Subsonic aircraft cruise aerodynamic efficiency evaluation method and device

Abstract

The invention belongs to the technical field of aircraft design, and particularly relates to a subsonic aircraft cruise aerodynamic efficiency evaluation method and device. The method comprises the following steps: S1, calculating two boundary Mach numbers of given aerodynamic efficiency; s2, discretizing a plurality of Mach number calculation points among the boundary Mach numbers, and interpolating a lift-drag ratio array for any Mach number calculation point based on a given lift coefficient array; s3, for any Mach number calculation point, determining upper and lower limits of a lift coefficient according to a lift-drag ratio array and lift coefficient data; and S4, drawing the lower half part of the equal aerodynamic efficiency curve formed by all the Mach number calculation points and the lower limit of the lift coefficient, and the upper half part of the equal aerodynamic efficiency curve formed by all the Mach number calculation points and the upper limit of the lift coefficient. According to the invention, the aerodynamic efficiency of aircraft cruise evaluation and the design accuracy can be improved.

Description

Technical Field

[0001] This application belongs to the field of aircraft design technology, and specifically relates to a method and device for evaluating the cruise aerodynamic efficiency of subsonic aircraft. Background Technology

[0002] Cruise aerodynamic efficiency is a key parameter for evaluating the aerodynamic performance of subsonic aircraft, especially transport aircraft. The goal of aircraft aerodynamic design is for cruise aerodynamic efficiency to equal its maximum aerodynamic efficiency. However, in reality, due to various reasons such as wing loading, inconsistencies between zero-lift drag and induced drag, the lift coefficient used during cruise deviates from the favorable lift coefficient, and the cruise aerodynamic efficiency deviates from the maximum aerodynamic efficiency. Accurately evaluating cruise aerodynamic efficiency is necessary for the optimization design of top-level aircraft parameters and drag. During the cruise phase, the aircraft's speed and lift coefficient change, and the aerodynamic efficiency also changes. Evaluating cruise aerodynamic efficiency requires calculating the aerodynamic efficiency at multiple cruise points, as well as the deviation of the aerodynamic efficiency from the maximum aerodynamic efficiency. How to accurately calculate these parameters is a problem that urgently needs to be solved to improve aircraft cruise efficiency. Summary of the Invention

[0003] To address the aforementioned issues, this application provides a method and apparatus for evaluating the cruise aerodynamic efficiency of subsonic aircraft, offering technical support for the evaluation of cruise efficiency of subsonic aircraft.

[0004] The first aspect of this application provides a method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft, mainly including:

[0005] Step S1: Calculate the two boundary Mach numbers for the given aerodynamic efficiency;

[0006] Step S2: Discretize multiple Mach number calculation points between boundary Mach numbers. For any Mach number calculation point, interpolate the lift-to-drag ratio array based on the given lift coefficient array.

[0007] Step S3: For any Mach number calculation point, determine the upper and lower limits of the lift coefficient based on the lift-to-drag ratio array and lift coefficient data;

[0008] Step S4: Plot the lower half of the isodynamic efficiency curve formed by all Mach number calculation points and their lower limit of lift coefficient, and the upper half of the isodynamic efficiency curve formed by all Mach number calculation points and their upper limit of lift coefficient.

[0009] Preferably, step S1 further includes:

[0010] Step S11: Obtain the Mach number array for the given cruise configuration and the corresponding maximum lift-to-drag ratio array;

[0011] Step S12: Determine the aerodynamic efficiency array, wherein the aerodynamic efficiency is the product of the Mach number of the cruise configuration and its corresponding maximum lift-to-drag ratio;

[0012] Step S13: Determine the maximum aerodynamic efficiency and its position ID in the aerodynamic efficiency array;

[0013] Step S14: Determine the given aerodynamic efficiency based on the given calculation ratio A. ;

[0014] Step S15: Based on the maximum aerodynamic efficiency The location ID divides the aerodynamic efficiency array into a left and right array, and the Mach number array into a left and right array;

[0015] Step S16: Using the given aerodynamic efficiency MK, interpolate the low value of Mach number in the left array corresponding to aerodynamic efficiency and Mach number, and interpolate the high value of Mach number in the right array corresponding to aerodynamic efficiency and Mach number, to form two boundary Mach numbers.

[0016] Preferably, in step S11, the number of Mach numbers in the Mach number array is not less than three.

