Numerical Investigation of Aerodynamic Characteristics of NACA 4312 Airfoil with Gurney Flap

This paper presents a two-dimensional Computational Fluid Dynamics (CFD) analysis on the effect of gurney flap on a NACA 4312 airfoil in a subsonic flow. These numerical simulations were conducted for flap heights 1.5%, 1.75%, 2% and 3% of chord length at fixed Reynold Number, Re (5×105) for different angle of attack (0o ~16o). ANSYS Fluent commercial software was used to conduct these simulations. The flow was considered as incompressible and K-omega Shear Stress Transport (SST) model was selected. The numerical results demonstrate that lift coefficient increase up to around 12o AoA (angle of attack) for NACA 4312 with and without gurney flap. For every AoA lift coefficient and drag coefficient presented proportionate behavior with flap height. However, lift co-efficient was decreased after around angle of attack due to flow separation. Maximum lift to drag ratio was found at around 4o AoA for every flap length and airfoil with flap of 1.5%C (chord length) had shown the most optimized aerodynamic performance through the analysis. This study concluded that airfoil with gurney flap displayed enhanced aerodynamic performance than the airfoil without gurney flap due to the delay in flow separation.

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Experimental Study on Aerodynamic Characteristics of a Gurney Flap on a Wind Turbine Airfoil under High Turbulent Flow Condition

Applied Sciences ◽

10.3390/app10207258 ◽

2020 ◽

Vol 10 (20) ◽

pp. 7258 ◽

Cited By ~ 1

Author(s):

Junwei Yang ◽

Hua Yang ◽

Weijun Zhu ◽

Nailu Li ◽

Yiping Yuan

Keyword(s):

Wind Tunnel ◽

Turbulent Flow ◽

Lift Coefficient ◽

Leading Edge ◽

Aerodynamic Characteristics ◽

Chord Length ◽

Turbulence Level ◽

Gurney Flaps ◽

Gurney Flap ◽

Delay Phenomenon

The objective of the current work is to experimentally investigate the effect of turbulent flow on an airfoil with a Gurney flap. The wind tunnel experiments were performed for the DTU-LN221 airfoil under different turbulence level (T.I. of 0.2%, 10.5% and 19.0%) and various flap configurations. The height of the Gurney flaps varies from 1% to 2% of the chord length; the thickness of the Gurney flaps varies from 0.25% to 0.75% of the chord length. The Gurney flap was vertical fixed on the pressure side of the airfoil at nearly 100% measured from the leading edge. By replacing the turbulence grille in the wind tunnel, measured data indicated a stall delay phenomenon while increasing the inflow turbulence level. By further changing the height and the thickness of the Gurney flap, it was found that the height of the Gurney flap is a very important parameter whereas the thickness parameter has little influence. Besides, velocity in the near wake zone was measured by hot-wire anemometry, showing the mechanisms of lift enhancement. The results demonstrate that under low turbulent inflow condition, the maximum lift coefficient of the airfoil with flaps increased by 8.47% to 13.50% (i.e., thickness of 0.75%), and the Gurney flap became less effective after stall angle. The Gurney flap with different heights increased the lift-to-drag ratio from 2.74% to 14.35% under 10.5% of turbulence intensity (i.e., thickness of 0.75%). However, under much a larger turbulence environment (19.0%), the benefit to the aerodynamic performance was negligible.

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Numerical and experimental investigation of the flow separation over NREL's S822 aerofoil and its control by suction and blowing

Renewable Energy and Environmental Sustainability ◽

10.1051/rees/2020006 ◽

2021 ◽

Vol 6 ◽

pp. 5

Author(s):

Nazar Aldabash‎‎ ◽

Andrew Wandel‎ ◽

Abdul Salam Darwish‎ ◽

Jayantha Epaarachchi‎

Keyword(s):

