Method and device for determining power influence correction quantity of drag coefficient of conveyer

Abstract

The application belongs to the technical field of aircraft design, and particularly relates to a method and device for determining a drag coefficient dynamic influence correction quantity of a transport aircraft, and is applied to a lower surface air-blowing flap dynamic lift transport aircraft. The method comprises the following steps: S1, determining a drag coefficient increment generated by airflow around a jet flap; S2, determining a drag coefficient increment converted from thrust loss; and S3, determining that the drag coefficient dynamic influence correction quantity is the sum of the drag coefficient increment generated by airflow around the jet flap and the drag coefficient increment converted from the thrust loss. The application can quickly and accurately calculate the dynamic influence correction quantity of the drag coefficient of a take-off and landing configuration of the lower surface air-blowing flap dynamic lift transport aircraft.

Description

Technical Field

[0001] The present application belongs to the field of aircraft design technology, and in particular relates to a method and device for determining a dynamic influence correction value of a transport aircraft's drag coefficient. Background Art

[0002] Once the configuration is determined, the lift and drag coefficients of a conventional aircraft depend only on the angle of attack and are independent of speed. Compared to conventional aircraft, the calculation of lift and drag for a powered lift aircraft with blown flaps is much more complex. The aerodynamic coefficient is very sensitive to the thrust coefficient, and aerodynamic force is closely related to thrust. Lift is composed of two parts: aerodynamic lift and jet flap interference lift. The aerodynamic lift coefficient is only related to the angle of attack and does not change with speed, while the jet flap interference lift coefficient is very sensitive to speed but not to the angle of attack. Jet flap interference lift is independent of speed and pressure. The drag of a powered lift aircraft has the same characteristics. The increase in drag coefficient converted from thrust loss is also closely related to the engine jet efficiency and the jet deflection angle. To improve the aircraft's aerodynamic performance during takeoff and landing and optimize the takeoff and landing configuration, it is necessary to be able to accurately calculate the impact of power on drag. Summary of the Invention

[0003] In order to solve the above problems, the present application provides a method and device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft, providing technical support for the calculation and evaluation of the drag characteristics of the take-off and landing configuration of a power-enhanced transport aircraft with lower surface blown flaps.

[0004] In a first aspect, the present application provides a method for determining a power-influence correction value for a transport aircraft's drag coefficient, which is applied to a power-enhanced lift transport aircraft with blown flaps on the lower surface. The method comprises:

[0005] Step S1: Determine the drag coefficient increment ΔC generated by the jet flap flow Db ;

[0006] Step S2: Determine the drag coefficient increment ΔC converted from thrust loss Dp ;

[0007] Step S3: Determine the drag coefficient dynamic influence correction value ΔC D for:

[0008] ΔC D =ΔC Db +ΔC Dp .

[0009] Preferably, step S1 further comprises:

[0010] Step S11: Determine the lift coefficient increment reference value ΔC generated by flap deflection Lθ , and the incremental correction value of the angle of attack of the lift coefficient ΔC Lα ;

[0011] Step S12: Determine the lift coefficient increment ΔC generated by the jet flap flow Lb :

[0012] ΔC Lb =ΔC Lθ +ΔC Lα ;

[0013] Step S13: Determine the drag coefficient increment ΔC generated by the jet flap flow Db for:

[0014]

[0015] Where AR is the aspect ratio and K is the correction factor.

[0016] Preferably, step S11 further includes:

[0017] Step S111: Calculate the wingspan factor φ and the engine tail jet momentum coefficient C affected by the jet flow. μ ;

[0018] Step S112: Based on the wingspan factor φ of the jet flow and the engine tail jet momentum coefficient C μ Determine the reference value of the lift coefficient increment ΔC generated by flap deflection Lθ ;

[0019] Step S113: Determine the lift coefficient angle of attack increment correction value ΔC based on the wingspan factor φ affected by the jet flow. Lα ;

[0020] Step S114: Determine the lift coefficient increment ΔC generated by the jet flap flow Lb for:

[0021] ΔC Lb =ΔC Lθ +ΔC Lα .

[0022] Preferably, in step S111, the wingspan factor φ affected by the jet flow is determined by the following formula:

[0023] φ=φ o -φ i ;

[0024] Among them, φ o is the spanwise influence factor of the outboard engine jet, φ i is the spanwise influence factor of the inboard engine jet.

