Method for quickly optimizing plane parameters of airplane wings
Technical Field
The invention belongs to the technical field of aviation, and particularly relates to a method for quickly optimizing plane parameters of an airplane wing.
Background
The traditional wing plane parameter optimization is performed professionally, the configuration aerodynamic performance obtained by the aerodynamic professional optimization is optimal, the configuration weight obtained by the weight professional optimization is optimal, but the optimization of the flight performance index of the airplane cannot be guaranteed. The modern calculation of aerodynamic force and weight needs to establish a digital model, the complex numerical calculation needs strong calculation resource guarantee, and the calculation period is long. In the face of a large number of wing configuration sample sizes, the traditional optimization method is not free from the attention.
Disclosure of Invention
The purpose of the invention is as follows: the method for quickly optimizing plane parameters of the airplane wings adopts a layered optimization strategy, simplifies a calculation model, reasonably selects the calculation method, and can realize the quick optimization of cross-professional wing configuration by taking aerodynamic force, weight and flight performance indexes of the airplane as optimization targets. .
The technical scheme of the invention is as follows:
a method for quickly optimizing plane parameters of an airplane wing comprises the following steps:
step 1: generating an airfoil configuration sample;
step 2: setting wing constraint conditions;
and step 3: screening airplane configurations;
and 4, step 4: determining an optimization strategy and establishing a configuration optimization calculation model;
and 5: selecting an optimization target parameter;
step 6: optimizing the wing configuration.
The method for generating the airfoil configuration sample in the step 1 further comprises the following steps:
step 1.1 according to the wing plane parameter aspect ratio AR and the leading edge sweep angle LambdaLEDetermining sample quantities of the three parameters, namely m, n and p, according to the value range and the step length of the root-tip ratio η;
step 1.2, on the premise of keeping the area of the wing, combining and generating q wing configuration samples according to the values of the plane parameters of the wing;
and 1.3, combining the aircraft configuration without the wing with all the wing configurations to generate q aircraft configuration samples.
Q airfoil configuration samples described in step 1.2, q being the product of m, n, and p.
The optimization constraint conditions in the step 2 comprise: drag divergence mach number, minimum used lift-drag ratio, maximum takeoff weight, and minimum range.
The screening of the wing configurations of step 3 further comprises the steps of:
step 3.1, performing aerodynamic calculation on q airplane configuration samples;
step 3.2, carrying out weight calculation on the q airplane configuration samples;
step 3.3, performing performance calculation on q airplane configuration samples;
and 3.4, judging whether the q airplane configuration samples meet the constraint according to the optimized constraint conditions, and finishing configuration screening.
Determining an optimization strategy and establishing a configuration optimization calculation model in the step 4,
the optimization strategy is a hierarchical optimization strategy, the first-round optimization is carried out according to constraint conditions and an optimization target by adopting a simplified calculation model and an engineering estimation method, airplane configuration samples which do not meet requirements are quickly screened out, the sample amount of secondary optimization is reduced, finally, the fine model and an accurate algorithm are adopted for carrying out secondary optimization on the airplane configuration samples screened by the first-round optimization, the secondary optimization is solved by adopting a CFD value considering viscosity, and higher calculation precision is ensured;
the optimization calculation model comprises:
weight calculation model:
WW=KXZ0.025(Wto·nymax)0.56Sref 0.65AR0.5tR -0.4(1+η)0.1SCZ 0.1/cos(ΛLE)
the upper formula Ww is the wing structure weight, Wto is the takeoff weight of the airplane, Sref is the wing reference area, Scz is the aerodynamic control surface area on the wing, nymaxIs the maximum normal overload coefficient, tRFor the wing root thickness, Kxz is the correction factor.
The first-wheel cruise segment voyage calculation model comprises the following steps:
in the above formula: l is cruise range, M is cruise Mach number, a is cruise altitude speed of sound, K is cruise lift-drag ratio, qkhFor cruising fuel consumption rate, W1Aircraft mass, W, as cruise originmidFor cruising mid-point aircraft weight, WfuleThe fuel weight consumed for cruising.
And finally optimizing a performance calculation model:
selecting an optimization target parameter in step 5, wherein the optimization target parameter is as follows: voyage, time of flight, aerodynamic efficiency and takeoff weight.
