The Experts below are selected from a list of 5943 Experts worldwide ranked by ideXlab platform

Kazimierz Adamiak - One of the best experts on this subject based on the ideXlab platform.

  • ehd flow produced by Electric Corona discharge in gases from fundamental studies to applications a review
    2016
    Co-Authors: Lin Zhao, Kazimierz Adamiak
    Abstract:

    ABSTRACTThis article summarizes the studies on the secondary electrohydrodynamic (EHD) flow produced by Electric Corona discharge in gas. Detailed information about the development of the fully coupled EHD flow model is presented. This model takes into account the interaction between the Electric field and the fluid flow field as well as the effect of the operational pressure. The theoretical model that was validated by experimental measurements was employed to analyze the dynamics of the EHD flow, the effect of EHD on Corona discharge in compressed gases, and the effect of the EHD flow on the flow pattern in the ESP channel. Selected results were presented and discussed. Examples of the practical applications of the EHD flow produced by Electric Corona discharge were presented, including the EHD thruster, EHD gas pump, and EHD mini-pump for Martian particle analyzer.

  • ehd flow in air produced by Electric Corona discharge in pin plate configuration
    2005
    Co-Authors: Lin Zhao, Kazimierz Adamiak
    Abstract:

    Abstract The electrohydrodynamic flow in air produced by the Electric Corona discharge in the pin–plate and pin–grid configurations has been investigated numerically and experimentally in this paper. The numerical algorithm based on the boundary and finite element methods and the method of characteristics is employed to obtain the distributions of the Electric field, the Electric potential and the space charge density. After the volume force has been calculated, the commercial FLUENT software is used to solve the airflow. Experimental axial velocity profiles outside the ground grid obtained with a hot-wire anemometer reasonably validate the simulation results.

  • dynamics of ehd flow in pin plate configuration generated by Electric Corona discharge in air
    2004
    Co-Authors: Lin Zhao, Kazimierz Adamiak
    Abstract:

    Publisher Summary This chapter explains the dynamics of electro-hydrodynamic (EHD) flow in pin-plate configuration generated by Electric Corona discharge in air. The characteristics of the electro-hydrodynamic flow in air produced by the Electric Corona discharge in a pin-plate configuration are investigated numerically. The numerical algorithm based on the Boundary Element Methods (BEMs) and Finite Element Methods (FEMs) and the Method of Characteristics (MOC) is employed to simulate the Electric field. The Electric field is calculated by means of the BEM, FEM and MOC. The FLUENT software is used to calculate the airflow parameters. The Electric Corona discharge produces the EHD flow with the velocity distribution pattern affected not only by the air gap geometry but also by the applied voltage; the length of time that it takes to reach the steady state axial velocity is greatly affected by the applied voltage. Usually, it takes several milliseconds to reach the steady state, and the higher the applied voltage, the shorter the time it takes to produce the steady EHD airflow. The chapter predicts the EHD flow patterns and the velocity distributions at different instants of time. The simulation results indicate that the applied voltage level greatly affects the transient dynamics of the process.

Lin Zhao - One of the best experts on this subject based on the ideXlab platform.

  • ehd flow produced by Electric Corona discharge in gases from fundamental studies to applications a review
    2016
    Co-Authors: Lin Zhao, Kazimierz Adamiak
    Abstract:

    ABSTRACTThis article summarizes the studies on the secondary electrohydrodynamic (EHD) flow produced by Electric Corona discharge in gas. Detailed information about the development of the fully coupled EHD flow model is presented. This model takes into account the interaction between the Electric field and the fluid flow field as well as the effect of the operational pressure. The theoretical model that was validated by experimental measurements was employed to analyze the dynamics of the EHD flow, the effect of EHD on Corona discharge in compressed gases, and the effect of the EHD flow on the flow pattern in the ESP channel. Selected results were presented and discussed. Examples of the practical applications of the EHD flow produced by Electric Corona discharge were presented, including the EHD thruster, EHD gas pump, and EHD mini-pump for Martian particle analyzer.

  • effects of ehd and external airflows on Electric Corona discharge in point plane mesh configurations
    2005
    Co-Authors: Lin Zhao, K Adamiak
    Abstract:

    The effect of airflow, including the electrohydrodynamic (EHD) flow produced by the Electric Corona discharge, and the flow generated externally on the Corona discharge has been investigated numerically in this paper. Contrary to the common assumption that the Corona discharge and the EHD flow can be decoupled by neglecting the convection term in the current density equation, the equations for the Electric field, charge transport and fluid flow have been solved simultaneously. The numerical algorithm is based on the boundary and finite element methods (BEM and FEM), the method of characteristics (MOC) and the finite volume method (FVM). The simulation results confirm that the EHD flow has a very small effect on the Corona discharge. However, in some configurations the external airflow may have considerable effect on the V-I characteristics of the system and the current density distribution on the ground electrode.

