scholarly journals Twist Morphing: A Simulation Approach to Compare Twist Morphed Wing and Flap Configuration

2021 ◽  
Vol 9 (10) ◽  
pp. 353-359
Author(s):  
Aditya Joshi
Keyword(s):  
Aerospace Industry ◽  
Alpha Angle ◽  
Angle Of Attack ◽  
Project Implementation ◽  
Simulation Approach ◽  
Aerodynamic Efficiency ◽  
Wing Morphing ◽  
Innovative Concept

Abstract: The aim of the work is to explore and justify an innovative concept in the niche of aerospace industry called as Wing Morphing. To narrow down the study, specifically twist morphing is taken into consideration. Wings with twist and their flap counterparts are compared in similar conditions and their aerodynamic efficiency is observed. The project implementation is done with XFLR5, a VLM solver software. The results show that this concept brings about an improvement in the aerodynamic efficiency without adding much to the drag penalty. Keywords: Wing Morphing, Twist Morphing, Cl (coefficient of lift), Cd (Coefficient of drag), Alpha (angle of attack)

Optimization Calculation of Javelin Throwing Results

2014 ◽  
Vol 716-717 ◽  
pp. 764-766
Author(s):  
Min Jiang ◽  
Ji He Zhou
Keyword(s):  
Mathematical Model ◽  
Wind Tunnel ◽  
Initial Velocity ◽  
Angle Of Attack ◽  
Wind Tunnel Experiment ◽  
Aerodynamic Efficiency ◽  
Optimization Calculation ◽  
Computer Optimization ◽  
Necessary And Sufficient

On the basis of javelin wind tunnel experiment, we established mathematical model of javelin flight to conduct a computer optimization and got the conclusions. When the initial velocity is in the range of 25m/s-30m/s, the best throwing condition is: the throwing angle is 40°, the angle of attack is 11°. The javelin throwing condition is not zero angle of attack was necessary and sufficient for obtained aerodynamic efficiency.

scholarly journals An analysis on Aerodynamics Performance Simulation of NACA 23018 Airfoil Wings on Cant Angles

2017 ◽  
Vol 2 (1) ◽  
pp. 31
Author(s):  
Setyo Hariyadi
Keyword(s):  
Numerical Study ◽  
Angle Of Attack ◽  
Performance Simulation ◽  
Freestream Velocity ◽  
Total Drag ◽  
Aerodynamic Efficiency ◽  
Aircraft Wings ◽  
Induced Drag ◽  
Wing Tip ◽  
Commercial Aircrafts

Winglet attached on the tip of aircraft wings to increase lift. Mainly, winglet used for increasing aerodynamic efficiency, it decreases induced drag caused by vortex on wings tip. The phenomenon of vortex is collision of high-pressured air below the wings meet the low-pressured air above it that cause turbulence. Induced drag may reach 40% of total drag during cruising, and 80-90% while take off. A procedure to decrease induced drag is using wing tip devices. It used on commercial aircrafts and the most frequently used is blended winglet. Numerical study conducted to examine the best aerodynamic performance of sub-sonic plane wings in angles of attack. Analysis on NACA 23018 airfoil wings with blended winglet on the tip was conducted. Freestream velocity of 40 m/s or Re = 1 × 106, and angle of attack (α) 0o, 5o, 10o, and 15o are used. Evaluation for parameter includes coefficient pressure (Cp), velocity profile, lift, drag, and ratio CL/CD. Obtained contour are pressure contour, velocity, and vorticity. In view of all this, there is increasing performance of aerodynamic with CL/CD ratio of wings with blended winglet and plain wing. Reaching current angle of attack, the function of winglet is gradually decrease.