[0017] Preferably, in step S15, when the aerodynamic efficiency array is divided into a left array and a right array, the maximum aerodynamic efficiency is located in both the left and right arrays.

[0018] Preferably, in step S2, at least 6 Mach number calculation points are discretized.

[0019] Preferably, in step S2, the given lift coefficient array is formed by discretizing multiple lift coefficients between the minimum and maximum lift coefficients according to a specified interval value.

[0020] Preferably, step S3 further includes:

[0021] Step S31: For any Mach number calculation point, calculate the lift-to-drag ratio Kx corresponding to that Mach number calculation point based on the given aerodynamic efficiency;

[0022] Step S32: Find the position of the maximum lift-to-drag ratio in the lift-to-drag ratio array corresponding to the Mach number calculation point, so as to divide the lift-to-drag ratio array into a left array and a right array, and at the same time divide the lift coefficient array into a left array and a right array.

[0023] Step S33: Using the lift-to-drag ratio corresponding to the Mach number calculation point, interpolate the lower limit CLl of the lift coefficient in the left array corresponding to the lift-to-drag ratio and the lift coefficient, and interpolate the upper limit CLu of the lift coefficient in the right array corresponding to the lift-to-drag ratio and the lift coefficient.

[0024] Preferably, step S4 further includes:

[0025] Step S5: In the array of lift coefficients, Mach number and lift-to-drag ratio that are used to construct the isodynamic efficiency curves, interpolate the specified cruise lift coefficient and cruise Mach number to obtain the cruise lift-to-drag ratio.

[0026] Step S6: Evaluate the cruise efficiency loss based on the cruise lift-to-drag ratio.

[0027] The second aspect of this application provides a device for evaluating the cruise aerodynamic efficiency of a subsonic aircraft, mainly comprising:

[0028] The boundary Mach number calculation module is used to calculate the two boundary Mach numbers for a given aerodynamic efficiency.

[0029] The lift-to-drag ratio array determination module is used to discretize multiple Mach number calculation points between boundary Mach numbers. For any Mach number calculation point, the lift-to-drag ratio array is interpolated based on the given lift coefficient array.

[0030] The lift coefficient upper and lower limit determination module is used to determine the upper and lower limits of the lift coefficient for any Mach number calculation point based on the lift-to-drag ratio array and lift coefficient data.

[0031] The isodynamic efficiency curve plotting module is used to plot the lower half of the isodynamic efficiency curve formed by all Mach number calculation points and their lower limit of lift coefficient, and the upper half of the isodynamic efficiency curve formed by all Mach number calculation points and their upper limit of lift coefficient.

[0032] Preferably, the boundary Mach number calculation module includes:

[0033] The maximum lift-to-drag ratio array calculation unit is used to obtain the Mach number array for a given cruise configuration and the corresponding maximum lift-to-drag ratio array.

[0034] An aerodynamic efficiency array calculation unit is used to determine the aerodynamic efficiency array, wherein the aerodynamic efficiency is the product of the Mach number of the cruise configuration and its corresponding maximum lift-to-drag ratio.

[0035] Position calculation unit, used to determine maximum aerodynamic efficiency and its position ID in the aerodynamic efficiency array;

[0036] A given aerodynamic efficiency acquisition unit is used to determine a given aerodynamic efficiency based on a given calculation ratio A. ;

[0037] Array grouping units, used to group according to maximum aerodynamic efficiency The location ID divides the aerodynamic efficiency array into a left and right array, and the Mach number array into a left and right array;

[0038] The boundary Mach number calculation unit is used to interpolate the low Mach number value in the left array corresponding to aerodynamic efficiency and Mach number using the given aerodynamic efficiency MK, and to interpolate the high Mach number value in the right array corresponding to aerodynamic efficiency and Mach number, thus forming two boundary Mach numbers.

[0039] Preferably, in the maximum lift-to-drag ratio array calculation unit, the number of Mach numbers in the Mach number array is not less than three.

[0040] Preferably, when the aerodynamic efficiency array is divided into a left array and a right array in the array grouping unit, the maximum aerodynamic efficiency is located in both the left and right arrays.

[0041] Preferably, in the lift-to-drag ratio array determination module, at least 6 Mach number calculation points are discretized.

[0042] Preferably, in the lift-to-drag ratio array determination module, the given lift coefficient array is formed by discretizing multiple lift coefficients between the minimum and maximum lift coefficients at specified intervals.

