Secondary flow structures due to interaction between a finite-span synthetic jet and a 3-D cross flow

Elimelech, Yossef; Vasile, Joseph; Amitay, Michael
September 2011
Physics of Fluids;Sep2011, Vol. 23 Issue 9, p094104
Academic Journal
An experimental investigation was performed to study the formation of secondary flow structures due to the interaction of a finite-span synthetic jet with a three-dimensional boundary layer over a finite and swept-back wing configuration (cross-sectional profile of the NACA 4421, aspect ratio of 4 and sweep back angle of 30°). The investigation was carried out at a chord based Reynolds number of 105, two angles of attack of 9° and 15.5°, and two blowing ratios of 0.8 and 1.2. Stereoscopic particle image velocimetry (PIV) data were collected around a single synthetic jet actuator in the mid-span of the swept-back wing configuration. The effect of the blowing ratio was analyzed based on the three-dimensional flow field using time-averaged and phase-averaged statistics. Detailed boundary layer profiles show the actuation effects in cases where the jet is introduced to locally attached or separated flow fields, which are determined by the model's angle of attack. Similar to the interaction of a synthetic jet with a flow over an unswept wing, the flow field in the vicinity of the synthetic jet orifice becomes highly three-dimensional with very distinct secondary flow structures. The flow field is governed by the superposition of two kinds of flow structures: (1) spanwise structures that are generated along the orifice's span due to the synthetic jet's vortex pairs and (2) streamwise structures that are associated with the finite span of the jet (edge vortices). These flow structures are formed almost immediately downstream of the synthetic jet orifice and evolve into a well-organized three-dimensional flow field farther downstream.


Related Articles

  • Experimental Study of Synthetic Jets with Cross Flow in Boundary Layer. Aloui, F.; Kourta, A.; Nasrallah, S. Ben // International Review of Mechanical Engineering;May2008, Vol. 2 Issue 3, p474 

    The synthetic jet actuator is a low power, highly compact fluidic device which has potential application in boundary layer flow control In this study, we have shown how synthetic jets work without cross flow and how effectively they modify the flow structure in the boundary layer. This paper...

  • Experimental study of the formation and scaling of a round synthetic jet. Shuster, Jennifer M.; Smith, Douglas R. // Physics of Fluids;Apr2007, Vol. 19 Issue 4, p045109 

    The flow field from a piston-cylinder synthetic jet actuator was investigated in detail over a range of dimensionless stroke values, L°/D°, and Reynolds numbers, ReU°. In each of the test flows examined, only one of these dimensionless groups was varied. The flow fields were examined...

  • Vortex dynamics of in-line twin synthetic jets in a laminar boundary layer. Xin Wen; Hui Tang; Fei Duan // Physics of Fluids;Aug2015, Vol. 27 Issue 8, p1 

    An experimental investigation is conducted on the vortices induced by twin synthetic jets (SJs) in line with a laminar boundary layer flow over a flat plate. The twin SJs operating at four different phase differences, i.e., Δφ = 0°, 90°, 180°, and 270°, are visualized using a...

  • Laser velocimetry of a plane mixing layer with a specific initial condition for study of turbulence characteristics of enhanced growth rate. Mehrjooei, Mojtaba; Montazerin, Nader; Damangir, Abraham // Journal of Mechanical Science & Technology;Apr2012, Vol. 26 Issue 4, p1049 

    Mixing layers are sensitive to the mixing angle and turbulence in the primary streams. Although there is extensive available research on this rather basic flow, there are still no suggestions for a clearly best configuration. For example, the combination of a laminar initial boundary layer and a...

  • Particle image velocimetry measurements of massively separated turbulent flows with rotation. Visscher, Jan; Andersson, Helge I. // Physics of Fluids;Jul2011, Vol. 23 Issue 7, p075108 

    Measurements of instantaneous velocity fields in the separated flow downstream of a backward-facing step in a rotating channel are presented for the first time. Particle image velocimetry (PIV) measurements were made for 13 different rotation numbers Ro at a bulk flow Reynolds number of about...

  • Dynamic stall process on a finite span model and its control via synthetic jet actuators. Taylor, K.; Amitay, M. // Physics of Fluids;2015, Vol. 27 Issue 7, p1 

    An experimental study of the process by which dynamic stall occurs on a finite span S809 airfoil was conducted at the Center for Flow Physics and Control at Rensselaer Polytechnic Institute. Understanding the flow field around a dynamically pitching airfoil helped in controlling the dynamic...

  • Active Vibration Control of a Wind Turbine Blade Using Synthetic Jets. Maldonado, Victor; Boucher, Matthew; Ostman, Rebecca; Amitay, Michael // International Journal of Flow Control;Dec2009, Vol. 1 Issue 4, p227 

    Active vibration control via an array of synthetic jet actuators was investigated experimentally in a wind tunnel. Using synthetic jets the flow over a small scale S809 finite wind turbine blade was controlled, resulting in reduction of the blade's structural vibrations. The effectiveness of the...

  • Experimental Visualization of the Flow Structure for Jet in Crossflow with a Curved Hole Passage. Jun Yu Liang; Shun Kang // Advances in Mechanical Engineering (Hindawi Publishing Corporati;2012, Vol. 4, p1 

    The objective of this paper is to investigate the influence of a hole curvature on the flow structure and characteristics downstream of JICF (jet in cross-Flow) by means of smoke visualization and particle image velocimetry (PIV). The experiment was performed in a low speed wind tunnel with...

  • Particle image velocimetry measurements of the interaction of synthetic jets with a zero-pressure gradient laminar boundary layer. Jabbal, Mark; Shan Zhong // Physics of Fluids;Jun2010, Vol. 22 Issue 6, p063603 

    An experimental investigation of the interaction between a synthetic jet actuator and a zero-pressure gradient laminar boundary layer is reported. The aim of this study is to quantify the impact of synthetic jet vortical structures; namely, hairpin vortices, stretched vortex rings and tilted...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics