scholarly journals Boundary Layer Control of Airfoil using Rotating Cylinder

2020 ◽  
Vol 8 (6) ◽  
pp. 4742-4750
Keyword(s):  
Leading Edge ◽  
Rotating Cylinder ◽  
Aerodynamic Characteristics ◽  
Favourable Result ◽  
Ansys Fluent ◽  
High Lift ◽  
Freestream Velocity ◽  
Aerodynamic Efficiency ◽  
Two Parameters ◽  
Layer Control

The requirement for improving the aerodynamic efficiency and delaying the formation of stall over the wing has been of prime importance within the field of aviation. The main objective of the project is to further improve upon these two parameters. The configuration used for analysis consists of a NACA 2412 airfoil of chord length 0.982m with a 64mm cylinder at the leading edge. Analysis is completed using ANSYS Fluent, with a freestream velocity of 10m/s. The aerodynamic characteristics of three configuration bare airfoil, Airfoil with static cylinder and Airfoil with rotating cylinder are tabulated and plotted. The comparison is then followed by pressure and velocity contours to visualize the flow over each configuration. The rotating cylinder configuration shows a improvement in the aerodynamics characteristics. The rotating cylinder configuration gives the most favourable result. This study has a potential application in high lift devices and can be used as stall delaying device

Aerodynamic study of single corrugated variable-camber morphing aerofoil concept

2021 ◽  
pp. 1-29
Author(s):  
K. Dhileep ◽  
D. Kumar ◽  
P.N. Gautham Vigneswar ◽  
P. Soni ◽  
S. Ghosh ◽  
...  
Keyword(s):  
Finite Volume ◽  
Interpolation Method ◽  
Beam Theory ◽  
Small Deformation ◽  
Aerodynamic Characteristics ◽  
Ansys Fluent ◽  
Aerodynamic Efficiency ◽  
Finite Element Software ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract Camber morphing is an effective way to control the lift generated by any aerofoil and potentially improve the range (as measured by the lift-to-drag ratio) and endurance (as measured by $C_l^{3/2}/C_d$ ). This can be especially useful for fixed-wing Unmanned Aerial Vehicles (UAVs) undergoing different flying manoeuvres and flight phases. This work investigates the aerodynamic characteristics of the NACA0012 aerofoil morphed using a Single Corrugated Variable-Camber (SCVC) morphing approach. Structural analysis and morphed shapes are obtained based on small-deformation beam theory using chain calculations and validated using finite-element software. The aerofoil is then reconstructed from the camber line using a Radial Basis Function (RBF)-based interpolation method (J.H.S. Fincham and M.I. Friswell, “Aerodynamic optimisation of a camber morphing aerofoil,” Aerosp. Sci. Technol., 2015). The aerodynamic analysis is done by employing two different finite-volume solvers (OpenFOAM and ANSYS-Fluent) and a panel method code (XFoil). Results reveal that the aerodynamic coefficients predicted by the two finite-volume solvers using a fully turbulent flow assumption are similar but differ from those predicted by XFoil. The aerodynamic efficiency and endurance factor of morphed aerofoils indicate that morphing is beneficial at moderate to high lift requirements. Further, the optimal morphing angle increases with an increase in the required lift. Finally, it is observed for a fixed angle-of-attack that an optimum morphing angle exists for which the aerodynamic efficiency becomes maximum.

scholarly journals Unsteady Aerodynamic Characteristics Simulations of Rotor Airfoil under Oscillating Freestream Velocity

2020 ◽  
Vol 10 (5) ◽  
pp. 1822
Author(s):  
Qing Wang ◽  
Qijun Zhao
Keyword(s):  
Three Dimensional ◽  
Grid Method ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Critical Value ◽  
Dynamic Stall ◽  
Navier Stokes ◽  
Freestream Velocity ◽  
Unsteady Aerodynamic ◽  
Edge Vortex

