Sergey Viktorovich Manuilovich

Bio: Sergey Viktorovich Manuilovich is an academic researcher. The author has contributed to research in topics: Plasma actuator & Swept wing. The author has an hindex of 3, co-authored 4 publications receiving 30 citations.

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

Abstract: 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.

On the possibility of laminar flow control on a swept wing by means of plasma actuators

Abstract: Theoretical assessment of the possibility of laminar §ow control (LFC) on a swept wing owing to volumetric force and heat impact of plasma actuators is presented. The proposed approach includes numerical modeling of dielectric barrier discharge (DBD) actuators, calculation of inviscid §ow over an in¦nite span swept wing, calculation of compressible boundary layer spatially modulated in spanwise direction, and numerical solution of linear stability problem for stationary modes of cross-§ow-type disturbances. Calculations have been performed for one set of geometrical and physical parameters describing plasma actuators to estimate qualitative features of volumetric force and heat input distributions. Inviscid §ow and boundary layer calculations were executed at free stream parameters corresponding to typical cruise §ight conditions. Estimation of volumetric force impact necessary for noticeable in§uence on cross-§owtype instability is obtained.

Conditioning of cross-flow instability modes using dielectric barrier discharge plasma actuators

Abstract: In the current study, selective forcing of cross-flow instability modes evolving on a swept wing at is achieved by means of spanwise-modulated plasma actuators, positioned near the leading edge. In the perspective of laminar flow control, the followed methodology holds on the discrete roughness elements/upstream flow deformation (DRE/UFD) approach, thoroughly investigated by e.g. Saric et al. (AIAA Paper 1998-781, 1998), Malik et al. (J. Fluid Mech., vol. 399, 1999, pp. 85-115) and Wassermann & Kloker (J. Fluid Mech., vol. 456, 2002, pp. 49-84). The possibility of using active devices for UFD provides several advantages over passive means, allowing for a wider range of operating numbers and pressure distributions. In the present work, customised alternating current dielectric barrier discharge plasma actuators have been designed, manufactured and characterised. The authority of the actuators in forcing monochromatic stationary cross-flow modes at different spanwise wavelengths is assessed by means of infrared thermography. Moreover, quantitative spatio-temporal measurements of the boundary layer velocity field are performed using time-resolved particle image velocimetry. The results reveal distinct steady and unsteady forcing contributions of the plasma actuator on the boundary layer. It is shown that the actuators introduce unsteady fluctuations in the boundary layer, amplifying at frequencies significantly lower than the actuation frequency. In line with the DRE/UFD strategy, forcing a sub-critical stationary mode, with a shorter wavelength compared to the naturally selected mode, results in less amplified primary vortices and related fluctuations, compared to the critical forcing case. The effect of the forcing on the flow stability is further inspected by combining the measured actuators body force with the numerical solution of the laminar boundary layer and linear stability theory. The simplified methodology yields fast and computationally cheap estimates on the effect of steady forcing (magnitude and direction) on the boundary layer stability.

Active Flow Control by Using Plasma Actuators

Abstract: 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.

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

Abstract: 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.