The Effect of Orifice Angle and Cavity Dimension on Rectangular Synthetic Jet Actuators

2011 ◽  
Author(s):  
Pooya Kabiri ◽  
Douglas G. Bohl ◽  
Goodarz Ahmadi
Keyword(s):  
Particle Image ◽  
Vortical Structure ◽  
Active Flow Control ◽  
Cross Flow ◽  
Synthetic Jet ◽  
Synthetic Jet Actuators ◽  
Image Velocimetry ◽  
Jet Actuators ◽  
Active Flow ◽  
Analytic Prediction

In the last decade, a great deal of interest has been focused on the application of synthetic jet actuators (SJA) for active flow control. SJAs delay separation by injecting vortex pairs into the cross flow and energizing the turbulent boundary layer. The goal of this study was to investigate the effects of the orifice angle on the performance of axisymmetric SJAs. The SJAs used in this experiment were composed of a piezoelectric (PZT) membrane, cavities and orifices. SJA’s with either a straight (90°) or angled (60°) orifices were characterized using hot-wire anemometry and Particle Image Velocimetry (PIV). It was found that the structure of the jet flow changed depending on the angle of the orifice with differences in the resulting vortical structure observed. The peak jet speed was found to be higher for the straight orifice than for the angled orifice contradicting the analytic prediction based on cavity dimension.

Development of synthetic jet actuators for active flow control at NASA Langley

2000 ◽  
Author(s):  
Fang-Jenq Chen ◽  
Chungsheng Yao ◽  
George Beeler ◽  
Robert Bryant ◽  
Robert Fox
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Synthetic Jet ◽  
Synthetic Jet Actuators ◽  
Jet Actuators ◽  
Active Flow

Particle image velocimetry of active flow control on a compressor cascade

2010 ◽  
Vol 50 (4) ◽  
pp. 799-811 ◽  
Author(s):  
M. Hecklau ◽  
R. van Rennings ◽  
V. Zander ◽  
W. Nitsche ◽  
A. Huppertz ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Control ◽  
Particle Image ◽  
Active Flow Control ◽  
Compressor Cascade ◽  
Image Velocimetry ◽  
Active Flow

Examination of a Variable-Diameter Synthetic Jet

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Spencer O. Albright ◽  
Stephen A. Solovitz
Keyword(s):  
Particle Image Velocimetry ◽  
Vortex Ring ◽  
Mass Flux ◽  
Particle Image ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Variable Diameter ◽  
Constant Diameter ◽  
Image Velocimetry ◽  
Jet Actuators

Synthetic jet actuators are used to produce net axial momentum flow without net mass flux. Through strategic application, such devices can be used for flow control, propulsive thrust, and cooling. A novel application uses a variable-diameter orifice to constrict the exiting flow, and the motion can be synchronized with the pulse of the jet. This device is examined using phase-locked particle image velocimetry (PIV), permitting investigation of the flow fields and momentum flow. When compared to fixed-diameter synthetic jets, the variable-diameter actuator produces a larger vortex ring that lingers nearer the aperture. In addition, the experiments show increased momentum when the aperture is contracted in phase with the pulsing jet, with peak levels more than twice that of a constant-diameter jet.

Experimental Study of the Dynamics of Synthetic Jet Actuators With Different Orifice Sizes

2005 ◽  
Author(s):  
Rahul Sekhri ◽  
Marco P. Schoen ◽  
Feng Lin ◽  
Brian G. Williams
Keyword(s):  
Experimental Study ◽  
Sound Pressure ◽  
Closed Loop ◽  
Solid Wall ◽  
Mechanical Vibration ◽  
Synthetic Jet ◽  
Control Laws ◽  
Synthetic Jet Actuators ◽  
Jet Actuators ◽  
Active Flow

Synthetic jet actuators (SJA) are one of the newly developed actuators that have demonstrated its great potentials in active flow applications, particularly in closed-loop flow controls. The SJA contains a piezoelectric membrane in a cavity, which vibrates and generates a periodic jet at the exit of the cavity through an orifice that is mounted flush with the solid wall of the flow field. In order to design the feedback control laws, it is crucial to be able to quantitatively capture the dynamics of SJA. In this paper, the dynamics of SJAs with six different orifice sizes are experimentally investigated. A synthesis using system identification for the purpose of constructing mathematical models of these zero mass-flux actuators is offered. The experimental study includes two output parameters, the acoustic sound pressure generated by the SJA and the mechanical membrane vibration of the SJA. State-space models for these outputs (sound pressure and mechanical vibration) are developed as a function of orifice size. These results form a foundation for future intelligent design of SJA.