  • ehd flow in air produced by Electric Corona discharge in pin plate configuration
    2005
    Co-Authors: Lin Zhao, Kazimierz Adamiak
    Abstract:

    Abstract The electrohydrodynamic flow in air produced by the Electric Corona discharge in the pin–plate and pin–grid configurations has been investigated numerically and experimentally in this paper. The numerical algorithm based on the boundary and finite element methods and the method of characteristics is employed to obtain the distributions of the Electric field, the Electric potential and the space charge density. After the volume force has been calculated, the commercial FLUENT software is used to solve the airflow. Experimental axial velocity profiles outside the ground grid obtained with a hot-wire anemometer reasonably validate the simulation results.

  • dynamics of ehd flow in pin plate configuration generated by Electric Corona discharge in air
    2004
    Co-Authors: Lin Zhao, Kazimierz Adamiak
    Abstract:

    Publisher Summary This chapter explains the dynamics of electro-hydrodynamic (EHD) flow in pin-plate configuration generated by Electric Corona discharge in air. The characteristics of the electro-hydrodynamic flow in air produced by the Electric Corona discharge in a pin-plate configuration are investigated numerically. The numerical algorithm based on the Boundary Element Methods (BEMs) and Finite Element Methods (FEMs) and the Method of Characteristics (MOC) is employed to simulate the Electric field. The Electric field is calculated by means of the BEM, FEM and MOC. The FLUENT software is used to calculate the airflow parameters. The Electric Corona discharge produces the EHD flow with the velocity distribution pattern affected not only by the air gap geometry but also by the applied voltage; the length of time that it takes to reach the steady state axial velocity is greatly affected by the applied voltage. Usually, it takes several milliseconds to reach the steady state, and the higher the applied voltage, the shorter the time it takes to produce the steady EHD airflow. The chapter predicts the EHD flow patterns and the velocity distributions at different instants of time. The simulation results indicate that the applied voltage level greatly affects the transient dynamics of the process.

R Morrow - One of the best experts on this subject based on the ideXlab platform.

  • theory of Electric Corona including the role of plasma chemistry
    1994
    Co-Authors: J J Lowke, R Morrow
    Abstract:

    The traditional theory of Corona is cast in terms of ionization and attachment coefficients and gives good quantitative predictions of the voltage for the onset of Corona as a function of the diameter of the Corona wires, temperature, pressureandcharacteristics of the gas. Furthermore, it gives a fair qualitative description of the Corona discharge itself as a function of space and time. The motion of electrons, positive ions and negative ions formed by electron attachment, can produce distortions to the Electric field by space charge effects which result inTrichel current pulses for negativevoltages and "streamers" for positive voltages. Recently it has been realized that the medium of the Corona discharge in air, for example, is not ordinary air, since the properties of the air are changed by the Corona discharge itself. Of particular importance for properties of the Corona discharge are the many excited states and metastable atoms and molecules that are created by the Corona discharge, which may influence the electron density by detachment of negative ions or make possible two-step ionization. Rate constants of those reactions of plasma chemistry, which involve electrons in the discharge, are a function of the local Electric field. In the present paper, mechanisms of plasma chemistry are proposed to explain the voltage for spark breakdown between Corona wires.

J J Lowke - One of the best experts on this subject based on the ideXlab platform.

  • theory of Electric Corona including the role of plasma chemistry
    1994
    Co-Authors: J J Lowke, R Morrow
    Abstract:

    The traditional theory of Corona is cast in terms of ionization and attachment coefficients and gives good quantitative predictions of the voltage for the onset of Corona as a function of the diameter of the Corona wires, temperature, pressureandcharacteristics of the gas. Furthermore, it gives a fair qualitative description of the Corona discharge itself as a function of space and time. The motion of electrons, positive ions and negative ions formed by electron attachment, can produce distortions to the Electric field by space charge effects which result inTrichel current pulses for negativevoltages and "streamers" for positive voltages. Recently it has been realized that the medium of the Corona discharge in air, for example, is not ordinary air, since the properties of the air are changed by the Corona discharge itself. Of particular importance for properties of the Corona discharge are the many excited states and metastable atoms and molecules that are created by the Corona discharge, which may influence the electron density by detachment of negative ions or make possible two-step ionization. Rate constants of those reactions of plasma chemistry, which involve electrons in the discharge, are a function of the local Electric field. In the present paper, mechanisms of plasma chemistry are proposed to explain the voltage for spark breakdown between Corona wires.

Mehrdad Ghalamchi - One of the best experts on this subject based on the ideXlab platform.

  • performance optimization of solar chimney power plant using Electric Corona wind
    2015
    Co-Authors: Shahin Nasirivatan, Alibakhsh Kasaeian, Mehrdad Ghalamchi
    Abstract:

    Abstract The effect of the Corona wind on the natural convection at absorber of a solar chimney power plant pilot was investigated experimentally. The aim of the study is to improve the efficiency of SCPP through enhanced the heat transfer coefficient of absorber with Corona wind. The results show that Corona wind enhanced the absorber convective heat transfer coefficient leading to increment in air the velocity and the output power of the SCPP. The amount of heat transfer of pilot increased more than 14.5% when applying voltage of 15 KV and the speed in chimney experienced about 72% amelioration.