Propeller aircraft resistance characteristic calculation method considering dynamic influence

Abstract

The invention provides a propeller-driven aircraft resistance characteristic calculation method considering dynamic influence. The influence of the attack angle, the speed, the engine tension, the engine number, the engine nacelle size and position, the tension line attack angle, the wing installation angle, the propeller diameter, the flap deflection angle, the flap chord length, the wing elongation and the aspect ratio, the propeller slip flow deflection angle and the slip flow viscosity loss on the resistance is fully considered, and the resistance coefficient of the propeller aircraft slip flow can be accurately obtained. The method is used for calculating the resistance generated by the slipstream of the propeller-driven aircraft, and can provide effective support for design, improvement and control of the propeller-driven aircraft.

Description

Technical Field

[0001] The present application belongs to the technical field of propeller aircraft resistance calculation, and specifically relates to a method for calculating the resistance characteristics of a propeller aircraft taking into account the influence of power. Background Art

[0002] Compared with jet aircraft, the calculation of propeller aircraft aerodynamic drag is more complicated. Propeller aircraft aerodynamic drag is not only related to speed pressure and angle of attack, but also closely related to aircraft drag coefficient, propeller diameter, engine size and installation position, wing configuration and flap configuration and other parameters.

[0003] Dynamic effects such as propeller slipstream viscosity loss will cause significant changes in the drag coefficient of propeller aircraft. Currently, there is a lack of a method to calculate the drag characteristics of propeller aircraft that fully considers the dynamic effects, making it difficult to accurately determine the drag generated by propeller aircraft and their slipstream, and to provide effective support for the design, improvement and control of propeller aircraft.

[0004] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0005] The purpose of the present application is to provide a method for calculating the drag characteristics of a propeller aircraft taking into account the influence of power, so as to overcome or alleviate at least one aspect of the known technical deficiencies.

[0006] The technical solution of this application is:

[0007] A method for calculating the drag characteristics of propeller aircraft considering the influence of power, including:

[0008] Step 1: Calculate the tension coefficient C T Downwelling deflection angle θ s ;

[0009] Step 2: Calculate the tension coefficient C T Downward flow viscous loss factor k s ;

[0010] Step 3: Take the tension coefficient C T Downwelling deflection angle θ s , Tensile coefficient C T Downward flow viscous loss factor k s , calculate the drag coefficient C considering the dynamic effect D ;

[0011] Step 4: Consider the drag coefficient C with dynamic influence D , calculate the drag coefficient C generated by the propeller slipstream Ds .

[0012] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, step 1 includes:

[0013] S11. Calculate the slipstream deflection angle in the zero pull coefficient state

[0014] S12, calculate the slipstream deflection angle when the pull coefficient is 1

[0015] S13, slipstream deflection angle at zero tension coefficient Slipstream deflection angle when the pull coefficient is 1 Calculation of tension coefficient C T Downwelling deflection angle θ s .

[0016] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, S11 is specifically:

[0017]

[0018] in,

[0019] AR is the wing aspect ratio;

[0020] [C L ]0 is the lift coefficient of the aircraft in the unpowered state

[0021] [C D ]0 is the drag coefficient of the aircraft in the unpowered state.

[0022] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, y ceff =0.5y c ;

[0023] in,

[0024] y ceff The effective span width of the flap covered by the engine nacelle;

[0025] y c is the span width of the flap interrupted by the engine nacelle;

[0026]

[0027] in,

[0028] I yc is the intermediate calculation parameter;

[0029] D is the diameter of the propeller disc;

[0030]

[0031] in,

[0032] H ZP is the intermediate calculation parameter;

[0033] z p is the height of the wing leading edge relative to the incoming flow;

[0034]

[0035] in,

[0036] I zp is the intermediate calculation parameter;

[0037] interp1 is a linear interpolation calculation function;

[0038] Dbsz 1 and Izpsz 1 are interpolation calculation arrays;

[0039]

[0040] in,

[0041] c is the chord length of the local wing;

[0042] K dc is the intermediate calculation parameter;

[0043] Dbsz2 and Kdsz2 are interpolation calculation arrays;

[0044]

[0045] in,

[0046] is the intermediate calculation parameter;