Experimental Investigation ◽

Wind Turbine ◽

Flow Separation ◽

Numerical Study ◽

Lift Coefficient ◽

Angle Of Attack ◽

Volumetric Flow Rate ◽

Aerodynamic Characteristics ◽

Careful Selection ◽

Suction And Blowing

In this study, a numerical and experimental investigation for the flow separation over 170 mm chord, the NREL S822 aerofoil low Reynolds number wind turbine blade aerofoil section has been investigated at 15.8 m/s wind speed using suction and blowing techniques for the locations between 0.15 and 0.41 of the chord to improve aerodynamic characteristics of a wind turbine rotor blade. In a numerical study, two-dimensional aerofoil (i.e. NREL S822), using Shear Stress Transport (SST (γ − Reθ)) turbulence model, is presented. Careful selection for the number of mesh was considered through an iterative process to achieve the optimum mesh number resulted in optimum values for the ratio of lift to drag coefficients (CL/CD). Values of the lift coefficient, drag coefficient, and separation location were investigated at an angle of attack 18°. Flow separation is monitored and predicted within the numerical results at the tested angles, which has been compared with the experimental results and should a fair agreement. The results revealed that the aerodynamic characteristics of NERL S822 aerofoil would be improved using the suction technique more than the suction and blowing techniques and there is a delay of flow separation with the increase of blowing or suction volumetric flow rate. Using these two techniques and careful selection of the mesh numbers with the right angle of attack can improve the aerofoil characteristics and therefore lead to improve the turbine performance characteristics.

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ANALISIS CFD KARAKTERISTIK AERODINAMIKA PADA SAYAP PESAWAT LSU-05 DENGAN PENAMBAHAN VORTEX GENERATOR (ANALYSIS OF CFD AERODYNAMIC CHARACTERISTICS AT THE WING OF AIRCRAFT LSU-05 WITH THE ADDITION OF VORTEX GENERATOR)

Jurnal Teknologi Dirgantara ◽

10.30536/j.jtd.2017.v15.a2518 ◽

2017 ◽

Vol 15 (1) ◽

pp. 45

Author(s):

Awalu Romadhon ◽

Dana Herdiana

Keyword(s):

Drag Coefficient ◽

Cfd Simulation ◽

Lift Coefficient ◽

Angle Of Attack ◽

Vortex Generator ◽

Aerodynamic Characteristics ◽

Unmanned Aircraft ◽

Vortex Generators ◽

Aircraft Wing ◽

Ansys Fluent

LSU-05 aircraft is one of the unmanned aerial vehicles (UAV), which is being developed by the Aeronautics Technology Center of LAPAN, whose mission is for research, observation, patrol, border surveillance, and investigation of natural disasters. This study aims to determine the effect of vortex generators on the aerodynamic characteristics of the LSU-05 Unmanned Aircraft wing. The method used is a numerical analysis with CFD simulation for predicting aerodynamic characteristics and flow phenomena that occur. The models used are the aircraft wing of the LSU-05 without vortex generator and with vortex generator designed with CATIA software. The simulation is using ANSYS Fluent software to determine changes in the aerodynamic characteristics of the wing after the addition of vortex generators such as the lift coefficient and drag coefficient. The results of the addition of vortex generator on LSU-05 wings are the increasing value of the maximum lift coefficient of the wing which becomes 1,34840 from 1,26450, it increases 0,0839 (6.63%) point, the increasing value of the drag coefficient on the angle of attack from -9⁰ to 11⁰, the decreasing value of the drag coefficient on the angle of attack 12⁰ up to 15⁰ and the increasing stall angle of wing from 11⁰ to 14⁰ or increased by 3⁰ (27,7%). AbstrakPesawat LSU-05 adalah salah satu pesawat tanpa awak (UAV) yang sedang dikembangkan oleh Pusat Teknologi Penerbangan LAPAN, yang mempunyai misi untuk kegiatan penelitian, observasi, patroli, pengawasan perbatasan wilayah, dan investigasi bencana alam. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan vortex generator terhadap karakteristik aerodinamika dari sayap Pesawat Tanpa Awak LSU-05. Metode yang digunakan adalah analisis numerik dengan simulasi CFD untuk memprediksi karakteristik aerodinamika dan fenomena aliran yang terjadi. Model yang digunakan adalah sayap pesawat LSU-05 tanpa vortex generator dan dengan vortex generator yang didesain dengan software CATIA. Simulasi menggunakan software ANSYS Fluent untuk mengetahui perubahan karakteristik aerodinamika sayap setelah penambahan vortex generator seperti koefisien lift dan koefisien drag. Hasil yang diperoleh dari penelitian penambahan vortex generator pada sayap Pesawat LSU-05 adalah peningkatan nilai koefisien lift maksimum sayap dari 1,26450 menjadi 1,34840 atau naik sebesar 0,0839 (6,63%), peningkatan nilai koefisien drag pada sudut serang -9⁰ s/d 11⁰, penurunan nilai koefisien drag pada sudut serang 12⁰ s.d 15⁰ dan peningkatan sudut stall sayap dari 11⁰ menjadi 14⁰ atau naik sebesar 3⁰ (27,7 %).