[0025] Preferably, in step S111, the engine tail jet momentum coefficient C is determined by the following formula: μ :

[0026]

[0027] Among them, S j is the sum of the wing areas affected by all engine jets, D j is the diameter of the engine i jet at the trailing edge of the flap, c' i is the chord length of the wing section corresponding to the engine i axis, n e is the number of engines, S ref is the wing reference area, C T is the thrust coefficient of the aircraft;

[0028] When F < 1.0, When F≥1.0, λ1=1; where Y=1-2F, F is the jet immersion factor of the flap, H f is the jet immersion depth of the flap, and λ2 is determined by the downward deflection angle θ of the flap relative to the engine axis. m Obtained by interpolation calculation.

[0029] Preferably, step S2 further comprises:

[0030] Step S21: Determine the engine jet efficiency factor η j ;

[0031] Step S22: Determine the downward deflection angle θ of the jet axis relative to the fuselage axis after the engine jet is deflected by the flap interference. j ;

[0032] Step S23: Determine the drag coefficient increment ΔC converted from thrust loss according to the following formula: Dp :

[0033] ΔC Dp =C T {cos(α+θ e )-η j cos(α+θ j )};

[0034]

[0035] q=0.5ρV 2 ;

[0036] Among them, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, P e is the engine thrust, ρ is the air density, V is the airspeed, q is the velocity pressure, θ e is the downward deviation angle of the engine axis relative to the fuselage axis, and α is the angle of attack.

[0037] Preferably, in step S21, the engine jet efficiency factor η is determined by the following formula: j :

[0038]

[0039] Among them, θ jc is the theoretical deflection angle of the engine jet caused by flap interference, when λ1=1 and θ d =0, θ jc =0, when λ1=1 and θ d ≠0, θ jc =θ d ,on the contrary:

[0040]

[0041]

[0042]

[0043] Among them, θ d is the deflection angle of the engine jet disturbed by the flaps.

[0044] Preferably, in step S22, the lower deflection angle θ is determined by the following formula: j :

[0045] θ j =θ jw +θ wi ;

[0046] Among them, θ jw is the downward deflection angle of the engine jet relative to the wing chord line, θ wi The installation angle of the wing section at the engine installation location.

[0047] A second aspect of the present application provides a device for determining a power-influence correction value for a transport aircraft drag coefficient, which is applied to a power-enhanced lift transport aircraft with blown flaps on the lower surface. The device comprises:

[0048] The first drag coefficient increment determination module is used to determine the drag coefficient increment ΔC generated by the jet flap flow Db ;

[0049] The second drag coefficient increment determination module is used to determine the drag coefficient increment ΔC converted from thrust loss. Dp ;

[0050] The drag coefficient dynamic influence correction value determination module is used to determine the drag coefficient dynamic influence correction value ΔC D for:

[0051] ΔC D =ΔCDb +ΔC Dp .

[0052] Preferably, the first drag coefficient increment determination module includes:

[0053] The lift coefficient increment parameter calculation unit is used to determine the lift coefficient increment reference value ΔC generated by flap deflection Lθ , and the incremental correction value of the angle of attack of the lift coefficient ΔC Lα ;

[0054] The lift coefficient increment determination unit determines the lift coefficient increment ΔC generated by the jet flap flow Lb :

[0055] ΔC Lb =ΔC Lθ +ΔC Lα ;

[0056] The first drag coefficient increment calculation unit is used to determine the drag coefficient increment ΔC caused by the jet flap flow Db for:

[0057]

[0058] Where AR is the aspect ratio and K is the correction factor.

[0059] Preferably, the lift coefficient incremental parameter calculation unit includes:

[0060] The wingspan factor and momentum coefficient calculation subunit is used to calculate the wingspan factor φ affected by the jet flow and the engine tail jet momentum coefficient C μ ;

[0061] The reference value calculation subunit is used to calculate the wingspan factor φ affected by the jet flow and the engine tail jet momentum coefficient C μ Determine the reference value ΔC of the lift coefficient increment of the flow around the jet flap Lθ ;

[0062] The correction value calculation subunit is used to determine the angle of attack increment correction value ΔC of the lift coefficient based on the wingspan factor φ affected by the jet Lα ;

[0063] The lift coefficient increment determination subunit is used to determine the lift coefficient increment ΔC generated by the jet flap flow Lb for:

[0064] ΔC Lb =ΔC Lθ +ΔC Lα .

