Research on the Aerodynamic Characteristics of Ellipse Wing Sail

2011 ◽  
Vol 347-353 ◽  
pp. 2249-2254
Author(s):  
Yi Huai Hu ◽  
Xiang Ming Zeng ◽  
Song Yue Li
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Aerodynamic Characteristic ◽  
Lift Coefficient ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
The Novel ◽  
Better Than

A kind of novel airfoil sail is proposed in this paper based on the research of traditional arc wing sails. The aerodynamic characteristic- the lift coefficient and drag coefficient is numerically calculated with FLUENT 6.0 and the results are verified by wind tunnel test. It is proved that the aerodynamic characteristic of the novel sail is much better than the arc wing sail.

The Effect of Canard to the Aerodynamic Behavior of Blended Wing Body Aircraft

2012 ◽  
Vol 225 ◽  
pp. 38-42
Author(s):  
Zurriati Mohd Ali ◽  
Wahyu Kuntjoro ◽  
Wisnoe Wirachman
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Aerodynamic Characteristic ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Moment Coefficient ◽  
Subsonic Wind Tunnel ◽  
Setting Angle ◽  
Blended Wing Body ◽  
The Moment

This paper presents a study on the effect of canard setting angle on the aerodynamic characteristic of a Blended Wing Body (BWB). Canard effects to BWB aerodynamic characteristics are not widely investigated. Hence the focus of the study is to investigate the variations of lifts, drags and moments when the angles of attack are varied at different canard setting angles. Wind tunnel tests were performed on BWB aircraft with canard setting angles,  ranging from -20˚ to 20˚. Angles of attack,  were varied from -10˚ to 10˚. Aspect ratio and canard planform area were kept fixed. All tests were conducted in the subsonic wind tunnel at Universiti Teknologi MARA, at Mach number of 0.1. The streamlines flow, at the upper surface of the canard was visualized using mini tuft. Result shows that the lift coefficient does not change much with different canard setting angles. As expected, the lift coefficient increases with increasing angles of attack at any canard setting angle. In general, the moment coefficient increases as the canard setting angle is increased. The results obtained in this research will be of importance to the understanding of aerodynamic behavior of BWB employing canard in its configuration.

Study on the Aerodynamic Characteristics and Galloping Instability of Conductors Covered with Sector-Shaped Ice by a Wind Tunnel Test

2020 ◽  
Vol 20 (06) ◽  
pp. 2040016
Author(s):  
Jia-Xiang Li ◽  
Jian Sun ◽  
Ye Ma ◽  
Shu-Hong Wang ◽  
Xing Fu
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Ice Thickness ◽  
Shape Parameters ◽  
Aerodynamic Coefficient ◽  
Wind Tunnel Tests ◽  
And Control

Conductors with sector-shaped ice are susceptible to galloping. To prevent and control galloping, it is necessary to study the conductor aerodynamic characteristics. Wind tunnel tests were performed to study the influence of two shape parameters (ice thickness and ice angle) of a conductor with sector-shaped ice on the aerodynamic characteristics considering the roughness of the surface. In addition, the unstable areas for galloping are discussed according to Den Hartog theory and Nigol theory. The results show that with increasing ice thickness, the aerodynamic coefficient curves fluctuate more strongly, and galloping tends to occur; with increasing ice angle, the unstable area becomes larger according to Nigol theory, and the increasing drag coefficient will suppress the unstable areas according to Den Hartog theory. With the increasing two shape parameters, the most affected ranges of the aerodynamic coefficient curves are 150–180∘.

