CN111159815B - A fast optimization method for aircraft wing plane parameters - Google Patents

Abstract

The invention discloses a method for rapidly optimizing plane parameters of an aircraft wing, which comprises the following steps: step 1: generating a wing configuration sample; step 2: setting wing constraint conditions; step 3: screening the aircraft configuration; step 4: determining an optimization strategy and establishing a configuration optimization calculation model; step 5: selecting optimization target parameters; step 6: the wing configuration is optimized, the flight performance index is taken as a final optimization target, a layering optimization strategy is adopted, a calculation model is simplified, a calculation method is reasonably selected, the optimization efficiency is effectively improved, the optimization period is shortened, and the problems of cross-specialty optimization, high optimization resource requirement and low optimization efficiency in the traditional optimization method are solved.

Description

A fast optimization method for aircraft wing plane parameters

Technical Field

The invention belongs to the field of aviation technology, and in particular relates to a method for quickly optimizing aircraft wing plane parameters.

Background Art

Traditionally, wing plane parameter optimization is carried out by profession. The configuration optimized by aerodynamic profession has the best aerodynamic performance, and the configuration optimized by weight profession has the best weight. However, these cannot guarantee the best flight performance indicators of the aircraft. Modern aerodynamic and weight calculations require the establishment of digital models. Complex numerical calculations require powerful computing resources and a long calculation cycle. Faced with a large number of wing configuration samples, traditional optimization methods seem to be unable to cope with the situation.

Summary of the invention

The purpose of this invention is to propose a method for rapid optimization of aircraft wing plane parameters, adopt a hierarchical optimization strategy, simplify the calculation model, and reasonably select the calculation method, so as to achieve rapid optimization of cross-disciplinary wing configuration with aircraft aerodynamics, weight and flight performance indicators as optimization targets.

The technical solution of the present invention:

A method for rapidly optimizing aircraft wing plane parameters comprises the following steps:

Step 1: Generate wing configuration samples;

Step 2: Set wing constraints;

Step 3: Screening aircraft configuration;

Step 4: Determine the optimization strategy and establish the configuration optimization calculation model;

Step 5: Select the optimization target parameters;

Step 6: Optimize the wing configuration.

The step 1 of generating the wing configuration sample further includes the following steps:

Step 1.1 According to the range and step size of the wing plane parameters aspect ratio AR, leading edge sweep angle Λ _LE and tip-to-root ratio η, determine the sample size of the above three parameters, which are m, n and p respectively;

Step 1.2: Under the premise of maintaining the wing area, according to the values of the wing plane parameters, q wing configuration samples are combined and generated;

Step 1.3 combines the wingless aircraft configuration with all wing configurations to generate q aircraft configuration samples.

The q wing configuration samples described in step 1.2, q is the product of m, n, and p.

The optimization constraints described in step 2 include: drag divergence Mach number, minimum operating lift-to-drag ratio, maximum take-off weight and minimum range.

The screening wing configuration described in step 3 further includes the following steps:

Step 3.1: Calculate the aerodynamic force for q aircraft configuration samples;

Step 3.2: Calculate the weight of q aircraft configuration samples;

Step 3.3: Calculate the performance of q aircraft configuration samples;

Step 3.4: Based on the optimization constraints, determine whether the q aircraft configuration samples meet the constraints and complete the configuration screening.

Determine the optimization strategy and establish the configuration optimization calculation model as described in step 4,

The optimization strategy is a hierarchical optimization strategy. In the first round of optimization, based on the constraints and optimization goals, a simplified calculation model and engineering estimation method are used to quickly screen out aircraft configuration samples that do not meet the requirements, thereby reducing the sample size of the secondary optimization. The final optimization uses a refined model and an accurate algorithm to perform secondary optimization on the aircraft configuration samples after the first round of screening. The secondary optimization uses a CFD numerical solution that takes viscosity into consideration to ensure a high calculation accuracy.

The optimization calculation model includes:

Weight calculation model:

_{W W ＝ K} ^​ _​ ^{​ ​} _​ ^{​ ​} _​ ^​ _​

In the above formula, Ww is the wing structure weight, Wto is the aircraft take-off weight, Sref is the wing reference area, Scz is the aerodynamic control surface area on the wing, _nymax is the maximum normal overload coefficient, _tR is the wing root thickness, and Kxz is the correction factor.

