Gas density and particle concentration measurements in shock-induced dusty-gas flows

1990 ◽  
Author(s):  
Gary D. Lock ◽  
James J. Gottlieb
Keyword(s):  
Particle Concentration ◽  
Gas Flows ◽  
Dusty Gas ◽  
Gas Density ◽  
Concentration Measurements

Modeling of dusty gas flows due to plume impingement on a lunar surface

2021 ◽  
Vol 33 (5) ◽  
pp. 053307
Author(s):  
Arun K. Chinnappan ◽  
Rakesh Kumar ◽  
Vaibhav K. Arghode
Keyword(s):  
Lunar Surface ◽  
Gas Flows ◽  
Dusty Gas

scholarly journals The Formation of Discontinuities in Gas Flows in the ISM and its Relation to the Galactic Synchrotron Radio Emission

1990 ◽  
Vol 140 ◽  
pp. 159-162
Author(s):  
V.G. Berman ◽  
L.S. Marochnik ◽  
Yu.N. Mishurov ◽  
A.A. Suchkov
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Radio Emission ◽  
Large Scale ◽  
Field Energy ◽  
Gas Flows ◽  
Interstellar Gas ◽  
Gas Density ◽  
Magnetic Field Energy ◽  
Wide Range

We show that large–scale motions of the interstellar gas, such as those associated with galactic density waves, easily develop, over a wide range of scales, shocks and discontinuities which are expected to generate turbulence. The latter is supposed to evoke diffusion of magnetic fields and cosmic rays on scales down to a few parsecs. We suggest that these processes may be of major importance in discussions of interconnections between the observed radio emission of the disks of spiral galaxies and the gas density distribution within them. In particular, we predict that the density of cosmic rays and magnetic field energy must be much less contrasted (on scales of ~1 pc and up to the scales of galactic shocks) than the gas density, hence the synchrotron radio emission is not as contrasted as is predicted under the hypothesis of a fully frozen-in magnetic field.

scholarly journals Features of Sizing and Enumeration of Silica and Polystyrene Nanoparticles by Nanoparticle Tracking Analysis (NTA)

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6611
Author(s):  
Zohair Usfoor ◽  
Katharina Kaufmann ◽  
Al Shahriar Hossain Rakib ◽  
Roland Hergenröder ◽  
Victoria Shpacovitch
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Particle Concentration ◽  
Refractive Indices ◽  
Nanoparticle Tracking Analysis ◽  
Polystyrene Nanoparticles ◽  
Transmission Electron ◽  
Concentration Measurements ◽  
Scanning Electron

Nanoparticle Tracking Analysis (NTA) allows for the simultaneous determination of both size and concentration of nanoparticles in a sample. This study investigates the accuracy of particle size and concentration measurements performed on an LM10 device. For experiments, standard nanoparticles of different sizes composed of two materials with different refractive indices were used. Particle size measurements were found to have a decent degree of accuracy. This fact was verified by the manufacturer-reported particle size—determined by transmission electron microscopy (TEM)—as well as by performed scanning electron microscopy (SEM) measurements. On the other hand, concentration measurements resulted in overestimation of the particle concentration in majority of cases. Thus, our findings confirmed the accuracy of nanoparticle sizing performed by the LM10 instrument and highlighted the overestimation of particle concentration made by this device. In addition, an approach of swift correction of the results of concentration measurements received for samples is suggested in the presented study.

scholarly journals Building Planets with Dusty Gas

2004 ◽  
Vol 213 ◽  
pp. 231-234
Author(s):  
S. T. Maddison ◽  
R. J. Humble ◽  
J. R. Murray
Keyword(s):  
Solar Nebula ◽  
Numerical Technique ◽  
Dynamical Evolution ◽  
Gas Flows ◽  
Dusty Gas ◽  
Dust Distribution ◽  
Self Gravity ◽  
Gas Medium

We have developed a new numerical technique for simulating dusty-gas flows. Our code incorporates gas hydrodynamics, self-gravity and dust drag to follow the dynamical evolution of a dusty-gas medium. We have incorporated several descriptions for the drag between gas and dust phases and can model flows with submillimetre, centimetre and metre size “dust”. We present calculations run on the APAC1 supercomputer following the evolution of the dust distribution in the pre-solar nebula.

