Method and device for evaluating single-shot failure take-off and climbing performance of transport plane

Abstract

The invention belongs to the technical field of aircraft design, and particularly relates to a method and a device for evaluating single-shot failure take-off and climbing performance of a transport plane, which are applied to a lower surface blowing flap power high-lift transport plane. The method comprises the following steps: S1, determining a resistance coefficient generated by single-engine failure rolling torque balancing; s2, determining a resistance coefficient generated by single-engine failure pitching moment balancing; s3, a resistance coefficient generated by single-engine failure yaw moment balancing is determined; and S4, calculating the maximum climbing gradient of single-shot failure takeoff. According to the method, the climbing gradient of single-shot failure takeoff of the blowing flap power high-lift transport plane can be quickly and accurately calculated, and the design efficiency of the plane is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft design, and in particular relates to a method and device for evaluating the take-off and climbing performance of a transport aircraft with a single engine failure. Background Art

[0002] The climb gradient with a single engine failure is an important parameter for evaluating the takeoff performance of transport aircraft. The aerodynamic force of the takeoff configuration of a powered lift aircraft with blown flaps is significantly affected by the power. Engine failure will produce rolling moment and yaw moment, and the trim moment will produce additional drag. Due to the flap disturbance, the engine jet is deflected downward, causing thrust loss. The conventional algorithm for the climb gradient with a single engine failure cannot be applied to powered lift aircraft with blown flaps. Summary of the invention

[0003] In order to solve the above problems, the present application provides a method and device for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure, providing technical support for the evaluation of the takeoff and climbing performance of a transport aircraft with a single engine failure using a lower surface blown flap power lift.

[0004] In a first aspect, the present application provides a method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure, which is applied to a power-assisted lift transport aircraft with lower surface blown flaps. The method comprises:

[0005] Step S1: Determine the drag coefficient C generated by the rolling moment trim due to single engine failure Da ;

[0006] Step S2: Determine the drag coefficient C generated by the pitch moment trim due to single engine failure De ;

[0007] Step S3: Determine the drag coefficient C generated by the yaw moment trim due to single engine failure Dr ;

[0008] Step S4: Calculate the maximum climb gradient tanθ for single-engine failure takeoff based on the following formula: max :

[0009]

[0010] Among them, θ max is the maximum flight path angle for takeoff climb, n e is the number of engines, P max is the maximum thrust of the engine, P xz is the engine thrust corrected for system power extraction, speed and altitude, K S is the system power extraction factor in takeoff state, K V is the speed correction factor of thrust, K h is the altitude correction factor, α is the fuselage angle of attack, η j is the jet efficiency factor of the engine in the lift-increasing state, θj is the downward deflection angle of the jet flow disturbed by the flap relative to the fuselage axis, q is the velocity pressure, ρ is the air density, V is the airspeed, S ref is the wing reference area, W is the aircraft weight, C Don is the lift coefficient in the increased lift state, C Doff is the drag coefficient of takeoff in non-powered lift state, C Db is the power effect correction of the full-engine takeoff drag coefficient, C DLG is the drag coefficient of the landing gear.

[0011] Preferably, in step S1, the drag coefficient C generated by the single engine failure rolling moment trim is determined according to the following formula: Da :

[0012]

[0013] Among them, δ a Aileron deflection angle for rolling moment trim, C Dδa is the increase in drag coefficient caused by aileron unit deflection angle, C l is the rolling moment coefficient caused by single engine failure, C lδa is the control efficiency of the aileron, ΔC L is the loss of lift coefficient of the wing on the side of the failed engine, L ye is the span length between the axis of the failed engine and the axis of the fuselage, C Lb is the lift coefficient increment generated by the full-engine takeoff jet flow around the flap, b w The wing span.

[0014] Preferably, step S2 further comprises:

[0015] Step S21: Determine the pitch moment coefficient increment C generated by the jet vector effect mp ;

[0016] Step S22: Determine the pitch moment coefficient increment C generated by the jet flap flow mb ;

[0017] Step S23: Determine the pitch moment coefficient C for takeoff and climb by the following formula: m :

[0018] C m =C moff +C mp +C mb Among them, C moff The pitch moment for takeoff climb in non-powered lift state;

[0019] Step S24: Determine the drag coefficient C generated by the single engine failure pitch moment trim using the following formula: De :

[0020] C De =C Dδe δ e ;

[0021]

[0022] Among them, δ e The elevator deflection angle to balance the pitch moment, C Dδe is the drag coefficient generated by the unit deflection angle of the elevator, C mδe The control efficiency of the elevator.