Flow separation control of NACA-2412 airfoil with bio-inspired nose

2019 ◽  
Vol 91 (7) ◽  
pp. 1058-1066 ◽  
Author(s):  
Mohamed Arif Raj Mohamed ◽  
Ugur Guven ◽  
Rajesh Yadav
Keyword(s):  
Flow Control ◽  
Flow Separation ◽  
Control Method ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Separation Control ◽  
Cetacean Species ◽  
Aerodynamic Efficiency ◽  
Content Type ◽  
Flow Separation Control

Purpose The purpose of this paper is to achieve an optimum flow separation control over the airfoil using passive flow control method by introducing bio-inspired nose near the leading edge of the NACA 2412 airfoil. Design/methodology/approach Two distinguished methods have been implemented on the leading edge of the airfoil: forward facing step, which induces multiple accelerations at low angle of attack, and cavity/backward facing step, which creates recirculating region (axial vortices) at high angle of attack. Findings The porpoise airfoil (optimum bio-inspired nose airfoil) delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the parasitic drag. The maximum increase in aerodynamic efficiency is 22.4 per cent, with an average increase of 8.6 per cent at all angles of attack. Research limitations/implications The computational analysis has been done for NACA 2412 airfoil at low subsonic speed. Practical implications This design improves the aerodynamic performance and increases structural strength of the aircraft wing compared to other conventional high-lift devices and flow-control devices. Originality/value Different bio-inspired nose designs which are inspired by the cetacean species have been analysed for NACA 2412 airfoil, and optimum nose design (porpoise airfoil) has been found.

scholarly journals Numerical Investigation on Aerodynamic Performance of Bird’s Airfoils

2020 ◽  
Author(s):  
Ashraf Omar ◽  
Rania Rahuma ◽  
Abdulhaq Emhemmed
Keyword(s):  
Reynolds Number ◽  
Low Reynolds Number ◽  
Angle Of Attack ◽  
Aerodynamic Performance ◽  
Airfoil Surface ◽  
Aerodynamic Efficiency ◽  
Gliding Flight ◽  
Surface Permeability ◽  
Low Reynolds ◽  
Better Than

In this work, the aerodynamic performance of four types of bird’s airfoils (eagle, stork, hawk, and albatross) at low Reynolds number and a range of angles of attack during fixed (unflapping) gliding flight was numerically investigated utilizing open-source computational fluid dynamics (CFD) code Stanford University unstructured (SU2) and K-ω Shear Stress Transport (K-ω SST) turbulence model. The flow of the simulated cases was assumed to be incompressible, viscous, and steady. For verification and comparison, a low Reynolds number man-made Eppler 193’s airfoil was simulated. The results revealed that stork has the greatest aerodynamic efficiency followed by albatross and eagle. However, at zero angle of attack, the albatross aerodynamic efficiency exceeded all the other birds by a significant amount. In terms of aerodynamics efficiency, stork’s and albatross’s airfoils performed better than Eppler 193 at angles of attack less than 8°, while at a higher angle of attack all studied birds’ airfoils performed better than Eppler 193. The effect of surface permeability was also investigated for the eagle’s airfoil where the permeable surface occupied one-third of the total airfoil surface. Permeability increased the generated lift and the aerodynamic efficiency of the eagle’s airfoil for angles of attack less than 10°. The increase reached 58% for the lift at zero angle of attack. After the specified angle, the permeability had an adverse effect on the flow which may be due to the transition to turbulent ahead of the permeable section.

A Aerodynamic Performance Research on a Wing Added Winglet

2012 ◽  
Vol 505 ◽  
pp. 489-493
Author(s):  
Zhi Ni Ren ◽  
Shi Xing Zhu
Keyword(s):  
Drag Reduction ◽  
Fuel Consumption ◽  
Angle Of Attack ◽  
Reduction Rate ◽  
Aerodynamic Performance ◽  
Good Choice ◽  
Aerodynamic Efficiency ◽  
Lift And Drag ◽  
Performance Research ◽  
Operation Cost

In order to reveal the science of adding winglet for Active aircraft, the paper calculates the aerodynamic efficiency of a wing added winglet using CFD technology, Aerodynamic benefit of the wing added winglet reaches the maximum when the angle of attack is 2 degree, the lift and drag reduction rate are 21.07% and 43.56% respectively. The results show that it is a good choice to add winglet for aircraft to reduce operation cost and fuel consumption.

scholarly journals Aerodynamic Shape Optimization of a Wavy Airfoil for Ultra-Low Reynolds Number Regime in Gliding Flight

