The Past and Future of the Monte Carlo Method in Thermal Radiation Transfer

2021 ◽  
Author(s):  
John R. Howell ◽  
Kyle Daun

Abstract The history and progress in Monte Carlo methods applied to radiative energy transfer are reviewed, with emphasis on advances over the past 25 years. Unresolved issues are outlined, and comments are included about the outlook for the method as impacted by the advances in massively parallel and quantum computers.

1989 ◽  
Vol 111 (1) ◽  
pp. 135-140 ◽  
Author(s):  
M. Kobiyama

A modified Monte Carlo method is suggested to reduce the computing time and improve the convergence stability of iterative calculations without losing other excellent features of the conventional Monte Carlo method. In this method, two kinds of radiative bundle are used: energy correcting bundles and property correcting bundles. The energy correcting bundles are used for correcting the radiative energy difference between two successive iterative cycles, and the property correcting bundles are used for correcting the radiative properties. The number of radiative energy bundles emitted from each control element is proportional to the difference in emissive energy between two successive iterative cycles.


2010 ◽  
Vol 6 (S272) ◽  
pp. 386-387
Author(s):  
Alicia Cruzado

AbstractFor a given photospheric model, we study the behavior of the BD as different density and temperature distributions in the circumstellar envelope are assumed. For non spherically symmetric envelopes, we analyze the variation of the BD when the angle of observation varies. The radiation transfer through the medium is handled by means of the Monte Carlo method. We calculate the flux emitted by the star+envelope system in a small wavelength range around the BD. The calculations are made under LTE conditions.


Author(s):  
I.S. Grigorev

The purpose of the paper was to study the scattering effect in the gas jet model on the angular dependence of the radiation intensity. Along with the Monte Carlo method used as the main calculation method, we applied a direct numerical solution of the equation of radiation transfer in a non-scattering medium, known as the discrete directions method, or Ray-Tracing Method. We compared the results obtained using the two methods when calculating a non-scattering medium in order to verify the solution according to the Monte Carlo scheme. Furthermore, we calculated the medium with an increasing value of the local scattering coefficient. Findings of research show the significant effect of scattering processes on the redistribution of radiation energy from the surface of the object. The computational algorithm is implemented on the CUDA C architecture. The use of analytical jet models, e.g. according to Abramovich's theory, and the results of calculations in the computational gas dynamics packages makes it possible to calculate the values of the radiation intensity for a wide class of objects


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
M.S. Al-Buriahi ◽  
Z.A. Alrowaili ◽  
Safa Ezzine ◽  
I.O. Olarinoye ◽  
Sultan Alomairy ◽  
...  

Abstract In this work, the Klein–Nishina (K–N) approach was used to evaluate the electronic, atomic, and energy-transfer cross sections of four elements, namely, zinc (Zn), tellurium (Te), barium (Ba), and bismuth (Bi), for different photon energies (0.662 MeV, 0.835 MeV, 1.170 MeV, 1.330 MeV, and 1.600 MeV). The obtained results were compared with the Monte Carlo method (Geant4 simulation) in terms of mass attenuation and mass energy-transfer coefficients. The results show that the K–N approach and Geant4 simulations are in good agreement for the entire energy range considered. As the photon energy increased from 0.662 MeV to 1.600 MeV, the values of the energy-transfer cross sections decreased from 81.135 cm2 to 69.184 cm2 in the case of Bi, from 50.832 cm2 to 43.344 cm2 for Te, from 54.742 cm2 to 46.678 cm2 for Ba, and from 29.326 cm2 to 25.006 cm2 for Zn. The obtained results and the detailed information of the attenuation properties for the studied elements would be helpful in developing a new generation of shielding materials against gamma rays.


2019 ◽  
pp. 15-24
Author(s):  
Vladimir Belov

Results of theoretical and experimental research of NLOS (NonLine of Sight) communication systems in the atmosphere, under water, and in mixed media based on publications of authors from China, Canada, Greece, the USA, Great Britain, Russia, and other countries are discussed in the present work. The theory of radiation transfer and the linear systems theory provide the basis for theoretical research. The radiation transfer equation is solved by the Monte–Carlo method in the singlescattering approximation. It is demonstrated that approximate methods are applicable when the average scattering multiplicity in open communication channels does not exceed 1. The Monte Carlo method is used to study the influence of opticalgeometric parameters of schemes of communication channels on the probabilities of communication errors, signal/noise ratios, limiting base lengths, attenuation of informationcarrying signals, and their superposition leading to communication errors. Examples of communications in the atmosphere in the UV range at distances up to 1300 m, in the visible range up to70 km, and under water up to 20 m are given. Search for optimal methods of signal modulation, development of software and hardware complexes for numerical simulation of the transfer properties of communication channels, refinement of analytical models of impulse transfer characteristics of noncoplanar schemes of bistatic optoelectronic communication systems (OECS), and research of the effect of winddriven sea waves and processes of radiation scattering in water are planned to study the efficiency of operation of the communication systems and to expand ranges of variations of the input NLOS and OECS parameters in the experiments carried out in natural water reservoirs.


Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1512
Author(s):  
Mikhail V. Tarasenkov ◽  
Matvei N. Zonov ◽  
Marina V. Engel ◽  
Vladimir V. Belov

A method for estimating the cloud adjacency effect on the reflectance of ground surface areas reconstructed from passive satellite observations through gaps in cloud fields is proposed. The method allows one to estimate gaps of cloud fields in which the cloud adjacency effect can be considered small (the increment of the reflectance Δrsurf≤ 0.005). The algorithm is based on statistical simulation by the Monte Carlo method of radiation transfer in stochastic broken cloudiness with a deterministic cylindrical gap. An interpolation formula is obtained for the radius of the cloud adjacency effect that can be used for the reconstruction the ground surface reflectance in real time without calculations by the Monte Carlo method.


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