[0043] Preferably, the lift coefficient upper and lower limit determination module includes:

[0044] The lift-to-drag ratio calculation unit is used to calculate the lift-to-drag ratio Kx corresponding to any Mach number calculation point based on the given aerodynamic efficiency.

[0045] The array grouping unit is used to find the position of the maximum lift-to-drag ratio in the lift-to-drag ratio array corresponding to the Mach number calculation point, so as to divide the lift-to-drag ratio array into a left array and a right array, and at the same time divide the lift coefficient array into a left array and a right array;

[0046] The lift coefficient upper and lower limit calculation unit is used to interpolate the lower limit CLl of the lift coefficient in the left array corresponding to the lift-drag ratio and lift coefficient based on the lift-drag ratio at the Mach number calculation point, and to interpolate the upper limit CLl of the lift coefficient in the right array corresponding to the lift-drag ratio and lift coefficient.

[0047] Preferably, the device further includes:

[0048] The cruise lift-to-drag ratio interpolation module is used to interpolate the cruise lift-to-drag ratio corresponding to a specified cruise lift coefficient and cruise Mach number from the lift coefficient array, Mach number array, and lift-to-drag ratio array that construct the iso-aerodynamic efficiency curve.

[0049] The cruise efficiency loss assessment module is used to assess cruise efficiency loss based on the cruise lift-to-drag ratio.

[0050] A third aspect of this application provides a computer device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the subsonic aircraft cruise aerodynamic efficiency evaluation method as described above.

[0051] A fourth aspect of this application provides a readable storage medium storing a computer program that, when executed by a processor, is used to implement the subsonic aircraft cruise aerodynamic efficiency evaluation method as described above.

[0052] This application can improve the accuracy of evaluating the aerodynamic efficiency of aircraft cruise and the design. Attached Figure Description

[0053] Figure 1 This is a flowchart of a preferred embodiment of the subsonic aircraft cruise aerodynamic efficiency evaluation method of this application.

[0054] Figure 2 These are the isodynamic efficiency curves of the simulated aircraft.

[0055] Figure 3 This is a schematic diagram of the structure of a computer device suitable for implementing the embodiments of this application. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0057] The first aspect of this application provides a method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft, such as... Figure 1 As shown, it mainly includes:

[0058] Step S1: Calculate the two boundary Mach numbers for the given aerodynamic efficiency;

[0059] Step S2: Discretize multiple Mach number calculation points between boundary Mach numbers. For any Mach number calculation point, interpolate the lift-to-drag ratio array based on the given lift coefficient array.

[0060] Step S3: For any Mach number calculation point, determine the upper and lower limits of the lift coefficient based on the lift-to-drag ratio array and lift coefficient data;

[0061] Step S4: Plot the lower half of the isodynamic efficiency curve formed by all Mach number calculation points and their lower limit of lift coefficient, and the upper half of the isodynamic efficiency curve formed by all Mach number calculation points and their upper limit of lift coefficient.

[0062] This application employs an aerodynamic data partitioning interpolation algorithm to calculate the Mach number, lift-to-drag ratio, and lift coefficient corresponding to a series of aerodynamic efficiency values, and plots isodynamic efficiency curves. The deviation of the cruise aerodynamic efficiency from the maximum aerodynamic efficiency is calculated for cruise aerodynamic efficiency evaluation.

[0063] In some alternative implementations, referring to Table 1, step S1 further includes:

[0064] Step S11: Obtain the Mach number array for the given cruise configuration. and the corresponding maximum lift-to-drag ratio array ;

[0065] Step S12: Determine the aerodynamic efficiency array The aerodynamic efficiency is the product of the Mach number of the cruise configuration and its corresponding maximum lift-to-drag ratio.

[0066] Step S13: Determine the maximum aerodynamic efficiency and its position ID in the aerodynamic efficiency array;

[0067] Step S14: Determine the given aerodynamic efficiency based on the given calculation ratio A. ;

[0068] Step S15: Based on the maximum aerodynamic efficiency The location ID divides the aerodynamic efficiency array into a left array. with the right array And dividing the Mach number array into a left array. with the right array ;

[0069] Step S16: Using the given aerodynamic efficiency MK, interpolate the low value of Mach number in the left array corresponding to aerodynamic efficiency and Mach number, and interpolate the high value of Mach number in the right array corresponding to aerodynamic efficiency and Mach number, to form two boundary Mach numbers.