[0023] Preferably, in step S21, the pitch moment coefficient increment C generated by the jet vector effect is determined by the following formula: mp :

[0024]

[0025] Among them, C T is the thrust coefficient for takeoff of an aircraft with a single engine failure, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, h cf L is the vertical distance of the flap aerodynamic pressure center below the center of gravity, f The axial distance behind the center of gravity of the flap aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e is the axial distance of the engine nozzle behind the center of gravity, c a is the average aerodynamic chord length of the wing.

[0026] Preferably, in step S22, the pitch moment coefficient increment C generated by the jet flap flow is determined by the following formula: mb :

[0027]

[0028] Among them, L0 is the axial distance between the leading edge of the wing and the center of gravity of the fuselage at the engine installation position. It is positive if it is located behind the center of gravity. L c is the axial distance behind the center of gravity of the wing's aerodynamic pressure center after the flaps are placed, and c' is the axial projection length of the wing chord length at the engine installation position.

[0029] Preferably, in step S3, the drag coefficient C generated by the single engine failure yaw moment trim is determined according to the following formula: Dr :

[0030]

[0031] Among them, δ rThe rudder deflection angle to balance the yaw moment, C Dδr is the drag coefficient generated by the rudder unit deflection angle, C n is the yaw moment coefficient caused by single engine failure, C nδr The control efficiency of the rudder.

[0032] Preferably, step S4 further includes determining the drag coefficient dynamic influence correction amount C by the following formula: Db :

[0033]

[0034] Among them, C Lb is the lift coefficient increment generated by the jet flap flow, C La C Lb The incremental correction part of the lift coefficient at medium angle of attack, AR is the aspect ratio, K is the correction coefficient.

[0035] The second aspect of the present application provides a transport aircraft single engine failure takeoff climbing performance evaluation device, which is applied to a lower surface blown flap powered lift transport aircraft, and the device comprises:

[0036] Rolling moment trim drag coefficient determination module, used to determine the drag coefficient C generated by single engine failure rolling moment trim Da ;

[0037] The pitch moment trim drag coefficient determination module is used to determine the drag coefficient C generated by the pitch moment trim of a single engine failure. De ;

[0038] The yaw moment trim drag coefficient determination module is used to determine the drag coefficient C generated by the yaw moment trim of a single engine failure Dr ;

[0039] The maximum climb gradient determination module is used to calculate the maximum climb gradient tanθ for single-engine failure takeoff based on the following formula max :

[0040]

[0041] Among them, θ max is the maximum flight path angle for takeoff climb, n e is the number of engines, P max is the maximum thrust of the engine, P xz is the engine thrust corrected for system power extraction, speed and altitude, K S is the system power extraction factor in takeoff state, K V is the speed correction factor of thrust, K h is the altitude correction factor, α is the fuselage angle of attack, η jis the jet efficiency factor of the engine in the lift-increasing state, θ j is the downward deflection angle of the jet flow disturbed by the flap relative to the fuselage axis, q is the velocity pressure, ρ is the air density, V is the airspeed, S ref is the wing reference area, W is the aircraft weight, C Don is the lift coefficient in the increased lift state, C Doff is the drag coefficient of takeoff in non-powered lift state, C Db is the power effect correction of the full-engine takeoff drag coefficient, C DLG is the drag coefficient of the landing gear.

[0042] Preferably, in the roll moment trim drag coefficient determination module, the drag coefficient C generated by the single engine failure roll moment trim is determined according to the following formula: Da :

[0043]

[0044] Among them, δ a Aileron deflection angle for rolling moment trim, C Dδa is the increase in drag coefficient caused by aileron unit deflection angle, C l is the rolling moment coefficient caused by single engine failure, C lδa is the control efficiency of the aileron, ΔC L is the loss of lift coefficient of the wing on the side of the failed engine, L ye is the span length between the axis of the failed engine and the axis of the fuselage, C Lb is the lift coefficient increment generated by the full-engine takeoff jet flow around the flap, b w The wing span.

[0045] Preferably, the pitch moment trim drag coefficient determination module comprises:

[0046] The first pitch moment coefficient increment determination unit is used to determine the pitch moment coefficient increment C generated by the jet vector effect. mp ;

[0047] The second pitch moment coefficient increment determination unit is used to determine the pitch moment coefficient increment C generated by the jet flap flow. mb ;

[0048] The pitch moment coefficient determination unit is used to determine the pitch moment coefficient C for takeoff climb using the following formula m :

[0049] C m =C moff +C mp +C mb Among them, C moff The pitch moment for takeoff climb in non-powered lift state;

[0050] The pitch moment trim drag coefficient determination unit is used to determine the drag coefficient C generated by the pitch moment trim of a single engine failure by the following formula De :

[0051] C De =C Dδe δ e ;

[0052]

[0053] Among them, δ e The elevator deflection angle to balance the pitch moment, C Dδe is the drag coefficient generated by the unit deflection angle of the elevator, C mδe The control efficiency of the elevator.

