Effects of the electric field on the virtual mass of a flowing fluid sphere

2009 ◽  
Vol 87 (10) ◽  
pp. 1095-1098
Author(s):  
Abdullah Abbas Kendoush
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Liquid Medium ◽  
Fluid Sphere ◽  
Virtual Mass ◽  
Flowing Fluid ◽  
Hydrodynamic Solution ◽  
Mass Coefficient

A hydrodynamic solution was used to calculate the virtual mass coefficients of a flowing fluid sphere in a liquid medium subjected to an electric field. The values of the virtual mass coefficient of the bubble and a drop were found to be different from the classical value of half. The new result was validated by comparison with the experimental data of other investigators.

The drag force on a collapsing bubble

2008 ◽  
Vol 222 (7) ◽  
pp. 1225-1235
Author(s):  
A A Kendoush
Keyword(s):  
Experimental Data ◽  
Drag Coefficient ◽  
Numerical Solutions ◽  
Bubble Surface ◽  
Dimensionless Time ◽  
Virtual Mass ◽  
Controlled Processes ◽  
Diffusion Controlled ◽  
Mass Coefficient ◽  
Theoretical Results

Equations were derived for the prediction of the drag coefficient of a collapsing bubble during its flow in liquid. Expressions were obtained analytically for the drag coefficient in terms of Reynolds, Peclet, and Jakob numbers as well as a dimensionless time for the collapse of a thermally controlled bubble. Equations were derived for the drag coefficient and virtual mass coefficient for a collapsing bubble under inertia-controlled and mass-diffusion-controlled processes. The flow and thermal parameters were obtained by solving the viscous dissipation integral around the bubble surface. These new theoretical results showed agreement with previously reported numerical solutions and experimental data. Some avenues for further research were pointed out.

The Virtual Mass Theory of a Taylor Bubble Rising in Vertical Pipes

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Abdullah Abbas Kendoush
Keyword(s):  
Experimental Data ◽  
Numerical Solutions ◽  
Inviscid Flow ◽  
Virtual Mass ◽  
Transient Conditions ◽  
Taylor Bubble ◽  
Low Viscosity ◽  
Present Solution ◽  
Mass Coefficient ◽  
Bubble Rising

Analytical solutions were obtained for the virtual mass of a Taylor bubble rising in a liquid confined by a circular pipe under transient conditions. The solution of the virtual mass coefficient was based on potential inviscid flow. The present solution is applicable to low viscosity liquids and to Capillary number (Ca)<0.005. The virtual mass solution showed dependence on bubble geometry. The present solution was validated by comparison with the available numerical solutions and experimental data of other investigators.

TEMPERATURE-DEPENDENCE OF PROTON CONDUCTIVITY IN HYDROGEN-BONDED MOLECULAR SYSTEMS

2007 ◽  
Vol 21 (19) ◽  
pp. 1239-1252 ◽  
Author(s):  
XIAO-FENG PANG ◽  
BO DENG ◽  
HUAI-WU ZHANG ◽  
YUAN-PING FENG
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Temperature Dependence ◽  
Electric Conductivity ◽  
Proton Conductivity ◽  
Model System ◽  
Time Dependent ◽  
Molecular Systems ◽  
Damping Effect ◽  
Hydrogen Bonded

The temperature-dependence of proton electric conductivity in hydrogen-bonded molecular systems with damping effect was studied. The time-dependent velocity of proton and its mobility are determined from the Hamiltonian of a model system. The calculated mobility of (3.57–3.76) × 10-6 m 2/ Vs for uniform ice is in agreement with the experimental value of (1 - 10) × 10-2 m 2/ Vs . When the temperature and damping effects of the medium are considered, the mobility is found to depend on the temperature for various electric field values in the system, i.e. the mobility increases initially and reaches a maximum at about 191 K, but decreases subsequently to a minimum at approximately 241 K, and increases again in the range of 150–270 K. This behavior agrees with experimental data of ice.

BALLISTIC ELECTRON ACCELERATION NEGATIVE-DIFFERENTIAL-CONDUCTIVITY DEVICES

2007 ◽  
Vol 17 (01) ◽  
pp. 173-176 ◽  
Author(s):  
BARBAROS ASLAN ◽  
LESTER F. EASTMAN ◽  
WILLIAM J. SCHAFF ◽  
XIAODONG CHEN ◽  
MICHAEL G. SPENCER ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Electron Acceleration ◽  
Negative Differential Conductivity ◽  
Differential Conductivity ◽  
Experimental Development ◽  
Ballistic Electron

We present the experimental development and characterization of GaN ballistic diodes for THz operation. Fabricated devices have been described and gathered experimental data is discussed. The major problem addressed is the domination of the parasitic resistances which significantly reduce the accelerating electric field across the ballistic region (intrinsic layer).

scholarly journals What Determines the Parameters of a Propagating Streamer: A Comparison of Outputs of the Streamer Parameter Model and of Hydrodynamic Simulations

