Mechanical improvement in solar aircraft by using tangent hyperbolic single-phase nanofluid

Solar power is the primary thermal energy source from the sunlight. This research has carried out the study of solar aircraft with solar radiation in enhancing efficiency. The thermal transfer inside the solar aircraft wings using a nanofluid past a parabolic surface trough collector (PTSC) is investigated thoroughly. The source of heat is regarded as solar radiation. For several impacts, such as porous medium, thermal radiation, and varying heat conductivity, the heat transmission performance of the wings is examined. By using the tangent hyperbolic nanofluid (THNF), the entropy analysis has been performed. The modeled momentum and energy equations are managed using the well-established numerical methodology known as the finite difference method. Two distinct kinds of nano solid-particles have been examined, such as Copper (Cu) and Zirconium dioxide (ZrO2), while Engine Oil (EO) being regarded as a based fluid. Different diagram parameters will be reviewed and revealed as figures and tables on speed, shear stress, temperature, and the surface drag coefficient and Nüselt number. It is observed that in terms of heat transfer for amplification of thermal radiation and changeable thermal conductance parameters, the performance of the aircraft wings raises. In contrast to traditional fluid, nanofluid is the best source of heat transmission. Cu-EO's thermal efficiency over ZrO2-EG falls to the minimum level of 12.6% and has reached a peak of 15.3%.

Effect of Cut-Out Shape on the Stresses in Aircraft Wing Ribs under Aerodynamic Load

Ribs in aircraft wings maintain the airfoil shape of the wing under aerodynamic loads and also support the resulting bending and shear loads that act on the wing. Aircrafts are designed for least weight and hence the wings are made of hollow torsion box and the ribs are designed with cut-outs to reduce the weight of the aircraft structure. These cut-outs on the ribs will lead to higher stresses and stress concentration that can lead to failure of the aircraft structures. The stresses depend on the shape of the cut-outs in the ribs and thus in the present work, the commercial software ANSYS was used to evaluate the stresses on the ribs with different shapes of cut-outs. Four different shapes of cut-out were considered to study the effect of cut-out shape on the stresses in the ribs. It was found that the best shape for the cut-outs on the ribs of wings to reduce weight is elliptical.

Stress Analysis of Composite Aircraft Wing using Coupled Fluid-Structural Analysis

Aircraft wings are designed with very low factor of safety to keep the aircraft weight minimum. Thus, for safe design of wings, stress analysis should be carried out under accurately estimated aerodynamic loads and this can be achieved only through coupled fluid-structure analysis. Moreover, modern aircraft wings are made of laminated composite structures and thus the purpose of this study is to employ ANSYS coupled fluid-structure analysis to find the best layup of composite wing of an aircraft that results in higher specific strength and specific stiffness. Firstly, Computational Fluid Dynamics (CFD) analysis has been carried out to find the actual aerodynamic load which is the pressure distribution around a three-dimensional wing. Then, this pressure distribution from CFD was used as a load input for detailed static structural analysis of the wing. Initially, strength and stiffness of an isotropic wing is evaluated and then the material of the wing was changed to composite laminates to achieve better structural performance with higher strength and stiffness to weight ratio. Stress analysis was carried out for different layups to predict the optimum layup that results in high strength and stiffness coupled with the least weight and it was found that the wing made of symmetric cross-ply laminate performs the best.

Characteristics of Separation and Induced Drag in the Use of Swept-back Wing Unmanned Aerial Vehicle

