Ivan Moralev

Flow Control over NACA 23012 Airfoil Model by Surface HF Plasma Actuator

It has been revealed that pulse periodic surface high frequency discharge operation can lead to stall delay for NACA23012 airfoil at Re <400k and M<0.3 1 . This work is devoted to the study of this plasma effect on the leading edge stall by means of PIV. Separation dynamics is studied in two regimes: single pulse excitation and burst excitation. One can conclude that separation region evolution consist of a series of local reattachment processes due to separate discharge pulses. Totally, separation point was shifted downstream by 25% chord length. The study was performed at airflow velocity 20m/s and Reynolds number Re~80k. The typical parameters of CHFD used in these experiments are the followings: HF frequency FHF~350 kHz, modulation frequency FM=10-10 4 Hz, mean HF power NHF< 100W.

Flow Around Wing Model with a Surface HF Discharge

Airflow around wing model W, controlled by pulse-repetitive HF discharge, is studied at flow velocities up to 100m/s, Pst~ 1 Bar and Re < 10 5 in this work. Transversal capacity coupled HF discharge (CHFD) with the typical frequency of f= 350 kHz is created on the model’s surface near its leading edge. It is revealed that there is drag decrease of the model W at high HF pulse power input in plasma and large attack angles (AoA). These results are sensitive to Strouchal’s number value. There are two drag minimums at the Sh~1 and the Sh~5. Mean power input in plasma doesn’t exceed 10 W/cm at the pulse HF power about of ~1 kW. Shadow pictures of the airflow around the wing model show a large-scale vortex creation near the separation line. There are acoustic waves (Fa~ 600 kHz) created by surface CHFD.

Surface HF Plasma Actuator in Airflow

The paper presents the first results on the experimental and numerical studied of the novel configuration of the HF discharge at the conical body in airflow. The effect of the three-electrode configuration is examined. The experimentally observed downstream stagnation and static pressure variation has shown significant flow modification in wide range of the flow Mach number (.5 – 2.). The voltage applied to the third electrode (“separator”) changes the observed discharge structure. The 2D time dependent numerical simulation can provide the qualitatively good correlation with the “averaged’ experimental data and not to be able to resolve the fine fast changing discharge structure.

Study of Structure and Dynamics of Enhanced Plasma Formations Created by Capillary Pulsed Discharge

The experimental researches on long-lived high-energetic enhanced plasmoid (LEP) creation by an erosive discharge have been carried out. The parameters of erosive discharge in a capillary with ablating walls are determined by high-current electric pulse and gas

Vortex Control by Non-Equilibrium Plasma

Study of a longitudinal plasmoid in swirl flow is very important both for plasma aerodynamics and extra energy release 1-8, 10 . A longitudinal heterogeneous plasmoid structure and its dynamics in the swirl flow were studied in our previous works in detail 1-6 . The present work is a continuation of the previous ones. The non-equilibrium combined discharge (DC discharge + HF discharge) is used in this experimental work. A pulsed repetitive power pumping in the swirl flow is created by the combined discharge. The plasma created by this discharge can disturb the initial swirl flow. Plasma and airflow parameters are measured by different diagnostic instrumentation including a high-speed camera, electric and current probes, an optical spectrometer and etc. Following main new experimental and theoretical results are obtained in this work: a velocity distribution and a gas temperature distribution are measured in the swirl flow at different discharge and gas flow parameters. Detail optical spectra with a high resolution in a vortex longitudinal plasmoid created by the combined electric discharge are obtained. Processing of these spectra gives an important information about nonequilibrium processes inside the longitudinal plasmoid in the swirl flow. Obtained results are used in a theoretical model of plasma and a chemical kinetics in the vortex heterogeneous plasmoid created by the non-equilibrium DC discharge. Numerical results on a swirl flow structure and its evolution at plasma on are obtained and compared with experimental results.