Application of an Integrated Flow and DBD Plasma Actuation Model to a High-Lift Airfoil: Part I — RANS

Volume 1: Symposia ◽

10.1115/ajkfluids2015-14213 ◽

2015 ◽

Author(s):

Hua Shan ◽

Shawn Aram ◽

Yu-Tai Lee

Keyword(s):

Numerical Simulation ◽

Charge Density ◽

Flow Separation ◽

Body Force ◽

Force Model ◽

Simulation Tool ◽

Dbd Plasma ◽

High Lift ◽

Net Charge ◽

Plasma Actuation

An integrated numerical simulation tool that couples the Reynolds averaged Navier-Stokes (RANS) or the large eddy simulation (LES) solver for incompressible flows with the dielectric barrier discharge (DBD) electro-hydrodynamic (EHD) body force model has been developed. The EHD body force model is based on solving the electrostatic equations for the electric potential due to applied voltage and the net charge density due to ionized air. The boundary condition for the charge density on the dielectric surface is obtained from a Space-Time Lumped-Element (STLE) circuit model that accounts for the time and space dependence of air ionization on the input voltage amplitude, frequency, electrode geometry, and dielectric properties. The development of the numerical simulation tool is based on the framework of NavyFOAM using a multi-domain approach. The electric potential equation, the net charge density equation, and the flow equations are solved in separate computational domains. All equations are discretized in space using the cell-centered finite volume method. Parallel computation is implemented using domain-decomposition and message passing interface (MPI). Due to a large disparity in time scales between the electric discharge and the flow, a multiple sub-cycle technique is used in coupling the plasma solver and the flow solver. This paper focuses on its application to numerical simulation of flow separation and control over a high-lift flapped airfoil at a Reynolds number of 240,000. The 2-D unsteady RANS simulation utilized the Wilcox k-ω, the SST k-ω, and the k-kl-ω turbulence models. For the baseline case, in comparison with the measurement, the k-kl-ω model captures the feature of the unsteadiness of flow field associated with flow separation and shedding of vortices, better than the Wilcox k-ω and SST k-ω models. In the RANS simulations for flow separation control with DBD plasma actuation, the actuator is driven by voltage signals of a continuous or an amplitude-modulated sine waveform with a range of voltage amplitudes. The numerical results indicate that the modulated forcing is more effective than the continuous forcing for a certain range of applied voltages. The electrical power consumption calculated by the plasma model fits to a parabolic curve as a function of the root-mean-square of applied voltage.

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Numerical Study of Dielectric Barrier Discharge Plasma Actuation

Volume 1B, Symposia: Fluid Machinery; Fluid-Structure Interaction and Flow-Induced Noise in Industrial Applications; Flow Applications in Aerospace; Flow Manipulation and Active Control: Theory, Experiments and Implementation; Multiscale Methods for Multiphase Flow; Noninvasive Measurements in Single and Multiphase Flows ◽

10.1115/fedsm2014-21108 ◽

2014 ◽

Cited By ~ 1

Author(s):

Hua Shan ◽

Yu-Tai Lee

Keyword(s):

Charge Density ◽

Electric Potential ◽

Body Force ◽

Barrier Discharge ◽

Input Voltage ◽

Dielectric Surface ◽

Force Model ◽

Dbd Plasma ◽

Net Charge ◽

Induced Flow

There has been an increasing interest in dielectric barrier discharge (DBD) plasma actuation for flow control in the past decade. Compared to other means of active flow controls, the DBD plasma actuations have several advantages, including absence of moving parts, a fast time response for unsteady applications, a very low mass of the device, no cavities or holes on control surfaces, and possibly low energy consumption. These features are especially important for applications with high g-loads, such as turbomachinery blades rotating at high speed. A computational method has been developed to couple a DBD electro-hydrodynamic (EHD) body force model with the Reynolds averaged Navier-Stokes (RANS) model for incompressible flows. The EHD body force model is based on solving the electrostatic equations for the electric potential due to applied voltage and the net charge density due to ionized air. The boundary condition for charge density on the dielectric surface is obtained from a Space-Time Lumped-Element (STLE) circuit model that accounts for time and space dependence of the air ionization on the input voltage amplitude, frequency, electrode geometry, and dielectric properties. Alternatively, an empirical formulation representing a Gaussian distribution of charge density on the dielectric surface can also be used. The EHD body force is calculated using the solutions obtained from solving the electric potential and the net charge density equations. As a comparison, a much simpler Linearized Electric Body Force (LEBF) model is also used to directly specify the spatial distribution of the averaged EHD body force. The coupled computational models have been implemented using a multiple-domain approach. The electric potential equation, the net charge density equation, and the flow equations are solved in separate computational domains. All equations are discretized in space using a cell-centered finite volume method. Parallel computation is implemented using domain-decomposition and message passing interface (MPI). Due to a large disparity in time scales between the electric discharge and the flow, a multiple sub-cycle technique is used in coupling the plasma solver and the flow solver. The DBD plasma induced flow in quiescent air is used as a test case and the computational results are validated against experimental measurement. A comparison between different EHD body force models is also presented. Then, the effect of driving duty-cycles with different waveforms and input voltage amplitudes is investigated in terms of electrical power, EHD thrust, and kinetic energy of induced flow.