[0070] The computational model for this embodiment is shown below:

[0071] ;

[0072] Parameters in the formula It is the Mach number Its corresponding maximum lift-to-drag ratio The accumulation of, There are n parameters An array. For maximum aerodynamic efficiency, This is the Mach number corresponding to maximum aerodynamic efficiency. yes In Mach number array The corresponding serial number. For Boundary The subarray on the left, This is the subarray on the right. For Boundary The subarray on the left, This is the subarray on the right. It is relative efficiency The corresponding aerodynamic efficiency.

[0073] In some alternative implementations, in step S11, the number of Mach numbers in the Mach number array is not less than three.

[0074] In some alternative implementations, in step S15, when the aerodynamic efficiency array is divided into a left array and a right array, the maximum aerodynamic efficiency is located in both the left and right arrays.

[0075] The example aircraft weighs 400 tons, and has a reference wing area of ​​558 m². 2 The aircraft's weight at the initial cruise point was 390t, its altitude was 9800m, and its cruise Mach number was 0.76; at the midpoint of the cruise, its weight was 330t, its altitude was 10300m, and its cruise Mach number was 0.77; at the final cruise point, its weight was 277t, its altitude was 10800m, and its cruise Mach number was 0.78. The lift-to-drag ratio curves for cruise Mach numbers of 0.74, 0.77, 0.79, and 0.81 are shown in Appendix Table 1.

[0076] Drawing example aircraft 99% With 98% The isodynamic efficiency curves are calculated while maintaining 99%. The applicable range of Mach number and lift coefficient is determined to evaluate the aerodynamic efficiency of the example aircraft during cruise. Taking A=99% as an example, the calculation results of step S1 are shown in Table 1.

[0077] Appendix Table 1: Relevant data for the calculation of two boundary velocities

[0078]

[0079] Step S2 is used to calculate the two-dimensional boost-to-drag ratio array. The calculation model is as follows:

[0080] ;

[0081] In the formula Based on and A Mach number array is constructed for plotting isodynamic efficiency curves. This is an array of lift coefficients constructed for interpolation calculations. and For array The minimum and maximum lift coefficients, This is the lift coefficient interval value; a recommended value is 0.005. array of lift coefficients The corresponding lift-to-drag ratio array is based on Mach number. The aerodynamic data was obtained through interpolation calculations. It consists of n A two-dimensional array of boost-to-resistance ratios. Mach number The corresponding boost-to-drag ratio array, based on , and Obtained by two-dimensional interpolation. It is a Mach number array and The corresponding two-dimensional boost-to-drag ratio array

[0082] In some alternative implementations, in step S2, at least 6 Mach number calculation points are discretized.

[0083] In some optional implementations, in step S2, the given lift coefficient array is formed by discretizing multiple lift coefficients between the minimum lift coefficient and the maximum lift coefficient according to a specified interval value.

[0084] Taking Table 2 as an example, as mentioned earlier, six Mach number calculation points are discretized from the minimum Mach number of 0.761 and the maximum Mach number of 0.781 given in Table 1, forming an array. ;

[0085] Then, based on the input lower limit of the lift coefficient CLs and the upper limit of the lift coefficient Cle, a given lift coefficient array is constructed. .

[0086] Appendix 2 Constructing the interpolation Mach number array and lift coefficient array

[0087]

[0088] Then, for any Mach number calculation point, the lift-to-drag ratio array is interpolated. See Table 3.

[0089] Next, in step S3, the lift coefficient of the isodynamic efficiency curve is calculated using the following calculation model:

[0090] ;

[0091] Where, in the formula Mach number The corresponding boost-to-drag ratio array, Mach number Maximum lift-to-drag ratio, for In array The serial number in for The corresponding lift coefficient. For Boundary The subarray on the left, This is the subarray on the right. For Boundary The subarray on the left, This is the subarray on the right. Aerodynamic efficiency Mach number in the curve The corresponding lift-to-drag ratio, yes Mach number in the lower half of the curve The corresponding lift coefficient, yes Mach number in the upper half of the curve Corresponding lift coefficient

[0092] In some alternative implementations, referring to Table 3, step S3 further includes:

[0093] Step S31: For any Mach number calculation point, calculate the lift-to-drag ratio Kx corresponding to that Mach number calculation point based on the given aerodynamic efficiency;