Shape optimization and experimental research of near space airship

2018 ◽  
Vol 233 (10) ◽  
pp. 3589-3602
Author(s):  
Dongli Ma ◽  
Guanxiong Li ◽  
Muqing Yang ◽  
Shaoqi Wang ◽  
Liang Zhang
Keyword(s):  
Wind Tunnel ◽  
Shape Optimization ◽  
Drag Coefficient ◽  
Force Measurement ◽  
Wind Tunnel Test ◽  
Volume Ratio ◽  
Aerodynamic Characteristics ◽  
Near Space ◽  
Transition Position ◽  
Favorable Pressure Gradient

Shape optimization has important effects on drag reduction of the near-space airship. This paper uses the Bezier curve to parameterize the hull of the airship. Based on multiple island genetic algorithms, the optimization platform combined with different programs is established, and a kind of low drag hull is obtained by optimization. Force measurement and flow observation wind tunnel test are used to research the aerodynamic characteristics of the ellipsoid hull and the optimized hull. Results show that, optimization mainly increases the volume ratio and the favorable pressure gradient region of the hull, therefore the surface area is reduced and transition position of the hull can be delayed. Compared with the LOTTE shape, transition position of the optimized shape moved backward by 13.78%, and the volume drag coefficient is reduced by 11.1%. It is known from the wind tunnel test that compared with the ellipsoid hull, transition position of the optimized shape moves backward obviously. Under the condition that the volume Reynolds number is 2.97 × 106, compared with the ellipsoid hull, volume drag coefficient of the optimized shape can reduce by 39.0%.

Wind Tunnel Test of Effect of Sound-Absorbing Material on Lift of Two-Element Airfoil

2013 ◽  
Vol 830 ◽  
pp. 17-23
Author(s):  
Yong Wei Gao ◽  
Qi Liang Zhu ◽  
Long Wang
Keyword(s):  
Wind Tunnel ◽  
High Frequency ◽  
Lift Coefficient ◽  
Wind Tunnel Test ◽  
Low Frequency ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Fluctuating Pressure ◽  
Flow Parameters ◽  
Absorbing Material

The flow parameters of fluctuating pressure and fluctuating velocity in the gap can be changed by the porous absorption material on the leading edge of upper surface of the flap of multi-element airfoil (GAW-1),and the aerodynamic characteristics is also altered. Experiment was conducted in the NF-3 wind tunnel. It turns out that porous absorption material has a significant effect on fluctuating velocity (i.e. turbulent kinetic energy), and the lift coefficient drops when fluctuating velocity increases ; but the influence on RMS of fluctuating pressure on upper surface is not obvious; the average speed in gap is reduced. The PSD of fluctuating pressure and fluctuating velocity show that low-frequency signal has a more obvious influence on lift of multi-element airfoils than high-frequency.

Effect of Icing Airfoil on Aerodynamic Performance of Horizontal Axis Wind Turbine

2021 ◽  
pp. 1-9
Author(s):  
Pham Huu Hoang ◽  
Takao Maeda ◽  
Yasunari Kamada ◽  
Tetsu Tada ◽  
Hanamura Maito ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Performance Test ◽  
Lift Coefficient ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Horizontal Axis Wind Turbine ◽  
Turbine Performance ◽  
Maximum Value

Abstract In this paper, the aerodynamic characteristics is clarified by the airfoil performance test of the model of icing airfoil in wind tunnel. As a results of wind tunnel test, the lift coefficient of model of icing airfoil becomes lower and the drag coefficient becomes higher than those of clean airfoil. With the use of these results, numerical analysis using aeroelastic code was carried out to clarify the influence of icing airfoil on wind turbine performance. As result of the analysis, the rated power with icing airfoil is obtained at higher wind speed than clean one, and the maximum value of output power is decreased by icing airfoil. Compared to clean airfoil, the amplitude of edgewise moment at blade root is increased, which is mainly caused by the effects of mass of icing on the blade.

scholarly journals EXPERIMENTAL ANALYSIS OF BLENDED WING BODY MODEL MICRO AIR VEHICLE USING WIND TUNNEL

2019 ◽  
pp. 126-135
Author(s):  
Md. Akhtar khan ◽  
Chinmaya padhy ◽  
Ch. Sanjay
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Experimental Analysis ◽  
Environmental Concern ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Cnc Machine ◽  
Blended Wing Body ◽  
And Performance

