Numerical non-LTE 3D radiative transfer using a multigrid method (trac #380)

[cloudy-bot]

reported by: @CloudyLex

Title:  
Numerical non-LTE 3D radiative transfer using a multigrid method
Authors:    
Bjørgen, Johan P.; Leenaarts, Jorrit
Publication:    
eprint arXiv:1701.01607
Publication Date:   
01/2017
Origin: 
ARXIV
Keywords:   
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Comment:    
Accepted for publication by A&A
Bibliographic Code: 
2017arXiv170101607B
Abstract

3D non-LTE radiative transfer problems are computationally demanding, and this 
sets limits on the size of the problems that can be solved. So far Multilevel 
Accelerated Lambda Iteration (MALI) has been to the method of choice to perform 
high-resolution computations in multidimensional problems. The disadvantage of 
MALI is that its computing time scales as $\mathcal{O}(n^2)$, with $n$ the number 
of grid points. When the grid gets finer, the computational cost increases 
quadratically. We aim to develop a 3D non-LTE radiative transfer code that is more 
efficient than MALI. We implement a non-linear multigrid, fast approximation storage 
scheme, into the existing Multi3D radiative transfer code. We verify our multigrid 
implementation by comparing with MALI computations. We show that multigrid can 
be employed in realistic problems with snapshots from 3D radiative-MHD 
simulations as input atmospheres. With multigrid, we obtain a factor 3.3-4.5 
speedup compared to MALI. With full-multigrid the speed-up increases to a factor 6. 
The speedup is expected to increase for input atmospheres with more grid points 
and finer grid spacing. Solving 3D non-LTE radiative transfer problems using non-
linear multigrid methods can be applied to realistic atmospheres with a substantial 
speed-up.

Migrated from https://www.nublado.org/ticket/380

{
    "status": "new",
    "changetime": "2019-02-04T13:02:49Z",
    "_ts": "1549285369825011",
    "description": "{{{\nTitle:\t\nNumerical non-LTE 3D radiative transfer using a multigrid method\nAuthors:\t\nBj\u00f8rgen, Johan P.; Leenaarts, Jorrit\nPublication:\t\neprint arXiv:1701.01607\nPublication Date:\t\n01/2017\nOrigin:\t\nARXIV\nKeywords:\t\nAstrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics\nComment:\t\nAccepted for publication by A&A\nBibliographic Code:\t\n2017arXiv170101607B\nAbstract\n\n3D non-LTE radiative transfer problems are computationally demanding, and this \nsets limits on the size of the problems that can be solved. So far Multilevel \nAccelerated Lambda Iteration (MALI) has been to the method of choice to perform \nhigh-resolution computations in multidimensional problems. The disadvantage of \nMALI is that its computing time scales as $\\mathcal{O}(n^2)$, with $n$ the number \nof grid points. When the grid gets finer, the computational cost increases \nquadratically. We aim to develop a 3D non-LTE radiative transfer code that is more \nefficient than MALI. We implement a non-linear multigrid, fast approximation storage \nscheme, into the existing Multi3D radiative transfer code. We verify our multigrid \nimplementation by comparing with MALI computations. We show that multigrid can \nbe employed in realistic problems with snapshots from 3D radiative-MHD \nsimulations as input atmospheres. With multigrid, we obtain a factor 3.3-4.5 \nspeedup compared to MALI. With full-multigrid the speed-up increases to a factor 6. \nThe speedup is expected to increase for input atmospheres with more grid points \nand finer grid spacing. Solving 3D non-LTE radiative transfer problems using non-\nlinear multigrid methods can be applied to realistic atmospheres with a substantial \nspeed-up.\n}}}\n",
    "reporter": "gary",
    "cc": "",
    "resolution": "",
    "time": "2017-01-13T15:24:11Z",
    "component": "radiative transfer",
    "summary": "Numerical non-LTE 3D radiative transfer using a multigrid method",
    "priority": "good to do",
    "keywords": "",
    "version": "trunk",
    "milestone": "no milestone",
    "owner": "nobody",
    "type": "enhancement"
}

[cloudy-bot]

@peter-van-hoof-noaccount changed milestone from "" to "no milestone"