[0047] α0 is the zero lift angle of attack when the aircraft flaps are fully retracted and the power is off;

[0048] c teff =fc t1 +(1-f)c t2 ;

[0049] in,

[0050] c teff is the effective chord length of the flap;

[0051] f is the weight coefficient;

[0052] c t1 is the chord length of the first flap of the double-slotted flap;

[0053] c t2 is the chord length of the second flap of the double-slotted flap;

[0054]

[0055] in,

[0056] Dbsz4 and Kdsz4 are interpolation calculation arrays;

[0057]

[0058] in,

[0059] δ is the deflection angle of the trailing edge double-slotted Fuller flap;

[0060] α p is the angle of attack of the incoming flow relative to the offline line;

[0061] i w is the angle of attack of the engine thrust line relative to the local wing chord line.

[0062] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, in S12, α p =α-θ pb ;

[0063] in,

[0064] α is the aircraft angle of attack;

[0065] θ pb It is the angle of attack of the engine tension line relative to the center axis of the fuselage.

[0066] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, in S12, i w =θ wi +θ pb ;

[0067] in,

[0068] θ wi is the installation angle of the local wing.

[0069] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, in S12,

[0070] in,

[0071] dabf is the intermediate calculation parameter;

[0072] δ t1 is the deflection angle of the first flap of the double-slotted flap;

[0073] δ t2is the deflection angle of the second flap of the double-slotted flap;

[0074] f=interp1(dabsz3,fsz3,dabf);

[0075] in,

[0076] Dbsz3 and Kdsz3 are interpolation calculation arrays;

[0077] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, S13 is specifically:

[0078] q0=0.5ρV0 2 ;

[0079] in,

[0080] q0 is the incoming flow velocity pressure;

[0081] ρ is the air density;

[0082] V0 is the incoming flow velocity;

[0083]

[0084] in,

[0085] T C The aircraft drag coefficient is defined based on the aircraft drag, incoming flow pressure and wing reference area;

[0086] N is the number of engines;

[0087] S ref is the wing reference area;

[0088] S p =πD 2 / 4;

[0089] in,

[0090] S p is the paddle disc area;

[0091] or,

[0092] in,

[0093] C T is the thrust coefficient of the engine defined based on propeller thrust, slipstream pressure and propeller disc area;

[0094] p e is the pulling force of the engine;

[0095] q s is the slip velocity pressure;

[0096]

[0097] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, step 2 includes:

[0098] S21, calculation factor for viscous loss of glide flow under zero tension coefficient

[0099] S22, calculate the viscous loss factor of the glide flow under zero tension coefficient 1

[0100] S23, Calculation factor of viscous loss under zero tension coefficient Zero tension coefficient 1 glide viscous loss calculation factor Calculation of tension coefficient C T Downward flow viscous loss factor k s ;

[0101] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, S21 is specifically:

[0102]

[0103] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, S22 is specifically:

[0104]

[0105] in,

[0106] J yc is the intermediate calculation parameter;

[0107] J iw =1+0.05i w ;

[0108] in,

[0109] J iw is the intermediate calculation parameter.

[0110] △[k s ] 1d =interp1(kj sz5,dkssz5,k d δ);

[0111] in,

[0112] △[k s ] 1d For a pull coefficient of 1, the flap deflection δ, and iw =0, z p = 0 when the slip flow viscosity loss factor increment;

[0113] kj sz5 and dkssz5 are interpolation calculation arrays;

[0114]

[0115] in,

[0116] is the slip flow viscous loss factor when the pull coefficient is 1 and the flap deflection angle is 0.

[0117] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, S23 is specifically:

[0118]

[0119] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, step three is specifically as follows:

[0120]

[0121] in,

[0122] r is the velocity ratio of incoming flow to slipstream;

[0123] C Xwf ' is the negative value of the drag coefficient of the wing + flap system considering the dynamic effect based on the slipstream pressure and the propeller disk area;

[0124] b w for wingspan;

[0125]

[0126] in,

[0127] C Dwf It is the drag coefficient of the wing + flap system considering the dynamic effect based on the incoming flow pressure and the wing reference area.

[0128] C D =C Dwf +C Dnw ;

[0129] in,

[0130] C D is the drag coefficient considering the influence of dynamic force.