[0094] Step S32: Calculate the lift-to-drag ratio array corresponding to the Mach number calculation point. Find the maximum lift-to-drag ratio Location To divide the boost-to-drag ratio array into left arrays and the right array At the same time, the lift coefficient array is divided into a left array. with the right array ;

[0095] Step S33: Using the lift-to-drag ratio corresponding to the Mach number calculation point, interpolate the lower limit CLl of the lift coefficient in the left array corresponding to the lift-to-drag ratio and the lift coefficient, and interpolate the upper limit CLu of the lift coefficient in the right array corresponding to the lift-to-drag ratio and the lift coefficient.

[0096] Taking the lift coefficient corresponding to Mach number 0.7729 as an example, this paper explains the calculation method of the lift coefficient corresponding to any Mach number on the isodynamic efficiency line. The relevant parameters are shown in Appendix Table 3.

[0097] Appendix Table 3: Relevant parameters for calculating the lift coefficient corresponding to Mach number 0.7729

[0098]

[0099] Finally, in step S4, the aerodynamic efficiency is plotted. Curves, such as Figure 2 As shown, the calculation model is:

[0100] .

[0101] In the formula This is an array of lift coefficients used to plot the lower half of the isodynamic efficiency curve. This is an array of lift coefficients used to plot the upper half of the isodynamic efficiency curve. To ensure that the aerodynamic efficiency is not less than The minimum value of the lift coefficient can be used. To ensure that the aerodynamic efficiency is not less than The maximum value of the lift coefficient is available.

[0102] Referring to Table 4, construct 99% An array of coordinate data for the aerodynamic efficiency curve.

[0103] Appendix 4 99% Relevant parameters for calculating aerodynamic efficiency curve coordinate data

[0104]

[0105] In some alternative implementations, step S4 is further followed by:

[0106] Step S5: In the array of lift coefficients, Mach number and lift-to-drag ratio that are used to construct the isodynamic efficiency curves, interpolate the specified cruise lift coefficient and cruise Mach number to obtain the cruise lift-to-drag ratio.

[0107] Step S6: Evaluate the cruise efficiency loss based on the cruise lift-to-drag ratio.

[0108] This embodiment is used to evaluate the aerodynamic efficiency of cruise, and the calculation model is as follows:

[0109] .

[0110] In the formula This is the cruise efficiency loss coefficient. For the weight of the aircraft, For wing reference area, air density, For the speed of sound, For the cruising Mach number, For cruising speed, For rapid pressure, This is the cruise lift coefficient. This is the cruise lift-to-drag ratio.

[0111] Tables 5-7 calculate the aerodynamic efficiency loss at the three cruise points.

[0112] Table 5 Efficiency Loss at Cruise Start Point

[0113]

[0114] Table 6 Efficiency Loss at Cruise Midpoint

[0115]

[0116] Table 7 Efficiency Loss at Cruise End

[0117]

[0118] Calculations show that the maximum aerodynamic efficiency of the example aircraft is 13.74, corresponding to a Mach number of 0.77 and a lift coefficient of 0.56. The aerodynamic efficiency is highest at the midpoint of the cruise, reaching 99.9% of the maximum efficiency, decreasing to 98.2% at the start and end of the cruise. To maintain 99% maximum aerodynamic efficiency, the cruise speed should be controlled between 0.761 and 0.781, and the lift coefficient should be controlled between 0.5124 and 0.6177. The iso-efficiency curves for 99% and 98% maximum aerodynamic efficiency of the example aircraft are attached. Figure 2 .

[0119] The second aspect of this application provides a subsonic aircraft cruise aerodynamic efficiency evaluation device corresponding to the above method, mainly comprising:

[0120] The boundary Mach number calculation module is used to calculate the two boundary Mach numbers for a given aerodynamic efficiency.

[0121] The lift-to-drag ratio array determination module is used to discretize multiple Mach number calculation points between boundary Mach numbers. For any Mach number calculation point, the lift-to-drag ratio array is interpolated based on the given lift coefficient array.

[0122] The lift coefficient upper and lower limit determination module is used to determine the upper and lower limits of the lift coefficient for any Mach number calculation point based on the lift-to-drag ratio array and lift coefficient data.

