کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
519917 | 867689 | 2014 | 18 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Multigroup diffusion preconditioners for multiplying fixed-source transport problems Multigroup diffusion preconditioners for multiplying fixed-source transport problems](/preview/png/519917.png)
Several preconditioners based on multigroup diffusion are developed for application to multiplying fixed-source transport problems using the discrete ordinates method. By starting from standard, one-group, diffusion synthetic acceleration (DSA), a multigroup diffusion preconditioner is constructed that shares the same fine mesh as the transport problem. As a cheaper but effective alternative, a two-grid, coarse-mesh, multigroup diffusion preconditioner is examined, for which a variety of homogenization schemes are studied to generate the coarse mesh operator. Finally, a transport-corrected diffusion preconditioner based on application of the Newton–Shulz algorithm is developed. The results of several numerical studies indicate the coarse-mesh, diffusion preconditioners work very well. In particular, a coarse-mesh, transport-corrected, diffusion preconditioner reduced the computational time of multigroup GMRES by up to a factor of 17 and outperformed best-case Gauss–Seidel results by over an order of magnitude for all problems studied.
Journal: Journal of Computational Physics - Volume 274, 1 October 2014, Pages 455–472