[0131] C Dnw The drag coefficient of the unpowered aircraft is deducted from the wing + flaps.

[0132] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, in step three, or,

[0133] in,

[0134] V s is the slipstream velocity.

[0135] According to at least one embodiment of the present application, in the above-mentioned method for calculating the drag characteristics of a propeller aircraft considering the influence of power, step 4 is specifically as follows:

[0136] C Ds =C D -[C D ]0.

[0137] This application has at least the following beneficial technical effects:

[0138] The invention provides a method for calculating the drag characteristics of propeller aircraft considering the influence of power, fully considering the influence of angle of attack, speed, engine thrust, number of engines, size and position of engine nacelle, angle of attack of thrust line, wing mounting angle, propeller diameter, flap deflection angle, flap chord length, wing span and aspect ratio, propeller slipstream deflection angle, and slipstream viscosity loss on drag, and can accurately obtain the drag coefficient of propeller aircraft and its slipstream, which is used for calculating the drag generated by propeller aircraft and its slipstream, and can provide effective support for the design, improvement and control of propeller aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0139] Figure 1 It is a schematic diagram of a method for calculating the drag characteristics of a propeller aircraft taking into account the influence of power provided in an embodiment of the present application.

[0140] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0141] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0142] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0143] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0144] A method for calculating the drag characteristics of propeller aircraft considering the influence of power, such as Figure 1 shown.

[0145] Step 1: Calculate the tension coefficient C T Downwelling deflection angle θ s .

[0146] S11. Calculate the slipstream deflection angle in the zero pull coefficient state

[0147]

[0148] in,

[0149] AR is the wing aspect ratio;

[0150] [C L ]0 is the lift coefficient of the aircraft in the unpowered state;

[0151] [C D ]0 is the drag coefficient of the aircraft in the unpowered state.

[0152] S12, calculate the slipstream deflection angle when the pull coefficient is 1

[0153] α p =α-θ pb …………2-1

[0154] in,

[0155] α p is the angle of attack of the incoming flow relative to the offline line;

[0156] α is the aircraft angle of attack;

[0157] θ pb It is the angle of attack of the engine tension line relative to the center axis of the fuselage.

[0158] i w =θ wi +θ pb …………2-2

[0159] in,

[0160] i w is the angle of attack of the engine pull line relative to the local wing chord line;

[0161] θ wi is the installation angle of the local wing.

[0162] y ceff =0.5y c …………2-3

[0163] in,

[0164] y ceff The effective span width of the flap covered by the engine nacelle;

[0165] y c It is the span width of the flap interrupted by the engine nacelle.

[0166]

[0167] in,

[0168] I yc is the intermediate calculation parameter;

[0169] D is the diameter of the paddle disc.

[0170]

[0171] in,

[0172] H ZP is the intermediate calculation parameter;

[0173] z p is the height of the wing leading edge relative to the incoming flow.

[0174]

[0175] in,

[0176] I zp is the intermediate calculation parameter;

[0177] interp1 is a linear interpolation calculation function;

[0178] Dbsz 1 and Izpsz1 are interpolation calculation arrays, as shown in the following table: Dbsz1 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 Izpsz1 0.74 0.92 1 1 1 0.88 0.54

[0179]

[0180] in,

[0181] c is the chord length of the local wing;

[0182] K dc is the intermediate calculation parameter;

[0183] Dbsz 2 and Kdsz2 are interpolation calculation arrays, as shown in the following table: Dbsz2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 KdZ 0 0.27 0.45 0.6 0.7 0.77 0.82 0.86 0.88

[0184]

[0185] in,

[0186] is the intermediate calculation parameter;

[0187] α0 is the zero lift angle of attack when the aircraft flaps are fully retracted and the power is off.

[0188]

[0189] in,

[0190] dabf is the intermediate calculation parameter;

[0191] δ t1 is the deflection angle of the first flap of the double-slotted flap;

[0192] δ t2 is the deflection angle of the second flap of the double-slotted flap.