[0065] Preferably, in the wingspan factor and momentum coefficient calculation subunit, the wingspan factor φ affected by the jet flow is determined by the following formula:

[0066] φ=φ o -φ i ;

[0067] Among them, φ o is the spanwise influence factor of the outboard engine jet, φ i is the spanwise influence factor of the inboard engine jet.

[0068] Preferably, in the wingspan factor and momentum coefficient calculation subunit, the engine tail jet momentum coefficient C is determined by the following formula: μ :

[0069]

[0070]

[0071] Among them, S j is the sum of the wing areas affected by all engine jets, D j is the diameter of the engine i jet at the trailing edge of the flap, c' i is the chord length of the wing section corresponding to the engine i axis, n e is the number of engines, S ref is the wing reference area, C T is the thrust coefficient of the aircraft;

[0072] When F < 1.0, When F≥1.0, λ1=1; where Y=1-2F, F is the jet immersion factor of the flap, H f is the jet immersion depth of the flap, and λ2 is determined by the downward deflection angle θ of the flap relative to the engine axis. m Obtained by interpolation calculation.

[0073] Preferably, the second drag coefficient increment determination module includes:

[0074] The jet efficiency factor determination subunit is used to determine the engine jet efficiency factor η j ;

[0075] The downward deflection angle determination subunit is used to determine the downward deflection angle θ of the axis relative to the fuselage axis after the engine jet is deflected by the flap interference j ;

[0076] The pitch moment coefficient increment determination subunit is used to determine the drag coefficient increment ΔC converted from thrust loss according to the following formula Dp :

[0077] ΔC Dp =C T {cos(α+θ e )-η j cos(α+θ j )};

[0078]

[0079] q=0.5ρV 2 ;

[0080] Among them, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, P e is the engine thrust, ρ is the air density, V is the airspeed, q is the velocity pressure, θ e is the downward deviation angle of the engine axis relative to the fuselage axis, and α is the angle of attack.

[0081] Preferably, in the jet efficiency factor determination subunit, the engine jet efficiency factor η is determined by the following formula: j :

[0082]

[0083] Among them, θ jc is the theoretical deflection angle of the engine jet caused by flap interference, when λ1=1 and θ d =0, θ jc =0, when λ1=1 and θ d ≠0, θ jc =θ d ,on the contrary:

[0084]

[0085]

[0086]

[0087] Among them, θ d is the deflection angle of the engine jet disturbed by the flaps.

[0088] Preferably, in the lower deflection angle determination subunit, the lower deflection angle θ is determined by the following formula: j :

[0089] θ j =θ jw +θ wi ;

[0090] Among them, θ jw is the downward deflection angle of the engine jet relative to the wing chord line, θ wi The installation angle of the wing section at the engine installation location.

[0091] A third aspect of the present application provides a computer device comprising 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 determining the dynamic influence correction amount of the drag coefficient of a transport aircraft as described above.

[0092] In a fourth aspect, the present application provides a readable storage medium storing a computer program. When the computer program is executed by a processor, it is used to implement the method for determining the dynamic influence correction amount of the drag coefficient of a transport aircraft as described above.

[0093] The present application can quickly and accurately calculate the dynamic influence correction amount of the drag coefficient of the take-off and landing configuration of a power-lift transport aircraft with blown flaps on the lower surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Figure 1 It is a flow chart of a preferred embodiment of the method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft of the present application.

[0095] Figure 2 It is a structural diagram of a computer device suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION

[0096] 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.

[0097] The first aspect of the present application provides a method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft, which is applied to a power-enhanced lift transport aircraft with blown flaps on the lower surface, such as Figure 1 As shown, the method mainly includes:

[0098] Step S1: Determine the drag coefficient increment ΔC generated by the jet flap flow Db ;

[0099] Step S2: Determine the drag coefficient increment ΔC converted from thrust loss Dp ;

[0100] Step S3: Determine the drag coefficient dynamic influence correction value ΔC D for:

[0101] ΔC D =ΔC Db +ΔC Dp .

[0102] In some optional embodiments, step S1 further includes:

[0103] Step S11: Determine the lift coefficient increment reference value ΔC generated by flap deflection Lθ , and the incremental correction value of the angle of attack of the lift coefficient ΔC Lα ;

[0104] Step S12: Determine the lift coefficient increment ΔC generated by the jet flap flow Lb :

[0105] ΔC Lb =ΔC Lθ +ΔC Lα ;

[0106] Step S13: Determine the drag coefficient increment ΔC generated by the jet flap flow Db for:

[0107]

[0108] Where AR is the aspect ratio and K is the correction factor.