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Numerical study of the aerodynamic and power characteristics of the cycloidal rotor, under incoming flow

Вычислительные технологии ◽

10.25743/ict.2018.23.6.004 ◽

2019 ◽

pp. 25-34

Author(s):

Александр Анатольевич Дектерев ◽

Артем Александрович Дектерев ◽

Юрий Николаевич Горюнов

Keyword(s):

Flow Velocity ◽

Numerical Study ◽

Lift Coefficient ◽

Simulation Method ◽

Aerodynamic Characteristics ◽

Incoming Flow ◽

Ansys Fluent ◽

Energy Characteristics ◽

Power Characteristics ◽

Calculation Results

Исследование направлено на разработку и апробацию методики численного моделирования аэродинамических и энергетических характеристик циклоидального ротора. За основу взята конфигурация ротора IAT21 L3. Для нее с использованием CFD-пакета ANSYS Fluent построена математическая модель и выполнен расчет. Проанализировано влияние скорости набегающего потока воздуха на движущийся ротор. Математическая модель и полученные результаты исследования могут быть использованы при создании летательных аппаратов с движителями роторного типа. This article addresses the study of the aerodynamic and energy characteristics of a cycloidal rotor subject to the influence of the incoming flow. Cycloidal rotor is one of the perspective devices that provide movement of aircrafts. Despite the fact that the concept of a cycloidal rotor arose in the early twentieth century, the model of a full-scale aircraft has not been yet realized. Foreign scientists have developed models of aircraft ranging in weight from 0.06 to 100 kg. The method of numerical calculation of the cycloidal rotor from the article [1] is considered and realized in this study. The purpose of study was the development and testing of a numerical simulation method for the cycloidal rotor and study aerodynamic and energy characteristics of the rotor in the hovering mode and under the influence of the oncoming flow. The aerodynamic and energy characteristics of the cycloidal rotor, rotating at a speed of 1000 rpm with incoming flow on it with velocities of 20-80 km/h, were calculated. The calculation results showed a directly proportional increase of thrust with an increase of the incoming on the rotor flow velocity, but the power consumed by the rotor was also increased. Increase of the incoming flow velocity leads to the proportional increasing of the lift coefficient and the coefficient of drag. Up to a speed of 80 km/h, an increase in thrust and power is observed; at higher speeds, there is a predominance of nonstationary effects and difficulties in estimating the aerodynamic characteristics of the rotor. In the future, it is planned to consider the 3D formulation of the problem combined with possibility of the flow coming from other sides.

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2D Numerical Simulation Study of Airfoil Performance

10.5194/wes-2021-45 ◽

2021 ◽

Author(s):

Nasser Shelil

Keyword(s):

Experimental Data ◽

Wind Tunnel ◽

Air Temperature ◽

Wind Turbines ◽

Aerodynamic Force ◽

Angle Of Attack ◽

Turbulence Models ◽

Aerodynamic Characteristics ◽

Operating Conditions ◽

Ansys Fluent

Abstract. The aerodynamic characteristics of DTU-LN221 airfoil is studied. ANSYS Fluent is used to simulate the airfoil performance with seven different turbulence models. The simulation results for the airfoil with different turbulence models are compared with the wind tunnel experimental data performed under the same operating conditions. It is found that there is a good agreement between the computational fluid dynamics (CFD) predicted aerodynamic force coefficients with wind tunnel experimental data especially with angle of attack between −5° to 10°. RSM is chosen to investigate the flow field structure and the surface pressure coefficients under different angle of attack between −5° to 10°. Also the effect of changing air temperature, velocity and turbulence intensity on lift and drag coefficients/forces are examined. The results show that it is recommended to operate the wind turbines airfoil at low air temperature and high velocity to enhance the performance of the wind turbines.