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 467
Author(s):  
Hui Tang ◽  
Yulong Lei ◽  
Xingzhong Li ◽  
Ke Gao ◽  
Yanli Li
Keyword(s):  
Reynolds Number ◽  
Shape Optimization ◽  
Stress Component ◽  
Angle Of Attack ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Efficiency ◽  
Aerodynamic Shape ◽  
Pressure Stress ◽  
Continuous Adjoint ◽  
Initial Geometry

The effect of the number of waves and the width of the ridge and valley in chord direction for a wavy airfoil was investigated at the angle of attack of 0 ∘ and Reynolds number of 10 3 through using the two-dimensional direct numerical simulation for four kinds of wavy airfoil shapes. A new method for parameterizing a wavy airfoil was proposed. In comparison with the original corrugated airfoil profile, the wavy airfoils that have more distinct waves show a lower aerodynamic efficiency and the wavy airfoils that have less distinct waves show higher aerodynamic performance. For the breakdown of the lift and drag concerning the pressure stress and friction stress contributions, the pressure stress component is significantly dominant for all wavy airfoil shapes concerning the lift. Concerning the drag, the pressure stress component is about 75 % for the wavy airfoils that have more distinct waves, while the frictional stress component is about 70 % for the wavy airfoils that have less distinct waves. From the distribution of pressure isoline and streamlines around wavy airfoils, it is confirmed that the pressure contributions of the drag are dominant due to high pressure on the upstream side and low pressure on the downside; the frictional contribution of the drag is dominant due to large surface areas of the airfoil facing the external flow. The effect of the angle of attack on the aerodynamic efficiency for various wavy airfoil geometries was studied as well. Aerodynamic shape optimization based on the continuous adjoint approach was applied to obtain as much as possible the highest global aerodynamic efficiency wavy airfoil shape. The optimal airfoil shape corresponds to an increase of 60 % and 62 % over the aerodynamic efficiency and the lift from the initial geometry, respectively, when optimal airfoil has an approximate drag coefficient compared to the initial geometry. Concerning an fixed angle of attack, the optimal airfoil is statically unstable in the range of the angle of attack from − 1 ∘ to 6 ∘ , statically quasi-stable from − 6 ∘ to − 2 ∘ , where the vortex is shedding at the optimal airfoil leading edge. Concerning an angle of attack passively varied due to the fluid force, the optimal airfoil keeps the initial angle of attack value with an initial disturbance, then quickly increases the angle of attack and diverges in the positive direction.

scholarly journals Investigation on airfoil operating in Ground Effect region

2014 ◽  
Vol 3 (4) ◽  
pp. 540 ◽  
Author(s):  
Nikhil Pillai ◽  
Anil T. ◽  
Aravind Radhakrishnan ◽  
Rahul Vinod ◽  
Sudheesh Kumar E. ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Advisory Committee ◽  
Special Class ◽  
Free Stream ◽  
Angle Of Attack ◽  
Ground Effect ◽  
Water Bodies ◽  
Cfd Analysis ◽  
Aerodynamic Efficiency ◽  
Wing In Ground Effect

The idea of using a wing in ground effect vehicle has been suggested with the objective of developing a very economical and efficient means of rapid transportation across water bodies. This paper investigates into wing in ground effect airfoil geometry. ANSYS is used to perform the CFD analysis of the airfoils. CFD analysis has been performed on various airfoils operating in the ground effect region and a special class of airfoil called DHMTU has been found to have maximum aerodynamic efficiency. The DHMTU studied here is DHMTU 8-40-2-10-3-6-2-15. Aerodynamic efficiency for this particular airfoil has been determined through CFD analysis at various angles of attack. It has been found that the DHMTU possesses superior aerodynamic efficiency at low angle of attack and the maximum aerodynamic efficiency is found at 60 angle of attack. From CFD analysis it has also been determined that as the proximity to the ground reduces, the value of lift increases. The characteristics of this airfoil at various air speeds have also been determined through CFD analysis. These studies have illustrated the unique characteristics of the DHMTU airfoils and indicated areas for further optimization of the design of ground effect airfoils. The use of this airfoil for the ground effect vehicle can further lead to increase in efficiency of the craft.Abbreviations:CFD                        Computational Fluid DynamicsDHMTU                Department Of Hydro-Mechanics of the Marine Technical UniversityNACA                    National Advisory Committee on AeronauticsL/D                         Lift to Drag RatioWIG                       Wing in GroundV                             Free stream velocityRe                           Reynolds number h/c                          Height to Chord RatioCL                          Coefficient of liftCD                          Coefficient of dragAOA                       Angle Of Attack

