Influence of the Trailing Edge Shape on the Aerodynamic Characteristics of an Airfoil at Low Re Number Using RANS

A comprehensive computational study, in both steady and unsteady flow conditions, has been carried out to investigate the aerodynamic characteristics of the Risø-B1-18 airfoil equipped with variable trailing edge geometry as produced by a hinged flap. The function of such flaps should be to decrease fatigue-inducing oscillations on the blades. The computations were conducted using a 2D incompressible RANS solver with a k-w turbulence model under the assumption of a fully developed turbulent flow. The investigations were conducted at a Reynolds number of Re = 1.6 · 106. Calculations conducted on the baseline airfoil showed excellent agreement with measurements on the same airfoil with the same specified conditions. Furthermore, a more widespread comparison with an advanced potential theory code is presented. The influence of various key parameters, such as flap shape, flap size and oscillating frequencies, was investigated so that an optimum design can be suggested for application with wind turbine blades. It is concluded that a moderately curved flap with flap chord to airfoil curve ratio between 0.05 and 0.10 would be an optimum choice.

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Effect of trailing edge dual synthesis jets actuator on aerodynamic characteristics of a straight-bladed vertical axis wind turbine

Energy ◽

10.1016/j.energy.2021.121792 ◽

2022 ◽

Vol 238 ◽

pp. 121792

Author(s):

Peilin Wang ◽

Qingsong Liu ◽

Chun Li ◽

Weipao Miao ◽

Shuai Luo ◽

...

Keyword(s):

Wind Turbine ◽

Vertical Axis ◽

Aerodynamic Characteristics ◽

Vertical Axis Wind Turbine ◽

Trailing Edge

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Lift Control Using MEMS-Based Moving Trailing-Edge Tabs

Adaptive Structures and Materials Systems ◽

10.1115/imece2002-33990 ◽

2002 ◽

Author(s):

C. P. van Dam ◽

C. Bauer ◽

D. T. Yen Nakafuji

Keyword(s):

Lift Coefficient ◽

Aerodynamic Characteristics ◽

Trailing Edge ◽

Aircraft Wings ◽

Lifting Surface ◽

Lifting Surfaces ◽

Lift Control

Micro-electro-mechanical (MEM) translational tabs are introduced for active lift control on aircraft. These tabs are mounted near the trailing edge of lifting surfaces such as aircraft wings and tails, deploy approximately normal to the surface, and have a maximum deployment height on the order of one percent of the section chord. Deployment of the tab effectively changes the sectional camber, thereby changing the aerodynamic characteristics of a lifting surface. Tabs with said deployment height generate a change in the section lift coefficient of approximately ±0.3. The microtab design and the techniques used to fabricate and test the tabs are presented.

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New combinational active control strategy for improving aerodynamic characteristics of airfoil and rotor

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410019893193 ◽

2019 ◽

Vol 234 (4) ◽

pp. 977-996

Author(s):

Yi-yang Ma ◽

Qi-jun Zhao ◽

Guo-qing Zhao

Keyword(s):

Flow Control ◽

Control Strategy ◽

Active Flow Control ◽

Leading Edge ◽

Aerodynamic Characteristics ◽

Synthetic Jet ◽

Dynamic Stall ◽

Trailing Edge ◽

Trailing Edge Flap ◽

Cfd Method

In order to improve the aerodynamic characteristics of rotor, a new active flow control strategy by combining a synthetic jet actuator and a variable droop leading-edge or a trailing-edge flap has been proposed. Their control effects are numerically investigated by computational fluid dynamics (CFD) method. The validated results indicate that variable droop leading-edge and synthetic jet can suppress the formation of dynamic stall vortex and delay flow separation over rotor airfoil. Compared with the baseline state, Cdmax and Cmmax are significantly reduced. Furthermore, parametric analyses on dynamic stall control of airfoil by the combinational method are conducted, and it indicates that the aerodynamic characteristics of the oscillating rotor airfoil can be significantly improved when the non-dimensional frequency ( k*) of variable droop leading-edge is about 1.0. At last, simulations are conducted for the flow control of rotor by the combinational method. The numerical results indicate that large droop angle of variable droop leading-edge can better reduce the torque coefficient of rotor and the trailing-edge flap has the capability of increasing the thrust of rotor. Also, the synthetic jet could further improve the aerodynamic characteristics of rotor.