The dynamic stall characteristics of rotor airfoil are researched by employing unsteady Reynolds-Averaged Navier-Stokes (RANS) method under oscillating freestream velocity conditions. In order to simulate the oscillating freestream velocity of airfoil under dynamic stall conditions, the moving-embedded grid method is employed to simulate the oscillating velocity. By comparing the simulated dynamic stall characteristics of two-dimensional airfoil and three-dimensional rotor, it is indicated that the dynamic stall characteristics of airfoil under oscillating freestream velocity reflect the actual dynamic stall characteristics of rotor airfoil in forward flight more accurately. By comparing the simulated results of OA209 airfoil under coupled freestream velocity/pitching oscillation conditions, it is indicated that the dynamic stall characteristics of airfoil associate with the critical value of Cp peaks (i.e., the dynamic stall characteristics of OA209 airfoil would be enhanced when the maximum negative pressure is larger than −1.08, and suppressed when this value is smaller than −1.08). By comparing the characteristics of vortices under different oscillating velocities, it indicates that the dissipation rate of leading edge vortex presents as exponent characteristics, and it is not sensitive to different oscillating velocities.

scholarly journals Effect of Leading-Edge Bulges on Aerodynamic Characteristics of Bionic Wingsail

2021 ◽  
Author(s):  
Chen Li ◽  
Peiting Sun ◽  
Hongming Wang
Keyword(s):  
Stokes Equations ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Suction Surface ◽  
Ansys Fluent ◽  
Navier Stokes Equations ◽  
Extension Direction ◽  
Lift And Drag

The leading-edge bulges along the extension direction are designed on the marine wingsail. The height and the spanwise wavelength of the protuberances are 0.1c and 0.25c, respectively. At Reynolds number Re=5×105, the Reynolds Averaged Navier-Stokes equations are applied to the simulation of the wingsail with the bulges thanks to ANSYS Fluent finite-volume solver based on the SST K-ω models. The grid independence analysis is carried out with the lift and drag coefficients of the wingsail at AOA = 8° and AOA=20°. The results show that while the efficiency of the wingsail is reduced by devising the leading-edge bulges before stall, the bulges help to improve the lift coefficient of the wingsail when stalling. At AOA=22° under the action of the leading-edge tubercles, a convective vortex is formed on the suction surface of the modified wingsail, which reduces the flow loss. So the bulges of the wingsail can delay the stall.

scholarly journals A PARAMETRIC STUDY ON CONTROL OF FLOW SEPARATION OVER AN AIRFOIL IN INCOMPRESSIBLE REGIME

2018 ◽  
Vol 19 (1) ◽  
pp. 270-288
Author(s):  
L Prabhu ◽  
J Srinivas
Keyword(s):  
Flow Separation ◽  
Passive Control ◽  
Leading Edge ◽  
Adverse Pressure Gradient ◽  
Aerodynamic Characteristics ◽  
Computational Effort ◽  
Gradient Field ◽  
Control Procedure ◽  
Ansys Fluent ◽  
Suction Velocity

This paper presents the effects of airfoil geometry on flow separation behavior and obtains the transition patterns at a specific angle of attack. A strong adverse pressure gradient field is observed at the leading edge of the airfoil, and it results in a flow detachment. Leading edge flow separation is studied along with the variation of skin friction coefficient over the airfoil. Novelty in the approach is the development of a hybrid control scheme to delay the flow separation with blowing/suction of air (termed active control) over the airfoil together with the tapping of flow from the pressure side as in a classical passive control procedure. The active controller delays the flow separation, while the passive controller is used to reduce the drag coefficient significantly and increases the total performance of an airfoil. The effectiveness of these controls is examined by varying the control parameters including blowing/suction velocity, the position of the slot in terms of percentage of chord and size of the slot. All the numerical simulations are carried out using ANSYS-Fluent software. A surrogate model is also developed to predict the aerodynamic characteristics conveniently without much computational effort. The outcome of this study reveals that the blowing/suction velocity has a higher influence in delaying the flow separation. ABSTRAK: Kertas ini membentangkan tentang kesan geometri aerofoil pada perubahan pemisah aliran udara dan memperoleh bentuk peralihan pada darjah yang tepat. Terdapat tekanan kuat yang tidak sesuai pada kawasan kecerunan di hujung hadapan permukaan aerofoil, dan ini menyebabkan aliran udara terpisah. Pemisah aliran udara pada hujung hadapan ini dikaji bersama koefisien geseran pada permukaan aerofoil. Pendekatan baru pada kaedah ini adalah berkaitan pembangunan skim kawalan hibrid bagi melengahkan aliran pemisah udara melalui tiupan/sedutan udara (kawalan aktif) ke atas aerofoil bersama ketukan pada aliran dari tepi tekanan seperti mana prosedur klasik kawalan pasif. Kawalan aktif ini melengahkan aliran pemisah udara, sebaliknya kawalan pasif telah digunakan bagi mengurangkan koefisien penangguhan dengan ketara dan menambahkan jumlah prestasi aerofoil. Keberhasilan kawalan-kawalan ini dikaji dengan mengubah parameter kawalan termasuk kelajuan tiupan/sedutan udara, posisi slot berdasarkan peratusan garis temu dan saiz slot. Semua simulasi-simulasi numerikal ini dijalankan menggunakan perisian Ansys-Fluent. Model pengganti turut dibangunkan untuk menjangka ciri-ciri aero-dinamik dengan mudah tanpa usaha pengiraan yang banyak. Keputusan kajian ini mendedahkan tentang kelajuan tiupan/sedutan udara berpengaruh besar dalam melambatkan pemisahan aliran udara.