[0109] In this embodiment, K is a function of K4 and is obtained by interpolation operation. The required interpolation data is shown in Table 1.

[0110] Table 1 Data required for parameter K interpolation

[0111] <![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

[0112] In this embodiment, K4 is generally related to the aspect ratio AR, and the specific calculation method is as follows:

[0113]

[0114] F1=interp1(atasz,Fsz,η p )

[0115] F2=interp1(atasz,Fsz,Δη).

[0116]

[0117] Δη=η o -η i

[0118] Wherein, interp1 is an interpolation function. For example, for parameter F1, it means that in the interpolation table constructed by the ata array and the F array, according to the ata value (η p ) interpolates the corresponding F value (F1).

[0119] In some optional implementations, step S11 further includes:

[0120] Step S121, calculate the wingspan factor φ and the engine tail jet momentum coefficient C of the jet flow μ ;

[0121] Step S122: Based on the wingspan factor φ of the jet flow and the engine tail jet momentum coefficient C μ Determine the reference value of the lift coefficient increment ΔC generated by flap deflection Lθ ;

[0122] Step S123: Determine the lift coefficient angle of attack increment correction value ΔC based on the wingspan factor φ affected by the jet flow. Lα ;

[0123] Step S124: Determine the lift coefficient increment ΔC generated by the jet flap flow Lb for:

[0124] ΔC Lb =ΔC Lθ +ΔC Lα .

[0125] In some optional implementations, in step S111, the wingspan factor φ affected by the jet flow is determined by the following formula:

[0126] φ=φ o -φ i ;

[0127] Among them, φ o is the spanwise influence factor of the outboard engine jet, φ i is the spanwise influence factor of the inboard engine jet.

[0128] In this embodiment, φ o The spanwise relative position η of the outer boundary line of the outer engine jet at the flap trailing edge o The interpolation calculation is obtained in the first two-dimensional interpolation table composed of ATH. Similarly, φ i The spanwise relative position η of the inner boundary line of the inner engine jet at the flap trailing edge i It is obtained by interpolation calculation in the second two-dimensional interpolation table composed of ATH. Among them:

[0129]

[0130]

[0131]

[0132] ATH=ARtanΛ 1 / 2 -8λ;

[0133] Among them, X eo 、X ei They are the outer and inner engine wing span installation positions respectively. jo 、D ji are the diameters of the outer and inner engine jets at the trailing edge of the flaps, respectively. s is the wing span b w Half of the length, that is, half the length. 1 / 2 is the 1 / 2 chord sweep angle of the wing, and λ is the wing tip-to-root ratio.

[0134] For example, the first two-dimensional interpolation table is shown in Table 2 below.

[0135] Table 2 First two-dimensional interpolation table

[0136]

[0137] In some optional embodiments, in step S111, the engine tail jet momentum coefficient C is determined by the following formula: μ :

[0138]

[0139]

[0140] Among them, S j is the sum of the wing areas affected by all engine jets, D j is the diameter of the engine i jet at the trailing edge of the flap, c' i is the chord length of the wing section corresponding to the engine i axis (flaps extended), n e is the number of engines, S ref is the wing reference area, C T is the thrust coefficient of the aircraft;

[0141] When F < 1.0, When F≥1.0, λ1=1; where Y=1-2F, F is the jet immersion factor of the flap, H f is the jet immersion depth of the flap, and λ2 is determined by the downward deflection angle θ of the flap relative to the engine axis. m Obtained by interpolation calculation.

[0142] Then, in step S112, the reference value ΔC of the lift coefficient increment of the jet flap flow is calculated according to the following formula:Lθ :

[0143]

[0144]

[0145]

[0146]

[0147]

[0148] Where K1 is a function of the momentum coefficient, G1 is a function of the wing aspect ratio AR and the parameter K2, K2 is the ratio of the flap extended chord length to the original chord length; θ f is the downward deflection angle of the upper surface of the trailing edge of the second flap relative to the chord, θ faux c is the downward angle of the chord line of the second flap relative to the chord line of the front flap; f is the sum of the chord lengths of the two flaps, c faux is the chord length of the second flap, c' is the chord length of the wing after the flaps are extended, and c is the chord length of the wing before the flaps are extended. K 3aux and K3 are functions of the momentum coefficient and the relative chord length of the flap, obtained by interpolation.

