An Active Flap Deployment System for Blade–Disturbance Interaction Alleviation

2004 ◽  
Vol 126 (6) ◽  
pp. 1006-1014 ◽  
Author(s):  
Carter T. Nelson ◽  
Othon K. Rediniotis
Keyword(s):  
Vortex Generator ◽  
Leading Edge ◽  
Experimental Tests ◽  
Design Tool ◽  
Trailing Edge ◽  
Blade Vortex Interaction ◽  
Aeroelastic Model ◽  
Trailing Edge Flap ◽  
Ultimate Objective ◽  
Active Flap

A new, actively deployable trailing edge flap system is introduced and an experimental investigation is undertaken to determine its effects on the disturbances created during blade–disturbance interactions (BDI), with blade–vortex interaction (BVI) alleviation being the ultimate objective. Experimental tests were conducted using a two-dimensional (2D) wind tunnel setup incorporating a pressure instrumented airfoil section with a deployable 20% trailing edge flap and an upstream vortex generator to produce the disturbance. Results of this study showed that the disturbances, caused by BDI events, to the pressure distribution over the airfoil occur mostly at the leading edge. Carefully synchronized deployment of the trailing edge flap during BDI events resulted in a reduction of this pressure disturbance. The aeroelastic response of the active flap was modeled via unsteady linear theory and the model was validated experimentally. The aeroelastic model shows good agreement with experimental results, which supports its use as a preliminary design tool for the actuation parameters of the active flap system.

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

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.

scholarly journals High-Bandwidth Morphing Actuator for Aeroelastic Model Control

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 13 ◽  
Author(s):  
Sebastiano Fichera ◽  
Irma Isnardi ◽  
John E. Mottershead
Keyword(s):  
Experimental Tests ◽  
Flight Mechanics ◽  
Light Weight ◽  
Servo Motor ◽  
Trailing Edge ◽  
Aeroelastic Model ◽  
Model Control ◽  
High Bandwidth ◽  
Design And Testing

The design and testing of a high-bandwidth continuous actuator for aeronauticalapplications is presented hereinafter. The actuator has a dual goal of controlling both the aeroelasticbehaviour and the flight mechanics of the model in which it is installed. In order to achieve theseaims, the actuation bandwidth of the active aerofoil, as well as its static camber variation, have to besufficiently high. The camber morph is achieved by using tailored piezoelectric patches in a sandwichconfiguration with a linear trailing edge slider to allow the necessary compliance. The morphingactuator is designed for a NACA 0018 aerofoil with a chord of 300mmand a span of 40 mm. Static anddynamic experimental tests are carried out on a prototype, and a camber variation control techniqueis implemented. It is proved that the actuator bandwidth is up to 25 Hz and the equivalent maximumdeflection is 15 degrees. This solution is shown to be a viable light-weight alternative to theconventional brushless/servo-motor approach currently used in aeroelastic models.

Trailing edge flap influence on leading edge vortex flap aerodynamics

1983 ◽  
Vol 20 (2) ◽  
pp. 165-169 ◽  
Author(s):  
Arthur C. Grantz ◽  
J. F. Marchman
Keyword(s):  
Leading Edge ◽  
Trailing Edge ◽  
Leading Edge Vortex ◽  
Edge Vortex ◽  
Trailing Edge Flap

Aerodynamic Aspects of Boundary Layer Control for High Lift at Low Speeds

1963 ◽  
Vol 67 (628) ◽  
pp. 201-223 ◽  
Author(s):  
John Williams ◽  
Sidney F. J. Butler
Keyword(s):  
Boundary Layer ◽  
Leading Edge ◽  
Boundary Layer Control ◽  
Trailing Edge ◽  
High Lift ◽  
Air Jets ◽  
Slot Suction ◽  
Trailing Edge Flaps ◽  
Trailing Edge Flap ◽  
Layer Control

Summary:The usefulness of boundary-layer control (B.L.C.) at the knee of a trailing-edge flap, over the wing nose close to the leading-edge or at the knee of a leading-edge flap is first noted. Various methods of providing B.L.C. are outlined, comprising slot blowing, slot suction, area suction, inclined air-jets, and specially-designed aerofoil shapes. The aerodynamic aspects of slot blowing over trailing-edge flaps and the wing nose are then examined in detail and both slot suction and area suction are also considered. The associated practical design features required for good performance are discussed and some flight-handling implications are mentioned.

