side force coefficient defined based on the propeller parameter β0, the propeller speed, and the diameter of the sideslip angle is Yβ ', calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area For propeller counter-rotation:

[0049]

[0050] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 4, the pitch moment coefficient derivative based on the incoming flow velocity pressure and the wing reference area is used. Calculate the sideslip angle correction ΔC of the pitching moment coefficient m , specifically:

[0051]

[0052] N is the number of engines;

[0053] ΔC mβ0 is the pitch moment coefficient correction produced by zero sideslip angle;

[0054] β e is the effective sideslip angle of the propeller.

[0055] According to at least one embodiment of the present application, in the above-mentioned method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft, in step 4, β e =β-ψ pb ;

[0056] in,

[0057] β is the fuselage sideslip angle;

[0058] ψ pb It is the lateral installation angle of the tension line to the fuselage.

[0059] This application has at least the following beneficial technical effects:

[0060] A method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft is provided, which reflects the influence of the sideslip angle, speed, engine thrust, number of engines, propeller diameter and rotation speed, and blade efficiency on the pitch moment, and can accurately calculate the sideslip angle correction value of the pitch moment coefficient, provide technical support for the calculation of the pitch moment characteristics of propeller aircraft, and support the safe operation of propeller aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic diagram of a method for determining a sideslip angle correction value of a pitch moment coefficient of a propeller aircraft provided in an embodiment of the present application.

[0062] In order to better illustrate the present embodiment, some contents of the drawings may be omitted, which is only used for illustrative purposes and should not be construed as limiting the present application. DETAILED DESCRIPTION

[0063] 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.

[0064] 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.

[0065] 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.

[0066] A method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft, such as Figure 1 shown.

[0067] Step 1: Calculate propeller parameter β0.

[0068]

[0069] in,

[0070] C' T is the propeller thrust coefficient defined based on engine thrust, propeller speed and propeller disk diameter;

[0071] p e is the pulling force of the engine;

[0072] ρ is the air density;

[0073] n is the propeller speed;

[0074] d is the propeller disc diameter.

[0075]

[0076] in,

[0077] J is the advance ratio of the propeller aircraft;

[0078] V0 is the incoming flow velocity.

[0079]

[0080] in,

[0081] σ e is the inherent effectiveness factor of the blade;

[0082] B is the number of blades.

[0083] σ e = = 0.0003B × AF ………… 2-1

[0084] in,

[0085] AF is the active factor of the blade.

[0086]

[0087] in,

[0088] c b is the chord length of the blade spanwise station section;

[0089] r is the spanwise position of the blade section;

[0090] R is the radius of the propeller disc.

[0091] When calculating the propeller parameter β0, the propeller thrust coefficient C' defined based on the engine thrust, propeller speed and propeller disk diameter can be calculated first. T , then discretize the propeller parameter β0 between [0,90], construct the propeller parameter β0 array, and use the interpolation algorithm to solve the value of the propeller parameter β0.

[0092] Step 2: Based on the propeller parameter β0, calculate the derivative C of the side force coefficient defined by the propeller speed and diameter to the sideslip angle Yβ '.

[0093] For propellers rotating in the same direction:

[0094]

[0095]

[0096] in,

[0097] C Yβ is the lateral force derivative based on the incoming flow velocity pressure and the wing reference area;

[0098] S p is the paddle disc area;

[0099] S ref is the reference area of ​​the wing.

[0100] S p =πd 2 / 4…………3-3

[0101] For propeller counter-rotation:

[0102]

[0103]

[0104] Step 3: Derivative C of the side force coefficient to the sideslip angle based on propeller parameter β0, propeller speed, and diameter Yβ ', calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area

[0105] For propellers rotating in the same direction:

[0106]

[0107] in,

[0108] is the derivative of the sideslip angle of the pitching moment coefficient defined based on the propeller speed and diameter.

[0109]

[0110] in,

[0111] C a is the average aerodynamic chord length.

[0112] For propeller counter-rotation:

[0113]

[0114] Step 4: Derivative of the pitch moment coefficient based on the incoming flow pressure and the wing reference area Calculate the sideslip angle correction ΔC of the pitching moment coefficient m .

[0115] β e =β-ψ pb …………7-1

[0116] in,

[0117] β e is the effective sideslip angle of the propeller;

[0118] β is the fuselage sideslip angle;

[0119] ψ pb It is the lateral installation angle of the tension line to the fuselage.

[0120]

[0121] in,

[0122] N is the number of engines;

[0123] ΔC mβ0 It is the pitching moment coefficient correction produced by zero sideslip angle.