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Aerodynamic and Vibration Characteristics of the Micro-Octocopter at Low Reynolds Number

Mobile Information Systems ◽

10.1155/2021/3691559 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Xiaohua Zou ◽

Mingsheng Ling ◽

Wenzheng Zhai

Keyword(s):

Reynolds Number ◽

Load Capacity ◽

Lift Coefficient ◽

Angle Of Attack ◽

Aerodynamic Characteristics ◽

Vibration Characteristics ◽

Low Reynolds ◽

Vibration Performance ◽

Drag Ratio ◽

Lift To Drag Ratio

With the development of flight technology, the need for stable aerodynamic and vibration performance of the aircraft in the civil and military fields has gradually increased. In this case, the requirements for aerodynamic and vibration characteristics of the aircraft have also been strengthened. The existing four-rotor aircraft carries limited airborne equipment and payload, while the current eight-rotor aircraft adopts a plane layout. The size of the propeller is generally fixed, including the load capacity. The upper and lower tower layout analyzed in this paper can effectively solve the problems of insufficient four-axis load and unstable aerodynamic and vibration performance of the existing eight-axis aircraft. This paper takes the miniature octorotor as the research object and studies the aerodynamic characteristics of the miniature octorotor at different low Reynolds numbers, different air pressures and thicknesses, and the lift coefficient and lift-to-drag ratio, as well as the vibration under different elastic moduli and air pressure characteristics. The research algorithm adopted in this paper is the numerical method of fluid-solid cohesion and the control equation of flow field analysis. The research results show that, with the increase in the Reynolds number within a certain range, the aerodynamic characteristics of the miniature octorotor gradually become better. When the elastic modulus is 2.5 E, the aircraft’s specific performance is that the lift increases, the critical angle of attack increases, the drag decreases, the lift-to-drag ratio increases significantly, and the angle of attack decreases. However, the transition position of the flow around the airfoil surface is getting closer to the leading edge, and its state is more likely to transition from laminar flow to turbulent flow. When the unidirectional carbon fiber-reinforced thickness is 0.2 mm and the thin arc-shaped airfoil with the convex structure has a uniform thickness of 2.5% and a uniform curvature of 4.5%, the aerodynamic and vibration characteristics of the octorotor aircraft are most beneficial to flight.

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Methods for selecting the supporting curve for the model of hysteresis loop

ITM Web of Conferences ◽

10.1051/itmconf/20181801003 ◽

2018 ◽

Vol 18 ◽

pp. 01003

Author(s):

O.N. Korsun ◽

A.V. Stulovskii

Keyword(s):

Hysteresis Loop ◽

Test Data ◽

Flow Separation ◽

Physical Interpretation ◽

Lift Coefficient ◽

Angle Of Attack ◽

Flight Test ◽

Separation Point ◽

Aerodynamic Coefficients

The article deals with a model describing the dependence of aerodynamic coefficients on the angle of attack for post-stall conditions. This paper also discusses the choice of parameters for the calculating the lift coefficient in such cases. In addition, it also considers some methods used to choose the shape of a supporting curve. The article also provides arguments concerning the physical interpretation of the coordinate of flow separation point in the implementation of the model. The examples of processing the flight test data are presented.

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Gurney Flap Implementation on a DU91W250 Airfoil

Proceedings ◽

10.3390/proceedings2231448 ◽

2018 ◽

Vol 2 (23) ◽

pp. 1448 ◽

Cited By ~ 1

Author(s):

Iñigo Aramendia ◽

Aitor Saenz-Aguirre ◽

Unai Fernandez-Gamiz ◽

Ekaitz Zulueta ◽

Jose Manuel Lopez-Guede ◽

...

Keyword(s):

Flow Control ◽

Numerical Study ◽

Lift Coefficient ◽

Optimization Technique ◽

Electrical Power ◽

Aerodynamic Performance ◽

Control Element ◽

Mechanical Fatigue ◽

Gurney Flap ◽

Fatigue Loads

The increasing capability of Wind Turbine (WT) based power generation systems has derived in an increment of the WT rotor diameter, i.e., longer rotor blades. This results in an increase of the electrical power generated but also in instabilities in the operation of the WT, especially due to the mechanical fatigue loads generated in its elements. In this context, flow control has appeared as a solution to improve the aerodynamic performance of the blades. These devices not only increase lift coefficient but also reduce mechanical fatigue loads. This paper presents a detailed numerical analysis of the effects of placing a passive flow control element, a Gurney Flap (GF), in a DU91W250 airfoil. Moreover, a numerical study of the influence of the GF length on the aerodynamic performance of the blade has been carried out. This study is considered as a basis for the development of an optimization technique of the GF length for long WT blades.

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Aerodynamic Characteristics of a Deformable Membrane Aerofoil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.553.255 ◽

2014 ◽

Vol 553 ◽

pp. 255-260

Author(s):

Viktor Šajn ◽

Igor Petrović ◽

Franc Kosel

Keyword(s):

Experimental Study ◽

Reynolds Number ◽

Wind Tunnel ◽

Lift Coefficient ◽

Fluid Structure Interaction ◽

Angle Of Attack ◽

Aerodynamic Characteristics ◽

Relative Difference ◽

Structure Interaction ◽

Deformable Membrane

In the paper, numerical and experimental study of low Reynolds number airflow around the deformable membrane airfoil (DMA) is presented. Simulations of a fluid-structure interaction between the fluid and the DMA were performed. In the experiment, the DMA model was made from a thin PVC sheet, which was wrapped around the steel rod at the leading and trailing edge. Measurements were performed in a wind tunnel at a chord Reynolds number of 85.7·103, over the angle of attack range from 0° to 15° and DMA shortening ratio from 0.025 to 0.150. Simulations were in an agreement with the experiment, since the average relative difference of coefficient of lift was smaller than 7.3%. For the same value of Reynolds number, DMA shows improved lift coefficient Cy= 2.18, compared to standard rigid airfoils.

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Experimental Aerodynamic Characteristics of a Compound Wing in Ground Effect

Journal of Fluids Engineering ◽

10.1115/1.4026618 ◽

2014 ◽

Vol 136 (5) ◽

Cited By ~ 2

Author(s):

Saeed Jamei ◽

Adi Maimun Abdul Malek ◽

Shuhaimi Mansor ◽

Nor Azwadi Che Sidik ◽

Agoes Priyanto

Keyword(s):

Reynolds Number ◽

Drag Coefficient ◽

Center Of Pressure ◽

Lift Coefficient ◽

Angle Of Attack ◽

Leading Edge ◽

Ground Effect ◽

Reynolds Numbers ◽

Aerodynamic Characteristics ◽

Ground Clearance

Wing configuration is a parameter that affects the performance of wing-in-ground effect (WIG) craft. In this study, the aerodynamic characteristics of a new compound wing were investigated during ground effect. The compound wing was divided into three parts with a rectangular wing in the middle and two reverse taper wings with anhedral angle at the sides. The sectional profile of the wing model is NACA6409. The experiments on the compound wing and the rectangular wing were carried to examine different ground clearances, angles of attack, and Reynolds numbers. The aerodynamic coefficients of the compound wing were compared with those of the rectangular wing, which had an acceptable increase in its lift coefficient at small ground clearances, and its drag coefficient decreased compared to rectangular wing at a wide range of ground clearances, angles of attack, and Reynolds numbers. Furthermore, the lift to drag ratio of the compound wing improved considerably at small ground clearances. However, this improvement decreased at higher ground clearance. The drag polar of the compound wing showed the increment of lift coefficient versus drag coefficient was higher especially at small ground clearances. The Reynolds number had a gradual effect on lift and drag coefficients and also lift to drag of both wings. Generally, the nose down pitching moment of the compound wing was found smaller, but it was greater at high angle of attack and Reynolds number for all ground clearance. The center of pressure was closer to the leading edge of the wing in contrast to the rectangular wing. However, the center of pressure of the compound wing was later to the leading edge at high ground clearance, angle of attack, and Reynolds number.

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