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Effect of Unguided Turning Angle and Trailing Edge Shape on Cooled Blade Loss

Volume 2C: Turbomachinery ◽

10.1115/gt2014-26215 ◽

2014 ◽

Cited By ~ 1

Author(s):

Andrey Granovskiy ◽

Mikhail Kostege ◽

Vladimir Vassiliev

Keyword(s):

Gas Turbines ◽

Numerical Procedure ◽

Suction Side ◽

Aerodynamic Characteristics ◽

Base Pressure ◽

Trailing Edge ◽

Flow Angle ◽

Generation Mechanisms ◽

Cooled Blade ◽

Blade Loss

A significant part of the overall loss in modern gas turbines is the trailing edge loss. This loss is, more strongly than other constituents, affected by operation, because the trailing edge can significantly change its shape due to degradation. Also by manufacturing of new parts and reconditioning the same tolerances as in other parts of blade lead to higher deviations of aerodynamic characteristics. Therefore the understanding of trailing edge loss generation mechanisms is of utmost importance for a sound blade design. In this work the results of combined experimental and numerical investigation of the trailing edge impact on the transonic cooled blade loss are presented. This study comprises the investigation of the unguided flow angle and the trailing edge shape on the profile losses and a base pressure. The unguided flow angle characterizes the curvature distribution on the aerofoil suction side. The numerical and experimental investigation of transonic cooled turbine cascades have shown that the increase of the unguided flow angle results in loss reduction due to increase of the base pressure downstream of the trailing edge. At the same time the deviation of the trailing edge from a round shape has detrimental effect on performance and conducted investigations allow quantification of this effect. The measurements were performed in a transonic wind tunnel and numerical simulations were done using in-house 2D Navier-Stokes code. The comparison of calculations with measurements showed that they are in reasonable agreement. The validated numerical procedure has been used for demonstration of possibility to reduce loss in aerofoil with thick trailing edge by tuning of the unguided flow angle. The use of the thick trailing edges at HP cooled turbines reduces restriction on tolerances, improves of manufacturability and reduces cost.

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Performance of S-Cambered Profiles With Cut-Off Trailing Edges

Journal of Fluids Engineering ◽

10.1115/1.2910308 ◽

1994 ◽

Vol 116 (3) ◽

pp. 522-527 ◽

Cited By ~ 2

Author(s):

Baby Chacko ◽

V. Balabaskaran ◽

E. G. Tulapurkara ◽

H. C. Radha Krishna

Keyword(s):

Lift Coefficient ◽

Forward Direction ◽

Aerodynamic Characteristics ◽

Reverse Direction ◽

Flow Conditions ◽

Reversed Flow ◽

Trailing Edge ◽

Reverse Mode ◽

Trailing Edges

The aerodynamic characteristics of an S-cambered profile are studied under forward and reversed flow conditions. The profile chord is cut by 3, 6, and 9 percent of the chord at the sharp trailing edge end and the performances of these profiles are compared. It is found that with increase in length of cutting the lift coefficient increases in forward direction and decreases in reverse direction of flow. Cutting off the sharp trailing edge improves the lift-drag characteristics in forward mode and deteriorates in the reverse mode.

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Aerodynamic characteristics of the continuous twisting trailing edge

Active and Passive Smart Structures and Integrated Systems IX ◽

10.1117/12.2558942 ◽

2020 ◽

Author(s):

Pyae Su ◽

Jose Mendoza ◽

Duyen Thi My Nguyen ◽

Eun Jung Chae

Keyword(s):

Aerodynamic Characteristics ◽

Trailing Edge

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Flight Development of the Avro CF-100 Mark 5 Aircraft

Journal of the Royal Aeronautical Society ◽

10.1017/s0368393100068140 ◽

1958 ◽

Vol 62 (566) ◽

pp. 118-122 ◽

Cited By ~ 1

Author(s):

D. C. Whittley

Keyword(s):

Boundary Layer ◽

Shock Wave ◽

Aspect Ratio ◽

Aerodynamic Characteristics ◽

Vortex Generators ◽

High Altitudes ◽

Trailing Edge ◽

Flap Deflection ◽

Performance Gains

SummaryImprovements made to the aerodynamic characteristics of the wing of the Avro CF-100 Mark 5 aircraft are discussed. Modifications to the wing included increase in aspect ratio, addition of vortex generators, and deflection of trailing edge plain flaps. The effect of flap deflection and addition of vortex generators on the aerodynamic characteristics of the wing are shown to be closely associated with interaction of the upper surface shock wave with the boundary layer. Performance gains were demonstrated at high subsonic speeds at high altitudes. Vortex generators improved the buffet boundary, whereas flap deflection both increased aircraft ceiling and improved buffet boundary.

