Active Control of Leading Edge Separation Within the German Flow Control Network

2009 ◽  
Author(s):  
Peter Scholz ◽  
Christian Kähler ◽  
Rolf Radespiel ◽  
Jochen Wild ◽  
Georg Wichmann
Keyword(s):  
Flow Control ◽  
Active Control ◽  
Leading Edge ◽  
Control Network ◽  
Edge Separation

Flow Control on a Transport Truck Side Mirror Using Plasma Actuators

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Theodoros Michelis ◽  
Marios Kotsonis
Keyword(s):  
Flow Control ◽  
Guide Vane ◽  
Leading Edge ◽  
Plasma Actuator ◽  
Plasma Actuators ◽  
Dbd Plasma ◽  
Reference Case ◽  
Image Velocimetry ◽  
Wind Tunnel Study ◽  
Edge Separation

A wind tunnel study is conducted toward hybrid flow control of a full scale transport truck side mirror at ReD=3.2×105. A slim guide vane is employed for redirecting high-momentum flow toward the mirror wake region. Leading edge separation from the guide vane is reduced or eliminated by means of an alternating current -dielectric barrier discharge (AC-DBD) plasma actuator. Particle image velocimetry (PIV) measurements are performed at a range of velocities from 15 to 25 m/s and from windward to leeward angles from -5deg to 5deg. Time-averaged velocity fields are obtained at the center of the mirror for three scenarios: (a) reference case lacking any control elements, (b) guide vane only, and (c) combination of the guide vane and the AC-DBD plasma actuator. The comparison of cases demonstrates that at 25 m/s windward conditions (-5deg) the guide vane is capable of recovering 17% momentum with respect to the reference case. No significant change is observed by activating the AC-DBD plasma actuator. In contrast, at leeward conditions (5deg), the guide vane results in a −20% momentum loss that is rectified to a 6% recovery with actuation. The above implies that for a truck with two mirrors, 23% of momentum may be recovered.

scholarly journals Separated Flow Control of Small Horizontal-Axis Wind Turbine Blades Using Dielectric Barrier Discharge Plasma Actuators

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1218 ◽  
Author(s):  
Hikaru Aono ◽  
Hiroaki Fukumoto ◽  
Yoshiaki Abe ◽  
Makoto Sato ◽  
Taku Nonomura ◽  
...  
Keyword(s):  
Flow Control ◽  
Discharge Plasma ◽  
Barrier Discharge ◽  
Leading Edge ◽  
Dielectric Barrier Discharge Plasma ◽  
Horizontal Axis Wind Turbine ◽  
Dielectric Barrier ◽  
Torque Generation ◽  
Barrier Discharge Plasma ◽  
Edge Separation

The flow control over the blades of a small horizontal-axis wind turbine (HAWT) model using a dielectric barrier discharge plasma actuator (DBD-PA) was studied based on large-eddy simulations. The numerical simulations were performed with a high-resolution computational method, and the effects of the DBD-PA on the flow fields around the blades were modeled as a spatial body force distribution. The DBD-PA was installed at the leading edge of the blades, and its impacts on the flow fields and axial torque generation were discussed. The increase in the ratios of the computed, cycle-averaged axial torque reasonably agreed with that of the available experimental data. In addition, the computed results presented a maximum of 19% increase in the cycle-averaged axial torque generation by modulating the operating parameters of the DBD-PA because of the suppression of the leading edge separation when the blade’s effective angles of attack were relatively high. Thus, the suppression of the leading edge separation by flow control can lead to a delay in the breakdown of the tip vortex as a secondary effect.

Dynamic Roughness as a Means of Leading-Edge Separation Flow Control

2012 ◽  
Vol 49 (1) ◽  
pp. 108-115 ◽  
Author(s):  
W. W. Huebsch ◽  
P. D. Gall ◽  
S. D. Hamburg ◽  
A. P. Rothmayer
Keyword(s):  
Flow Control ◽  
Leading Edge ◽  
Separation Flow ◽  
Dynamic Roughness ◽  
Edge Separation

scholarly journals Flow control of leading edge separation using DBD plasma actuator

2014 ◽  
Vol 80 (813) ◽  
pp. FE0118-FE0118 ◽  
Author(s):  
Yasuaki KOZATO ◽  
Yuta HIROSE ◽  
Satoshi KIKUCHI ◽  
Shigeki IMAO
Keyword(s):  
Flow Control ◽  
Leading Edge ◽  
Plasma Actuator ◽  
Dbd Plasma ◽  
Edge Separation

scholarly journals A Critical Review of Supersonic Flow Control for High-Speed Applications

2021 ◽  
Vol 11 (15) ◽  
pp. 6899
Author(s):  
Abdul Aabid ◽  
Sher Afghan Khan ◽  
Muneer Baig
Keyword(s):  
Supersonic Flow ◽  
Flow Control ◽  
Active Control ◽  
Critical Review ◽  
High Speed ◽  
Passive Control ◽  
Control Method ◽  
Sudden Expansion ◽  
Control Approach ◽  
Cost Efficient

In high-speed fluid dynamics, base pressure controls find many engineering applications, such as in the automobile and defense industries. Several studies have been reported on flow control with sudden expansion duct. Passive control was found to be more beneficial in the last four decades and is used in devices such as cavities, ribs, aerospikes, etc., but these need additional control mechanics and objects to control the flow. Therefore, in the last two decades, the active control method has been used via a microjet controller at the base region of the suddenly expanded duct of the convergent–divergent (CD) nozzle to control the flow, which was found to be a cost-efficient and energy-saving method. Hence, in this paper, a systemic literature review is conducted to investigate the research gap by reviewing the exhaustive work on the active control of high-speed aerodynamic flows from the nozzle as the major focus. Additionally, a basic idea about the nozzle and its configuration is discussed, and the passive control method for the control of flow, jet and noise are represented in order to investigate the existing contributions in supersonic speed applications. A critical review of the last two decades considering the challenges and limitations in this field is expressed. As a contribution, some major and minor gaps are introduced, and we plot the research trends in this field. As a result, this review can serve as guidance and an opportunity for scholars who want to use an active control approach via microjets for supersonic flow problems.

Rotational temperature imaging of a leading-edge separation in hypervelocity flow

2019 ◽  
Author(s):  
Laurent M. Le Page ◽  
Matthew Barrett ◽  
Sean O’Byrne ◽  
Sudhir L. Gai
Keyword(s):  
Rotational Temperature ◽  
Leading Edge ◽  
Temperature Imaging ◽  
Edge Separation

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.

Flow Control for an Airfoil with Leading-Edge Rotation: An Experimental Study

2000 ◽  
Vol 37 (4) ◽  
pp. 617-622 ◽  
Author(s):  
Ahmed Z. Al-Garni ◽  
Abdullah M. Al-Garni ◽  
Saad A. Ahmed ◽  
Ahmet Z. Sahin
Keyword(s):  
Experimental Study ◽  
Flow Control ◽  
Leading Edge
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