[0054] Preferably, in the first pitch moment coefficient increment determining unit, the pitch moment coefficient increment C generated by the jet vector effect is determined by the following formula: mp :

[0055]

[0056] Among them, C T is the thrust coefficient for takeoff of an aircraft with a single engine failure, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, h cf L is the vertical distance of the flap aerodynamic pressure center below the center of gravity, f The axial distance behind the center of gravity of the flap aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e is the axial distance of the engine nozzle behind the center of gravity, c a is the average aerodynamic chord length of the wing.

[0057] Preferably, in the second pitch moment coefficient increment determining unit, the pitch moment coefficient increment C generated by the jet flap flow is determined by the following formula: mb :

[0058]

[0059] Among them, L0 is the axial distance between the leading edge of the wing and the center of gravity of the fuselage at the engine installation position. It is positive if it is located behind the center of gravity. L c is the axial distance behind the center of gravity of the wing's aerodynamic pressure center after the flaps are placed, and c' is the axial projection length of the wing chord length at the engine installation position.

[0060] Preferably, in the yaw moment trim drag coefficient determination module, the drag coefficient C generated by the single engine failure yaw moment trim is determined according to the following formula: Dr :

[0061]

[0062] Among them, δ r The rudder deflection angle to balance the yaw moment, C Dδr is the drag coefficient generated by the rudder unit deflection angle, C n is the yaw moment coefficient caused by single engine failure, C nδr The control efficiency of the rudder.

[0063] Preferably, the maximum climb gradient determination module further includes a drag coefficient dynamic influence correction amount calculation unit, which is used to determine the drag coefficient dynamic influence correction amount C by the following formula: Db :

[0064]

[0065] Among them, C Lb is the lift coefficient increment generated by the jet flap flow, C La C Lb The incremental correction part of the lift coefficient at medium angle of attack, AR is the aspect ratio, K is the correction coefficient.

[0066] A third aspect of the present application provides a computer device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for evaluating the takeoff and climb performance of a transport aircraft with a single engine failure as described above.

[0067] A fourth aspect of the present application provides a readable storage medium, which stores a computer program. When the computer program is executed by a processor, it is used to implement the method for evaluating the takeoff and climb performance of a transport aircraft with a single engine failure as described above.

[0068] The application can quickly and accurately calculate the climb gradient of a single-engine failure takeoff of a blown flap powered lift transport aircraft, thereby improving the efficiency of aircraft design. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 It is a flow chart of a preferred embodiment of the method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure of the present application.

[0070] Figure 2 It is a schematic diagram of the structure of a computer device suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals 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 cannot 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 combination with the drawings.

[0072] The first aspect of the present application provides a method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure, which is applied to a power-assisted lift transport aircraft with blown flaps on the lower surface, such as Figure 1 As shown, the method mainly includes:

[0073] Step S1: Determine the drag coefficient C generated by the rolling moment trim due to single engine failure Da ;

[0074] Step S2: Determine the drag coefficient C generated by the pitch moment trim due to single engine failure De ;

[0075] Step S3: Determine the drag coefficient C generated by the yaw moment trim due to single engine failure Dr ;

[0076] Step S4: Calculate the maximum climb gradient tanθ for single-engine failure takeoff based on the following formula: max :

[0077]

[0078] Among them, θ max is the maximum flight path angle for takeoff climb, n e is the number of engines, P max is the maximum thrust of the engine, P xz is the engine thrust corrected for system power extraction, speed and altitude, K S is the system power extraction factor in takeoff state, K V is the speed correction factor of thrust, K h is the altitude correction factor, α is the fuselage angle of attack, η j is the jet efficiency factor of the engine in the lift-increasing state, θ j is the downward deflection angle of the jet flow disturbed by the flap relative to the fuselage axis, q is the velocity pressure, ρ is the air density, V is the airspeed, S ref is the wing reference area, W is the aircraft weight, CDon is the lift coefficient in the increased lift state, C Doff is the drag coefficient for takeoff in non-powered lift mode (untrim), C Db is the power effect correction of the full-engine takeoff drag coefficient, C DLG is the drag coefficient of the landing gear.

[0079] In some optional implementations, in step S1, the drag coefficient C generated by the single engine failure rolling moment trim is determined according to the following formula: Da :

[0080]

[0081] Among them, δ a Aileron deflection angle for rolling moment trim, C Dδa is the increase in drag coefficient caused by aileron unit deflection angle, C l is the rolling moment coefficient caused by single engine failure, C lδa is the control efficiency of the aileron, ΔC L is the loss of lift coefficient of the wing on the side of the failed engine, L ye is the span length between the axis of the failed engine and the axis of the fuselage, C Lb is the lift coefficient increment generated by the full-engine takeoff jet flow around the flap, b w The wing span.