[0123] The isodynamic efficiency curve plotting module is used to plot the lower half of the isodynamic efficiency curve formed by all Mach number calculation points and their lower limit of lift coefficient, and the upper half of the isodynamic efficiency curve formed by all Mach number calculation points and their upper limit of lift coefficient.

[0124] In some alternative implementations, the boundary Mach number calculation module includes:

[0125] The maximum lift-to-drag ratio array calculation unit is used to obtain the Mach number array for a given cruise configuration and the corresponding maximum lift-to-drag ratio array.

[0126] An aerodynamic efficiency array calculation unit is used to determine the aerodynamic efficiency array, wherein the aerodynamic efficiency is the product of the Mach number of the cruise configuration and its corresponding maximum lift-to-drag ratio.

[0127] Position calculation unit, used to determine maximum aerodynamic efficiency and its position ID in the aerodynamic efficiency array;

[0128] A given aerodynamic efficiency acquisition unit is used to determine a given aerodynamic efficiency based on a given calculation ratio A. ;

[0129] Array grouping units, used to group according to maximum aerodynamic efficiency The location ID divides the aerodynamic efficiency array into a left and right array, and the Mach number array into a left and right array;

[0130] The boundary Mach number calculation unit is used to interpolate the low Mach number value in the left array corresponding to aerodynamic efficiency and Mach number using the given aerodynamic efficiency MK, and to interpolate the high Mach number value in the right array corresponding to aerodynamic efficiency and Mach number, thus forming two boundary Mach numbers.

[0131] In some alternative implementations, the number of Mach numbers in the Mach number array in the maximum lift-to-drag ratio array calculation unit is not less than three.

[0132] In some alternative implementations, when the aerodynamic efficiency array is divided into a left array and a right array in the array grouping unit, the maximum aerodynamic efficiency is located in both the left and right arrays.

[0133] In some alternative implementations, at least six Mach number calculation points are discretized in the lift-to-drag ratio array determination module.

[0134] In some optional embodiments, in the lift-to-drag ratio array determination module, the given lift coefficient array is formed by discretizing multiple lift coefficients between the minimum lift coefficient and the maximum lift coefficient at specified intervals.

[0135] In some optional embodiments, the lift coefficient upper and lower limit determination module includes:

[0136] The lift-to-drag ratio calculation unit is used to calculate the lift-to-drag ratio Kx corresponding to any Mach number calculation point based on the given aerodynamic efficiency.

[0137] The array grouping unit is used to find the position of the maximum lift-to-drag ratio in the lift-to-drag ratio array corresponding to the Mach number calculation point, so as to divide the lift-to-drag ratio array into a left array and a right array, and at the same time divide the lift coefficient array into a left array and a right array;

[0138] The lift coefficient upper and lower limit calculation unit is used to interpolate the lower limit CLl of the lift coefficient in the left array corresponding to the lift-drag ratio and lift coefficient based on the lift-drag ratio at the Mach number calculation point, and to interpolate the upper limit CLl of the lift coefficient in the right array corresponding to the lift-drag ratio and lift coefficient.

[0139] In some alternative embodiments, the apparatus further includes:

[0140] The cruise lift-to-drag ratio interpolation module is used to interpolate the cruise lift-to-drag ratio corresponding to a specified cruise lift coefficient and cruise Mach number from the lift coefficient array, Mach number array, and lift-to-drag ratio array that construct the iso-aerodynamic efficiency curve.

[0141] The cruise efficiency loss assessment module is used to assess cruise efficiency loss based on the cruise lift-to-drag ratio.

[0142] In a third aspect of this application, a computer device is provided, 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 subsonic aircraft cruise aerodynamic efficiency evaluation method as described above.

[0143] In a fourth aspect, this application provides a readable storage medium storing a computer program that, when executed by a processor, implements the subsonic aircraft cruise aerodynamic efficiency evaluation method as described above. This computer-readable storage medium may be included in the apparatus described in the above embodiments; or it may exist independently and not incorporated into the apparatus. The aforementioned computer-readable storage medium carries one or more programs that, when executed by the apparatus, process data according to the method described above.

[0144] The following is for reference. Figure 3 It shows a schematic diagram of the structure of a computer device 400 suitable for implementing the embodiments of this application. Figure 3 The computer device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments described in this application.