The swept-back wing has been used in almost all aircraft wings. This is necessary to reduce the pressure drag from the wings so that there is an increase in aerodynamic performance. The aerodynamic performance is the ratio between the total drag coefficient and the lift coefficient. This research attempts to explain the swept-back wing phenomenon in unmanned aerial vehicles (UAV) on Eppler 562 airfoil. The numerical simulation uses the k-ε turbulent model at Reynolds number (Re) = 2.34 x 104. Variation of backward swept angle Λ = 0°, 15°, and 30°. The separation growth Λ = 0° occurred more on the wing root, while Λ = 15° and Λ = 30° occurred more on the wingtip. At Λ = 15°, as the angle of attack increases, the area of the separation increases, and the area of the transition towards the separation decreases. The reattach area also has an increase in the area of the trailing edge. At Λ = 30°, with an increase in the angle of attack, there is a shift from the wingtip area to the mid-span. The area of separation and transition to separation has increased significantly. The re-attach area at α = 8o has not been seen, so at α = 12o it has been seen significantly. The vorticity on the x-axis shows Λ = 15°, and Λ = 30° has a wider area while on the z-axis, Λ = 15°, and Λ = 30° have stronger vortex strength. However, in the mid-span, Λ = 0° has a stronger result.

ОЦІНКА ЕФЕКТИВНОСТІ ФОРМ КРИЛА ВАЖКИХ ЛІТАКІВ НА ОСНОВІ ЇХ КОЕФІЦІЄНТА ЕЛІПТИЧНОСТІ

The most important step in the choice of the parameters of trapezoidal wings is to ensure the design of the change in the circulation on their scope, as close as possible to the distribution of circulation in the elliptic wing as possible, which leads to the minimum value of its inductive resistance at a given value of the lift.Recently, when solving such a problem, the method of forming the main geometric sizes of the wing was distributed in terms of the equality of the so-called forms of trapezoidal () and equal to the elliptic area () wings.This approach turned out to be quite effective in the formation of geometric parameters of the wings of light and medium aircraft.However, for heavy aircraft with a large area of the wing, the plan of which is formed by three and more trapezes, there were difficulties in determining the coefficients of forms, which required the specified models for determining the coefficients of ellipticity () in assessing the effectiveness of heavy aircraft wings with their multivariate modification changes.The use of a refined model of the ellipticity coefficient is made on the examples of evaluating the effectiveness of trapezoidal wings of such heavy aircraft as IL-86, C-5A, IL-76 and An-124-100. It has been established that the wings of IL-76 and C-5A airplanes are the highest ellipticity. An-124-100 domestic aircraft wing is somewhat inferior to them in the magnitude of the ellipticity coefficient, which should be borne in mind when developing subsequent modifications of this aircraft.

Absolute Nodal Coordinate Formulations for Aeroelastic Analysis of Next-Generation Aircraft Wings

Future aircraft have a high aspect ratio wing (HARW). The low induced drag of the wing can reduce fuel consumption, which enables eco-friendly flight. HARW cannot be designed by using conventional linear aeroelastic analysis methods because it undergoes very flexible motion. Although absolute nodal coordinate formulations (ANCF) have been widely used for analyzing various flexible structures, their application to HAWR is limited because the derivation of the ANCF elastic force for wing cross section is difficult. In this paper, we first describe three ANCF-based beam models that address the difficulty. The three models have different characteristics. Second, an aeroelastic coupling between the beam models and a medium-fidelity aerodynamic model based on unsteady vortex lattice method (UVLM) is briefly explained. Especially, the advantage of ANCF in the aeroelastic coupling is emphasized. Finally, we newly compare the three ANCF-based models in structural and aeroelastic analyses. From the viewpoint of the convergence performance and calculation time, we found the best ANCF-based beam model among the three models in static structural and aeroelastic analyses, while the three models have comparable performances in dynamic structural and aeroelastic analyses. These findings contribute to the development of aeroelastic analysis framework based on ANCF and the design of next-generation aircraft wings.

Wing Flutter Analysis Using Computational Fluid-Structure Interaction Dynamics

Wing flutter plays a significant role in the performance and life of lifting surfaces such as aircraft wings. It is an instability that causes the wing to no longer be capable of damping out random vibration, and it occurs at the point called the critical speed. Currently, the determination of this critical speed poses a large challenge for aircraft designers, as there is no method that can quickly calculate the conditions that will cause the wing flutter instability. This paper presents wing flutter analyses using computational fluid-structure interaction dynamics. The computed results reveal the potential speed and accuracy of the computational method, which will allow designers to rapidly determine whether their vehicle will be capable of operating safely within its design envelope.