[0082] In some optional implementations, step S2 further includes:

[0083] Step S21: Determine the pitch moment coefficient increment C generated by the jet vector effect mp ;

[0084] Step S22: Determine the pitch moment coefficient increment C generated by the jet flap flow mb ;

[0085] Step S23: Determine the pitch moment coefficient C for takeoff and climb by the following formula: m :

[0086] C m =C moff +C mp +C mb Among them, C moff The pitch moment for takeoff climb in non-powered lift state;

[0087] Step S24: Determine the drag coefficient C generated by the single engine failure pitch moment trim using the following formula: De :

[0088] C De =C Dδe δe ;

[0089]

[0090] Among them, δ e The elevator deflection angle to balance the pitch moment, C Dδe is the drag coefficient generated by the unit deflection angle of the elevator, C mδe The control efficiency of the elevator.

[0091] In some optional embodiments, in step S21, the pitch moment coefficient increment C generated by the jet vector effect is determined by the following formula: mp :

[0092]

[0093] Among them, C T is the thrust coefficient for takeoff of an aircraft with a single engine failure, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, h cf L is the vertical distance of the flap aerodynamic pressure center below the center of gravity, f The axial distance behind the center of gravity of the flap aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e is the axial distance of the engine nozzle behind the center of gravity, c a is the average aerodynamic chord length of the wing.

[0094] In some optional embodiments, in step S22, the pitch moment coefficient increment C generated by the jet flap flow is determined by the following formula: mb :

[0095]

[0096] Among them, L0 is the axial distance between the leading edge of the wing and the center of gravity of the fuselage at the engine installation position. It is positive if it is located behind the center of gravity. L c is the axial distance behind the center of gravity of the wing's aerodynamic pressure center after the flaps are extended, and c' is the axial projection length of the wing chord length (flaps extended) at the engine installation position.

[0097] In some optional implementations, in step S3, the drag coefficient C generated by the single engine failure yaw moment trim is determined according to the following formula: Dr :

[0098]

[0099] Among them, δ r The rudder deflection angle to balance the yaw moment, C Dδris the drag coefficient generated by the rudder unit deflection angle, C n is the yaw moment coefficient caused by single engine failure, C nδr The control efficiency of the rudder.

[0100] In some optional embodiments, step S4 further includes determining the drag coefficient dynamic influence correction value C by the following formula: Db :

[0101]

[0102] Among them, C Lb is the lift coefficient increment generated by the jet flap flow, C La C Lb The incremental correction part of the lift coefficient at medium angle of attack, AR is the aspect ratio, K is the correction coefficient.

[0103] In this step, K is a function of K4 and is obtained by interpolation operation. The required interpolation data is shown in Table 1 below.

[0104] Table 1 Data required for parameter K interpolation

[0105] <![CDATA[(K4) 2 ]]> 0 0.02 0.04 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13 0.14 K 0 0.001 0.003 0.012 0.02 0.027 0.037 0.05 0.058 0.07 0.85 0.1

[0106] In the above table, the value of K4 can be calculated by the following formula:

[0107]

[0108] Among them, interp1 is a one-dimensional interpolation function.

[0109] The present application can determine whether the aircraft design meets the requirements based on the final calculated maximum climb gradient for aircraft takeoff. If it does not meet the requirements, the parameters involved in the above calculation process can be redesigned and assigned, thereby speeding up the efficiency of aircraft design.

[0110] The example aircraft uses the lower surface blowing flap power lift technology, and the aircraft reference wing area is 353m 2 , wingspan 50.6m, aspect ratio 7.25, wing 1 / 4 chord sweep angle 21°, tip-to-root ratio 0.24. Four high-bypass turbofan engines are hung under the aircraft wing, each with a thrust of 185KN. The engine thrust axis is -5° relative to the local wing chord. The span-wise installation position of the inner engine is 29.6% of the half span, where the wing section installation angle is 3°, and the span-wise installation position of the outer engine is 55% of the half span, where the wing section installation angle is 2.5°.

