Konstantin V. Kosmachevskii

Non-Self-Maintained Discharge Plasma in Propane–Air Mixture

Theoretical modeling of electron-molecule processes in propane-air mixture in external electric field and electron beam have been made. Evolution of main charged and neutral particles in time has been obtained. Gas temperature evolution has allowed to make conclusions on the ignition of propane-air mixture at different concentrations of propane in humid propane-air mixture. The delay time of ignition decreases in lean mixtures.

Kinetic Model of Pulsed Discharge in Humid Air

This paper is devoted to analysis of humid air plasmas of pulsed discharge application possibilities for heating of thin layers over water surface where the concentration of water molecules in a layer over water surface contains ~0.5%-4% of water molecules in the temperature range 30 °C-110 °C. Main neutral and charged components have been calculated with the help of detailed plasma-chemical code. Considerable generation of ozone has been detected. This can explain the results of successful discharge sterilization experiment.

Plasma Jet Ignition of a Propane–Air Stoichiometric Mixture (Cylindrical Jet)

Studies of a plasma jet formation and its injection into a propane-air mixtures counterflow have been performed regarding enhancing combustion and ignition by plasma jets. A computational model involves a realistic equation of state, plasma radiation associated with plasma formation inside the plasma generator, and coupling between the internal nozzle and external flow fields. A one-step effective propane-oxygen chemical reaction with energy release was used for modeling of ignition and combustion. Our model uses an Implicit Free-Lagrange method for the computations. The results of computations demonstrate the ignition of propane-air mixtures stimulated by plasma jet generators, each with a power of 15 kW. The incident propane-air stoichiometric mixture temperature is 1000 K.

Prebreakdown Air Ionization in the Atmosphere

This paper is devoted to analyzing the creation and destruction of electrons at early stages of electric-discharge development in air at altitudes of 0–90 km. The processes of ionization in an external electric field and background ionization, electron attachment and detachment from atomic and molecular oxygen, negative-ion charge exchange and conversion are considered. The pressure and temperature dependences of the rate constants for the processes have been taken into account. The electric field strength at which effective air ionization begins is shown to decrease with increasing altitude. Numerical simulations based on a detailed plasma-chemical model with allowance made for the gas heating by a discharge have been performed.

Non-self-maintained gas discharge for flammable gases impact

Investigations on creation of a non-selfmaintained discharge based on electron beam from the electron accelerator EOL-400M for impact on propane-air mixture have been made. Experiments on detection of some plasma and gas parameters have been realized. Works on modeling of electron-molecule processes in propane-air mixture in external electric field and E-beam at different values of stoichiometricity have been realized.

Plasma Jet Ignition of Propane–Air Stoichiometric Mixture (Flat Jet)

Plasma jet ignition and combustion of stoichiometric propane-air mixture are considered at application of a flat plasma jet in the crossflow. Computationally, it is demonstrated that a flat plasma jet from a slot creates a combustion wave in the fuel that realizes the combustion.

Features of Combined Plasmas

A plasma-aerodynamic model of the interaction of airflow and E-beam (EB) plasma has been developed. The results of the 2-D numerical simulation of the process of plasma jet generation under EB impact in air are presented. The complicated structure of plasma flow is caused by the nonuniformity of EB power put into the gas. The generation of active particles NO+ and NO takes place during the EB-flow interaction.

Hot filaments for plasma aerodynamic applications

Fundamental theoretical and computer investigations devoted to analysis of hot filaments of streamer MW discharge features and to shock wave propagation through the disturbed by MW filaments area has been made. This analysis includes: a) modeling of the hot fila- ment heating in dead air; b) modeling of SW (M=2) propagation through the hot filament; c) consideration of different filament forms and temperatures. Analysis has shown that rise of the filament temperature up to 2500-3000 K and producing of high concentrations of O and NO components can decrease ignition time of hydrocarbon fuel by hot MW filaments. Analysis of shock wave (SW) propagation through the hot filaments showed that there is strong influence on SW, which leads to SW destruction if long filaments directed in the same way as the SW. This shows the possibility of MW hot filament applicability for flow control.

IGNITION OF A PROPANE-AIR STOICHIOMETRIC MIXTURE BY A PLASMA JET GENERATOR WITH A DIVERGENT NOZZLE

Studies of plasma jet injection into a propane-air mixture counterflow have been performed regarding enhancing combustion and ignition by plasma jets. A computational model that we have used is discussed that involves a realistic equation of state, plasma radiation associated with plasma formation inside the plasma jet as well as coupling between the internal nozzle and external flow fields. A one-step effective propane-oxygen chemical reaction model with energy release was used for simulating ignition and combustion. Our model uses an implicit free- Lagrange method for the computations. Results of computations demonstrated ignition of propane-air mixtures stimulated by plasma jet generators each with a power of 15 kW. The incident propane-air stoichiometric mixture temperature was 1000 К. This concept can be applied for creation of quasi-planar jets in a real scramjet using a row of such plasma generators For analysis of ignition and combustion properties of the hydrocarbons in air it is necessary choose the key chemical reactions leading to them. The literature on propane combustion is rather vast and includes different approaches to combustion modeling 7-13

Theoretical Analysis of Ionization in Long-Term Air Discharge Plasmas at Atmospheric Pressure

Present investigations are devoted to analysis of air ionization at large spatial and timescales which can be realized in plasma devices. A numerical analysis of plasma creation and gas heating has been made for dry and humid air at atmospheric pressure. Sharp explosion-type rise of electron concentrations and gas temperature at long times have been obtained.