In this study, the optimization of a low-speed wing with functional constraints is discussed. The aerodynamic analysis tool developed by the coupling of the numerical nonlinear lifting-line method to Xfoil is used to obtain lift and drag coefficients of the baseline wing. The outcomes are compared with the results of the solver based on the nonlinear lifting-line theory implemented into XLFR5 and the transition shear stress transport model implemented into ANSYS-Fluent. The agreement between the results at the low and moderate angle of attack values is observed. The sequential quadratic programming algorithm of the MATLAB optimization toolbox is used for the solution of the constrained optimization problems. Three different optimization problems are solved. In the first problem, the maximization of C 3/2 L /C D is the objective function, while level flight condition at maximum C 3/2 L /C D is defined as a constraint. The functional constraints related to the wing weight, the wing planform area, and the root bending moment are added to the first optimization problem, and the second optimization problem is constructed. The third optimization problem is obtained by adding the level flight condition and the available power constraints at the maximum speed and the level flight condition at the minimum speed of the baseline unmanned air vehicle to the second problem. It is demonstrated that defining the root bending moment, the wing area, and the available power constraints in the aerodynamic optimization problems leads to more realistic wing planform and airfoil shapes.
In this numerical study, the effects of the initial y plus, which is a dimensionless wall distance, on the results of aerodynamic coefficients of designed a wing using NACA 4412 airfoil are investigated. For this purpose, the wing is designed and external flow analysis is carried out according to constant altitude. ANSYS Fluent, which is a Computational Fluid Dynamics (i.e. CFD) program and solves the problems according to the Finite Volume Method (i.e. FVM), is used for external flow analysis. Pressure-based method is used for numerical studies. Thus, the differences of coefficients on the wall, which are the results of the change in the initial y plus, are calculated ideally. Because of one of the best methods to solve the problems on transition zone, γ-Reθ SST turbulence model is used for this study. Using this model for each analysis, first element heights (i.e. the distance to the nearest wall) are calculated according to 9 different y plus (i.e. 1, 5, 10, 30, 45, 60, 75, 90, 105). According to the first element heights, the inflation layers are created on the wing and the 3D control volumes are formed along the boundary region. To be more comprehensible, orthogonal quality-skewness values, expressing the quality of control volumes, are presented for each boundary. The changes in lift coefficients and drag coefficients on the same wing according to these 9 different y plus are presented numerically. In addition, obtained results are evaluated and as described in the literature, it is observed that to calculate the aerodynamic forces with the γ-Reθ SST turbulence model is directly proportional to the initial y plus. As a consequence, this paper demonstrates that there are obvious differences detection of separation and determination of reattach region of flow occurring on the wing according to the initial y plus.
This paper presents the basic results of the morphing wing planform optimization of an experimental unmanned air vehicle for minimum drag at steady level flight. The aerodynamic design tool that consists of the three-dimensional panel method, two-dimensional boundary layer solution and generalized reduced gradient method-based optimization is appropriate for fixed wing and morphing wing conceptual and preliminary design. The morphing concept is implemented into the solution with the geometric constraints of the wing planform and the airfoil shape design variables. The drag that is created by other components of the aircraft is calculated according to empirical formulas. Wing drag and aircraft drag comparisons between baseline wing (BASE), optimum fixed wing and morphing wing are discussed with the obtained planform and airfoil shapes.
Bu çalışmada, NACA 0012 simetrik kanat profiline sahip, ticari amaçlı bir yolcu uçağının yatay dengeleyicisi ve bu yatay dengeleyicinin ucuna yerleştirilen iki farklı kıvrık kanat ucu yapısının üzerinde farklı hücum açılarında oluşan aerodinamik kuvvetler incelenmiştir. Yatay dengeleyici, SolidWorks tasarım programında 200 noktadan oluşan kanat profili eğrisi ve belirlenen V açısı, ok açısı ve sivrilme oranları kullanılarak tasarlanmıştır. Bu tasarım C 1 olarak tanımlanmıştır. C 1 tasarımının uç kısmına, aynı ok açısına, bükme açısına, sivrilme oranına, açıklığa, yüksekliğe sahip; fakat uç kısmındaki kanat profili kalınlığı farklı olan iki kıvrık kanat ucu yapısı tasarlanarak toplamda üç kanat tasarımı elde edilmiştir. Bu tasarımlar sırası ile C 2 ve C 3 olarak adlandırılmıştır. Üç farklı tasarımın aerodinamik analizi, bir hesaplamalı akışkanlar dinamiği programı olan Fluent kullanılarak yapılmıştır. On üç farklı hücum açısında gerçekleştirilen analizler sonucunda elde edilen sonuçlara göre tasarımların üzerindeki sürükleme (C D) ve taşıma (C L) katsayılarındaki değişimler gözlemlenmiştir. Elde edilen sonuçlara göre, C 2 tasarımı için analizlerin yapıldığı bütün hücum açılarında daha yüksek taşıma kuvvetinin sürükleme kuvvetine oranına (C L /C D) sahip olduğu görülmüştür. C 3 tasarımı için ise-1 derece hücum açısındaki sonuç haricinde aynı sonuç elde edilmiştir.
Purpose This paper aims to minimize aircraft fuel consumption during the cruise phase when the flight is subjected to a specific time of arrival for different weights and distances. Design/methodology/approach The approach adopted herein uses sequential quadratic programming algorithm from MATLAB optimization toolbox, which includes a mathematical model of a jet airliner based on the Base of Aircraft Data as a function evaluator, to find out the impact of meet-time of arrival constraints on fuel consumption. The cruising speeds at predefined segments and the altitude are defined as the design variables. Findings The algorithm determines the optimum cruise altitudes and speeds for minimum fuel consumption in the case of no time constraints, also, for different time constraints where the flight time shall be reduced by increasing speed and lowering the altitude in most of the investigated cases. Practical implications The algorithm computes the optimum speed and the altitude according to different flight scenarios with the meet-time of arrival constraints for minimum fuel consumption which affects the direct operating cost of the flight. The algorithm might greatly help in decision-making for the meet-time of arrival operations. Originality/value Developing an algorithm to optimize the speed and the altitude of an aircraft based on weight and range for minimization of fuel consumption. It is a pioneer study in the literature that deals with the effect of meet-time constraints on fuel consumption.
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