Stall Delay and Leading-Edge Suction for a Pitching Airfoil with Trailing-Edge Flap

AIAA Journal ◽  
2020 ◽  
Vol 58 (12) ◽  
pp. 5146-5155
Author(s):  
Guosheng He ◽  
Julien Deparday ◽  
Lars Siegel ◽  
Arne Henning ◽  
Karen Mulleners
Keyword(s):  
Leading Edge ◽  
Trailing Edge ◽  
Pitching Airfoil ◽  
Trailing Edge Flap

Three-Dimensional and Rotational Aerodynamics on the NREL Phase VI Wind Turbine Blade

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Alvaro Gonzalez ◽  
Xabier Munduate
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Three Dimensional ◽  
Separated Flow ◽  
Leading Edge ◽  
Wind Turbine Blade ◽  
Trailing Edge ◽  
Rotating Blade ◽  
Nrel Phase Vi ◽  
Edge Separation

This work undertakes an aerodynamic analysis over the parked and the rotating NREL Phase VI wind turbine blade. The experimental sequences from NASA Ames wind tunnel selected for this study respond to the parked blade and the rotating configuration, both for the upwind, two-bladed wind turbine operating at nonyawed conditions. The objective is to bring some light into the nature of the flow field and especially the type of stall behavior observed when 2D aerofoil steady measurements are compared to the parked blade and the latter to the rotating one. From averaged pressure coefficients together with their standard deviation values, trailing and leading edge separated flow regions have been found, with the limitations of the repeatability of the flow encountered on the blade. Results for the parked blade show the progressive delay from tip to root of the trailing edge separation process, with respect to the 2D profile, and also reveal a local region of leading edge separated flow or bubble at the inner, 30% and 47% of the blade. For the rotating blade, results at inboard 30% and 47% stations show a dramatic suppression of the trailing edge separation, and the development of a leading edge separation structure connected with the extra lift.

Steady longitudinal vortices in supersonic turbulent separated flows

2011 ◽  
Vol 672 ◽  
pp. 451-476 ◽  
Author(s):  
ERICH SCHÜLEIN ◽  
VICTOR M. TROFIMOV
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Roughness Element ◽  
Vortex Generator ◽  
Vortex Pair ◽  
Leading Edge ◽  
Separated Flows ◽  
Vortex Generators ◽  
Longitudinal Vortices ◽  
Oil Flow

Large-scale longitudinal vortices in high-speed turbulent separated flows caused by relatively small irregularities at the model leading edges or at the model surfaces are investigated in this paper. Oil-flow visualization and infrared thermography techniques were applied in the wind tunnel tests at Mach numbers 3 and 5 to investigate the nominally 2-D ramp flow at deflection angles of 20°, 25° and 30°. The surface contour anomalies have been artificially simulated by very thin strips (vortex generators) of different shapes and thicknesses attached to the model surface. It is shown that the introduced streamwise vortical disturbances survive over very large downstream distances of the order of 104 vortex-generator heights in turbulent supersonic flows without pressure gradients. It is demonstrated that each vortex pair induced in the reattachment region of the ramp is definitely a child of a vortex pair, which was generated originally, for instance, by the small roughness element near the leading edge. The dependence of the spacing and intensity of the observed longitudinal vortices on the introduced disturbances (thickness and spanwise size of vortex generators) and on the flow parameters (Reynolds numbers, boundary-layer thickness, compression corner angles, etc.) has been shown experimentally.

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