Method for determining takeoff weight of airplane after wing area adjustment

Abstract

The invention belongs to the technical field of aircraft design, and particularly relates to a method for determining the takeoff weight of an aircraft after wing area adjustment, which comprises the following steps: step 1, based on an original wing configuration, calculating the wing structure weight Ww0, the task fuel weight Wful0 and the used empty aircraft weight Wkj0 under the original wing configuration to obtain the used empty aircraft weight Wnw without wings; step 2, based on the new wing configuration after wing area adjustment, calculating the weight Ww of the wing structure under the new wing configuration by using the takeoff weight Wto of the airplane in the previous round; 3, based on the new wing configuration obtained after wing area adjustment, the task fuel oil weight Wful under the new wing configuration is calculated through the airplane take-off weight Wto of the last round; 4, calculating the takeoff weight Wto'of the aircraft under the new wing configuration based on the wing structure weight Ww and the task fuel weight Wful under the new wing configuration, the weight Wnw of the used empty aircraft without the wings and the aircraft commercial load Wsz, and 5, obtaining the final takeoff weight of the aircraft under the new wing configuration.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft design, and specifically relates to a method for determining the take-off weight of an aircraft after wing area adjustment. Background Art

[0002] The take-off weight of an aircraft is related to its range and fuel consumption, and is an important indicator of aircraft design. Reducing the take-off weight of an aircraft can significantly improve the performance of the aircraft, especially the performance of a transport aircraft.

[0003] Optimizing wing load is an effective way to improve the aerodynamic efficiency of an aircraft during cruise. When the lift coefficient of an aircraft during cruise is larger than the favorable lift coefficient during cruise, the cruise lift-to-drag ratio loss is large. By reducing the wing area and increasing the wing load, the lift coefficient of an aircraft during cruise can be increased, thereby improving the aerodynamic efficiency of an aircraft during cruise. Reducing the wing area can also reduce the wing structure weight, empty weight, mission fuel weight, and aircraft takeoff weight while ensuring that the range remains unchanged.

[0004] After adjusting the wing area, determining the take-off weight of the aircraft is an important part of aircraft design. However, currently, there is a lack of convenient, efficient and accurate calculation methods for this. In view of this, this application is proposed. Summary of the invention

[0005] The purpose of this application is to provide a method for determining the take-off weight of an aircraft after wing area adjustment, so as to conveniently, efficiently and accurately calculate the take-off weight of an aircraft after wing area adjustment, and support the design work of the aircraft.

[0006] The technical solution of this application is:

[0007] A method for determining the take-off weight of an aircraft after wing area adjustment, comprising:

[0008] Step 1: Based on the original wing configuration, calculate the wing structure weight W under the original wing configuration w0 , Mission fuel weight W ful0 、Use empty weight W kj0 , the empty weight W without the wings is obtained nw ;

[0009] Step 2: Based on the new wing configuration after wing area adjustment, use the aircraft takeoff weight W from the previous round to , calculate the wing structure weight W under the new wing configuration w ;

[0010] Step 3: Based on the new wing configuration after wing area adjustment, use the aircraft takeoff weight W from the previous round to , calculate the mission fuel weight W under the new wing configuration ful ;

[0011] Step 4: Wing structure weight W based on the new wing configuration w , Mission fuel weight W ful and the empty weight W without the wings nw 、Aircraft Commercial Load W sz , calculate the aircraft takeoff weight W under the new wing configuration to ';

[0012] Step 5: Determine the takeoff weight W of the aircraft under the new wing configuration to 'With the previous round of aircraft takeoff weight W to Is the relative error of less than the set threshold value Δ? If so, the aircraft take-off weight under the final new wing configuration is obtained; if not, steps 2 to 5 are repeated.

[0013] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, step 1 includes:

[0014]

[0015] in,

[0016] W to0 is the takeoff weight of the aircraft with the original wing configuration;

[0017] n ymax0 is the maximum normal overload of the aircraft under the original wing configuration;

[0018] S w0 is the wing area under the original wing configuration;

[0019] AR 0 is the wing aspect ratio under the original wing configuration;

[0020] η 0 In the original wing configuration, the wing has a slightly lower root ratio;

[0021] K s0 is the area factor of the wing control surface under the original wing configuration;

[0022] tc 0 is the average thickness of the wing under the original wing configuration;

[0023] Λ 1 / 40 It is the 1 / 4 chord sweep angle of the wing under the original wing configuration.

