scholarly journals Clarification of Unsteady Characteristics in Separated Flow over Axisymmetric Paraboloid at High Angles of Attack.

2000 ◽  
Vol 48 (562) ◽  
pp. 377-384 ◽  
Author(s):  
Tadateru ISHIDE ◽  
Nobuhide NISHIKAWA ◽  
Fumihiko MIKAMI
Keyword(s):  
Separated Flow ◽  
Unsteady Characteristics ◽  
High Angles Of Attack

Plasma Control of Separated Flow Asymmetry on a Cone at High Angles of Attack

2004 ◽  
Author(s):  
A. Maslov ◽  
B. Zanin ◽  
A. Sidorenko ◽  
V. Fomichev ◽  
A. Pavlov ◽  
...  
Keyword(s):  
Separated Flow ◽  
Flow Asymmetry ◽  
High Angles Of Attack ◽  
Plasma Control

scholarly journals On the prospects of improving the numerical analysis of symmetric airfoils at low Reynolds numbers and high angles of attack by a LES approach: the case of NACA0021 profile

2020 ◽  
Vol 197 ◽  
pp. 08015
Author(s):  
Simone Giaccherini ◽  
Filippo Mariotti ◽  
Lorenzo Pinelli ◽  
Michele Marconcini ◽  
Alessandro Bianchini
Keyword(s):  
Turbine Blades ◽  
Separated Flow ◽  
Reynolds Numbers ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
High Fidelity ◽  
Complex Flow ◽  
Energy Applications ◽  
Low Reynolds ◽  
High Angles Of Attack

The working conditions of airfoils along modern wind turbine blades are putting new focus on the importance of properly characterizing the aerodynamic performance of different airfoil families also at high angles of attack (AoAs) beyond stall and at Reynolds numbers much lower (from few thousands to one million) than those commonly analyzed before. Several test cases are showing that even higher-order computational methods (like RANS/URANS CFD) are unable to properly capture the complex flow physics taking place past the blades, when deep stall occurs or when the AoA changes so rapidly to provoke the onset of dynamic stall. To fill this gap, the use of high-fidelity methods, like the Large Eddy Simulation (LES) is proposed, even though it implies a massive increase of the calculation cost. In order to analyze the prospects of using LES in comparison to RANS for low Reynolds, high AoAs, this work presents an in-depth study of the NACA 0021 aerodynamics at the Reynolds number of 80,000, by means of both traditional RANS approaches and high-fidelity (LES) simulations using the OpenFOAM suite. The selected airfoil has been showing in fact several issues in the correct characterization of its performance in similar conditions in many recent wind energy applications. The LES approach showed the ability to overcome the limitations of traditional RANS simulations, improving the accuracy of the results and reducing their dispersion thanks to the fact that the flow structures in the separated-flow regions are properly captured. Overall, this work underlines that accurate investigations of the aerodynamic performance of the NACA 0021 at low Reynolds require multiple sensitivity studies when RANS approaches are used, and suggests the use of LES simulations in order to increase the accuracy of estimations, especially when studying the stalledflow operating conditions of the airfoil.

scholarly journals The Visualization of Separated Flow over Slender Bodies at High Angles of Attack.

1994 ◽  
Vol 14 (55) ◽  
pp. 243-252 ◽  
Author(s):  
Mingyang JIA ◽  
Tadaharu WATANUKI ◽  
Hirotoshi KUBOTA
Keyword(s):  
Separated Flow ◽  
Slender Bodies ◽  
High Angles Of Attack

High Angle of Attack Missile Aerodynamics

1993 ◽  
Vol 207 (1) ◽  
pp. 15-19
Author(s):  
P C Dexter
Keyword(s):  
Angle Of Attack ◽  
Separated Flow ◽  
The Body ◽  
Major Influence ◽  
Control Problems ◽  
High Angle ◽  
High Angle Of Attack ◽  
Wing Stall ◽  
High Angles Of Attack

A major influence in the aerodynamics of missiles is the significant amount of separated flow encountered for most flight conditions. This flow may be of an ordered nature, forming vortices, or random, such as encountered in wing stall. At high angles of attack the vortices of the body leeside flow may become unpredictably asymmetric, even on geometrically symmetric configurations, and their interactions with wing and tail panels can result in possible control problems. The modelling of such flows both accurately and easily is beyond present capabilities.

scholarly journals The Vizualization of Separated Flow over Slender Bodies at High Angles of Attack

1992 ◽  
Vol 12 (1Supplement) ◽  
pp. 203-205
Author(s):  
Mingyang JIA ◽  
Tadaharu WATANUKI ◽  
Hirotoshi KUBOTA
Keyword(s):  
Separated Flow ◽  
Slender Bodies ◽  
High Angles Of Attack

Effective plasma buffet and drag control for laminar transonic aerofoil

2018 ◽  
Vol 234 (1) ◽  
pp. 58-67
Author(s):  
Pavel A Polivanov ◽  
Andrey A Sidorenko ◽  
Anatoly A Maslov
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Laminar Boundary Layer ◽  
High Efficiency ◽  
Separated Flow ◽  
Plasma Actuators ◽  
Layer Interaction ◽  
Boundary Layer Interaction ◽  
Unsteady Characteristics ◽  
Transonic Buffet

The effect of plasma actuators on shock wave–laminar boundary layer interaction was studied experimentally on transonic laminar aerofoil. The unsteady characteristics of the separation zone including the transonic buffet were measured. Two kinds of electrical discharge actuators were used for the flow control. Successful suppression of separated flow and laminar transonic buffet by plasma actuators was demonstrated. An analysis of the effect of power and frequency of the discharge on shock wave–laminar boundary layer interaction was carried out. High efficiency ratio of the separation control by plasma actuators was achieved in the experiments.

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