scholarly journals Corrigendum: An Investigation of the Accuracy of Numerical Solutions of Boltzmann's Equation for Electron Swarms in Gases with Large Inelastic Cross Sections

1982 ◽  
Vol 35 (4) ◽  
pp. 473 ◽  
Author(s):  
Ivan D Reid
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Cross Sections ◽  
Numerical Solutions ◽  
Computer Codes ◽  
Boltzmann's Equation ◽  
Boltzmann’S Equation

An error has been found in the computer codes used in the Monte Carlo simulations. The correction for this error alters some of the values of Dol by up to several per cent. The conclusions presented in the paper are however not affected.

scholarly journals An Investigation of the Accuracy of Numerical Solutions of Boltzmann's Equation for Electron Swarms in Gases with Large Inelastic Cross Sections

1979 ◽  
Vol 32 (3) ◽  
pp. 231 ◽  
Author(s):  
Ivan D Reid
Keyword(s):  
Monte Carlo Simulation ◽  
Cross Sections ◽  
Numerical Solutions ◽  
Transport Coefficients ◽  
Distribution Functions ◽  
Monte Carlo Simulation Technique ◽  
Energy Distribution Functions ◽  
Boltzmann's Equation ◽  
Term Approximation ◽  
Boltzmann’S Equation

A Monte Carlo simulation technique has been used to test the accuracy of electron energy distribution functions and transport coefficients calculated using conventional numerical solutions of Boltzmann's equation based on a two-term approximation. The tests have been applied to a number of model gases, some of which have characteristics close to those of real gases, and include cases where the scattering is anisotropic. The results show that, in general, previous application of the numerical solution to real gases has been valid.

PREDICTION OF CONVECTIVE HEAT TRANSFER OF NANOFLUIDS BASED ON FRACTAL-MONTE CARLO SIMULATIONS

2013 ◽  
Vol 24 (01) ◽  
pp. 1250090 ◽  
Author(s):  
BO-QI XIAO ◽  
GUO-PING JIANG ◽  
YI YANG ◽  
DONG-MEI ZHENG
Keyword(s):  
Heat Transfer ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Numerical Solutions ◽  
Probability Model ◽  
Average Diameter ◽  
Physical Mechanisms ◽  
Proposed Model

With the consideration of the Brownian motion of nanoparticles in fluids, the probability model for the size of nanoparticles and the model for convective heat transfer of nanofluids are derived based on the fractal character of nanoparticles. The proposed model is expressed as a function of the size of nanoparticles, the volumetric nanoparticle concentration, the thermal conductivity of base fluids, fractal dimension of nanoparticles and the temperature, as well as the random number. It is found that the convective heat flux of nanofluids decreases with increasing of the average diameter of nanoparticles. This model has the characters of both analytical and numerical solutions. The Monte Carlo simulations combined with the fractal geometry theory are performed. Every parameter of the proposed formula on convective heat transfer of nanofluids has clear physical meaning. So the proposed model can reveal the physical mechanisms of convective heat transfer of nanofluids.

scholarly journals A complete data set for the simulation of electron transport through gaseous tetrahydrofuran in the energy range 1–100 $$\hbox {eV}$$

2021 ◽  
Vol 75 (12) ◽  
Author(s):  
A. García-Abenza ◽  
A. I. Lozano ◽  
L. Álvarez ◽  
J. C. Oller ◽  
F. Blanco ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Electron Transport ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Cross Sections ◽  
Gas Cell ◽  
Data Set ◽  
Total Electron ◽  
Magnetically Confined ◽  
Scattering Cross Sections

Abstract A self-consistent data set, with all the necessary inputs for Monte Carlo simulations of electron transport through gaseous tetrahydrofuran (THF) in the energy range 1–100 eV, has been critically compiled in this study. Accurate measurements of total electron scattering cross sections (TCSs) from THF have been obtained, and considered as reference values to validate the self-consistency of the proposed data set. Monte Carlo simulations of the magnetically confined electron transport through a gas cell containing THF for different beam energies (3, 10 and 70 eV) and pressures (2.5 and 5.0 mTorr) have also been performed by using a novel code developed in Madrid. In order to probe the accuracy of the proposed data set, the simulated results have been compared with the corresponding experimental data, the latter obtained with the same experimental configuration where the TCSs have been measured. Graphic Abstract

scholarly journals Monte Carlo simulations of two-component drop growth by stochastic coalescence

2009 ◽  
Vol 9 (4) ◽  
pp. 1241-1251 ◽  
Author(s):  
L. Alfonso ◽  
G. B. Raga ◽  
D. Baumgardner
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Numerical Solutions ◽  
Initial Conditions ◽  
Stochastic Algorithm ◽  
Aerosol Composition ◽  
Aerosol Mass ◽  
Two Component ◽  
Framework Species ◽  
Stochastic Coalescence