[0024] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, step 1 includes:

[0025]

[0026] in,

[0027] K R0 is the aircraft transition range factor under the original wing configuration;

[0028] R 0 is the aircraft range under the original wing configuration;

[0029] K t0 is the aircraft standby time factor under the original wing configuration;

[0030] V 0 is the cruising speed of the aircraft under the original wing configuration;

[0031] K z0 is the comprehensive correction factor of the aircraft under the original wing configuration;

[0032] K 0 is the average lift-to-drag ratio of the aircraft during cruising under the original wing configuration;

[0033] C e0 is the engine fuel consumption rate under the original wing configuration.

[0034] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, under the original wing configuration, the aircraft transition range factor K R0 Take 1.1.

[0035] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, under the original wing configuration, the aircraft standby time factor K t0 Take 0.5.

[0036] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, under the original wing configuration, the aircraft comprehensive correction factor K z0 , take 1.04.

[0037] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, step 1 includes:

[0038] W kj0 =W to0 -W ful0 -W sz ;

[0039] in,

[0040] W sz For commercial aircraft.

[0041] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, step 1 includes:

[0042] W nw =W kj0 -W w0 .

[0043] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of the aircraft after wing area adjustment, step 2 includes:

[0044]

[0045] in,

[0046] W to is the take-off weight of the aircraft in the previous round;

[0047] n ymax is the maximum normal overload of the aircraft under the new wing configuration;

[0048] S w is the wing area under the new wing configuration;

[0049] AR is the wing aspect ratio under the new wing configuration;

[0050] η is the wing root-to-wing ratio under the new wing configuration;

[0051] K s is the area factor of the wing control surface under the new wing configuration;

[0052] tc is the average thickness of the wing under the new wing configuration;

[0053] Λ 1 / 4 It is the 1 / 4 chord sweep angle of the wing under the new wing configuration.

[0054] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of the aircraft after the wing area is adjusted, step three includes:

[0055]

[0056] in,

[0057] K R is the aircraft transfer range factor under the new wing configuration;

[0058] R is the aircraft range under the new wing configuration;

[0059] K t is the aircraft standby time factor under the new wing configuration;

[0060] V is the cruising speed of the aircraft under the new wing configuration;

[0061] K z is the comprehensive correction factor of the aircraft under the new wing configuration;

[0062] K is the average lift-to-drag ratio of the aircraft during cruising under the new wing configuration;

[0063] C e This is the engine fuel consumption rate under the new wing configuration.

[0064] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, under the new wing configuration, the aircraft transfer range factor K R Take 1.1.

[0065] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, under the new wing configuration, the aircraft standby time factor K t Take 0.5.

[0066] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of an aircraft after wing area adjustment, under the new wing configuration, the aircraft comprehensive correction factor K z Take 1.04.

[0067] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of the aircraft after the wing area is adjusted, step 4 includes:

[0068] W to '=W w +W ful +W nw +W sz .

[0069] According to at least one embodiment of the present application, in the above-mentioned method for determining the take-off weight of the aircraft after wing area adjustment, the threshold value Δ is set to 0.1%.

[0070] This application has at least the following beneficial technical effects:

[0071] A method for determining the take-off weight of an aircraft after wing area adjustment is provided. Based on the fact that there is a coupling relationship between the take-off weight of the aircraft, the wing structure weight and the mission fuel weight, a cyclic iteration method is designed to calculate the take-off weight of the aircraft under the final new wing configuration after the wing area adjustment. The take-off weight of the aircraft after the wing area adjustment can be obtained conveniently, efficiently and accurately, effectively supporting the design work of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic diagram of a method for determining an aircraft takeoff weight after wing area adjustment provided in an embodiment of the present application.