An experimental aerodynamic analysis is performed to obtain aerodynamic characteristics and performance of a blended wing-body aircraft (BWB) using Low Speed Wind Tunnel. The BWB design concept is a revolutionary way of understanding the hike of fuel cost, increase in air travelers and environmental concern. Recognizing the potential of the aircraft an experimental analysis is conducted on BWB to understand aerodynamic performance parameters like lift coefficient (CL), drag coefficient (CD) and the Lift-to-Drag (L/D) ratio .The aluminium BWB model is manufactured using CNC machine and is tested in Wind tunnel at different angle of attack varying from 0° to 16° at speed of 12 m/s ,25 m/s and 35 m/s velocity. The present BWB UAV design has achieved an unprecedented capability in terms of sustainability of flight at high angle of attack, low parasite drag coefficient and decent maximum lift coefficient. This study indicates some significant benefits for the BWB relative to the conventional aircraft configuration. KEYWORDS: Blended Wing Body (BWB), Aerodynamics, Unmanned Aerial Vehicle (UAV), Wind Tunnel

Experimental investigations of flow over NACA airfoils 0021 and 4412 of wind turbine blades with and without Tubercles

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Critical Region ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Wind Turbine Blades

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.

scholarly journals Features of flow around transport aircraft model with running propellers by modelled engine failure in wind tunnel

2021 ◽  
Vol 2103 (1) ◽  
pp. 012206
Author(s):  
V I Chernousov ◽  
A A Krutov ◽  
E A Pigusov
Keyword(s):  
Wind Tunnel ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Light Transport ◽  
Transport Aircraft ◽  
Engine Failure ◽  
The One ◽  
Low Speed Wind Tunnel ◽  
Control Surfaces ◽  
Landing Mode

Abstract This paper presents the experiment results of modelling the one engine failure at the landing mode on a model of a light transport airplane in the T-102 TsAGI low speed wind tunnel. The effect of starboard and port engines failure on the aerodynamic characteristics and stability of the model is researched. The model maximum lift coefficient is reduced about ≈8% and there are the same moments in roll and yaw for starboard and port engines failure case. It was found that the failure of any engine has little impact on the efficiency of control surfaces. Approaches of compensation of forces and moments arising in the engine failure case were investigated.

Aerodynamics of Gliding Flight in a Falcon and Other Birds

1970 ◽  
Vol 52 (2) ◽  
pp. 345-367 ◽  
Author(s):  
VANCE A. TUCKER ◽  
G. CHRISTIAN PARROTT
Keyword(s):  
Wind Tunnel ◽  
High Performance ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Wing Span ◽  
Technical Errors ◽  
Gliding Flight ◽  
Air Speed ◽  
D Values ◽  
D Value

1. A live laggar falcon (Falco jugger) glided in a wind tunnel at speeds between 6.6 and 15.9 m./sec. The bird had a maximum lift to drag ratio (L/D) of 10 at a speed of 12.5 m./sec. As the falcon increased its air speed at a given glide angle, it reduced its wing span, wing area and lift coefficient. 2. A model aircraft with about the same wingspan as the falcon had a maximum L/D value of 10. 3. Published measurements of the aerodynamic characteristics of gliding birds are summarized by presenting them in a diagram showing air speed, sinking speed and L/D values. Data for a high-performance sailplane are included. The soaring birds had maximum L/D values near 10, or about one quarter that of the sailplane. The birds glided more slowly than the sailplane and had about the same sinking speed. 4. The ‘equivalent parasite area’ method used by aircraft designers to estimate parasite drag was modified for use with gliding birds, and empirical data are presented to provide a means of predicting the gliding performance of a bird in the absence of wind-tunnel tests. 5. The birds in this study had conventional values for parasite drag. Technical errors seem responsible for published claims of unusually low parasite drag values in a vulture. 6. The falcon adjusted its wing span in flight to achieve nearly the maximum possible L/D value over its range of gliding speeds. 7. The maximum terminal speed of the falcon in a vertical dive is estimated to be 100 m./sec.

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