Recent developments in hydrodynamic stability of two-phase flows

2012 ◽  
Vol 9 (1) ◽  
pp. 125-130
Author(s):  
A.N. Osiptsov ◽  
S.A. Boronin
Keyword(s):  
Boundary Layer ◽  
Particle Concentration ◽  
Volume Fraction ◽  
Time Interval ◽  
Dusty Gas ◽  
Two Phase Flows ◽  
Two Phase ◽  
Layer Width ◽  
Dispersed Flows ◽  
Optimal Disturbances

In the framework of two-continuum model, the stability of plane-parallel dispersed flows is analyzed. Several flow configurations are considered and several new factors are analyzed. The factors include: particle velocity slip and particle concentration non-uniformity in the main flow, non-Stokesian components of the interphase force and finite volume fraction of the dispersed phase. It is found that the new factors modify significantly the parameters of the fastest growing mode and change the critical Reynolds number of two-phase flows. A method for studying algebraic (non-modal) instability and optimal disturbances to dispersed flows is proposed. While studying the non-modal instability of the dusty-gas boundary-layer flow with a non-uniform particle concentration, we found that the disturbances with the maximum energy gain at a limited time interval are streamwise-elongated structures (streaks). As compared to the flow of a particle-free fluid, optimal disturbances to the dusty-gas flow gain much larger kinetic energy even at the boundary layer width-averaged mass concentration of ten percent, which leads to significant amplification of non-modal instability mechanism due to the presence of suspended particles.

scholarly journals Supersonic dusty-gas flows with Knudsen effect in interphase momentum exchange

2004 ◽  
Vol 20 (5) ◽  
pp. 465-470
Author(s):  
Wang Boyi ◽  
A. N. Osiptsov ◽  
L. A. Egorova ◽  
V. I. Sakharov
Keyword(s):  
Gas Flows ◽  
Dusty Gas ◽  
Momentum Exchange ◽  
Knudsen Effect

scholarly journals Evaluation of Exposure Risk in the Weaving Process of MWCNT-Coated Yarn with Real-time Particle Concentration Measurements and Characterization of Dust Particles

2012 ◽  
Vol 50 (2) ◽  
pp. 147-155 ◽  
Author(s):  
Mitsutoshi TAKAYA ◽  
Mariko ONO-OGASAWARA ◽  
Yasushi SHINOHARA ◽  
Hisayo KUBOTA ◽  
Shuji TSURUOKA ◽  
...  
Keyword(s):  
Real Time ◽  
Particle Concentration ◽  
Dust Particles ◽  
Exposure Risk ◽  
Concentration Measurements

An indirect method of measuring gas- and particulate-phase velocities of shock-induced dusty-gas flows

1992 ◽  
Vol 70 (2-3) ◽  
pp. 122-133
Author(s):  
James J. Gottlieb
Keyword(s):  
Phase Velocity ◽  
Mass Conservation ◽  
Time Of Arrival ◽  
Gas Flows ◽  
Dusty Gas ◽  
Particulate Phase ◽  
Two Phase ◽  
Gas Phases ◽  
Direct Measurements ◽  
Particulate Concentration

A method of indirectly measuring the temporally varying velocities of both the particulate and gas phases in the nonequilibrium region of a shock wave moving at constant speed in a dusty-gas mixture is described. This method is implemented by using experimental data from shock-induced air flows containing glass beads 40 μm in diameter in a dusty-gas shock-tube facility featuring a large horizontal channel 197 mm high by 76 mm wide with a special dust-injection device. Simultaneous measurements of the shock-front speed with time-of-arrival gauges, particulate concentration by light extinctiometry, and combined particulate concentration and gas density by beta-ray absorption are used in conjunction with two mass conservation laws to provide these indirect two-phase velocity measurements. Direct measurements of the particulate-phase velocity by laser-Doppler velocimetry are also presented for comparison, and the capability of the indirect velocity-measurement method is assessed.

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