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1664
Author(s):  
Nikolai G. Lehtinen ◽  
Robert Marskar
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Electric Discharge ◽  
Propagation Velocity ◽  
The Novel ◽  
Hydrodynamic Simulation ◽  
Hydrodynamic Simulations ◽  
Important Stage ◽  
Streamer Discharges

Electric streamer discharges (streamers) in the air are a very important stage of lightning, taking place before formation of the leader discharge, and with which an electric discharge starts from conducting objects which enhance the background electric field, such as airplanes. Despite years of research, it is still not well understood what mechanism determines the values of a streamer’s parameters, such as its radius and propagation velocity. The novel Streamer Parameter Model (SPM) was made to explain this mechanism, and to provide a way to efficiently calculate streamer parameters. Previously, we demonstrated that SPM results compared well with a limited set of experimental data. In this article, we compare SPM predictions to the published hydrodynamic simulation (HDS) results.

scholarly journals Моделирование плазмы короткодугового ксенонового разряда сверхвысокого давления

2019 ◽  
Vol 89 (10) ◽  
pp. 1556
Author(s):  
Н.А. Тимофеев ◽  
В.С. Сухомлинов ◽  
G. Zissis ◽  
И.Ю. Мухараева ◽  
Д.В. Михайлов ◽  
...  
Keyword(s):  
Experimental Data ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Arc Discharge ◽  
Plasma Temperature ◽  
Cathode Region ◽  
Ultrahigh Pressure ◽  
Thoriated Tungsten ◽  
Ionization Balance

AbstractWe have studied a high- (ultrahigh-) pressure short-arc discharge in xenon with thoriated tungsten cathodes. A system of equations formulated based on earlier experimental data indicating possible emission of cathode material (thorium) into the discharge gap has made it possible to determine the electric field strength, plasma temperature, and concentration of thorium atoms as well as thorium and xenon ions in the plasma. The problem has been solved for a model discharge between planar electrodes. The results indicate the key role of thorium atoms in the cathode region. Thorium atoms determine the ionization balance and other electrokinetic properties of plasma. Emission of thorium atoms reduces the plasma temperature at the cathode, which turns out to be noticeably lower than the plasma temperature near the anode; this is a new result that agrees with experimental data. Other electrokinetic characteristics of the plasma (in particular, charged particle concentration and electric field strength) are also in good agreement with the experiment.

scholarly journals Anisotropic Diffusion and the Townsend?Huxley Experiment

1973 ◽  
Vol 26 (4) ◽  
pp. 469 ◽  
Author(s):  
JJ Lowke
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Electron Mobility ◽  
Diffusion Coefficients ◽  
Applied Electric Field ◽  
Anisotropic Diffusion ◽  
Diffusion Tubes ◽  
New Formula ◽  
The Relationship ◽  
Diffusion Tube

The relationship between current ratios and electron diffusion coefficients for the Townsend-Huxley experiment is reanalysed with the assumption that diffusion can be represented by two coefficients DT and DL for diffusion transverse and parallel respectively to the applied electric field. When the new formula is used to interpret previous experimental data obtained with a diffusion tube of length 2 cm, the derived values of DT/fl become independent of pressure (fl being the electron mobility). For longer diffusion tubes (~ 6 cm), current ratios are insensitive to DL and the results differ insignificantly from those obtained using the formula previously derived on the assumption that diffusion is isotropic.

ROTATION OF THE AXISIMMETRIC DIELECTRIC BODIES (DEB) IN ELECTRORHEOLOGICAL SUSPENSIONS (ERS)

1996 ◽  
Vol 10 (23n24) ◽  
pp. 2903-2915 ◽  
Author(s):  
ZINOVIY P. SHULMAN ◽  
VALERIY NOSOV
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Rotation Speed ◽  
Electrophysical Properties ◽  
Engineering Applications ◽  
Dielectric Bodies ◽  
Electrorheological Suspensions

Consideration is given to rotation of nonconducting bodies in electrorheological suspensions. Experimental data are presented describing the effect of an electric field on the rotation speed as well as on rheological and electrophysical properties of ERS. The dependence of speed on temperature and the rotor geometry is considered in some detail. Two examples of engineering applications are presented.

Recirculation within a fluid sphere at moderate Reynolds numbers

2002 ◽  
Vol 465 ◽  
pp. 293-300 ◽  
Author(s):  
D. A. BARRY ◽  
J.-Y. PARLANGE
Keyword(s):  
Experimental Data ◽  
Vertical Velocity ◽  
Laboratory Data ◽  
Major Axis ◽  
Reynolds Numbers ◽  
Fluid Sphere ◽  
Stagnation Region ◽  
Data Set ◽  
Different Levels

Motion of a single fluid sphere is described by two theories, each characterized by different levels of Hill's vortex circulation within the sphere. An existing experimental data set giving measurements of vertical velocity along the major axis of the sphere is re-examined. Contrary to published discussions of that experiment, we find that the theory of Parlange agrees better with the laboratory data than that of Harper & Moore. This agreement supports the key difference between the two theories, i.e. that the fluid within the sphere is unlikely to have a singular (infinite) velocity as it moves upwards towards the stagnation region at the top of the sphere.

Sign in / Sign up

Export Citation Format

Share Document