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Numerical Modeling of Dielectric Barrier Discharge Plasma Actuation

Journal of Fluids Engineering ◽

10.1115/1.4031880 ◽

2016 ◽

Vol 138 (5) ◽

Cited By ~ 5

Author(s):

Hua Shan ◽

Yu-Tai Lee

Keyword(s):

Charge Density ◽

Dielectric Barrier Discharge ◽

Body Force ◽

Incompressible Flows ◽

Barrier Discharge ◽

Computational Method ◽

Force Model ◽

Dbd Plasma ◽

Net Charge ◽

Dielectric Barrier

A computational method has been developed to couple the electrohydrodynamic (EHD) body forces induced by dielectric barrier discharge (DBD) actuation with unsteady Reynolds-Averaged Navier–Stokes (URANS) model or large eddy simulation (LES) for incompressible flows. The EHD body force model is based on solving the electrostatic equations for electric potential and net charge density. The boundary condition for net charge density on the dielectric surface is obtained from a space–time lumped-element (STLE) circuit model or an empirical model. The DBD–URANS/LES coupled solver has been implemented using a multiple-domain approach and a multiple subcycle technique. The DBD plasma-induced flow in a quiescent environment is used to validate the coupled solver, evaluate different EHD body force models, and compare the performance of the actuator driven by voltage with various waveforms and amplitudes.

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Application of an Integrated Flow and DBD Plasma Actuation Model to a High-Lift Airfoil: Part II — LES

Volume 1: Symposia ◽

10.1115/ajkfluids2015-14212 ◽

2015 ◽

Author(s):

Shawn Aram ◽

Hua Shan ◽

Yu-Tai Lee

Keyword(s):

Electric Potential ◽

Body Force ◽

Numerical Study ◽

Pulse Amplitude ◽

Boundary Layer Separation ◽

Critical Voltage ◽

Force Model ◽

Dbd Plasma ◽

Experimental Conditions ◽

High Lift

A numerical study is conducted to explore the effect of a single dielectric barrier discharge (SDBD) plasma actuator for controlling a turbulent boundary layer separation on a deflected flap of a high-lift airfoil at a chord-based Reynolds number of 240000. An integrated numerical model consisting of a DBD electro-hydrodynamic (EHD) body force model and computational fluid dynamics (CFD) package called NavyFoam is employed in this study. The EHD body force is calculated by solving the Partial Deferential Equation (PDE)-based electrostatic equations for electric potential due to applied voltage and net charged density due to ionized air. The electric potential equation, the net charge density equation, and the flow equations are solved in separate computational domains. Comparison of current computational results against experimental data indicates reasonable agreement between the two studies for the baseline flow as well as controlled cases using two AC waveforms including sine and pulse-amplitude-modulated sine with different modulation frequencies. Performance of the actuator is also examined for the square and pulse AC waveforms. It is found that at the experimental conditions, the pulse-amplitude-modulated sine waveform provides the most lift enhancement in comparison with other waveforms used in this study, despite the least power input that it requires to operate. The effect of the input voltage amplitude on the performance of the actuator is also examined for the sine and pulse-amplitude-modulated sine waveforms. It is shown that beyond a critical voltage, the sine wave is more effective in improving the aerodynamic performance of the airfoil than the other waveform.