[0073] In order to better illustrate the present embodiment, some contents of the drawings may be omitted, which is only used for illustrative purposes and should not be construed as limiting the present application. DETAILED DESCRIPTION

[0074] 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.

[0075] 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.

[0076] 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.

[0077] The wing structure weight is a function of the wing area, aspect ratio, thickness, overload and aircraft takeoff weight. The mission fuel weight is a function of the aircraft takeoff weight, cruising speed, cruise lift-to-drag ratio and engine fuel consumption rate. There is a coupling relationship between the aircraft takeoff weight, wing structure weight and mission fuel weight. Based on this, the present application provides a method for determining the aircraft takeoff weight after wing area adjustment, which is used for aircraft wing area optimization and aircraft takeoff weight control. Figure 1 shown.

[0078] Step 1: Based on the original wing configuration, calculate the wing structure weight W under the original wing configuration w0 , Mission fuel weight W ful0 、Use empty weight W kj0 , the empty weight W without the wings is obtained nw .

[0079]

[0080] in,

[0081] W to0 is the takeoff weight of the aircraft with the original wing configuration;

[0082] n ymax0 is the maximum normal overload of the aircraft under the original wing configuration;

[0083] S w0 is the wing area under the original wing configuration;

[0084] AR 0 is the wing aspect ratio under the original wing configuration;

[0085] η 0 In the original wing configuration, the wing has a slightly lower root ratio;

[0086] K s0 is the area factor of the wing control surface under the original wing configuration;

[0087] tc 0 is the average thickness of the wing under the original wing configuration;

[0088] Λ 1 / 40 It is the 1 / 4 chord sweep angle of the wing under the original wing configuration.

[0089]

[0090] in,

[0091] K R0 is the aircraft transfer range factor under the original wing configuration. Generally, 10% of the mission range can be used for transfer. Therefore, K R0 The default value can be taken as 1.1;

[0092] R 0 is the aircraft range under the original wing configuration;

[0093] K t0 is the aircraft standby time factor under the original wing configuration, which can generally be taken as 0.5, i.e. half an hour of standby time;

[0094] V 0 is the cruising speed of the aircraft under the original wing configuration;

[0095] K z0 It is the comprehensive correction factor of the aircraft under the original wing configuration. The default value is generally 1.04 and can be adjusted according to the actual situation.

[0096] K 0 is the average lift-to-drag ratio of the aircraft during cruising under the original wing configuration;

[0097] C e0 is the engine fuel consumption rate under the original wing configuration.

[0098] W kj0 =W to0 -W ful0 -W sz …………(3)

[0099] in,

[0100] W sz For commercial aircraft.

[0101] W nw =W kj0 -W w0 …………(4)

[0102] Step 2: Based on the new wing configuration after wing area adjustment, use the aircraft takeoff weight W from the previous round to , calculate the wing structure weight W under the new wing configuration w .

[0103]

[0104] in,

[0105] W to is the take-off weight of the aircraft in the previous round;

[0106] n ymax is the maximum normal overload of the aircraft under the new wing configuration;

[0107] S w is the wing area under the new wing configuration;

[0108] AR is the wing aspect ratio under the new wing configuration;

[0109] η is the wing root-to-wing ratio under the new wing configuration;

[0110] K s is the area factor of the wing control surface under the new wing configuration;

[0111] tc is the average thickness of the wing under the new wing configuration;

[0112] Λ 1 / 4 It is the 1 / 4 chord sweep angle of the wing under the new wing configuration.

[0113] Step 3: Based on the new wing configuration after wing area adjustment, use the aircraft takeoff weight W from the previous round to , calculate the mission fuel weight W under the new wing configuration ful .

[0114]

[0115] in,

[0116] K R is the aircraft transfer range factor under the new wing configuration. Generally, 10% of the mission range can be used for transfer. Therefore, K R The default value can be taken as 1.1;

[0117] R is the aircraft range under the new wing configuration;

[0118] K t The aircraft standby time factor under the new wing configuration is generally 0.5, which means half an hour of standby time;

[0119] V is the cruising speed of the aircraft under the new wing configuration;

[0120] K z It is the comprehensive correction factor of the aircraft under the new wing configuration. The default value is generally 1.04 and can be adjusted according to the actual situation.