[0193] f=interp1(dabsz3,fsz3,dabf)…………2-10

[0194] in,

[0195] Dbsz3 and Kdsz3 are interpolation calculation arrays, as shown in the following table: dabsz3 0 0.2 0.4 0.6 0.8 1 fsz3 0 0.16 0.34 0.55 0.76 1

[0196] c teff =fc t1 +(1-f)c t2 …………2-11

[0197] in,

[0198] c teff is the effective chord length of the flap;

[0199] f is the weight coefficient;

[0200] c t1 is the chord length of the first flap of the double-slotted flap;

[0201] c t2 is the chord length of the second flap of the double-slotted flap.

[0202]

[0203] in,

[0204] Dbsz4 and Kdsz4 are interpolation calculation arrays, as shown in the following table: Dbsz4 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 KdZ 0 0.27 0.45 0.6 0.7 0.77 0.82 0.86 0.88

[0205]

[0206] in,

[0207] δ is the deflection angle of the trailing edge double-slotted Fuller flap.

[0208] S13, slipstream deflection angle at zero tension coefficient Slipstream deflection angle when the pull coefficient is 1 Calculation of tension coefficient C T Downwelling deflection angle θ s .

[0209] q0=0.5ρV0 2 …………3-1

[0210] in,

[0211] q0 is the incoming flow velocity pressure;

[0212] ρ is the air density;

[0213] V0 is the incoming flow velocity;

[0214]

[0215] in,

[0216] T C The aircraft drag coefficient is defined based on the aircraft drag, incoming flow pressure and wing reference area;

[0217] N is the number of engines;

[0218] S ref is the reference area of ​​the wing.

[0219] S p =πD 2 / 4…………3-3

[0220] in,

[0221] S p is the paddle disc area.

[0222] or,

[0223] in,

[0224] C T is the thrust coefficient of the engine defined based on propeller thrust, slipstream pressure and propeller disc area;

[0225] p e is the pulling force of the engine;

[0226] q s is the slip velocity pressure.

[0227]

[0228] Step 2: Calculate the tension coefficient C T Downward flow viscous loss factor k s .

[0229] S21, calculation factor for viscous loss of glide flow under zero tension coefficient

[0230]

[0231] S22, calculate the viscous loss factor of the glide flow under zero tension coefficient 1

[0232]

[0233] in,

[0234] J yc is the intermediate calculation parameter.

[0235] J iw =1+0.05i w …………5-2

[0236] in,

[0237] J iw is the intermediate calculation parameter.

[0238] △[k s ] 1d =interp1(kj sz5,dkssz5,k d δ)…………5-3

[0239] in,

[0240] △[k s ] 1d For a pull coefficient of 1, the flap deflection δ, and i w =0, z p = 0 when the slip flow viscosity loss factor increment;

[0241] kj sz5 and dkssz5 are interpolation calculation arrays, as shown in the following table: kj sz5 0 5 10 15 20 25 30 35 There is no overlapping cross-section area on the propeller disc of a single engine dkssz5 0 0.014 0.028 0.047 0.066 0.085 0.112 0.14 Overlapping cross-section of propeller disc on one side of the engine dkssz5 0 0.003 0.006 0.01 0.015 0.022 0.029 0.04

[0242]

[0243] in,

[0244] is the slip flow viscous loss factor when the pull coefficient is 1 and the flap deflection angle is 0.

[0245] δ=δ t1 +δ t2 …………5-5

[0246] S23, Calculation factor of viscous loss under zero tension coefficient Zero tension coefficient 1 glide viscous loss calculation factor Calculation of tension coefficient C T Downward flow viscous loss factor k s .

[0247]

[0248] Step 3: Take the tension coefficient C T Downwelling deflection angle θ s , Tensile coefficient C T Downward flow viscous loss factor k s , calculate the drag coefficient C considering the dynamic effect D .

[0249] Consider the airflow reverse force of the dynamic effect.

[0250] or,

[0251] in,

[0252] r is the velocity ratio of incoming flow to slipstream;

[0253] V s is the slipstream velocity.

[0254]

[0255] in,

[0256] C Xwf ' is the negative value of the drag coefficient of the wing + flap system considering the dynamic effect based on the slipstream pressure and the propeller disk area;

[0257] b w For wingspan.

[0258]

[0259] in,

[0260] C Dwf It is the drag coefficient of the wing + flap system considering the dynamic effect based on the incoming flow pressure and the wing reference area.

