Mathematical modeling of velocity and number density profiles of particles across the flame propagation through a micro-iron dust cloud

2010 ◽  
Vol 176 (1-3) ◽  
pp. 146-153 ◽  
Author(s):  
Mehdi Bidabadi ◽  
Ali Haghiri ◽  
Alireza Rahbari
Keyword(s):  
Mathematical Modeling ◽  
Flame Propagation ◽  
Dust Cloud ◽  
Number Density ◽  
Density Profiles

Theoretical Investigation of Particle Behavior on Flame Propagation in Lycopodium Dust Cloud

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Alireza Rahbari ◽  
Kau-Fui Wong ◽  
Moslem Akbari Vakilabadi ◽  
Alireza Khoeini Poorfar ◽  
Abolfazl Afzalabadi
Keyword(s):  
Flame Propagation ◽  
Particle Concentration ◽  
Particle Density ◽  
Dust Cloud ◽  
Flame Structure ◽  
Dust Particles ◽  
Lagrangian Equation ◽  
Density Profiles ◽  
Combustion Region ◽  
Maximum Particle

The main aim of this research is focused on determining the velocity and particle density profiles across the flame propagation of microlycopodium dust particles. In this model, it is tried to incorporate the forces acting on the particles such as thermophoretic, gravitational, and buoyancy in the Lagrangian equation of motion. For this purpose, it is considered that the flame structure has four zones (i.e., preheat, vaporization, reaction, and postflame zones) and the temperature profile, as the unknown parameter in the thermophoretic force, is extracted from this model. Consequently, employing the Lagrangian equation with the known elements results in the velocity distribution versus the forefront of the combustion region. Satisfactory agreement is achieved between the present model and previously published experiments. It is concluded that the maximum particle concentration and velocity are gained on the flame front with the gradual decrease in the distance away from this location.

scholarly journals Retrieval of sodium number density profiles in the mesosphere and lower thermosphere from SCIAMACHY limb emission measurements

2016 ◽  
Vol 9 (1) ◽  
pp. 295-311 ◽  
Author(s):  
M. P. Langowski ◽  
C. von Savigny ◽  
J. P. Burrows ◽  
V. V. Rozanov ◽  
T. Dunker ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Lower Thermosphere ◽  
High Latitudes ◽  
Full Width ◽  
Half Maximum ◽  
Number Density ◽  
Data Set ◽  
Density Profiles ◽  
Atom Concentration ◽  
Mesosphere And Lower Thermosphere

Abstract. An algorithm has been developed for the retrieval of sodium atom (Na) number density on a latitude and altitude grid from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) limb measurements of the Na resonance fluorescence. The results are obtained between 50 and 150 km altitude and the resulting global seasonal variations of Na are analyzed. The retrieval approach is adapted from that used for the retrieval of magnesium atom (Mg) and magnesium ion (Mg+) number density profiles recently reported by Langowski et al. (2014). Monthly mean values of Na are presented as a function of altitude and latitude. This data set was retrieved from the 4 years of spectroscopic limb data of the SCIAMACHY mesosphere and lower thermosphere (MLT) measurement mode (mid-2008 to early 2012). The Na layer has a nearly constant peak altitude of 90–93 km for all latitudes and seasons, and has a full width at half maximum of 5–15 km. Small but significant seasonal variations in Na are identified for latitudes less than 40°, where the maximum Na number densities are 3000–4000 atoms cm−3. At middle to high latitudes a clear seasonal variation with a winter maximum of up to 6000 atoms cm−3 is observed. The high latitudes, which are only measured in the summer hemisphere, have lower number densities, with peak densities being approximately 1000 Na atoms cm−3. The full width at half maximum of the peak varies strongly at high latitudes and is 5 km near the polar summer mesopause, while it exceeds 10 km at lower latitudes. In summer the Na atom concentration at high latitudes and at altitudes below 88 km is significantly smaller than that at middle latitudes. The results are compared with other observations and models and there is overall a good agreement with these.

Radiation heat transfer in transient dust cloud flame propagation

2013 ◽  
Vol 26 (4) ◽  
pp. 862-868 ◽  
Author(s):  
Mehdi Bidabadi ◽  
Saeedreza Zadsirjan ◽  
Seyed Alireza Mostafavi
Keyword(s):  
Heat Transfer ◽  
Flame Propagation ◽  
Radiation Heat Transfer ◽  
Dust Cloud ◽  
Radiation Heat

Flame propagation of local LDPE dust cloud in a semi-open duct

2019 ◽  
Vol 101 ◽  
pp. 209-216 ◽  
Author(s):  
Lei Pang ◽  
Ran Ma ◽  
Shoutao Hu ◽  
Pengfei Lv ◽  
Kai Yang
Keyword(s):  
Flame Propagation ◽  
Dust Cloud

Calculated electron number density profiles for the aeroassist flight experiment

1992 ◽  
Vol 29 (5) ◽  
pp. 621-626 ◽  
Author(s):  
Robert B. Greendyke ◽  
Peter A. Gnoffo ◽  
R. Wes Lawrence
Keyword(s):  
Electron Number Density ◽  
Number Density ◽  
Electron Number ◽  
Density Profiles ◽  
Flight Experiment

Detection of correlation among galaxies within clusters from their two-dimensional number density profiles

1993 ◽  
Vol 402 ◽  
pp. 398 ◽  
Author(s):  
Eduard Salvador-Sole ◽  
Manuel Sanroma ◽  
Guillermo Gonzales-Casado
Keyword(s):  
Two Dimensional ◽  
Number Density ◽  
Density Profiles

scholarly journals Testing Gravity using Void Profiles

2014 ◽  
Vol 11 (S308) ◽  
pp. 555-560 ◽  
Author(s):  
Yan-Chuan Cai ◽  
Nelson Padilla ◽  
Baojiu Li
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Modified Gravity ◽  
Large Scale ◽  
Line Of Sight ◽  
Number Density ◽  
Density Profiles ◽  
Photometric Redshift ◽  
Redshift Survey ◽  
Near Future

AbstractWe investigate void properties inf(R)models using N-body simulations, focusing on their differences from General Relativity (GR) and their detectability. In the Hu-Sawickif(R)modified gravity (MG) models, the halo number density profiles of voids are not distinguishable from GR. In contrast, the samef(R)voids are more empty of dark matter, and their profiles are steeper. This can in principle be observed by weak gravitational lensing of voids, for which the combination of a spectroscopic redshift and a lensing photometric redshift survey over the same sky is required. Neglecting the lensing shape noise, thef(R)model parameter amplitudesfR0=10-5and 10-4may be distinguished from GR using the lensing tangential shear signal around voids by 4 and 8 σ for a volume of 1 (Gpc/h)3. The line-of-sight projection of large-scale structure is the main systematics that limits the significance of this signal for the near future wide angle and deep lensing surveys. For this reason, it is challenging to distinguishfR0=10-6from GR. We expect that this can be overcome with larger volume. The halo void abundance being smaller and the steepening of dark matter void profiles inf(R)models are unique features that can be combined to break the degeneracy betweenfR0and σ8.

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