Abstract. The evolution of two-dimensional drop distributions is simulated in this study using a Monte Carlo method. The stochastic algorithm of Gillespie (1976) for chemical reactions in the formulation proposed by Laurenzi et al. (2002) was used to simulate the kinetic behavior of the drop population. Within this framework, species are defined as droplets of specific size and aerosol composition. The performance of the algorithm was checked by a comparison with the analytical solutions found by Lushnikov (1975) and Golovin (1963) and with finite difference solutions of the two-component kinetic collection equation obtained for the Golovin (sum) and hydrodynamic kernels. Very good agreement was observed between the Monte Carlo simulations and the analytical and numerical solutions. A simulation for realistic initial conditions is presented for the hydrodynamic kernel. As expected, the aerosol mass is shifted from small to large particles due to collection process. This algorithm could be extended to incorporate various properties of clouds such several crystals habits, different types of soluble CCN, particle charging and drop breakup.

Coupling of Heat and Momentum Transfer Between Nanostructured Surfaces

2009 ◽  
Author(s):  
Alexander A. Donkov ◽  
Steffen Hardt ◽  
Sudarshan Tiwari ◽  
Axel Klar
Keyword(s):  
Heat Transfer ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Numerical Solutions ◽  
Small Scale ◽  
Molecular Flow ◽  
Transition Regime ◽  
Free Molecular Flow ◽  
Direction Parallel ◽  
Nanostructured Surfaces

Heat transfer between nanostructured surfaces separated by a thin gas film is studied in the free-molecular flow and in the transition regime. Besides topographic features the surfaces are characterized by regions with different boundary conditions displaying either diffuse or specular reflection of the molecules. The thermal conductivity of the materials on both sides of the gas film is assumed to be very high such that isothermal conditions may be applied at both surfaces. We analyze the problem using a combination of analytical techniques in the free-molecular flow regime and Monte-Carlo simulations. Under certain conditions, when the surfaces are held at different temperatures heat transfer is accompanied by a transfer of momentum such that a force is created parallel to the surfaces. This force can be significant and vanishes in the classical regime when the continuum transport equations can be applied. It is only observed if the reflection symmetry in a direction parallel to the surfaces is broken. We derive an analytical expression for the thermally-induced force as a function of the geometric parameters characterizing the surface topography and compare the results to Monte-Carlo simulations. The latter provide numerical solutions of the Boltzmann equation both in the free-molecular flow and in the transition regime. The scenario studied points to a novel method for conversion of thermal into kinetic energy and may find applications in small-scale energy converters.

scholarly journals Number albedo of low-energy photons for water, aluminum, and iron

2007 ◽  
Vol 22 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Vladan Ljubenov ◽  
Rodoljub Simovic ◽  
Srpko Markovic ◽  
Radovan Ilic
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Energy Range ◽  
Photon Number ◽  
Fluorescence Yield ◽  
Low Energy ◽  
Initial Photon ◽  
Computer Codes

Number albedo of water, aluminum, and iron for incident photons in the energy range from 20 keV to 100 keV is presented in this paper. The results are obtained through Monte Carlo simulations of photon reflection by using MCNP-4C, FOTELP-2K3, and PENELOPE-2005 computer codes. The calculated values are compared with the classical data published by B. P. Bulatov and his collaborators. The influence of fluorescence yield to the photon number albedo of an iron target at the initial photon energies below 40 keV is detected and analyzed.

X-Ray Emission of Porous Materials In The Scanning Electron Microscope Computed Using Monte Carlo Simulations

1997 ◽  
Vol 3 (S2) ◽  
pp. 883-884 ◽  
Author(s):  
Raynald Gauvin
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Monte Carlo Simulations ◽  
Porous Materials ◽  
Cross Sections ◽  
Quantitative Methods ◽  
Electron Trajectories ◽  
X Ray ◽  
Scanning Electron

Conventional quantitative X-ray microanalysis in the scanning electron microscope or in the electron microprobe is valid for specimens of bulk homogeneous composition and with flat and polished surfaces. Quantitative methods, using X-ray microanalysis and Monte Carlo simulations of electron trajectories in solids, have been developed for the chemical analysis of spherical inclusions embedded in a matrix and for multilayered specimens. In this paper, the effect of porosity and of the size of the pores are investigated concerning their effect on X-ray emission using Monte Carlo simulation of electron trajectories in solids since porous materials are of great technological importance.This new Monte Carlo program uses elastic Mott cross-sections to compute electron trajectories and the Joy & Luo modification of the continuous Bethe law of energy loss and the details are given elsewhere. This program assumes that all the pores are spherical and have the same size.

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