scholarly journals Unsteady Simulation of a Synthetic Jet Actuator with Cylindrical Cavity Using a 3-D Lattice Boltzmann Method

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Hongbin Mu ◽  
Qingdong Yan ◽  
Wei Wei ◽  
Pierre E. Sullivan
Keyword(s):  
Lattice Boltzmann Method ◽  
Mass Flux ◽  
Lattice Boltzmann ◽  
Cylindrical Cavity ◽  
Active Flow Control ◽  
Control Device ◽  
Synthetic Jet ◽  
Synthetic Jet Actuator ◽  
Zero Net Mass Flux ◽  
Boltzmann Method

A synthetic jet actuator is a zero-net mass-flux device that imparts momentum to its surroundings and has proved to be a useful active flow control device. Using the lattice Boltzmann method (LBM) with the Bhatnagar-Gross-Krook (BGK) collision models, a 3-D simulation of a synthetic jet with cylindrical cavity employing a sinusoidal velocity inlet boundary condition was conducted. The velocity distributions are illustrated and discussed, and the numerical results are validated against previous experimental data. The computed results show the ingestion and expulsion flow over one working cycle as well as the evolution of vortices important to the control of the separated shear layer. Zero-net mass-flux behavior is confirmed.

A Study on Synthetic Jet Actuator Diaphragm

2015 ◽  
Vol 14 (02) ◽  
pp. 91-105
Author(s):  
Siddhartha Sankar Deka ◽  
Rituraj Gautam ◽  
Anoop Singh ◽  
Gautam Kumar ◽  
Promod Kumar Patowari
Keyword(s):  
Structural Characteristics ◽  
Active Flow Control ◽  
Control Device ◽  
Synthetic Jet ◽  
Circular Disc ◽  
Response Analysis ◽  
Synthetic Jet Actuator ◽  
Piezoelectric Patch ◽  
Annular Disc ◽  
Patch Configuration

A synthetic jet actuator (SJA) is one of the most widely used active flow control device which uses a vibrating diaphragm enclosed within a cavity to generate the fluid jet. The effectiveness of the actuator greatly depends upon the design of cavity and orifice and the diaphragm properties. A lot of emphasis is being laid on the cavity and orifice design, but very few literatures can be found dealing with the diaphragm of the SJA. Thus, in this paper a study of the SJA diaphragm actuated by piezoelectric ceramics of different geometries is being presented. Three different diaphragm materials — brass, poly-silicon and aluminum and five different geometries of the piezoelectric actuators — annular disc shaped actuator patch, annular shaped actuator, rectangular shaped actuator patch and circular disc shaped actuator patch and two cantilever arrangements are being considered. A static analysis is carried out and a comparison of the parameters which affect the performance of the SJA is done. Frequency response analysis is also carried out to obtain a better understanding of the diaphragm's structural characteristics. The results thus obtained show that an annular disc piezoelectric patch configuration shows the best behavior as compared to the other actuator configurations and is closely followed by circular disc piezoelectric patch configuration.

STUDY THE ORIFICE EFFECTS OF A SYNTHETIC JET ACTUATOR DESIGN

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Md Nizam Dahalan ◽  
Shuhaimi Mansor ◽  
Muhammad Muzakkir Faiz Ali
Keyword(s):  
Coming Out ◽  
Active Flow Control ◽  
Input Voltage ◽  
Control Device ◽  
Synthetic Jet ◽  
Constant Input ◽  
Synthetic Jet Actuator ◽  
Jet Velocity ◽  
Actuator Design ◽  
Pulse Jet

The synthetic jet actuator is an active flow control device that is used to improve the aerodynamic performance on working surfaces such as wings, helicopter blades and ground vehicles. The performance of synthetic jet actuator depends on the design of the orifice and cavity, and the oscillating driver. Piezoelectric diaphragm was used as an oscillating driver because of its small size and easier installation. The focus of this project is to study the effects of orifice size and shape for a synthetic jet actuator design. The effects were studied on circular and rectangular shapes, and different sizes of orifice. Meanwhile, the configurations of the cavity are fixed. Experiments were performed to determine the maximum pulse jet velocity and turbulence intensities of the jet coming out of the orifice, driven by the Piezoelectric diaphragm at different frequencies, at constant input voltage of 2V. The experiment mainly involved the measurement of the exit pulse jet velocity using a hot-wire anemometer. The results demonstrated that the circular orifice produced higher maximum pulse jet velocity and smaller sizes orifices, both circular and rectangular, results in higher velocity jets.

Study of a Crossflow over a Zero-Net-Mass-Flux Synthetic Jet Driven by a Vibrating Diaphragm

2011 ◽  
Vol 27 (4) ◽  
pp. 503-509 ◽  
Author(s):  
L.-Y. Tseng ◽  
A.-S. Yang ◽  
J.-C. Lin
Keyword(s):  
Boundary Layer ◽  
Flow Control ◽  
Turbulent Flows ◽  
Mass Flux ◽  
Moving Boundary ◽  
Active Flow Control ◽  
Flow Characteristics ◽  
Synthetic Jet ◽  
Computational Domain ◽  
Zero Net Mass Flux

ABSTRACTMiniature synthetic jet actuators are low operating power, zero-net-mass-flux and very compact devices which have demonstrated their capability in modifying the subsonic flow characteristics for boundary layer flow control. In order to improve the design active flow control systems, the present study aims to examine the formation and interaction of unsteady flowfield of a synthetic jet with external crossflow. In view of a single synthetic jet emitting into a turbulent boundary layer crossflow via a circular orifice, the theoretical model utilized the transient three-dimensional conservation equations of mass and momentum for compressible, turbulent flows with a negligible temperature variation over the computational domain. The motion of a movable membrane plate was also treated as the moving boundary by prescribing the displacement on the plate surface. The predictions by the computational fluid dynamics (CFD) software ACE+®were compared with the measured transient phase-averaged velocities in literature for code validation. The predictions showed the time evolution of the large vortical structure originating from the jet orifice and its successive interaction with the crossflow to change the flow structure inside the boundary layer.

Cavity Effect of Synthetic Jet Actuators Based on Piezoelectric Diaphragm

2012 ◽  
Vol 225 ◽  
pp. 85-90 ◽  
Author(s):  
Md Nizam Dahalan ◽  
S. Mansor ◽  
Airi Ali
Keyword(s):  
Active Flow Control ◽  
Fast Response ◽  
Synthetic Jet ◽  
Synthetic Jet Actuator ◽  
Air Jet ◽  
Air Supply ◽  
Jet Velocity ◽  
Cavity Thickness ◽  
Zero Net Mass Flux ◽  
Cavity Effect

An active flow control technology known as synthetic jet actuator (SJA) is a zero-net mass-flux device to create pulsed jet that produces momentum to its surroundings and uses a vibrating diaphragm inside the cavity to generate an oscillatory flow through a small orifice. The performance of SJA depends on the design of an orifice and cavity, and oscillating membrane. SJA design based on piezoelectric diaphragm used in this project because of their size, lightweight, no need for external air supply, without the pipe complex, fast response time and low power consumption. This paper describes the cavity effect to SJA designs and experiments were performed to determine the air jet velocity produced through the orifice using a hot-wire anemometer at a different cavity thickness. The results demonstrate that the jet velocity increase would be better if the cavity thickness is reduced. However, more studies are needed to optimize the size of cavity and orifice for appropriate applications.

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