Flow Control with Synthetic Jet Actuators under Adverse Pressure Gradient Laminar Boundary Layer

2014 ◽  
Author(s):  
Melika Gül ◽  
Oguz Uzol ◽  
İ. Sinan Akmandor
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Flow Control ◽  
Laminar Boundary Layer ◽  
Adverse Pressure Gradient ◽  
Synthetic Jet ◽  
Synthetic Jet Actuators ◽  
Jet Actuators

scholarly journals Investigation into clustering of synthetic jet actuators for flow separation control applications

2005 ◽  
Vol 109 (1091) ◽  
pp. 35-44 ◽  
Author(s):  
S. C. Liddle ◽  
N. J. Wood
Keyword(s):  
Boundary Layer ◽  
Flow Control ◽  
Input Signal ◽  
Streamwise Velocity ◽  
Synthetic Jet ◽  
Small Scale ◽  
Signal Phase ◽  
Control Applications ◽  
Synthetic Jet Actuators ◽  
Jet Actuators

Abstract An investigation into the behaviour of clustered synthetic jet Actuators for flow-control applications is described. Experiments have been undertaken with two small-scale synthetic jet actuators in a zero-pressure gradient boundary-layer, in order to investigate the effect of configuration yaw angle and relative input signal phase. Oil-flow visualisation and hotwire anemometry techniques were used, demonstrating that changes in the downstream flow structure could be observed. Compared to a streamwise configuration, in which a symmetrical counter-rotating vortex pair was produced by the synthetic jet-boundary-layer interaction, a broader asymmetric interaction was produced in a 15° yaw configuration. Streamwise velocity contour plots, illustrating the development of the interaction downstream, over four phase angles, were presented. Significant differences in the PSD analyses of downstream streamwise velocity time histories were found, suggesting that input signal phase could influence the stability and hence effectiveness of flow structures used in flow-control applications.

Turbine Cascade Flow Control Using a “Wake Filling” Pulsed Plasma Actuator

2005 ◽  
Author(s):  
H. Perez-Blanco ◽  
Robert Van Dyken ◽  
Aaron Byerley ◽  
Tom McLaughlin
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Laminar Boundary Layer ◽  
Separation Bubble ◽  
Adverse Pressure Gradient ◽  
Suction Side ◽  
Plasma Actuator ◽  
Pulsed Plasma ◽  
Power Cost ◽  
Hot Film

Separation bubbles in high-camber blades under part-load conditions have been addressed via continuous and pulsed jets, and also via plasma actuators. Numerous passive techniques have been employed as well. In this type of blades, the laminar boundary layer cannot overcome the adverse pressure gradient arising along the suction side, resulting on a separation bubble. When separation is abated, a common explanation is that kinetic energy added to the laminar boundary layer speeds up its transition to turbulent. In the present study, a plasma actuator installed in the trailing edge (i.e. “wake filling configuration”) of a cascade blade is used to excite the flow in pulsed and continuous ways. The pulsed excitation can be directed to the frequencies of the large coherent structures (LCS) of the flow, as obtained via a hot-film anemometer, or to much higher frequencies present in the suction-side boundary layer, as given in the literature. It is found that pulsed frequencies much higher than that of LCS reduce losses and improve turning angles further than frequencies close to those of LCS. With the plasma actuator 50% on time, good loss abatement is obtained. Larger “on time” values yield improvements, but with decreasing returns. Continuous high-frequency activation results in the largest loss reduction, at increased power cost. The effectiveness of high frequencies may be due to separation abatement via boundary layer excitation into transition, or may simply be due to the creation of a favorable pressure gradient that averts separation as the actuator ejects fluid downstream. Both possibilities are discussed in light of the experimental evidence.

10703 Study on condition of synthetic jet actuators for flow control around pantograph panhead using CFD analysis

2013 ◽  
Vol 2013.19 (0) ◽  
pp. 99-100
Author(s):  
Yasushi TAKANO ◽  
Takafumi OZAWA ◽  
Takeshi Mitsumodi ◽  
Yuichi SATO ◽  
Mitsuru IKEDA ◽  
...  
Keyword(s):  
Flow Control ◽  
Synthetic Jet ◽  
Cfd Analysis ◽  
Synthetic Jet Actuators ◽  
Jet Actuators
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