Calculation model for the first cruise segment:

W_mid＝W₁-0.5W_fule

W _mid = W ₁ - 0.5 W _full

In the above formula: L is the cruise range, M is the cruise Mach number, a is the speed of sound at the cruise altitude, K is the cruise lift-to-drag ratio, q _kh is the cruise fuel consumption rate, W ₁ is the aircraft mass at the cruise starting point, W _mid is the aircraft weight at the cruise midpoint, and W _fule is the fuel weight consumed in the cruise.

Final optimization performance calculation model:

The optimization target parameters selected in step 5 are: range, flight time, aerodynamic efficiency and take-off weight.

The optimized wing configuration described in step 6 is specifically as follows: through two rounds of optimization, the wing corresponding to the aircraft configuration with the best performance is selected as the final optimized configuration.

Beneficial effects of the invention: The invention proposes a method for rapid optimization of aircraft wing plane parameters, which is a cross-professional method for rapid optimization of wing plane parameters. It takes flight performance indicators as the ultimate optimization target, adopts a hierarchical optimization strategy, simplifies the calculation model, and reasonably selects the calculation method to effectively improve the optimization efficiency and shorten the optimization cycle, thus solving the problems of cross-professional optimization, high optimization resource requirements, and low optimization efficiency in traditional optimization methods. The optimization method provided by the invention can realize the rapid optimization of cross-professional wing configurations with aircraft aerodynamic efficiency, weight, and flight performance indicators as optimization targets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of the method of the present invention.

DETAILED DESCRIPTION

The present invention is further described below in conjunction with the accompanying drawings. A method for rapidly optimizing the plane parameters of an aircraft wing according to the present invention optimizes the plane parameters of the wing of a certain type of transport aircraft, comprising the following steps:

Step 1: Generate wing configuration samples;

Step 1.1 According to the range and step size of the wing plane parameters aspect ratio AR, leading edge sweep angle Λ _LE and tip-to-root ratio η, determine the sample size of the above three parameters, which are m, n, and p respectively, and q is the product of m, n, and p;

Table 1 Wing plane parameters of a certain type of aircraft

Step 1.2: Under the premise of maintaining the wing area, 484 wing configuration samples are generated according to the values of the wing plane parameters;

Step 1.3 combines the wingless aircraft configuration with all wing configurations to generate 484 aircraft configuration samples.

Step 2: Set the wing constraints,

1) The critical cruise Mach number is not less than 0.78.

2) The maximum take-off weight of the aircraft shall not exceed 73.5t.

3) At maximum take-off weight, the range with a commercial load of 19.2 tons shall not be less than 4,900 km.

Step 3: Screening aircraft configuration;

Step 3.1: Calculate the aerodynamic force for 484 aircraft configuration samples;

Step 3.2: Calculate the weight of 484 aircraft configuration samples;

Step 3.3: Calculate the performance of 484 aircraft configuration samples;

Step 3.4: Based on the optimization constraints, determine whether the 484 aircraft configuration samples meet the constraints and complete the configuration screening.

Step 4: Determine the optimization strategy and establish the configuration optimization calculation model;

The optimization strategy is a hierarchical optimization strategy. In the first round of optimization, based on the constraints and optimization goals, a simplified calculation model and engineering estimation method are used to quickly screen out aircraft configuration samples that do not meet the requirements, thereby reducing the sample size of the secondary optimization. The final optimization uses a refined model and an accurate algorithm to perform secondary optimization on the aircraft configuration samples after the first round of screening. The secondary optimization uses a CFD numerical solution that takes viscosity into consideration to ensure a high calculation accuracy.

The optimization calculation model includes:

Weight calculation model:

In the above formula, Ww is the wing structure weight, Wto is the aircraft take-off weight, Sref is the wing reference area, Scz is the aerodynamic control surface area on the wing, _nymax is the maximum normal overload coefficient, _tR is the wing root thickness, and Kxz is the correction factor.

Calculation model for the first cruise segment:

W_mid＝W₁-0.5W_fule

W _mid = W ₁ - 0.5 W _full

In the above formula: L is the cruise range, M is the cruise Mach number, a is the speed of sound at the cruise altitude, K is the cruise lift-to-drag ratio, q _kh is the cruise fuel consumption rate, W ₁ is the aircraft mass at the cruise starting point, W _mid is the aircraft weight at the cruise midpoint, and W _fule is the fuel weight consumed in the cruise.