[0121] K is the average lift-to-drag ratio of the aircraft during cruising under the new wing configuration;

[0122] C e This is the engine fuel consumption rate under the new wing configuration.

[0123] Step 4: Wing structure weight W based on the new wing configuration w , Mission fuel weight W ful and the empty weight W without the wings nw 、Aircraft Commercial Load W sz , calculate the aircraft takeoff weight W under the new wing configuration to '.

[0124] W to '=W w +W ful +W nw +W sz …………(7)

[0125] or,

[0126] W to '=W kj +W ful +W sz …………(8)

[0127] W kj =W nw +W w …………(9)

[0128] in,

[0129] Wkj is the empty weight W of the new wing configuration kj0 .

[0130] Step 5: Determine the takeoff weight W of the aircraft under the new wing configuration to 'With the previous round of aircraft takeoff weight W to Is the relative error of less than the set threshold value Δ? If so, the aircraft take-off weight under the final new wing configuration is obtained; if not, steps 2 to 5 are repeated.

[0131] In |W to '-W to | / W to When <Δ, the takeoff weight of the aircraft under the new wing configuration can be finally determined to be W to or W to ', Δ can be taken as 0.1%.

[0132] The method for determining the take-off weight of an aircraft after wing area adjustment disclosed in the above embodiment is based on the fact that there is a coupling relationship between the take-off weight of the aircraft, the weight of the wing structure and the mission fuel weight. A cyclic iteration method is designed to calculate the take-off weight of the aircraft under the final new wing configuration after the wing area adjustment. The take-off weight of the aircraft after the wing area adjustment can be obtained conveniently, efficiently and accurately, effectively supporting the design work of the aircraft.

[0133] In a specific example, the aircraft has a commercial load of 80t, a range of 8500km, a cruising speed of 830km / h, a cruising lift-to-drag ratio of 18, and an engine fuel consumption rate of 0.53kg / (kg.h). The wing area under the original wing configuration is 610m2, and the aircraft take-off weight is 386t, of which the empty weight is 175.9818t, the wing structure weight is 43.18928t, and the mission fuel weight is 130.0182t, including mission fuel, 30-minute standby fuel, and 850km transfer backup fuel. The cruise lift coefficient is 0.47 and the lift-to-drag ratio is 17.8. After the wing area is adjusted, the wing area under the new wing configuration is 580m2, the cruise lift coefficient is 0.493, and the cruise lift-to-drag ratio increases to 18.

[0134] Based on the method for determining the take-off weight of an aircraft after wing area adjustment disclosed in the above embodiment, taking the range of 8500km as the design constraint, the take-off weight of the aircraft under the new wing configuration of 580m2 wing is solved, and the iterative calculation process is as follows: Ww / t Wful / t Wkj / t Wto / t 1 43.18928 130.0182 175.9818 386 2 41.58833 128.5735 164.3809 382.9544 3 41.40523 127.559 164.1978 381.7568 4 41.33306 127.1601 164.1256 381.2858 5 41.30465 127.0032 164.0972 381.1005 6 41.29346 126.9415 164.086 381.0275 7 41.28906 126.9172 164.0816 380.9989 8 41.28733 126.9077 164.0799 380.9876 9 41.28665 126.9039 164.0792 380.9831

[0135] After 9 rounds of iterative calculations, it was found that the take-off weight of the aircraft with the new 580m2 wing configuration was 380.983t, which was 5013kg less than the take-off weight of the aircraft with the original wing configuration. Among them, the wing structure weight was reduced by 1902kg and the mission fuel weight was reduced by 3111kg.