[0149] In step S113, the lift coefficient angle of attack increment correction value ΔC is calculated according to the following formula: Lα :

[0150]

[0151] Among them, θ wi is the installation angle of the engine axis relative to the wing section relative to the fuselage axis, The relative thickness of the wing with flaps extended.

[0152] In some optional embodiments, step S2 further includes:

[0153] Step S21: Determine the engine jet efficiency factor η j ;

[0154] Step S22: Determine the downward deflection angle θ of the jet axis relative to the fuselage axis after the engine jet is deflected by the flap interference. j ;

[0155] Step S23: Determine the pitch moment coefficient increment ΔC generated by the thrust vectoring effect according to the following formula: mp :

[0156]

[0157]

[0158]

[0159] q=0.5ρV 2

[0160] Among them, C T is the thrust coefficient of the aircraft, P e is the engine thrust, ρ is the air density, V is the airspeed, q is the velocity pressure, 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's aerodynamic pressure center, h e is the vertical distance of the engine nozzle below the center of gravity, L e It is the axial distance of the engine nozzle behind the center of gravity.

[0161] In some optional embodiments, in step S21, the engine jet efficiency factor η is determined by the following formula: j :

[0162]

[0163] Among them, θ jc is the theoretical deflection angle of the engine jet caused by flap interference, when λ1=1 and θ d =0, θ jc =0, when λ1=1 and θ d ≠0, θ jc =θ d ,on the contrary:

[0164]

[0165]

[0166]

[0167] Among them, θ d is the deflection angle of the engine jet disturbed by the flaps.

[0168] In some optional embodiments, in step S22, the lower deflection angle θ is determined by the following formula: j :

[0169] θ j =θ jw +θ wi ;

[0170] Among them, θ jwis the downward deflection angle of the engine jet relative to the wing chord line, θ wi The installation angle of the wing section at the engine installation location.

[0171] In this embodiment, θ jw =θ d +θ ew ;

[0172] θ d =asin(sibsinθ m );

[0173] θ m =θ f -θ ew ;

[0174] θ f =δ f +θ fte ;

[0175] θ e =θ ew +θ wi

[0176] Among them, δ f is the flap downward deflection angle, θ fte is the angle between the upper surface of the flap trailing edge and the flap chord, θ ew is the downward angle of the engine axis relative to the wing chord line, θ m is the downward deflection angle of the flap relative to the engine axis, θ d is the deflection angle of the jet disturbed by the flap, and the parameter sib is obtained by interpolation from the given interpolation table.

[0177] In a second aspect, the present application provides a device for determining a power influence correction value of a transport aircraft drag coefficient corresponding to the above method, which is applied to a power-enhanced lift transport aircraft with blown flaps on the lower surface. The device comprises:

[0178] The first drag coefficient increment determination module is used to determine the drag coefficient increment ΔC generated by the jet flap flow Db ;

[0179] The second drag coefficient increment determination module is used to determine the drag coefficient increment ΔC converted from thrust loss. Dp ;

[0180] The drag coefficient dynamic influence correction value determination module is used to determine the drag coefficient dynamic influence correction value ΔC D for:

[0181] ΔC D =ΔC Db +ΔC Dp .

[0182] In some optional embodiments, the first drag coefficient increment determination module includes:

[0183] The lift coefficient increment parameter calculation unit is used to determine the lift coefficient increment reference value ΔC generated by flap deflection Lθ , and the incremental correction value of the angle of attack of the lift coefficient ΔC Lα ;

[0184] The lift coefficient increment determination unit determines the lift coefficient increment ΔC generated by the jet flap flow Lb :

[0185] ΔC Lb =ΔC Lθ +ΔC Lα ;

[0186] The first drag coefficient increment calculation unit is used to determine the drag coefficient increment ΔC caused by the jet flap flow Db for:

[0187]

[0188] Where AR is the aspect ratio and K is the correction factor.