[0111] Aircraft takeoff configuration: leading edge slat deflection angle 15°, trailing edge double slot Fuller flap deflection angle 15°+10°, flap trailing edge upper surface downward inclination angle 8°. After the flap is extended, the chord length of the wing is 1.2 times the original chord length, the flap chord length is 32% of the wing chord length, of which the chord length of the second section of the flap is 7% of the wing chord length. The depth of the inner flap part immersed in the engine jet is 2.33m, the diameter of the jet at the trailing edge of the flap is 5.43m, and the local wing chord length is 8.73m. The depth of the outer flap part immersed in the engine jet is 2.1m, the diameter of the jet at the trailing edge of the flap is 4.89m, and the local wing chord length is 6.48m. The engine jet efficiency factor is 0.907, and the jet downward deflection angle is 12.25°.

[0112] Calculation status: single engine failure climbing airspeed 90m / s, altitude 20m, climbing angle of attack 5°. Input data: The drag coefficient of the example aircraft takeoff configuration at an angle of attack of 5° in the powerless state is 0.1263, the drag coefficient of the landing gear is 0.015, and the pitch moment coefficient is -0.207. The system power extraction factor is 0.035, the speed correction factor of the thrust is 0.763, the altitude correction factor is 0.995, the lift coefficient increment generated by the full-engine takeoff jet flow flap is 0.1302, and the drag coefficient increment is 0.0145.

[0113] First, in step S1, the drag coefficient C generated by the rolling moment trim due to single engine failure is calculated. Da is 0.0151. Then, in step S2, the drag coefficient C generated by the pitch moment trim due to single engine failure is calculated. De is 0.0085, and then in step S3 the drag coefficient C generated by the yaw moment trim due to single engine failure is calculated. Dr is 0.0072. Finally, the maximum climb gradient tanθ for single-engine failure takeoff is calculated according to the formula in step S4. max The maximum climb gradient of the example aircraft during a go-around is 4.04%, which meets the 3% requirement for a single-engine failure takeoff climb gradient for transport aircraft in the standard.

[0114] In a second aspect, the present application provides a transport aircraft single-engine failure takeoff and climbing performance evaluation device corresponding to the above method, which is applied to a lower surface blown flap powered lift transport aircraft, and the device comprises:

[0115] Rolling moment trim drag coefficient determination module, used to determine the drag coefficient C generated by single engine failure rolling moment trim Da ;

[0116] The pitch moment trim drag coefficient determination module is used to determine the drag coefficient C generated by the pitch moment trim of a single engine failure. De ;

[0117] The yaw moment trim drag coefficient determination module is used to determine the drag coefficient C generated by the yaw moment trim of a single engine failure Dr ;

[0118] The maximum climb gradient determination module is used to calculate the maximum climb gradient tanθ for single-engine failure takeoff based on the following formula max :

[0119]

[0120] Among them, θ max is the maximum flight path angle for takeoff climb, n e is the number of engines, P max is the maximum thrust of the engine, P xz is the engine thrust corrected for system power extraction, speed and altitude, K S is the system power extraction factor in takeoff state, K V is the speed correction factor of thrust, K h is the altitude correction factor, α is the fuselage angle of attack, η j is the jet efficiency factor of the engine in the lift-increasing state, θ j is the downward deflection angle of the jet flow disturbed by the flap relative to the fuselage axis, q is the velocity pressure, ρ is the air density, V is the airspeed, S ref is the wing reference area, W is the aircraft weight, C Don is the lift coefficient in the increased lift state, C Doff is the drag coefficient for takeoff in non-powered lift mode (untrim), C Db is the power effect correction of the full-engine takeoff drag coefficient, C DLG is the drag coefficient of the landing gear.

[0121] In some optional implementations, in the roll moment trim drag coefficient determination module, the drag coefficient C generated by the single engine failure roll moment trim is determined according to the following formula: Da :

[0122]

[0123] Among them, δ a Aileron deflection angle for rolling moment trim, C Dδa is the increase in drag coefficient caused by aileron unit deflection angle, C l is the rolling moment coefficient caused by single engine failure, C lδa is the control efficiency of the aileron, ΔC L is the loss of lift coefficient of the wing on the side of the failed engine, L ye is the span length between the axis of the failed engine and the axis of the fuselage, C Lbis the lift coefficient increment generated by the full-engine takeoff jet flow around the flap, b w The wing span.

[0124] In some optional implementations, the pitch moment trim drag coefficient determination module includes:

[0125] The first pitch moment coefficient increment determination unit is used to determine the pitch moment coefficient increment C generated by the jet vector effect. mp ;

[0126] The second pitch moment coefficient increment determination unit is used to determine the pitch moment coefficient increment C generated by the jet flap flow. mb ;

[0127] The pitch moment coefficient determination unit is used to determine the pitch moment coefficient C for takeoff climb using the following formula m :

[0128] C m =C moff +C mp +C mb Among them, C moff The pitch moment for takeoff climb in non-powered lift state;

[0129] The pitch moment trim drag coefficient determination unit is used to determine the drag coefficient C generated by the pitch moment trim of a single engine failure by the following formula De :

[0130] C De =C Dδe δ e ;

[0131]

[0132] Among them, δ e The elevator deflection angle to balance the pitch moment, C Dδe is the drag coefficient generated by the unit deflection angle of the elevator, C mδe The control efficiency of the elevator.