[0145] like Figure 3As shown, the computer device 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage section 408 into a random access memory (RAM) 403. The RAM 403 also stores various programs and data required for the operation of the device 400. The CPU 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0146] The following components are connected to I / O interface 405: an input section 406 including a keyboard, mouse, etc.; an output section 407 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to I / O interface 405 as needed. A removable medium 411, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 410 as needed so that computer programs read from it can be installed into storage section 408 as needed.

[0147] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 409, and / or installed from removable medium 411. When the computer program is executed by central processing unit (CPU) 401, it performs the functions defined in the methods of this application. It should be noted that the computer storage medium of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in connection 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, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on a computer-readable medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0148] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0149] The modules or units described in the embodiments of this application can be implemented in software or hardware. The described modules or units can also be located in a processor, and the names of these modules or units do not necessarily constitute a limitation on the module or unit itself.

[0150] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft, characterized in that, include: Step S1: Calculate the two boundary Mach numbers for the given aerodynamic efficiency; Step S2: Discretize multiple Mach number calculation points between boundary Mach numbers. For any Mach number calculation point, interpolate the lift-to-drag ratio array based on the given lift coefficient array. Step S3: For any Mach number calculation point, determine the upper and lower limits of the lift coefficient based on the lift-to-drag ratio array and lift coefficient data; Step S4: Draw the lower half of the isodynamic efficiency curve formed by all Mach number calculation points and their lower limit of lift coefficient, and the upper half of the isodynamic efficiency curve formed by all Mach number calculation points and their upper limit of lift coefficient.

2. The method for evaluating the cruise aerodynamic efficiency of subsonic aircraft as described in claim 1, characterized in that, Step S1 further includes: Step S11: Obtain the Mach number array for the given cruise configuration and the corresponding maximum lift-to-drag ratio array; Step S12: Determine the aerodynamic efficiency array, wherein the aerodynamic efficiency is the product of the Mach number of the cruise configuration and its corresponding maximum lift-to-drag ratio; Step S13: Determine the maximum aerodynamic efficiency and its position ID in the aerodynamic efficiency array; Step S14: Determine the given aerodynamic efficiency based on the given calculation ratio A. ; Step S15: Based on the maximum aerodynamic efficiency The location ID divides the aerodynamic efficiency array into a left and right array, and the Mach number array into a left and right array; Step S16: Using the given aerodynamic efficiency MK, interpolate the low value of Mach number in the left array corresponding to aerodynamic efficiency and Mach number, and interpolate the high value of Mach number in the right array corresponding to aerodynamic efficiency and Mach number, to form two boundary Mach numbers.

3. The method for evaluating the cruise aerodynamic efficiency of subsonic aircraft as described in claim 2, characterized in that, In step S11, the number of Mach numbers in the Mach number array is no less than three.

4. The method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft as described in claim 2, characterized in that, In step S15, when the aerodynamic efficiency array is divided into a left array and a right array, the maximum aerodynamic efficiency is located in both the left and right arrays.

5. The method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft as described in claim 1, characterized in that, In step S2, at least 6 Mach number calculation points are discretized.

6. The method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft as described in claim 1, characterized in that, In step S2, the given lift coefficient array is formed by discretizing multiple lift coefficients between the minimum and maximum lift coefficients according to a specified interval value.

7. The method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft as described in claim 1, characterized in that, Step S3 further includes: Step S31: For any Mach number calculation point, calculate the lift-to-drag ratio Kx corresponding to that Mach number calculation point based on the given aerodynamic efficiency; Step S32: Find the position of the maximum lift-to-drag ratio in the lift-to-drag ratio array corresponding to the Mach number calculation point, so as to divide the lift-to-drag ratio array into a left array and a right array, and at the same time divide the lift coefficient array into a left array and a right array. Step S33: Using the lift-to-drag ratio corresponding to the Mach number calculation point, interpolate the lower limit CLl of the lift coefficient in the left array corresponding to the lift-to-drag ratio and the lift coefficient, and interpolate the upper limit CLu of the lift coefficient in the right array corresponding to the lift-to-drag ratio and the lift coefficient.

8. The method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft as described in claim 1, characterized in that, Step S4 is followed by the following: Step S5: In the array of lift coefficients, Mach number and lift-to-drag ratio that are used to construct the isodynamic efficiency curves, interpolate the specified cruise lift coefficient and cruise Mach number to obtain the cruise lift-to-drag ratio. Step S6: Evaluate the cruise efficiency loss based on the cruise lift-to-drag ratio.