[0124] In a specific example, the propeller aircraft has a wing area of ​​65m2, an average aerodynamic chord length of 2.5m, two turboprop engines rotating in the same direction are suspended under the wing, the propeller disk diameter is 4.4m, the number of blades is 6, the blade parameter AF is 188, and the lateral installation angle of the engine thrust axis relative to the fuselage axis is 0°. The incoming flow velocity is 75m / s, the engine speed is 23.6 rpm, the corresponding engine thrust is 33.56KN, and the pitch moment coefficient of zero sideslip angle is 0.006. Using the method for determining the sideslip angle correction value of the pitch moment coefficient of the propeller aircraft disclosed in the above embodiment, the pitch moment coefficient correction value of the propeller aircraft with a sideslip angle of 10° is calculated, and the specific process is as follows:

[0125] 1. Calculate β0 as shown in the following table:

[0126] Calculation of C Yβ ' and C Yβ , as shown in the following table:

[0127] 3. Calculation as well as As shown in the following table:

[0128] 4. Calculate ΔC m , as shown in the following table:

[0129] 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 determining a sideslip angle correction value of a pitch moment coefficient of a propeller aircraft, characterized in that: include: Step 1: Calculate propeller parameter β0; Step 2: Based on the propeller parameter β0, calculate the derivative C of the side force coefficient defined by the propeller speed and diameter to the sideslip angle Yβ '; Step 3: Derivative C of the side force coefficient to the sideslip angle based on propeller parameter β0, propeller speed, and diameter Yβ ', calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area Step 4: Derivative of the pitch moment coefficient based on the incoming flow pressure and the wing reference area Calculate the sideslip angle correction ΔC of the pitching moment coefficient m .

2. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 1, characterized in that: In step 1, the propeller parameter β0 is calculated as follows: in, C' T is the propeller thrust coefficient defined based on engine thrust, propeller speed and propeller disk diameter; σ e is the inherent effectiveness factor of the blade; J is the advance ratio of the propeller aircraft; B is the number of blades.

3. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 2, characterized in that: In step one, in, p e is the pulling force of the engine; ρ is the air density; n is the propeller speed; d is the propeller disc diameter.

4. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 3, characterized in that: In step one, in, V0 is the incoming flow velocity.

5. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 4, characterized in that: In step 1, σ e = = 0.0003B × AF; in, AF is the active factor of the blade.

6. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 5, characterized in that: In step one, in, c b is the chord length of the blade spanwise station section; r is the spanwise position of the blade section; R is the radius of the propeller disc.

7. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 6, characterized in that: In step 2, based on the propeller parameter β0, the derivative C of the side force coefficient defined by the propeller speed and diameter with respect to the sideslip angle is calculated. Yβ ', for propellers rotating in the same direction:

8. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 7, characterized in that: In step 2, based on the propeller parameter β0, the derivative C of the side force coefficient defined by the propeller speed and diameter with respect to the sideslip angle is calculated. Yβ ', for the propellers rotating in opposite directions:

9. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 8, characterized in that: In step 3, the derivative C of the side force coefficient with respect to the sideslip angle is defined based on the propeller parameter β0, the propeller speed, and the diameter. Yβ ', calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area For propellers rotating in the same direction: in, is the derivative of the pitching moment coefficient based on the propeller speed and diameter to the sideslip angle, and is the derivative of the side force coefficient based on the propeller speed and diameter to the sideslip angle based on the propeller parameter β0. Yβ 'calculate; S p is the paddle disc area; S ref is the wing reference area; C a is the average aerodynamic chord length.

10. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 9, characterized in that: In step three, 11. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 10, characterized in that: In step 3, the derivative C of the side slip angle based on the propeller parameter β0, the side force coefficient defined based on the propeller speed and diameter is Yβ , calculate the derivative of the pitching moment coefficient based on the incoming flow pressure and the wing reference area For propeller counter-rotation:

12. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 11, characterized in that: In step 4, the pitch moment coefficient derivative based on the incoming flow pressure and the wing reference area is Calculate the sideslip angle correction ΔC of the pitching moment coefficient m , specifically: N is the number of engines; ΔC mβ0 is the pitch moment coefficient correction produced by zero sideslip angle; β e is the effective sideslip angle of the propeller.

13. The method for determining the sideslip angle correction value of the pitch moment coefficient of a propeller aircraft according to claim 12, characterized in that: In step 4, β e =β-ψ pb ; in, β is the fuselage sideslip angle; ψ pb It is the lateral installation angle of the tension line to the fuselage.

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