A Flow Study of Pulsed Jet Cross-Flow Interaction by Micro Particle Image Velocimetry

2006 ◽  
Author(s):  
Kenichi Watanabe ◽  
Tomonori Nakatsuka ◽  
Daichi Suzuki ◽  
Takashi Nagumo ◽  
Masahiro Motosuke ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Particle Image Velocimetry ◽  
Flow Control ◽  
Particle Image ◽  
Low Reynolds Number ◽  
Cross Flow ◽  
Synthetic Jet ◽  
Pulsed Jet ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry

Recent development of micro devices is remarkable as in the examples of Micro-TAS, Lab-on-a-chip or ultra micro gas turbine. In order to make the micro devices smaller and more effective, an appropriate use of a micro scale jet as an actuator can be a key technology. Aiming at the development of a measurement system of the micro flow control devices in the future micro aerodynamics, we have established a system to measure a continuous jet, a pulsed jet and a synthetic jet for the flow control in the low Reynolds number air flow with a micro length scale. The two-dimensional flow field around the micro jet using micro particle image velocimetry (PIV) was measured. The jet was injected through the device using an acoustic speaker. It was observed that a saddle point existed at the certain phase where the velocity is 0 at the boundary of the jet blowing and suction phase for the synthetic jet into a still air. It was found that the pulsed jet and the synthetic jet are more effective in the fluid mixing in the low Reynolds number flow than the continuous jet. The dead water region was observed downstream of the jet in case of the jet injection into cross flow. It was recognized that the synthetic jet at the certain oscillation frequency generated a vortex pair near the jet hole.

Study of the airflow induced by a sliding discharge plasma actuator

2019 ◽  
Vol 33 (02) ◽  
pp. 1950011
Author(s):  
Hao Dong ◽  
Zheng Li ◽  
Xi Geng ◽  
Zhiwei Shi ◽  
Qijie Sun
Keyword(s):  
Electrical Discharge ◽  
Particle Image ◽  
Discharge Plasma ◽  
Active Flow Control ◽  
Plasma Actuator ◽  
Ac Power ◽  
Image Velocimetry ◽  
New Type ◽  
Active Flow ◽  
Sliding Discharge

Sliding discharge, as a new type of electrical discharge, is being gradually applied in plasma active flow control in recent years. In this work, the particle image velocimetry (PIV) experiments were conducted to investigate the airflow characteristics induced by the sliding discharge plasma actuator at varied voltage signals. The results show that the integral thrust produced by the negative alternating current (AC) power is stronger than normal AC power under the same voltage magnitude. The induced airflow direction changes along with the changing of two power voltage signals. Furthermore, the angle of the induced airflow is mainly linear with the loading voltage.

scholarly journals Synthetic jet actuator with two opposite diaphragms

2020 ◽  
Vol 24 (1) ◽  
pp. 17-25
Author(s):  
Emil Smyk ◽  
Sylwester Wawrzyniak ◽  
Kazimierz Peszyński
Keyword(s):  
Reynolds Number ◽  
Active Flow Control ◽  
Input Power ◽  
Synthetic Jet ◽  
Energetic Efficiency ◽  
Synthetic Jet Actuator ◽  
Jet Actuators ◽  
Device Use ◽  
Active Flow ◽  
Key Parameter

AbstractThe synthetic jet actuators are one of the most investigated types of actuators used in heat transfer and active flow control. The energetic efficiency of actuators is a key parameter determining the possibility of device use. The actuators with two or more diaphragms have higher efficiency than the actuators with only one. The paper presents the investigations of the acoustic synthetic jet actuator with two opposite diaphragms. In the paper, synthetic jet velocity, Reynolds number and the energetic efficiency as a function of oscillating actuator frequency, for a different cavity, orifice configuration and one real input power P0 = 2 W were studied. The possibility of theoretical calculation of first and second resonance frequency were checked. The coupling ratio for actuators was calculated. The maximum energetic efficiency was η = 8.67% and Reynolds number Re = 8503. The possibility of using the same dependencies and rules during the design of actuators with two opposite diaphragms as in the case of actuators with one diaphragm was demonstrated. The results may be useful in the design of the actuators of the two membranes.

Sign in / Sign up

Export Citation Format

Share Document