The optimized wing configuration in the step 6 specifically comprises the following steps: and (4) taking the wing corresponding to the airplane configuration with the best performance as the final optimized configuration through two-wheel optimization.
The invention has the beneficial effects that: the invention provides a method for quickly optimizing plane parameters of an airplane wing, which is a method for quickly optimizing plane parameters of cross-professional wings. The optimization method provided by the invention can realize the rapid optimization of the configuration of the cross-professional wing by taking the aerodynamic efficiency, weight and flight performance indexes of the airplane as optimization targets.
Drawings
FIG. 1 is a flow chart of the method of the present invention.
Detailed Description
The invention is further described with reference to the accompanying drawings, and the method for rapidly optimizing plane parameters of an airplane wing, which is disclosed by the invention, optimizes plane parameters of a certain type of transport airplane wing, and comprises the following steps:
step 1: generating an airfoil configuration sample;
step 1.1 according to the wing plane parameter aspect ratio AR and the leading edge sweep angle LambdaLEDetermining sample quantities of the three parameters according to the value range and the step length of the root-tip ratio η, wherein the sample quantities are m, n and p respectively, and q is the product of m, n and p;
TABLE 1 plane parameters of certain type of airplane wing
Step 1.2, on the premise of keeping the area of the wing, generating 484 wing configuration samples in a combined mode according to values of wing plane parameters;
step 1.3, combining the wing-free aircraft configuration with all the wing configurations to generate 484 aircraft configuration samples.
Step 2: the constraint conditions of the wings are set up,
1) the cruise critical mach number is not less than 0.78.
2) The maximum takeoff weight of the airplane is not more than 73.5 t.
3) Under the maximum takeoff weight, the range of the commercial 19.2t is not less than 4900 km.
And step 3: screening airplane configurations;
step 3.1, performing aerodynamic calculation on 484 airplane configuration samples;
step 3.2, carrying out weight calculation on 484 airplane configuration samples;
step 3.3, carrying out performance calculation on 484 airplane configuration samples;
and 3.4, judging whether the 484 airplane configuration samples meet the constraint according to the optimized constraint conditions, and finishing configuration screening.
And 4, step 4: determining an optimization strategy and establishing a configuration optimization calculation model;
the optimization strategy is a hierarchical optimization strategy, the first-round optimization is carried out according to constraint conditions and an optimization target by adopting a simplified calculation model and an engineering estimation method, airplane configuration samples which do not meet requirements are quickly screened out, the sample amount of secondary optimization is reduced, finally, the fine model and an accurate algorithm are adopted for carrying out secondary optimization on the airplane configuration samples screened by the first-round optimization, the secondary optimization is solved by adopting a CFD value considering viscosity, and higher calculation precision is ensured;
the optimization calculation model comprises:
weight calculation model:
the upper formula Ww is the wing structure weight, Wto is the takeoff weight of the airplane, Sref is the wing reference area, Scz is the aerodynamic control surface area on the wing, nymaxIs the maximum normal overload coefficient, tRFor the wing root thickness, Kxz is the correction factor.
The first-wheel cruise segment voyage calculation model comprises the following steps:
in the above formula: l is cruise range, M is cruise Mach number, a is cruise altitude speed of sound, K is cruise lift-drag ratio, qkhFor cruising fuel consumption rate, W1Aircraft mass, W, as cruise originmidFor cruising mid-point aircraft weight, WfuleThe fuel weight consumed for cruising.
And finally optimizing a performance calculation model:
step 5, selecting an optimization target parameter, wherein the optimization target parameter is as follows: voyage, time of flight, aerodynamic efficiency and takeoff weight.
Step 6, optimizing the wing configuration, specifically: through two-round optimization, the wing corresponding to the airplane configuration with the best performance is taken as the final optimized configuration, through the first round of optimization screening, only 8 configurations which meet the optimization constraint condition are left in 484 airplane configuration samples, and a two-round optimization model algorithm is adopted for the configurations, and the specific examples of the invention are as follows:
1) optimizing the target parameter into a voyage;
2) optimizing the configuration of the rear wing: wing plane parameters: the aspect ratio is 9.5, the sweep angle at the leading edge is 28 degrees, and the tip-root ratio is 0.28.
3) Aircraft optimization performance data: the maximum voyage is 4917.9km, the takeoff weight is 73.49t, and the cruise average use lift-drag ratio is 15.6.