Discrete Ordinate Method for Radiation Transport in Multi-Phase Computer Codes

2007 ◽  
pp. 643-643
Author(s):  
Nikolay I. Kolev
Keyword(s):  
Radiation Transport ◽  
Discrete Ordinate Method ◽  
Discrete Ordinate ◽  
Computer Codes ◽  
Multi Phase

scholarly journals Optimization and parallelization of the discrete ordinate method for radiation transport simulation in OpenFOAM: Hierarchical combination of shared and distributed memory approaches

2021 ◽  
Vol 1 ◽  
pp. 2
Author(s):  
Jose Moreno-SanSegundo ◽  
Cintia Casado ◽  
David Concha ◽  
Antonio S. Montemayor ◽  
Javier Marugán
Keyword(s):  
Distributed Memory ◽  
Radiation Transport ◽  
Computational Time ◽  
Limiting Factor ◽  
Discrete Ordinate Method ◽  
Discrete Ordinate ◽  
Radiation Sources ◽  
Transport Problems ◽  
Volume Models ◽  
Spatial Cell

This paper describes the reduction in memory and computational time for the simulation of complex radiation transport problems with the discrete ordinate method (DOM) model in the open-source computational fluid dynamics platform OpenFOAM. Finite volume models require storage of vector variables in each spatial cell; DOM introduces two additional discretizations, in direction and wavelength, making memory a limiting factor. Using specific classes for radiation sources data, changing the store of fluxes and other minor changes allowed a reduction of 75% in memory requirements. Besides, a hierarchical parallelization was developed, where each node of the standard parallelization uses several computing threads, allowing higher speed and scalability of the problem. This architecture, combined with optimization of some parts of the code, allowed a global speedup of x15. This relevant reduction in time and memory of radiation transport opens a new horizon of applications previously unaffordable.

scholarly journals An Efficient Implementation of the Finite-volume Method For the Solution of Radiation Transport in Circuit Breakers

2017 ◽  
Vol 4 (2) ◽  
pp. 177-181
Author(s):  
A. Mazaheri ◽  
J. Y. Trépanier ◽  
R. Camarero ◽  
P. Robin-Jouan
Keyword(s):  
Finite Volume ◽  
Radiation Transport ◽  
Computation Time ◽  
Discrete Ordinate Method ◽  
Discrete Ordinate ◽  
Circuit Breakers ◽  
Explicit Approach ◽  
Order Of Magnitude ◽  
Implicit Approach ◽  
Volume Method

In this paper, we propose to revisit the method to solve the radiation transport equation in circuit breakers to reduce the computation time. It is based on an explicit approach using a space marching algorithm. The method can further be accelerated using a Cartesian grid and using the axisymmetric assumption. Comparisons performed in terms of accuracy and efficiency between the P1 model, the implicit finite-volume discrete ordinate method and the space-marching finite-volume discrete ordinate method show that the explicit approach is more that an order of magnitude faster than the implicit approach, for the same accuracy.

Simulation of Focused Radiation Propagation and Transient Heat Transfer in Turbid Tissues

2009 ◽  
Author(s):  
Jian Jiao ◽  
Zhixiong Guo
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Pulse Train ◽  
Radiation Transport ◽  
Time Dependent ◽  
Transfer Model ◽  
Discrete Ordinate Method ◽  
Discrete Ordinate ◽  
Physiological Properties ◽  
Focused Beam

Thermal analysis of a cylindrical tissue subject to a train of ultrashort pulse irradiations was made by developing a combined time-dependent radiation and conduction bio-heat transfer model. Ultrashort pulsed radiation transport in the cylindrical tissue is simulated using the transient discrete ordinate method. Treatment of focused beam is introduced. The model skin tissue is stratified as three layers with different optical, thermal and physiological properties. Comparisons between the collimated irradiation and focused beam are conducted. The effect of pulse train is investigated.

scholarly journals Modelling and Simulation of the Radiant Field in an Annular Heterogeneous Photoreactor Using a Four-Flux Model

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
O. Alvarado-Rolon ◽  
R. Natividad ◽  
R. Romero ◽  
L. Hurtado ◽  
A. Ramírez-Serrano
Keyword(s):  
Photocatalytic Oxidation ◽  
Reaction Rate ◽  
Comsol Multiphysics ◽  
Discrete Ordinate Method ◽  
Discrete Ordinate ◽  
Cylindrical Coordinates ◽  
Volumetric Rate ◽  
Flux Model ◽  
Reaction Rate Equation ◽  
Good Agreement

This work focuses on modeling and simulating the absorption and scattering of radiation in a photocatalytic annular reactor. To achieve so, a model based on four fluxes (FFM) of radiation in cylindrical coordinates to describe the radiant field is assessed. This model allows calculating the local volumetric rate energy absorption (LVREA) profiles when the reaction space of the reactors is not a thin film. The obtained results were compared to radiation experimental data from other authors and with the results obtained by discrete ordinate method (DOM) carried out with the Heat Transfer Module of Comsol Multiphysics® 4.4. The FFM showed a good agreement with the results of Monte Carlo method (MC) and the six-flux model (SFM). Through this model, the LVREA is obtained, which is an important parameter to establish the reaction rate equation. In this study, the photocatalytic oxidation of benzyl alcohol to benzaldehyde was carried out, and the kinetic equation for this process was obtained. To perform the simulation, the commercial software COMSOL Multiphysics v. 4.4 was employed.

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