[0133] In some optional implementations, in the first pitch moment coefficient increment determining unit, the pitch moment coefficient increment C generated by the jet vector effect is determined by the following formula: mp :

[0134]

[0135] Among them, C T is the thrust coefficient for takeoff of an aircraft with a single engine failure, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, h cfL is the vertical distance of the flap aerodynamic pressure center below the center of gravity, f The axial distance behind the center of gravity of the flap aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e is the axial distance of the engine nozzle behind the center of gravity, c a is the average aerodynamic chord length of the wing.

[0136] In some optional embodiments, in the second pitch moment coefficient increment determining unit, the pitch moment coefficient increment C generated by the jet flap flow is determined by the following formula: mb :

[0137]

[0138] Among them, L0 is the axial distance between the leading edge of the wing and the center of gravity of the fuselage at the engine installation position. It is positive if it is located behind the center of gravity. L c is the axial distance behind the center of gravity of the wing's aerodynamic pressure center after the flaps are placed, and c' is the axial projection length of the wing chord length at the engine installation position.

[0139] In some optional implementations, in the yaw moment trim drag coefficient determination module, the drag coefficient C generated by single engine failure yaw moment trim is determined according to the following formula: Dr :

[0140]

[0141] Among them, δ r The rudder deflection angle to balance the yaw moment, C Dδr is the drag coefficient generated by the rudder unit deflection angle, C n is the yaw moment coefficient caused by single engine failure, C nδr The control efficiency of the rudder.

[0142] In some optional embodiments, the maximum climb gradient determination module further includes a drag coefficient power influence correction value calculation unit, which is used to determine the drag coefficient power influence correction value C by the following formula: Db :

[0143]

[0144] Among them, C Lb is the lift coefficient increment generated by the jet flap flow, C La C Lb The incremental correction part of the lift coefficient at medium angle of attack, AR is the aspect ratio, K is the correction coefficient.

[0145] In a third aspect of the present application, a computer device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for evaluating the takeoff and climb performance of a transport aircraft with a single engine failure.

[0146] In a fourth aspect of the present application, a readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the above-mentioned method for evaluating the takeoff and climb performance of a transport aircraft with a single engine failure. The computer-readable storage medium may be included in the device described in the above-mentioned embodiment; or it may exist independently without being assembled into the device. The above-mentioned computer-readable storage medium carries one or more programs, and when the above-mentioned one or more programs are executed by the device, the data is processed according to the above-mentioned method.

[0147] Reference below Figure 2 , which shows a schematic structural diagram of a computer device 400 suitable for implementing the embodiments of the present application. Figure 2 The computer device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0148] like Figure 2 As shown, the computer device 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage part 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the device 400 are also stored. The CPU 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0149] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, etc.; an output section 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, a modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to the I / O interface 405 as needed. A removable medium 411, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 410 as needed, so that a computer program read therefrom is installed into the storage section 408 as needed.

[0150] In particular, according to the embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 409, and / or installed from the removable medium 411. When the computer program is executed by the central processing unit (CPU) 401, the above functions defined in the method of the present application are executed. It should be noted that the computer storage medium of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, - but not limited to - a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, an apparatus or a device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, an apparatus or a device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0151] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0152] The modules or units involved in the embodiments described in this application may be implemented by software or hardware. The modules or units described may also be set in a processor, and the names of these modules or units do not constitute limitations on the modules or units themselves in some cases.

[0153] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure, which is applied to a transport aircraft with a powered lift booster with blown flaps on the lower surface, is characterized in that: The method includes: Step S1: Determine the drag coefficient C generated by the rolling moment trim due to single engine failure Da ; Step S2: Determine the drag coefficient C generated by the pitch moment trim due to single engine failure De ; Step S3: Determine the drag coefficient C generated by the yaw moment trim due to single engine failure Dr ; Step S4: Calculate the maximum climb gradient tanθ for single-engine failure takeoff based on the following formula: max : Among them, θ max is the maximum flight path angle for takeoff climb, n e is the number of engines, P max is the maximum thrust of the engine, P xz is the engine thrust corrected for system power extraction, speed and altitude, K S is the system power extraction factor in takeoff state, K V is the speed correction factor of thrust, K h is the altitude correction factor, α is the fuselage angle of attack, η j is the jet efficiency factor of the engine in the lift-increasing state, θ j is the downward deflection angle of the jet flow disturbed by the flap relative to the fuselage axis, q is the velocity pressure, ρ is the air density, V is the airspeed, S ref is the wing reference area, W is the aircraft weight, C Don is the lift coefficient in the lift-enhanced state, C Doff is the drag coefficient of takeoff in non-powered lift state, C Db is the power effect correction of the full-engine takeoff drag coefficient, C DLG is the drag coefficient of the landing gear.