[0136] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for determining the take-off weight of an aircraft after wing area adjustment, characterized in that: include: Step 1: Based on the original wing configuration, calculate the wing structure weight W under the original wing configuration w0 , Mission fuel weight W ful0 、Use empty weight W kj0 , the empty weight W without the wings is obtained nw ; Step 2: Based on the new wing configuration after wing area adjustment, use the aircraft takeoff weight W from the previous round to , calculate the wing structure weight W under the new wing configuration w ; Step 3: Based on the new wing configuration after wing area adjustment, use the aircraft takeoff weight W from the previous round to , calculate the mission fuel weight W under the new wing configuration ful ; Step 4: Wing structure weight W based on the new wing configuration w , Mission fuel weight W ful and the empty weight W without the wings nw 、Aircraft Commercial Load W sz , calculate the aircraft takeoff weight W under the new wing configuration to '; Step 5: Determine the takeoff weight W of the aircraft under the new wing configuration to 'With the previous round of aircraft takeoff weight W to Is the relative error of less than the set threshold value Δ? If so, the aircraft take-off weight under the final new wing configuration is obtained; if not, steps 2 to 5 are repeated.

2. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 1, characterized in that: In step one, there are: in, W to0 is the takeoff weight of the aircraft with the original wing configuration; n ymax0 is the maximum normal overload of the aircraft under the original wing configuration; S w0 is the wing area under the original wing configuration; AR0 is the wing aspect ratio under the original wing configuration; η0 is the wing root-to-wing ratio under the original wing configuration; K s0 is the area factor of the wing control surface under the original wing configuration; tc0 is the average thickness of the wing under the original wing configuration; Λ 1 / 40 It is the 1 / 4 chord sweep angle of the wing under the original wing configuration.

3. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 2, characterized in that: In step one, there are: in, K R0 is the aircraft transition range factor under the original wing configuration; R0 is the aircraft range under the original wing configuration; K t0 is the aircraft standby time factor under the original wing configuration; V0 is the cruising speed of the aircraft under the original wing configuration; K z0 is the comprehensive correction factor of the aircraft under the original wing configuration; K0 is the average lift-to-drag ratio used by the aircraft during cruising under the original wing configuration; C e0 is the engine fuel consumption rate under the original wing configuration.

4. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 3, characterized in that: Under the original wing configuration, the aircraft transfer range factor K R0 Take 1.

1.

5. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 4, characterized in that: Under the original wing configuration, the aircraft standby time factor K t0 Take 0.

5.

6. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 5, characterized in that: Under the original wing configuration, the aircraft comprehensive correction factor K z0 , take 1.

04.

7. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 6, characterized in that: In step one, there are: IN kj0 =In to0 -IN ful0 -IN sz ; in, W sz For commercial aircraft.

8. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 7, characterized in that: In step one, there are: IN nw =In kj0 -IN w0 。 9. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 8, characterized in that: In step 2, there are: in, W to is the take-off weight of the aircraft in the previous round; n ymax is the maximum normal overload of the aircraft under the new wing configuration; S w is the wing area under the new wing configuration; AR is the wing aspect ratio under the new wing configuration; η is the wing root-to-wing ratio under the new wing configuration; K s is the area factor of the wing control surface under the new wing configuration; tc is the average thickness of the wing under the new wing configuration; Λ 1 / 4 It is the 1 / 4 chord sweep angle of the wing under the new wing configuration.

10. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 9, characterized in that: In step three, there are: in, K R is the aircraft transfer range factor under the new wing configuration; R is the aircraft range under the new wing configuration; K t is the aircraft standby time factor under the new wing configuration; V is the cruising speed of the aircraft under the new wing configuration; K z is the comprehensive correction factor of the aircraft under the new wing configuration; K is the average lift-to-drag ratio of the aircraft during cruising under the new wing configuration; C e This is the engine fuel consumption rate under the new wing configuration.

11. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 10, characterized in that: Under the new wing configuration, the aircraft transfer range factor K R Take 1.

1.

12. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 11, characterized in that: Under the new wing configuration, the aircraft standby time factor K t Take 0.

5.

13. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 12, characterized in that: Under the new wing configuration, the aircraft comprehensive correction factor K z Take 1.

04.

14. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 13, characterized in that: In step 4, there are: IN to '=W w +W ful +W nw +W sz 。 15. The method for determining the take-off weight of an aircraft after wing area adjustment according to claim 14, characterized in that: The threshold Δ is set to 0.1%.

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