EFFECTS OF HELICOPTER HORIZONTAL TAIL CONFIGURATIONS ON AERODYNAMIC DRAG CHARACTERISTICS

2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Iskandar Shah Ishak ◽  
Muhammad Fitri Mougamadou Zabaroulla
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Aerodynamic Drag ◽  
Angle Of Attack ◽  
Aerodynamic Efficiency ◽  
Wind Tunnel Tests ◽  
Tunnel Model ◽  
The Subject ◽  
And Performance ◽  
Selection Of

Experimental aerodynamic investigations remain the subject of interest in rotorcraft community since the flow around the helicopter is dominated by complex aerodynamics and flow interaction phenomena. The objective of this study is to determine the aerodynamic drag characteristics of helicopter horizontal tail by conducting wind tunnel tests. To fulfil the objective, three of the most common helicopter horizontal tail configurations namely Forward Stabilizer, Low-aft Stabilizer and T-tail Stabilizer, were fabricated as a simplified scaled-down wind tunnel model mated with a standard ellipsoidal fuselage. The test wind speed for this experimental work was 30 m/s, determined from Reynolds sweep, which was corresponding to Reynolds number of 2.8 x 105. Wind tunnel tests were performed at variations angle of attack ranging from -15O to 15O with 5O interval. The results tell that at zero yaw and zero pitch angles, Forward Stabilizer contributed the least drag coefficient at 0.277 implying the configuration could be the best for cruising flight segment. Contrarily to T-tail Stabilizer, this configuration contributed the most drag coefficient at 0.303, which was 9% higher than the former. The T-tail Stabilizer was also found to be the most sensitive to the change of angle of attack where the drag was drastically increased up to 131.35% at -15O angle of attack compares to at zero angle of attack. These findings had successfully testified that the type of stabilizer configuration does significantly influencing the aerodynamic drag characteristics of helicopter. Subsequently, the selection of stabilizer must wisely be done to have the best aerodynamic efficiency and performance for the helicopter. 

Fluid–structure coupling mechanism and its aerodynamic effect on membrane aerofoils

2018 ◽  
Vol 848 ◽  
pp. 1127-1156 ◽  
Author(s):  
Sonia Serrano-Galiano ◽  
Neil D. Sandham ◽  
Richard D. Sandberg
Keyword(s):  
Angle Of Attack ◽  
Three Dimensional ◽  
Coupled System ◽  
Elastic Membrane ◽  
Coupling Mechanism ◽  
Immersion Method ◽  
Aerodynamic Efficiency ◽  
Fluid Structure ◽  
Wave Nature ◽  
Membrane Vibrations

Fluid–structure interactions of elastic membrane aerofoils are investigated at Reynolds number $Re=10\,000$ and low angle of attack. The dynamics of the fluid and membrane coupled system are solved using direct numerical simulation (DNS), where the geometry and boundary conditions were applied using a boundary data immersion method. Although membrane aerofoils improve the aerodynamic performance close to stall conditions compared to rigid aerofoils, it has previously been found that membrane aerofoils show lower aerodynamic efficiency at low angles of attack. This study focuses on the coupling mechanism at an angle of attack of 8 degrees, which is below the stall angle. The dynamic behaviour of the coupled system was characterised via spectral analysis in the wavenumber and frequency domain, which allowed the propagating wave nature of the membrane vibrations and their effect on the surrounding pressure field to be clarified. The membrane vibrations are found to introduce upstream-propagating pressure waves that appear to be responsible for a loss in aerodynamic efficiency compared to a rigid aerofoil. Comparison of two- and three-dimensional results reveals that the three-dimensional flow development causes a decrease in the amplitude of the system fluctuations, but the same coupling mechanism is present.

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