[0189] In some optional implementations, the lift coefficient incremental parameter calculation unit includes:

[0190] The wingspan factor and momentum coefficient calculation subunit is used to calculate the wingspan factor φ affected by the jet flow and the engine tail jet momentum coefficient C μ ;

[0191] The reference value calculation subunit is used to calculate the wingspan factor φ affected by the jet flow and the engine tail jet momentum coefficient C μ Determine the reference value ΔC of the lift coefficient increment of the flow around the jet flap Lθ ;

[0192] The correction value calculation subunit is used to determine the angle of attack increment correction value ΔC of the lift coefficient based on the wingspan factor φ affected by the jet Lα ;

[0193] The lift coefficient increment determination subunit is used to determine the lift coefficient increment ΔC generated by the jet flap flow Lb for:

[0194] ΔC Lb =ΔC Lθ +ΔC Lα .

[0195] In some optional embodiments, in the wingspan factor and momentum coefficient calculation subunit, the wingspan factor φ affected by the jet flow is determined by the following formula:

[0196] φ=φ o -φ i ;

[0197] Among them, φ o is the spanwise influence factor of the outboard engine jet, φ i is the spanwise influence factor of the inboard engine jet.

[0198] In some optional embodiments, in the wingspan factor and momentum coefficient calculation subunit, the engine tail jet momentum coefficient C is determined by the following formula: μ :

[0199]

[0200]

[0201] Among them, S j is the sum of the wing areas affected by all engine jets, D j is the diameter of the engine i jet at the trailing edge of the flap, c' i is the chord length of the wing section corresponding to the engine i axis, n e is the number of engines, S ref is the wing reference area, C T is the thrust coefficient of the aircraft;

[0202] When F < 1.0, When F≥1.0, λ1=1; where Y=1-2F, F is the jet immersion factor of the flap, H f is the jet immersion depth of the flap, and λ2 is determined by the downward deflection angle θ of the flap relative to the engine axis. m Obtained by interpolation calculation.

[0203] In some optional embodiments, the second drag coefficient increment determination module includes:

[0204] The jet efficiency factor determination subunit is used to determine the engine jet efficiency factor η j ;

[0205] The downward deflection angle determination subunit is used to determine the downward deflection angle θ of the axis relative to the fuselage axis after the engine jet is deflected by the flap interference j ;

[0206] The pitch moment coefficient increment determination subunit is used to determine the drag coefficient increment ΔC converted from thrust loss according to the following formula Dp :

[0207] ΔC Dp =C T{cos(α+θ e )-η j cos(α+θ j )};

[0208]

[0209] q=0.5ρV 2 ;

[0210] Among them, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, P e is the engine thrust, ρ is the air density, V is the airspeed, q is the velocity pressure, θ e is the downward deviation angle of the engine axis relative to the fuselage axis, and α is the angle of attack.

[0211] In some optional embodiments, in the jet efficiency factor determination subunit, the engine jet efficiency factor η is determined by the following formula: j :

[0212]

[0213] Among them, θ jc is the theoretical deflection angle of the engine jet caused by flap interference, when λ1=1 and θ d =0, θ jc =0, when λ1=1 and θ d ≠0, θ jc =θ d ,on the contrary:

[0214]

[0215]

[0216]

[0217] Among them, θ d is the deflection angle of the engine jet disturbed by the flaps.

[0218] In some optional embodiments, in the lower deflection angle determination subunit, the lower deflection angle θ is determined by the following formula: j :

[0219] θ j =θ jw +θ wi ;

[0220] Among them, θ jw is the downward deflection angle of the engine jet relative to the wing chord line, θ wi The installation angle of the wing section at the engine installation location.

[0221] 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 determining a correction value for a dynamic influence of a transport aircraft's drag coefficient.

[0222] In a fourth aspect, the present application provides a readable storage medium storing a computer program that, when executed by a processor, implements the method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft as described above. The computer-readable storage medium may be included in the apparatus described in the above embodiments, or it may exist independently and not be incorporated into the apparatus. The computer-readable storage medium carries one or more programs, and when executed by the apparatus, the one or more programs process data according to the method described above.

[0223] Reference below Figure 2 , which shows a 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 limit the functions and scope of use of the embodiments of the present application.

[0224] like Figure 2 As shown, 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 portion 408 into a random access memory (RAM) 403. Various programs and data required for the operation of device 400 are also stored in RAM 403. CPU 401, ROM 402, and RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to bus 404.

[0225] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, and the like; an output section 407 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 408 including a hard disk; and a communication section 409 including a network interface card such as a LAN card or a modem. 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. Removable media 411, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 410 as needed, so that computer programs read therefrom can be installed into the storage section 408 as needed.

[0226] 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 component 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 having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code embodied on a computer-readable medium may be transmitted using any suitable medium, including, but not limited to, wireless, wire, optical cable, RF, etc., or any suitable combination thereof.

