This paper analyses numerical efforts regarding nanosecond (NS) surface dielectric barrier discharge (SDBD) modelling in atmospheric air. Numerical results of the discharge structure for positive and negative applied voltage pulse polarity, and the features of the physical models and boundary conditions used, are discussed. The results of 2D simulations of the quasi-uniform SDBD mode are presented and compared with the results of other research teams, and with experimental data, to reveal the most appropriate approaches. New results of numerical simulations and analytical estimations of the energy into gas deposition due to NS SDBD driven by a single NS voltage pulse are presented. The problems relating to NS SDBD modelling are discussed.

https://iopscience.iop.org/article/10.1088/1361-6595/aae63e/pdf

Numerical modelling of nanosecond surface dielectric barrier discharge evolution in atmospheric air

Laminar flow control research at TsAGI: Past and present

Electrogasdynamic laminar flow control on a swept wing

Active flow control has recently received an increasing attention since it allows to directly manipulate the flow-field around a surface only when it is effectively requested. Aerodynamic plasma actuators supplied by a dielectric barrier discharge (DBD) can be used for this purpose. Usually, sinusoidal voltages in the range 5–50 kV peak and frequencies between 1 and 100 kHz are utilized to ignite this plasma typology. The surface discharge produced by these devices is able to tangentially accelerate the flow field by means of the electrohydrodynamic (EHD) interaction. DBDs generate non-thermal plasmas characterized by low input energies and limited temperature increments. Plasma actuators can be easily designed by following the shape of the aerodynamic body and can be used over heat-sensitive surfaces. These aerodynamic devices have demonstrated to produce boundary layer modifications with induced speeds up to 10 m/s. Their use over airfoils, flaps, and blades have shown the possibility to delay the transition between laminar to turbulent regime, to prevent flow separation enhancing lift and reducing drag. Moreover, the adoption of these actuators over landing gears and trailing edges may induce a noise reduction effect. Dielectric materials, electrodes configuration, and supplying waveforms are most relevant parameters to be considered to enhance actuator performance. On a parallel plane, on/off actuation strategy is a key point in the use of these devices when utilized over aerodynamic surfaces impinged within an external flow.

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Active Flow Control by Using Plasma Actuators

Theoretical approach to assessment of a possibility of laminar flow control on an infinite span swept wing owing to volumetric force and heat impact of plasma actuators is presented. The proposed approach includes numerical modeling of dielectric barrier discharge actuators, calculation of inviscid flow over a given airfoil, calculation of compressible boundary layer spatially modulated in spanwise direction, numerical solution of linear stability problem for stationary modes of cross-flow-type instability. Calculations have been performed for one set of parameters describing plasma actuators and airflow parameters corresponding to cruise flight conditions. Estimation of minimal force impact necessary for noticeable influence on cross-flow-type instability is obtained.

Attenuation of Cross-Flow-Type Instability in Compressible Boundary Layer by Means of Plasma Actuators

Numerical research of the gas pressure influence on a conduction current in a dielectric barrier discharge (DBD), the average volumetric force acting on gas from the discharge, and the power of heat release in the discharge is carried out for aerodynamic applications. The calculations are implemented with use of the earlier proposed boundary problem about the DBD generation near a flat dielectric plate. This problem statement takes into account such factors as the finite thickness of the exposed electrode, finite rates of desorption and the recombination of charged particles on the dielectric surface, and the electric field induced by a superficial charge. Represented are the results of numerical modeling of the incompressible Poiseuille and Couette flows under the time-averaged transverse force impact of DBD actuators placed along the main flow. The possibility of significant influence of an additional transfer of the main flow momentum due to the cross-flow (induced by actuators) on the structure and the characteristics of the considered shear flows is demonstrated.

Modeling of dielectric barrier discharge actuators at various gas pressures and estimation of their influence on shear flows

Attenuation of cross flow-type instability in a 3d boundary layer due to volumetric force impact

Features of numerical modeling of a dielectric barrier discharge

The numerical simulation of spatial-periodic systems of electrogasdynamic actuators (plasma actuators), using the dielectric barrier discharge (DBD) for a volumetric force impact on a gas flow was carried out. Both the typically used design of actuators and the advanced design with an additional screening electrode are considered. The mathematical model of the dielectric barrier discharge in air was formulated in the drift-diffusion approximation without accounting for convective transfer of the charged particles. The following volumetric reactions are taken into consideration, namely, the ionization of nitrogen and oxygen by electron impacts, the attachment of electrons to oxygen, the detachment of electrons from negative ions, and the ion-ion and the electron-ion recombination. The two types of boundary conditions were considered at the open dielectric surface, namely, the model of instantaneous recombination and the model of finite rates of recombination and electron desorption. The numerical simulation both for the typical and for the advanced actuator systems was done with the same set of problem parameters. It was shown that the advanced scheme provides the better energy efficiency of the system of DBD actuators. It was also found that the main integral characteristics of the DBD actuator weakly depend on the type of boundary conditions used on the dielectric surface. The new simplified design of a system of DBD actuators was proposed.

Alexander Petrovich Kuryachii

Papers

Modeling of dielectric barrier discharge actuators at various gas pressures and estimation of their influence on shear flows

Attenuation of cross flow-type instability in a 3d boundary layer due to volumetric force impact

Features of numerical modeling of a dielectric barrier discharge

About increase of efficiency of plasma multi-actuator system for boundary layer control

Investigation of a simplified scheme of multiple plasma actuator for boundary layer control