scholarly journals Moving Surface Boundary Layer Control Analysis and the Influence of the Magnus Effect on an Aerofoil with a Leading-Edge Rotating Cylinder

2019 ◽  
Author(s):  
Md. Abdus Salam ◽  
Bhuiyan Shameem Mahmood Ebna Hai ◽  
M. A. Taher Ali ◽  
Debanan Bhadra ◽  
Nafiz Ahmed Khan
Keyword(s):  
Boundary Layer ◽  
Free Stream ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Rotating Cylinder ◽  
Boundary Layer Control ◽  
Surface Boundary ◽  
Surface Boundary Layer ◽  
Lower Velocity ◽  
Layer Control

A number of experimental and numerical studies point out that incorporating a rotating cylinder can superiorly enhance the aerofoil performance, especially for higher velocity ratios. Yet, there have been less or no studies exploring the effects of lower velocity ratio at a higher Reynolds number. In the present study, we investigated the effects of Moving Surface Boundary-layer Control (MSBC) at lower velocity ratios (i.e. cylinder tangential velocity to free stream velocity) and higher Reynolds number on a symmetric aerofoil (e.g. NACA 0021) and an asymmetric aerofoil (e.g. NACA 23018). In particular, the aerodynamic performance with and without rotating cylinder at the leading edge of the NACA 0021 and NACA 23018 aerofoil was studied on the wind tunnel installed at Aerodynamics Laboratory. The aerofoil section was tested in the low subsonic wind tunnel, and the lift coefficient and the drag coefficient were studied for different angles of attack. The experiments were conducted for two Reynolds numbers: 200000 and 250000 corresponding to two free stream velocities: 20 m/s and 25 m/s, respectively, for six different angle of attacks (-5°, 0°, 5°, 10°, 15° and 20°). This study demonstrates that the incorporation of a leading edge rotating cylinder results in an increase of lift coefficient at lower angle of attacks (maximum around 33%) and delay in stall angle (from 10° to 15°) relative to the aerofoil without rotating cylinder.

scholarly journals Analisis karakteristik aerodinamika telescopic wing dengan konfigurasi sayap flying wing dan glider menggunakan metode pendekatan simulasi CFD

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Azhim Asyratul Azmi ◽  
Satriawan Dini Hariyanto ◽  
Arif Hidayat
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Characteristics ◽  
Morphing Wing ◽  
Aircraft Wing ◽  
High Lift ◽  
Tip Vortices ◽  
Wing Tip

A telescopic wing is a shape-changing method of the aircraft wing known as the morphing wing system. Wingspan extends capability on telescopic wing increasing the aspect ratio to get a high lift force. The telescopic wing on a flying wing configuration as an external wing and glider wing as an internal wing can be used to increase the coefficient lift (CL) when carrying out special missions. The aerodynamic characteristics using the Computational Fluid Dynamic (CFD) simulation approach is presented. For the 40% internal wingspan, the highest CL increment was 12.9% at a 10o angle of attack. For the 50% internal wingspan, the highest CL increment was 14.9% at a 10o angle of attack. on the 40% internal wing, the highest coefficient drag (CD) increment was 4.7%, and the largest CD increment on 50% internal was 9.5% at the angle of attack of 20o. The pressure distribution along the internal wingspan was uneven from an angle of attack of 15o due to the wing tip vortices of the external wing. Streamline pattern shown a bubble separation from the leading edge at an internal wing root by external wing tip vortices.Keywords: Morphing wing, telescopic wing, flying wing, glider

