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Stereoscopic PIV measurement of boundary layer affected by DBD actuator
Procházka, Pavel P. ; Uruba, Václav
The effect of ionic wind generated by plasma actuator on developed boundary layer inside a narrow channel was investigated recently. Since the main investigated plane was parallel to the channel axis, the description of flow field was not evaluated credibly. This paper is dealing with cross-section planes downstream the actuator measured via 3D time-resolved PIV. The actuator position is in spanwise or in streamwise orientation so that ionic wind is blown in the same direction as the main flow or in opposite direction or perpendicularly. The interaction between boundary layer and ionic wind is evaluated for three different velocities of main flow and several parameters of plasma actuation (steady and unsteady regime, frequency etc.). Statistical properties of the flow are shown as well as dynamical behaviour of arising longitudinal vortices are discussed via phase-locked measurement and decomposition method.
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The impact of plasma induced flow on the boundary layer in a narrow channel
Procházka, Pavel P. ; Uruba, Václav
The induced flow generated by dielectric barrier discharge (DBD) actuator working in steady and unsteady regime will be used to modify properties of naturally developer boundary layer (BL) in short and length rectangular perspex channel which is connected to the blow-down wind tunnel. The actuator is placed in spanwise configuration and the inlet velocities will range between 5 and 20 m•s-1. Previously, mean flow field and statistical quantities were subjugated to investigation. In this paper, there will be presented dynamical features of the BL as well as tracking of coherent structures using phase-averaging. Proper Orthogonal Decomposition (POD) of influenced flow field and frequency analysis will be presented. These results should be taken into account regarding to use in the flow around a bluff body.
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Physical principle dealing with development of vortices formed by DBD actuator
Procházka, Pavel P. ; Uruba, Václav
Several configurations of vortex trains generated by plasma dielectric barrier discharge were measured by method of time-resolved PIV with application of phase-averaging of data. Mainly dynamics of vortical structures was studied in terms of vortex core trajectory, convective velocity, vortex diameter and vortex circulation. The generally valid physical mechanism of such vortices based on gained information will be introduced and presented. This mechanism will be considered with regards to the use for active flow control thus it could be very helpful in the future works dealing with plasma flow control.
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