[0261] C D =C Dwf +C Dnw …………7-4

[0262] in,

[0263] C D is the drag coefficient considering the influence of dynamic force.

[0264] C Dnw The drag coefficient of the unpowered aircraft is deducted from the wing + flaps.

[0265] Step 4: Consider the drag coefficient C with dynamic influence D , calculate the drag coefficient C generated by the propeller slipstream Ds

[0266] C Ds =C D -[C D ]0…………8-1

[0267] In a specific embodiment, the propeller aircraft has a wing area of ​​65m2, a wingspan of 26.2m, and an aspect ratio of 10.56. Two turboprop engines are suspended under the wing, with a propeller disk diameter of 4.4m, a local wing chord length of 2.6m, a thrust axis angle of attack of 1° relative to the fuselage axis, and a local wing installation angle of 3°. Takeoff configuration: the double-slotted Fuller flap at the trailing edge has a deflection angle of 20°+8°, and the relative chord length of the two flaps is 0.2+0.1. The span length of the flap interrupted by the engine nacelle is 1.0m, and the height of the leading edge of the local wing of the engine from the thrust axis is 0.246m. The lift coefficient of the aircraft at an angle of attack of 13.5° in the unpowered state is 2.18, and the drag coefficient is 0.217. The zero lift angle of attack of the flap-retracted configuration is -2°, the fuselage drag coefficient is 0.0063, and the horizontal tail drag coefficient is 0.0015. The incoming flow velocity is 75m / s, and the corresponding engine thrust is 33.56KN. The drag coefficient of the aircraft at an angle of attack of 13.5° considering the influence of power is calculated using the calculation method for the drag characteristics of propeller aircraft considering the influence of power disclosed in the above embodiment, as follows:

[0268] 1) Calculation As shown in Table 1 below: parameter value Annotation AR 10.6 enter <![CDATA[[C L ]0]]> 2.18 enter <![CDATA[[C D ]0]]> 0.217 enter 7.56° Formula 1-1

[0269] 2) Calculation As shown in Table 2 below:

[0270] 3) Calculate θ s , as shown in Table 3 below:

[0271] 4) Calculation As shown in Table 4 below:

[0272] 5) Calculation As shown in Table 5 below:

[0273] 6) Calculate k s , as shown in Table 6 below:

[0274] 7) Calculate C D , as shown in Table 7 below:

[0275] 8) Calculate C D , as shown in Table 8 below parameter value Annotation <![CDATA[C D ]]> 0.3293 Table 7 <![CDATA[[C D ]0]]> 0.217 enter <![CDATA[C Ds ]]> 0.1123 Formula 8-1

[0276] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for calculating the drag characteristics of a propeller aircraft considering the influence of power, characterized in that: include: Step 1: Calculate the tension coefficient C T Downwelling deflection angle θ s ; Step 2: Calculate the tension coefficient C T Downward flow viscous loss factor k s ; Step 3: Take the tension coefficient C T Downwelling deflection angle θ s , Tensile coefficient C T Downward flow viscous loss factor k s , calculate the drag coefficient C considering the dynamic effect D ; Step 4: Consider the drag coefficient C with dynamic influence D , calculate the drag coefficient C generated by the propeller slipstream Ds .

2. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 1, characterized in that: Step one includes: S11. Calculate the slipstream deflection angle in the zero pull coefficient state S12, calculate the slipstream deflection angle when the pull coefficient is 1 S13, slipstream deflection angle at zero tension coefficient Slipstream deflection angle when the pull coefficient is 1 Calculation of tension coefficient C T Downwelling deflection angle θ s .

3. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 2, characterized in that: S11 is as follows: in, AR is the wing aspect ratio; [C L ]0 is the lift coefficient of the aircraft in the unpowered state, [C D ]0 is the drag coefficient of the aircraft in the unpowered state.

4. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 3, characterized in that: y ceff =0.5y c ; in, y ceff The effective span width of the flap covered by the engine nacelle; y c is the span width of the flap interrupted by the engine nacelle; in, I yc is the intermediate calculation parameter; D is the diameter of the propeller disc; in, H ZP is the intermediate calculation parameter; z p is the height of the wing leading edge relative to the incoming flow; in, I zp is the intermediate calculation parameter; interp1 is a linear interpolation calculation function; Dbsz1 and Izpsz1 are interpolation calculation arrays; in, c is the chord length of the local wing; K dc is the intermediate calculation parameter; Dbsz2 and Kdsz2 are interpolation calculation arrays; in, is the intermediate calculation parameter; α0 is the zero lift angle of attack when the aircraft flaps are fully retracted and the power is off; c teff =fc t1 +(1-f)c t2 ; in, c teff is the effective chord length of the flap; f is the weight coefficient; c t1 is the chord length of the first flap of the double-slotted flap; c t2 is the chord length of the second flap of the double-slotted flap; in, Dbsz4 and Kdsz4 are interpolation calculation arrays; in, δ is the deflection angle of the trailing edge double-slotted Fuller flap; α p is the angle of attack of the incoming flow relative to the offline line; i w is the angle of attack of the engine thrust line relative to the local wing chord line.

5. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 4, characterized in that: In S12, α p = α - θ pb ; in, α is the aircraft angle of attack; θ pb It is the angle of attack of the engine tension line relative to the center axis of the fuselage.

6. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 5, characterized in that: In S12, i w = θ wi + θ pb ; in, θ wi is the installation angle of the local wing.

7. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 6, characterized in that: In S12, in, dabf is the intermediate calculation parameter; δ t1 is the deflection angle of the first flap of the double-slotted flap; δ t2 is the deflection angle of the second flap of the double-slotted flap; f=interp1(dabsz3,fsz3,dabf); in, Dbsz3 and Kdsz3 are interpolation calculation arrays.

8. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 7, characterized in that: S13 is specifically: q0=0.5ρV0 2 ; in, q0 is the incoming flow velocity pressure; ρ is the air density; V0 is the incoming flow velocity; in, T C The aircraft drag coefficient is defined based on the aircraft drag, incoming flow pressure and wing reference area; N is the number of engines; S ref is the wing reference area; S p =πD 2 / 4; in, S p is the paddle disc area; or, in, C T is the thrust coefficient of the engine defined based on propeller thrust, slipstream pressure and propeller disc area; p e is the pulling force of the engine; q s is the slip velocity pressure; 9. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 8, characterized in that: Step 2 includes: S21, calculation factor for viscous loss of glide flow under zero tension coefficient S22, calculate the viscous loss factor of the glide flow under zero tension coefficient 1 S23, Calculation factor of viscous loss under zero tension coefficient Zero tension coefficient 1 glide viscous loss calculation factor Calculation of tension coefficient C T Downward flow viscous loss factor k s .

10. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 9, characterized in that: S21 is specifically:

11. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 10, characterized in that: S22 is specifically: in, J yc is the intermediate calculation parameter; J iw =1+0.05i w ; in, J iw is the intermediate calculation parameter. △[k s ] 1d =interp1(kj sz5,dkssz 5,k d δ); in, △[k s ] 1d For a pull coefficient of 1, the flap deflection δ, and i w =0, z p = 0 when the slip flow viscosity loss factor increment; kj sz5 and dkssz 5 are interpolation calculation arrays; in, is the slip flow viscous loss factor when the pull coefficient is 1 and the flap deflection angle is 0.

12. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 11, characterized in that: S23 is specifically:

13. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 12, characterized in that: Step three is as follows: in, r is the velocity ratio of incoming flow to slipstream; C Xwf ' is the negative value of the drag coefficient of the wing + flap system considering the dynamic effect based on the slipstream pressure and the propeller disk area; b w for wingspan; in, C Dwf The drag coefficient of the wing + flap system considering the dynamic effect based on the incoming flow pressure and the wing reference area; C D =C Dwf +C Dnw ; in, C D is the drag coefficient considering the influence of dynamic force; C Dnw The drag coefficient of the unpowered aircraft is deducted from the wing + flaps.

14. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 13, characterized in that: In step three, or, in, V s is the slipstream velocity.

15. The method for calculating the drag characteristics of a propeller aircraft considering the influence of power according to claim 14, characterized in that: Step 4 is as follows: C Ds =C D -[C D ]0。

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