2. The method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure as claimed in claim 1, characterized in that: In step S1, the drag coefficient C generated by the single engine failure rolling moment trim is determined according to the following formula: Da : Among them, δ a Aileron deflection angle for rolling moment trim, C Dδa is the increase in drag coefficient caused by aileron unit deflection angle, C l is the rolling moment coefficient caused by single engine failure, C lδa is the control efficiency of the aileron, ΔC L is the loss of lift coefficient of the wing on the side of the failed engine, L ye is the span length between the axis of the failed engine and the axis of the fuselage, C Lb is the lift coefficient increment generated by the full-engine takeoff jet flow around the flap, b w The wing span.

3. The method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure as claimed in claim 1, characterized in that: Step S2 further comprises: Step S21: Determine the pitch moment coefficient increment C generated by the jet vector effect mp ; Step S22: Determine the pitch moment coefficient increment C generated by the jet flap flow mb ; Step S23: Determine the pitch moment coefficient C for takeoff and climb by the following formula: m : C m =C moff +C mp +C mb Among them, C moff The pitch moment for takeoff climb in non-powered lift state; Step S24: Determine the drag coefficient C generated by the single engine failure pitch moment trim using the following formula: De : C De =C Dδe d e ; Among them, δ e The elevator deflection angle to balance the pitch moment, C Dδe is the drag coefficient generated by the unit deflection angle of the elevator, C mδe The control efficiency of the elevator.

4. The method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure as claimed in claim 3, characterized in that: In step S21, the pitch moment coefficient increment C generated by the jet vector effect is determined by the following formula: mp : Among them, C T is the thrust coefficient for takeoff of an aircraft with a single engine failure, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, h cf L is the vertical distance of the flap aerodynamic pressure center below the center of gravity, f The axial distance behind the center of gravity of the flap aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e is the axial distance of the engine nozzle behind the center of gravity, c a is the average aerodynamic chord length of the wing.

5. The method for evaluating takeoff and climbing performance of a transport aircraft with a single engine failure as claimed in claim 3, characterized in that: In step S22, the pitch moment coefficient increment C generated by the jet flap flow is determined by the following formula: mb : Among them, L0 is the axial distance between the leading edge of the wing and the center of gravity of the fuselage at the engine installation position. It is positive if it is located behind the center of gravity. L c is the axial distance behind the center of gravity of the wing's aerodynamic pressure center after the flaps are placed, and c' is the axial projection length of the wing chord length at the engine installation position.

6. The method for evaluating takeoff and climbing performance of a transport aircraft with a single engine failure as claimed in claim 1, characterized in that: In step S3, the drag coefficient C generated by the single engine failure yaw moment trim is determined according to the following formula: Dr : Among them, δ r The rudder deflection angle to balance the yaw moment, C Dδr is the drag coefficient generated by the rudder unit deflection angle, C n is the yaw moment coefficient caused by single engine failure, C nδr The control efficiency of the rudder.

7. The method for evaluating takeoff and climbing performance of a transport aircraft with a single engine failure as claimed in claim 1, characterized in that: Step S4 further includes determining the drag coefficient dynamic influence correction value C by the following formula: Db : Among them, C Lb is the lift coefficient increment generated by the jet flap flow, C La C Lb The incremental correction part of the lift coefficient at medium angle of attack, AR is the aspect ratio, K is the correction coefficient.

8. A transport aircraft single engine failure takeoff and climbing performance evaluation device, applied to a lower surface blown flap powered lift transport aircraft, characterized in that: The device includes: Rolling moment trim drag coefficient determination module, used to determine the drag coefficient C generated by single engine failure rolling moment trim Da ; The pitch moment trim drag coefficient determination module is used to determine the drag coefficient C generated by the pitch moment trim of a single engine failure. De ; The yaw moment trim drag coefficient determination module is used to determine the drag coefficient C generated by the yaw moment trim of a single engine failure Dr ; The maximum climb gradient determination module is used to calculate the maximum climb gradient tanθ for single-engine failure takeoff based on the following formula max : Among them, θ max is the maximum flight path angle for takeoff climb, n e is the number of engines, P max is the maximum thrust of the engine, P xz is the engine thrust corrected for system power extraction, speed and altitude, K S is the system power extraction factor in takeoff state, K V is the speed correction factor of thrust, K h is the altitude correction factor, α is the fuselage angle of attack, η j is the jet efficiency factor of the engine in the lift-increasing state, θ j is the downward deflection angle of the jet flow disturbed by the flap relative to the fuselage axis, q is the velocity pressure, ρ is the air density, V is the airspeed, S ref is the wing reference area, W is the aircraft weight, C Don is the lift coefficient in the lift-enhanced state, C Doff is the drag coefficient of takeoff in non-powered lift state, C Db is the power effect correction of the full-engine takeoff drag coefficient, C DLG is the drag coefficient of the landing gear.