Final optimization performance calculation model:

Step 5: Select the optimization target parameters, which are: range, flight time, aerodynamic efficiency and take-off weight.

Step 6 optimizes the wing configuration, specifically: through two rounds of optimization, the wing corresponding to the best performance aircraft configuration is selected as the final optimized configuration. After the first round of optimization screening, only 8 configurations satisfy the optimization constraints among the 484 aircraft configuration samples. The two-round optimization model algorithm is used for these configurations. The specific examples of the present invention are as follows:

1) The optimization target parameter is the flight distance;

2) Optimized wing configuration: Wing plane parameters: aspect ratio 9.5, leading edge sweep angle 28 degrees, tip-to-root ratio 0.28.

3) Aircraft optimized performance data: maximum range 4917.9km, take-off weight 73.49t, average cruise lift-to-drag ratio 15.6.

Claims (6)

1. a method for fast optimization of aircraft wing plane parameters, is characterized in that: comprise the following steps: Step 1: generate wing configuration samples; Step 2: Set wing constraints; Step 3: Screen the aircraft configuration; Include the following steps: Step 3.1 Carry out aerodynamic calculation on q aircraft configuration samples; Step 3.2 carries out weight calculation to q aircraft configuration samples; Step 3.3 performs performance calculation on q aircraft configuration samples; Step 3.4 According to the optimization constraints, judge whether the q aircraft configuration samples meet the constraints, and complete the configuration screening; Step 4: Determine the optimization strategy and establish a configuration optimization calculation model; The optimization strategy described is a layered optimization strategy. The first round of optimization is based on constraints and optimization objectives, using simplified calculation models and engineering estimation methods to quickly screen out aircraft configuration samples that do not meet the requirements, and reduce the sample size for the second optimization. , the final optimization uses fine models and precise algorithms to perform secondary optimization on the aircraft configuration samples after the first round of screening, and the secondary optimization uses CFD numerical solutions considering viscosity to ensure high calculation accuracy; The described optimization calculation model includes: Weight Calculation Model:

The above formula Ww is the weight of the wing structure, Wto is the take-off weight of the aircraft, Sref is the reference area of the wing, Scz is the area of the aerodynamic control surface on the wing, _nymax is the maximum normal overload coefficient, t _R is the thickness of the wing root, Kxz is the correction coefficient; Calculation model for the voyage of the first round of cruising segment:

In the above formula: L is the cruise range, M is the Mach number of the cruise, a is the speed of sound at the cruise altitude, K is the lift-to-drag ratio of the cruise, q _kh is the fuel consumption rate of the cruise, W ₁ is the mass of the aircraft at the starting point of the cruise, and W _mid is the cruise. Point aircraft weight, W _fule is the fuel consumption for cruising; The final optimized performance calculation model:

; Step 5: Select the optimization target parameters; Step 6: Optimize the wing configuration. 2. a kind of aircraft wing plane parameter rapid optimization method according to claim 1, is characterized in that: the generation wing configuration sample described in step 1, also comprises the following steps: Step 1.1 determines the sample sizes of the above three parameters according to the range and step size of the wing plane parameter aspect ratio AR, the leading edge sweep angle Λ _LE and the tip-to-root ratio η, which are respectively m, n, p; In step 1.2, under the premise of maintaining the wing area, according to the values of the wing plane parameters, q wing configuration samples are combined to generate; Step 1.3 combines the wingless aircraft configuration with all wing configurations to generate q aircraft configuration samples. 3. a kind of aircraft wing plane parameter rapid optimization method according to claim 2, is characterized in that: the q wing configuration samples described in step 1.2, q is the product of m, n, p. 4. A kind of aircraft wing plane parameter rapid optimization method according to claim 1, is characterized in that: the wing constraint condition that step 2 sets comprises: resistance divergence Mach number, minimum use lift-to-drag ratio, maximum take-off weight and Minimum range. 5. a kind of aircraft wing plane parameter rapid optimization method according to claim 1, is characterized in that: the selection optimization target parameter described in step 5, described optimization target parameter is: range, flight time, aerodynamic efficiency and takeoff weight. 6. A method for quickly optimizing aircraft wing plane parameters according to claim 1, characterized in that: the optimized wing configuration described in step 6 is specifically: through two rounds of optimization, take the best aircraft configuration The corresponding wing is the final optimized configuration.

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