[0227] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of code includes one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two 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 box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0228] The modules or units described in the embodiments of this application may be implemented in software or hardware. The modules or units described may also be provided in a processor, and the names of these modules or units do not, in certain circumstances, limit the modules or units themselves.

[0229] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft, applied to a power-lift transport aircraft with blown flaps on the lower surface, characterized in that: The method includes: Step S1: Determine the drag coefficient increment ΔC generated by the jet flap flow Db ; Step S2: Determine the drag coefficient increment ΔC converted from thrust loss Dp ; Step S3: Determine the drag coefficient dynamic influence correction value ΔC D for: △C D =△C Db +△C Dp ; Step S1 further comprises: Step S11: Determine the lift coefficient increment reference value ΔC generated by flap deflection Lθ , and the incremental correction value of the angle of attack of the lift coefficient △C Lα ; Step S12: Determine the lift coefficient increment ΔC generated by the jet flap flow Lb : △C Lb =△C Lθ +△C Lα ; Step S13: Determine the drag coefficient increment ΔC generated by the jet flap flow Db for: Where AR is the aspect ratio and K is the correction factor; Step S2 further comprises: Step S21: Determine the engine jet efficiency factor η j ; Step S22: Determine the downward deflection angle θ of the jet axis relative to the fuselage axis after the engine jet is deflected by the flap interference. j ; Step S23: Determine the drag coefficient increment ΔC converted from thrust loss according to the following formula: Dp : △C Dp =C T {cos(α+θ e )-or j cos(α+θ j )}; q=0.5ρV 2 ; Among them, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, P e is the engine thrust, ρ is the air density, V is the airspeed, q is the velocity pressure, θ e is the downward deviation angle of the engine axis relative to the fuselage axis, and α is the angle of attack.

2. The method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 1, characterized in that: Step S11 further includes: Step S111: Calculate the wingspan factor φ and the engine tail jet momentum coefficient C affected by the jet flow. μ ; Step S112: Based on the wingspan factor φ of the jet flow and the engine tail jet momentum coefficient C μ Determine the reference value of the lift coefficient increment △C caused by flap deflection Lθ ; Step S113: Determine the lift coefficient angle of attack increment correction value ΔC based on the wingspan factor φ affected by the jet flow. Lα ; Step S114: Determine the lift coefficient increment ΔC generated by the flow around the jet flap Lb for: △C Lb =△C Lθ +△C Lα 。 3. The method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 2, characterized in that: In step S111, the wingspan factor φ affected by the jet flow is determined by the following formula: f=f o -f i ; Among them, φ o is the spanwise influence factor of the outboard engine jet, φ i is the spanwise influence factor of the inboard engine jet.

4. The method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 2, characterized in that: In step S111, the engine tail jet momentum coefficient C is determined by the following formula: μ : Among them, S j is the sum of the wing areas affected by all engine jets, D j is the diameter of the engine i jet at the trailing edge of the flap, c' i is the chord length of the wing section corresponding to the engine i axis, n e is the number of engines, S ref is the wing reference area, C T is the thrust coefficient of the aircraft; When F<1.0, When F≥1.0, λ1=1; where Y=1-2F, F is the jet immersion factor of the flap, H f is the jet immersion depth of the flap, and λ2 is determined by the downward deflection angle θ of the flap relative to the engine axis. m Obtained by interpolation calculation.

5. The method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 1, wherein: In step S21, the engine jet efficiency factor η is determined by the following formula: j : Among them, θ jc is the theoretical deflection angle of the engine jet caused by flap interference, when λ1=1 and θ d =0, θ jc =0, when λ1=1 and θ d ≠0, θ jc =θ d ,on the contrary: Among them, θ d is the deflection angle of the engine jet disturbed by the flaps.

6. The method for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 1, characterized in that: In step S22, the lower deflection angle θ is determined by the following formula: j : i j =θ jw +θ wi ; Among them, θ jw is the downward deflection angle of the engine jet relative to the wing chord line, θ wi The installation angle of the wing section at the engine installation location.