9. A device for evaluating the cruise aerodynamic efficiency of a subsonic aircraft, characterized in that, include: The boundary Mach number calculation module is used to calculate the two boundary Mach numbers for a given aerodynamic efficiency. The lift-to-drag ratio array determination module is used to discretize multiple Mach number calculation points between boundary Mach numbers. For any Mach number calculation point, the lift-to-drag ratio array is interpolated based on the given lift coefficient array. The lift coefficient upper and lower limit determination module is used to determine the upper and lower limits of the lift coefficient for any Mach number calculation point based on the lift-to-drag ratio array and lift coefficient data. The isodynamic efficiency curve plotting module is used to plot the lower half of the isodynamic efficiency curve formed by all Mach number calculation points and their lower limit of lift coefficient, and the upper half of the isodynamic efficiency curve formed by all Mach number calculation points and their upper limit of lift coefficient.

10. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 9, characterized in that, The boundary Mach number calculation module includes: The maximum lift-to-drag ratio array calculation unit is used to obtain the Mach number array for a given cruise configuration and the corresponding maximum lift-to-drag ratio array. An aerodynamic efficiency array calculation unit is used to determine the aerodynamic efficiency array, wherein the aerodynamic efficiency is the product of the Mach number of the cruise configuration and its corresponding maximum lift-to-drag ratio. Position calculation unit, used to determine maximum aerodynamic efficiency and its position ID in the aerodynamic efficiency array; A given aerodynamic efficiency acquisition unit is used to determine a given aerodynamic efficiency based on a given calculation ratio A. ; Array grouping units, used to group according to maximum aerodynamic efficiency The location ID divides the aerodynamic efficiency array into a left and right array, and the Mach number array into a left and right array; The boundary Mach number calculation unit is used to interpolate the low Mach number value in the left array corresponding to aerodynamic efficiency and Mach number using the given aerodynamic efficiency MK, and to interpolate the high Mach number value in the right array corresponding to aerodynamic efficiency and Mach number, thus forming two boundary Mach numbers.

11. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 10, characterized in that, In the maximum lift-to-drag ratio array calculation unit, the number of Mach numbers in the Mach number array is no less than three.

12. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 10, characterized in that, In the array grouping unit, when the aerodynamic efficiency array is divided into a left array and a right array, the maximum aerodynamic efficiency is located in both the left and right arrays.

13. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 9, characterized in that, In the lift-to-drag ratio array determination module, at least 6 Mach number calculation points are discretized.

14. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 9, characterized in that, In the lift-to-drag ratio array determination module, the given lift coefficient array is formed by discretizing multiple lift coefficients between the minimum and maximum lift coefficients at specified intervals.

15. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 9, characterized in that, The lift coefficient upper and lower limit determination module includes: The lift-to-drag ratio calculation unit is used to calculate the lift-to-drag ratio Kx corresponding to any Mach number calculation point based on the given aerodynamic efficiency. The array grouping unit is used to find the position of the maximum lift-to-drag ratio in the lift-to-drag ratio array corresponding to the Mach number calculation point, so as to divide the lift-to-drag ratio array into a left array and a right array, and at the same time divide the lift coefficient array into a left array and a right array; The lift coefficient upper and lower limit calculation unit is used to interpolate the lower limit CLl of the lift coefficient in the left array corresponding to the lift-drag ratio and lift coefficient based on the lift-drag ratio at the Mach number calculation point, and to interpolate the upper limit CLl of the lift coefficient in the right array corresponding to the lift-drag ratio and lift coefficient.

16. The subsonic aircraft cruise aerodynamic efficiency evaluation device as described in claim 9, characterized in that, The device further includes: The cruise lift-to-drag ratio interpolation module is used to interpolate the cruise lift-to-drag ratio corresponding to a specified cruise lift coefficient and cruise Mach number from the lift coefficient array, Mach number array, and lift-to-drag ratio array that construct the iso-aerodynamic efficiency curve. The cruise efficiency loss assessment module is used to assess cruise efficiency loss based on the cruise lift-to-drag ratio.

17. A computer device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and executable on the processor, the processor executing the computer program to implement the subsonic aircraft cruise aerodynamic efficiency evaluation method as described in any one of claims 1-8.

18. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it is used to implement the method for evaluating the cruise aerodynamic efficiency of a subsonic aircraft as described in any one of claims 1-8.

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