scholarly journals Supersonic Turbulent Boundary-Layer Separation Control Using a Morphing Surface

AIAA Journal ◽  
2021 ◽  
pp. 1-15
Author(s):  
Vilas J. Shinde ◽  
Datta V. Gaitonde ◽  
Jack J. McNamara
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Separation ◽  
Separation Control ◽  
Layer Separation

Turbulent boundary layer separation control and loss evaluation of low profile vortex generators

2011 ◽  
Vol 35 (8) ◽  
pp. 1505-1513 ◽  
Author(s):  
Davide Lengani ◽  
Daniele Simoni ◽  
Marina Ubaldi ◽  
Pietro Zunino ◽  
Francesco Bertini
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Separation ◽  
Vortex Generators ◽  
Separation Control ◽  
Layer Separation ◽  
Low Profile

Experimental study of laminar and turbulent boundary layer separation control of shark skin

2016 ◽  
Vol 12 (1) ◽  
pp. 016009 ◽  
Author(s):  
Farhana Afroz ◽  
Amy Lang ◽  
Maria Laura Habegger ◽  
Philip Motta ◽  
Robert Hueter
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Separation ◽  
Separation Control ◽  
Shark Skin ◽  
Layer Separation

scholarly journals Turbulent boundary layer separation control using plasma actuator at Reynolds number 2000000

2016 ◽  
Vol 29 (5) ◽  
pp. 1237-1246 ◽  
Author(s):  
Xin Zhang ◽  
Yong Huang ◽  
Xunnian Wang ◽  
Wanbo Wang ◽  
Kun Tang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Separation ◽  
Plasma Actuator ◽  
Separation Control ◽  
Layer Separation

Turbulent Boundary Layer Separation Control by Using DBD Plasma Actuators: Part I—Experimental Investigation

2010 ◽  
Author(s):  
Xiaofei Xu ◽  
Huu Duc Vo ◽  
Njuki Mureithi ◽  
Xue Feng Zhang
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Separation ◽  
Plasma Actuators ◽  
Separation Control ◽  
Dbd Plasma ◽  
Control Techniques ◽  
Layer Separation ◽  
Plasma Actuation ◽  
Turbulent Separation

Turbulent boundary layer separation is an important issue for a variety of applications, one of which is S-shaped aircraft engine intakes. The turbulent separation at the engine intake causes inlet flow distortion, which can deteriorate engine performance, cause fatigue and reduce engine component life. Various flow control techniques have been applied for turbulent boundary layer separation control, such as vortex generators, vortex generator jets and synthetic jets. The recent advent of dielectric barrier discharge (DBD) plasma actuators can potentially provide a robust method for the control of turbulent boundary layer separation. Compared to other flow control techniques, these new actuators are simple, robust and devoid of moving mechanical parts, which make them ideal for aerodynamic applications. The present work studies the effects of DBD plasma actuators on the suppression of 2-D turbulent boundary layer separation induced by an imposed adverse pressure gradient. First, the flow field with and without actuation in a low-speed wind tunnel is investigated experimentally by Particle Image Velocimetry (PIV) measurements. The results show that plasma actuation can suppress turbulent boundary layer separation in both continuous and pulsed modes. In the pulsed mode, the actuation with an optimal actuation frequency, corresponding to a dimensionless frequency of order one, is found to most effectively suppress the turbulent separation. Moreover, the effects of plasma actuation on the flow is demonstrated and analyzed by using Proper Orthogonal Decomposition (POD). The effect of the actuation is found to be correlated to the second POD mode which corresponds to large flow fluctuations.

Instantaneous Behavior of Streamwise Vortices for Turbulent Boundary Layer Separation Control

2006 ◽  
Vol 129 (2) ◽  
pp. 226-235 ◽  
Author(s):  
K. P. Angele ◽  
F. Grewe
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Separation Bubble ◽  
Vortex Generator ◽  
Boundary Layer Separation ◽  
Separation Control ◽  
Streamwise Vortices ◽  
Layer Separation ◽  
Vortex Size ◽  
The Mean

The present study investigates turbulent boundary layer separation control by means of streamwise vortices with focus on the instantaneous vortex behavior. A turbulent boundary layer is exposed to a pressure gradient that generates a separation bubble with substantial backflow. The separation bubble is controlled by conventional passive vortex generators creating pairs of counterrotating vortices. Quantitative information is achieved by applying Particle Image Velocimetry (PIV) to the cross-stream plane of the vortices. The characteristics of a pair of counter-rotating vortices shed from a vortex generator is investigated in the near-field downstream of the vortex generator. The vortices were found to grow with the boundary layer in the downstream direction, and the maximum vorticity decreases as the circulation is conserved. The vortices are nonstationary, and the movements in the spanwise direction are larger than those in the wall-normal direction, due to the presence of the wall. The vortices fluctuate substantially and move over a spanwise distance, which is approximately equal to their size. The most probable instantaneous separation between the two vortices shed from one vortex generator equals the difference between their mean positions. The unsteadiness of the vortices contributes to the observed maxima in the Reynolds stresses around the mean vortex centers. The instantaneous vortex size and the instantaneous maximum vorticity are also fluctuating properties, and the instantaneous vortex is generally smaller and stronger than the mean vortex. A correlation was found between a large instantaneous vortex size and a low instantaneous maximum vorticity (and vice versa), suggesting that the vortices are subjected to vortex stretching.

Sign in / Sign up

Export Citation Format

Share Document