7. A device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft, applied to a power-lift transport aircraft with blown flaps on the lower surface, characterized in that: The device includes: The first drag coefficient increment determination module is used to determine the drag coefficient increment △C generated by the jet flap flow Db ; The second drag coefficient increment determination module is used to determine the drag coefficient increment △C converted from thrust loss Dp ; The drag coefficient dynamic influence correction value determination module is used to determine the drag coefficient dynamic influence correction value △C D for: △C D =△C Db +△C Dp ; The first drag coefficient increment determination module includes: Lift coefficient increment parameter calculation unit, used to determine the lift coefficient increment reference value △C generated by flap deflection Lθ , and the incremental correction value of the angle of attack of the lift coefficient △C Lα ; Lift coefficient increment determination unit, determines the lift coefficient increment △C generated by the jet flap flow Lb : △C Lb =△C Lθ +△C Lα ; The first drag coefficient increment calculation unit is used to determine the drag coefficient increment △C caused by the jet flap flow Db for: Where AR is the aspect ratio and K is the correction factor; The second drag coefficient increment determination module includes: The jet efficiency factor determination subunit is used to determine the engine jet efficiency factor η j ; The downward deflection angle determination subunit is used to determine the downward deflection angle θ of the axis relative to the fuselage axis after the engine jet is deflected by the flap interference j ; The pitch moment coefficient increment determination subunit is used to determine the drag coefficient increment △C converted from thrust loss according to the following formula Dp : △C Dp =C T {cos(α+θ e )-or j cos(α+θ j )}; q=0.5ρV 2 ; Among them, θ e is the downward deflection angle of the engine axis relative to the fuselage axis, P e is the engine thrust, ρ is the air density, V is the airspeed, q is the velocity pressure, θ e is the downward deviation angle of the engine axis relative to the fuselage axis, and α is the angle of attack.

8. The device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 7, characterized in that: The lift coefficient incremental parameter calculation unit includes: The wingspan factor and momentum coefficient calculation subunit is used to calculate the wingspan factor φ affected by the jet flow and the engine tail jet momentum coefficient C μ ; The reference value calculation subunit is used to calculate the wingspan factor φ affected by the jet flow and the engine tail jet momentum coefficient C μ Determine the reference value of the lift coefficient increment of the jet flap flow △C Lθ ; The correction value calculation subunit is used to determine the angle of attack increment correction value △C of the lift coefficient based on the wingspan factor φ affected by the jet Lα ; The lift coefficient increment determination subunit is used to determine the lift coefficient increment △C generated by the jet flap flow Lb for: △C Lb =△C Lθ +△C Lα 。 9. The device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 8, characterized in that: In the wingspan factor and momentum coefficient calculation subunit, the wingspan factor φ affected by the jet is determined by the following formula: f=f o -f i ; Among them, φ o is the spanwise influence factor of the outboard engine jet, φ i is the spanwise influence factor of the inboard engine jet.

10. The device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 8, wherein: In the wingspan factor and momentum coefficient calculation subunit, the engine tail jet momentum coefficient C is determined by the following formula: μ : Among them, S j is the sum of the wing areas affected by all engine jets, D j is the diameter of the engine i jet at the trailing edge of the flap, c' i is the chord length of the wing section corresponding to the engine i axis, n e is the number of engines, S ref is the wing reference area, C T is the thrust coefficient of the aircraft; When F<1.0, When F≥1.0, λ1=1; where Y=1-2F, F is the jet immersion factor of the flap, H f is the jet immersion depth of the flap, and λ2 is determined by the downward deflection angle θ of the flap relative to the engine axis. m Obtained by interpolation calculation.

11. The device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 7, wherein: In the jet efficiency factor determination subunit, the engine jet efficiency factor η is determined by the following formula: j : Among them, θ jc is the theoretical deflection angle of the engine jet caused by flap interference, when λ1=1 and θ d =0, θ jc =0, when λ1=1 and θ d ≠0, θ jc =θ d ,on the contrary: Among them, θ d is the deflection angle of the engine jet disturbed by the flaps.

12. The device for determining the dynamic influence correction value of the drag coefficient of a transport aircraft according to claim 7, wherein: In the lower deflection angle determination subunit, the lower deflection angle θ is determined by the following formula: j : i j =θ jw +θ wi ; Among them, θ jw is the downward deflection angle of the engine jet relative to the wing chord line, θ wi The installation angle of the wing section at the engine installation location.

13. 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 determining the dynamic influence correction amount of the drag coefficient of a transport aircraft according to any one of claims 1 to 6.

14. 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 determining the dynamic influence correction amount of the drag coefficient of a transport aircraft according to any one of claims 1 to 6.

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