9. The transport aircraft single engine failure takeoff and climbing performance evaluation device according to claim 8, characterized in that: In the roll moment trim drag coefficient determination module, the drag coefficient C generated by the roll moment trim of a single engine failure is determined according to the following formula: Da : Among them, δ a Aileron deflection angle for rolling moment trim, C Dδa is the increase in drag coefficient caused by aileron unit deflection angle, C l is the rolling moment coefficient caused by single engine failure, C lδa is the control efficiency of the aileron, ΔC L is the loss of lift coefficient of the wing on the side of the failed engine, L ye is the span length between the axis of the failed engine and the axis of the fuselage, C Lb is the lift coefficient increment generated by the full-engine takeoff jet flow around the flap, b w The wing span.

10. The transport aircraft single engine failure takeoff and climbing performance evaluation device according to claim 8, characterized in that: The pitch moment trim drag coefficient determination module comprises: The first pitch moment coefficient increment determination unit is used to determine the pitch moment coefficient increment C generated by the jet vector effect. mp ; The second pitch moment coefficient increment determination unit is used to determine the pitch moment coefficient increment C generated by the jet flap flow. mb ; The pitch moment coefficient determination unit is used to determine the pitch moment coefficient C for takeoff climb using the following formula m : C m =C moff +C mp +C mb Among them, C moff The pitch moment for takeoff climb in non-powered lift state; The pitch moment trim drag coefficient determination unit is used to determine the drag coefficient C generated by the pitch moment trim of a single engine failure by the following formula De : C De =C Dδe d e ; Among them, δ e The elevator deflection angle to balance the pitch moment, C Dδe is the drag coefficient generated by the unit deflection angle of the elevator, C mδe The control efficiency of the elevator.

11. The transport aircraft single engine failure takeoff and climbing performance evaluation device according to claim 10, characterized in that: In the first pitch moment coefficient increment determining unit, the pitch moment coefficient increment C generated by the jet vector effect is determined by the following formula: mp : Among them, C T is the thrust coefficient for takeoff of an aircraft with a single engine failure, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, h cf L is the vertical distance of the flap aerodynamic pressure center below the center of gravity, f The axial distance behind the center of gravity of the flap aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e is the axial distance of the engine nozzle behind the center of gravity, c a is the average aerodynamic chord length of the wing.

12. The transport aircraft single engine failure takeoff and climbing performance evaluation device according to claim 10, characterized in that: In the second pitch moment coefficient increment determining unit, the pitch moment coefficient increment C generated by the jet flap flow is determined by the following formula: mb : Among them, L0 is the axial distance between the leading edge of the wing and the center of gravity of the fuselage at the engine installation position. It is positive if it is located behind the center of gravity. L c is the axial distance behind the center of gravity of the wing's aerodynamic pressure center after the flaps are placed, and c' is the axial projection length of the wing chord length at the engine installation position.

13. The transport aircraft single engine failure takeoff and climbing performance evaluation device according to claim 8, characterized in that: In the yaw moment trim drag coefficient determination module, the drag coefficient C generated by single engine failure yaw moment trim is determined according to the following formula: Dr : Among them, δ r The rudder deflection angle to balance the yaw moment, C Dδr is the drag coefficient generated by the rudder unit deflection angle, C n is the yaw moment coefficient caused by single engine failure, C nδr The control efficiency of the rudder.

14. The transport aircraft single engine failure takeoff and climbing performance evaluation device according to claim 8, characterized in that: The maximum climb gradient determination module further includes a drag coefficient power influence correction amount calculation unit, which is used to determine the drag coefficient power influence correction amount C by the following formula: Db : Among them, C Lb is the lift coefficient increment generated by the jet flap flow, C La C Lb The incremental correction part of the lift coefficient at medium angle of attack, AR is the aspect ratio, K is the correction coefficient.

15. A computer device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure as described in any one of claims 1 to 7.

16. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it is used to implement the method for evaluating the takeoff and climbing performance of a transport aircraft with a single engine failure as described in any one of claims 1 to 7.

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