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Numerical Simulation of Flow Induced by Multiple DBD Plasma Actuators

Volume 1A, Symposia: Turbomachinery Flow Simulation and Optimization; Applications in CFD; Bio-Inspired and Bio-Medical Fluid Mechanics; CFD Verification and Validation; Development and Applications of Immersed Boundary Methods; DNS, LES and Hybrid RANS/LES Methods; Fluid Machinery; Fluid-Structure Interaction and Flow-Induced Noise in Industrial Applications; Flow Applications in Aerospace; Active Fluid Dynamics and Flow Control — Theory, Experiments and Implementation ◽

10.1115/fedsm2016-7583 ◽

2016 ◽

Author(s):

Hua Shan ◽

Shawn Aram ◽

Yu-Tai Lee

Keyword(s):

Numerical Simulation ◽

Boundary Layer ◽

Flow Separation ◽

Plasma Actuator ◽

Plasma Actuators ◽

Separation Control ◽

Simulation Tool ◽

Streamwise Direction ◽

Dbd Plasma ◽

Flow Separation Control

Active flow separation control using dielectric barrier discharge (DBD) plasma actuators oriented in the spanwise direction has been successfully investigated by the authors using an integrated numerical simulation tool that couples the unsteady Reynolds averaged Navier-Stokes (URANS) or large eddy simulation (LES) solver for incompressible flows with the DBD electro-hydrodynamic (EHD) body force model. Although many experimental and numerical investigations have indicated that the spanwise-oriented DBD plasma actuator is an effective flow control method, the application is difficult to extend from model-scale to full-scale problems, partly due to the required high amplitude and high bandwidth excitation. Also, the flow control mechanism associated with a spanwise-oriented DBD actuator is mainly direct momentum injection, therefore, the effectiveness of actuation is sensitive to the location of the DBD actuator relative to the location of flow separation. On the other hand, a few experimental studies have shown promising results using the DBD Vortex Generator (DBD-VG) consisting of multiple plasma DBD actuators oriented in the streamwise direction. By generating streamwise vortices extending a long distance downstream, the DBD-VGs enhance the mixing of the inner and outer layers of turbulent boundary layer flows. As a result, the boundary layer can better withstand an adverse pressure gradient. When applied to flow separation control, the effectiveness of the DBD-VGs should be less sensitive to location of flow separation. The present work extends the capability of the integrated numerical simulation tool from a single spanwise-oriented DBD plasma actuator to multiple DBD plasma actuators oriented in any direction, including the streamwise direction. As a demonstration of the new capability in the DBD-URANS coupled solver, numerical simulations of flow induced by a DBD-VG actuator with an array of exposed electrodes in a quiescent environment, as well as in a turbulent boundary layer over a flat plate, are carried out. The numerical simulation successfully reproduced the longitudinal vortices embedded in the boundary layer.

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Plasma actuation effect on a NACA 4412 airfoil

Aircraft Engineering and Aerospace Technology ◽

10.1108/aeat-04-2021-0101 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Burak Karadag ◽

Cem Kolbakir ◽

Ahmet Selim Durna

Keyword(s):

Reynolds Number ◽

Flow Separation ◽

Open Loop ◽

Electrode Configuration ◽

Small Scale ◽

Low Velocity ◽

Dbd Plasma ◽

Content Type ◽

Plasma Actuation ◽

Electric Wind

Purpose This paper aims to investigate the effects of a dielectric barrier discharge (DBD) plasma actuator (PA) qualitatively on aerodynamic characteristics of a 3 D-printed NACA 4412 airfoil model. Design/methodology/approach Airflow visualization study was performed at a Reynolds number of 35,000 in a small-scale open-loop wind tunnel. The effect of plasma actuation on flow separation was compared for the DBD PA with four different electrode configurations at 10°, 20° and 30° angles of attack. Findings Plasma activation may delay the onset of flow separation up to 6° and decreases the boundary layer thickness. The effects of plasma diminish as the angle of attack increases. Streamwise electrode configuration, in which electric wind is produced in a direction perpendicular to the freestream, is more effective in the reattachment of the airflow compared to the spanwise electrode configuration, in which the electric wind and the free stream are in the same direction. Practical implications The Reynolds number is much smaller than that in cruise aircraft conditions; however, the results are promising for low-velocity subsonic airflows such as improving control capabilities of unmanned aerial vehicles. Originality/value Superior efficacy of spanwise-generated electric wind over streamwise-generated one is demonstrated at a very low Reynolds number. The results in the plasma aerodynamics literature can be reproduced using ultra-low-cost off-the-shelf components. This is important because high voltage power amplifiers that are frequently encountered in the literature may be prohibitively expensive especially for resource-limited university aerodynamics laboratories.

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