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Numerical assessment of a deformable trailing-edge flap on aerodynamic load control of a pitching S809 airfoil using OpenFOAM

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650919838142 ◽

2019 ◽

Vol 233 (7) ◽

pp. 890-900

Author(s):

Mahbod Seyednia ◽

Mehran Masdari ◽

Shidvash Vakilipour

Keyword(s):

Phase Shift ◽

Flow Control ◽

Hysteresis Loops ◽

Aerodynamic Characteristics ◽

Aerodynamic Load ◽

Trailing Edge ◽

Numerical Work ◽

Pitching Motion ◽

Trailing Edge Flap ◽

Fatigue Loads

Due to the unsteady nature of the flow around horizontal-axis wind turbines, the blades are subjected to severe unsteady and fatigue loads. This necessitates an in-depth aerodynamic analysis of flow control techniques to enhance the performance of a wind turbine as well as the lifetime of its components. Using OpenFOAM package in this study, a series of two-dimensional incompressible simulations are performed to present a deeper insight into the aerodynamic characteristics of an oscillating deformable trailing-edge flap, as a promising flow control device, in a sinusoidal pitching motion of an S809 airfoil. Herein, it is of particular interest to investigate the effects of deformable trailing-edge flap size, oscillation frequency, and the phase shift with reference to airfoil motion on lift and drag hysteresis loops. For this purpose, a pure-pitching motion of an S809 airfoil without flap deflection is considered as the benchmark problem in which the airfoil oscillates in the near-stall region at [Formula: see text]. After validation and verification of our simulations through comparison against the corresponding experimental and numerical work, a comprehensive investigation is conducted to study the effects of the aforementioned parameters on the aerodynamic loads. Our results reveal the fact that an out-of-phase deflection of the deformable trailing-edge flap with a frequency equal to the airfoil frequency can significantly mitigate the fatigue load. Under these circumstances, an increase in the deformable trailing-edge flap size can also help the airfoil experience less-severe loads in a cycle of motion. Furthermore, higher values of deformable trailing-edge flap frequency or other values of phase shift except the out-of-phase oscillation cannot alleviate fatigue loads. An airfoil under these conditions can, however, enhance the resultant load required for a blade rotation in the case of low wind periods.

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AERODYNAMIC CHARACTERISTIC OF THE ACTIVE COMPLIANT TRAILING EDGE CONCEPT

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194516601733 ◽

2016 ◽

Vol 42 ◽

pp. 1660173

Author(s):

RUI NIE ◽

JINHAO QIU ◽

HONGLI JI ◽

DAWEI LI

Keyword(s):

Flow Separation ◽

Aerodynamic Characteristic ◽

High Strength ◽

Aerodynamic Characteristics ◽

Structure Design ◽

Field Analysis ◽

Design Parameters ◽

Morphing Wing ◽

Trailing Edge ◽

Noise Characteristics

This paper introduces a novel Morphing Wing structure known as the Active Compliant Trailing Edge (ACTE). ACTE structures are designed using the concept of “distributed compliance” and wing skins of ACTE are fabricated from high-strength fiberglass composites laminates. Through the relative sliding between upper and lower wing skins which are connected by a linear guide pairs, the wing is able to achieve a large continuous deformation. In order to present an investigation about aerodynamics and noise characteristics of ACTE, a series of 2D airfoil analyses are established. The aerodynamic characteristics between ACTE and conventional deflection airfoil are analyzed and compared, and the impacts of different ACTE structure design parameters on aerodynamic characteristics are discussed. The airfoils mentioned above include two types (NACA0012 and NACA64A005.92). The computing results demonstrate that: compared with the conventional plane flap airfoil, the morphing wing using ACTE structures has the capability to improve aerodynamic characteristic and flow separation characteristic. In order to study the noise level of ACTE, flow field analysis using LES model is done to provide noise source data, and then the FW-H method is used to get the far field noise levels. The simulation results show that: compared with the conventional flap/aileron airfoil, the ACTE configuration is better to suppress the flow separation and lower the overall sound pressure level.

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