Design and Modeling of the Fowler Flap With Adaptive Elements

Aerospace ◽  
2006 ◽  
Author(s):  
Oleksandr Kozlov
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Deformation Behaviour ◽  
Leading Edge ◽  
Element Model ◽  
High Lift ◽  
Aerodynamic Efficiency ◽  
Transport Aircraft ◽  
Sma Actuators ◽  
Active Flap

This paper describes the process of the designing of the Fowler flap with adaptive elements. Modern passenger and transport aircraft use high lift devices for take off and landing. Of great importance for the creation of high lift during take off and landing is the shape and size of the gap between wing and extended Fowler flap. To improve the deformation behaviour of the leading edge of this flap, and to improve the geometry of the gap, it was decided to use shape memory alloy (SMA) actuators in the flap structure. First, the complex finite element model of the passive flap was created and then this model was extended with active elements, which are modelling the SMA actuators. As a result, the complex finite element model of the active flap was obtained. This modelling was done using software MATLAB and a finite element model was created using software ANSYS. The main result of this work is that with help of SMA actuators integrated in the flap it was possible to influence and improve the geometry of the gap between the wing and the extended flap, resulting in the aerodynamic efficiency of this flap being increased.

scholarly journals The Effect of Spoiler Shape and Setting Angle on Racing Cars Aerodynamic Performance

2020 ◽  
Vol 5 (1) ◽  
pp. 11-20
Author(s):  
Hesam Eftekhari ◽  
Abdulkareem Sh. Mahdi Al-Obaidi ◽  
Shahrooz Eftekhari
Keyword(s):  
Drag Coefficient ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Ansys Fluent ◽  
Aerodynamic Efficiency ◽  
Race Car ◽  
Setting Angle ◽  
Being There ◽  
Lift And Drag ◽  
Lift And Drag Coefficient

Automotive racing is one of the favorite sports of human being. There have been many developments in past decades by car engineers to improve the performance of the engine and increase the aerodynamic efficiency of the race cars to achieve a better lap time and get a better placement safely. One of the ways to improve the aerodynamic performance of a race car is to use rear spoilers. This study by using ANSYS FLUENT numerically investigated the effect of the spoiler shape and setting angle on the aerodynamic characteristics of a race car and then it was validated by conducting wind tunnel experiment. Lift and drag coefficient of NACA0012, NACA4412, and S1223 are determined in Reynold’s number of 2×105 as an airfoil and as spoiler on ERC model which is a conceptual car model inspired by Porsche 911. It was found that ERC model with spoiler would have better aerodynamic efficiency compared to ERC model without spoiler. Also, S1223 at -6 degrees was identified as the optimized configuration as it generates the highest downforce. Even though the drag coefficient at this setting angle is slightly higher, but in terms of stability and handling IT is at its best. Overall, this study would help car manufacturers, for racing and commercial purposes, to have a better insight into the effect of spoiler configuration on the aerodynamic performance of cars. Hence, the stability, handling, and efficiency of the cars can be further improved by selecting the suitable spoiler configuration.

scholarly journals Investigation and Improvement of Stall Characteristic of High-Lift Configuration without Slats

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Zhao Yang ◽  
Jie Li ◽  
Jing Jin ◽  
Heng Zhang ◽  
Youxu Jiang
Keyword(s):  
Evaluation Method ◽  
Leading Edge ◽  
Suction Side ◽  
Aerodynamic Characteristics ◽  
Angle Distribution ◽  
Detached Eddy Simulation ◽  
High Lift ◽  
Eddy Simulation ◽  
Business Jet ◽  
Delayed Detached Eddy Simulation

In order to simplify the manufacturing process or because of the limitation of the propulsion system, business jet, small civil airplane, and turboprop aircraft are always designed without leading-edge slats, which poses a great challenge to the flight safety during takeoff and landing. Focusing on the low-speed stall and poststall conditions, we investigated the aerodynamic characteristics and flow mechanism of high-lift configuration without slats using an improved delayed detached eddy simulation (IDDES) model which is validated by numerical simulations of the Common Research Model (CRM). Based on the analysis of the calculated results, conclusion can be made that the stall behavior of the configurations is directly related to the onset and evaluation of flow separation on the suction side. And through further research, an efficient evaluation method that is capable of qualitatively predicting the stall performance of two-element high-lift configuration by stall angle distribution of wing sections is proposed. By using the evaluation method, together with design rules summarized from the present study, high-lift configuration with mild-stall characteristic can be obtained in the preliminary stage of design.

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