Improved domain partitioning on tree-based mesh-refined lattice Boltzmann method

Hasegawa, Yuta; Aoki, Takayuki*; Kobayashi, Hiromichi*; Idomura, Yasuhiro; Onodera, Naoyuki

Keisan Kogaku Koenkai Rombunshu (CD-ROM), 26, 6 Pages, 2021/05

We introduce an improved domain partitioning method called "tree cutting approach" for the aerodynamics simulation code based on the lattice Boltzmann method (LBM) with the forest-of-octrees-based local mesh refinement (LMR). The conventional domain partitioning algorithm based on the space-filling curve (SFC), which is widely used in LMR, caused a costly halo data communication which became a bottleneck of our aerodynamics simulation on the GPU-based supercomputers. Our tree cutting approach adopts a hybrid domain partitioning with the coarse structured block decomposition and the SFC partitioning in each block. This hybrid approach improved the locality and the topology of the partitioned sub-domains and reduced the amount of the halo communication to one-third of the original SFC approach. The code achieved speedup on 8 GPUs, and achieved speedup at the performance of 2207 MLUPS (mega-lattice update per second) on 128 GPUs with strong scaling test.

None

Miura, Kinya*; *

JNC TJ1400 99-027, 32 Pages, 1999/03

JNC-TJ1400-99-027.pdf:1.45MB

no abstracts in English

Development of nonlinear finite element method program provided the h-version adaptive Mesh division function

; Tsukimori, Kazuyuki

PNC TN9410 98-069, 128 Pages, 1998/05

PNC-TN9410-98-069.pdf:2.55MB

There is a growing tendency to need structural analysis aided expert system, which adopts advanced analysis techniques and is useful adaptive design of large reactor. This report describes about development of the h-version adaptive mesh division function based on Yuge & Iwai method. From points of view about securing of analysis precision, reduction of work to make analysis data and decrease in calculation costs, to analyze smoothly the nonlinear problems is the main object of this system. The h-version adaptive mesh technique is the method that increases locally finite element mesh density, depending on dividing the elements that the absorbed energy quantity exceeds a standard value every increment step. We developed this h-version adaptive mesh division function and incorporate it in the general nonlinear finite element code. For the function this system has, we show the following. (1)It is possible to apply this system to the thermos elastic-plastic nonlinear problem. (2)The provided finite elements (a)4-Node Quadrilateral Plane-Stress Element (b)4-Node Quadrilateral P1ane-Strain Element (c)4-Node Quadrilateral Axisymmetric Solid Element (d)4-Node Layered Shell Element (3)The provided constitutive model (a)Ono-model (b)kinetic hardening rule (c)ORNL 10 cycles hardening rule (4)The repetition technique : Newton-Raphson technique (5)The application possible force type (a)The concentrated forces (b)The distributed forces (c)The self forces (d)The temperature forces (6)It is possible to apply the cyclic repetition force. (7)The dividing the elements technique (a)Rectifying the strain of the element shape depending on the aspect ratio (b)Dividing the elements that the absorbed energy quantity exceeds a standard value every increment step. (c)Add the function of input the plural absorbed energy quantity that is the estimate value of the division elements. The programming and giving the tests about this system was put into by RCCM.

Real-time visualization system for computational fluid dynamics on distributed-memory parallel computers; Application to STEM2 code in simulating acid rain

Muramatsu, Kazuhiro; Kitabata, Hideyuki*; Matsumoto, Hideki*; Takei, Toshifumi*; Doi, Shun*

Dai-8-Kai NEC, HPC Kenkyukai Rombunshu, p.45 - 51, 1998/00

no abstracts in English

Real-time visualization system for computational fluid dynamics on parallel computers

Doi, Shun*; Matsumoto, Hideki*; Takei, Toshifumi*; Aikawa, Hiroshi

Keisan Kogaku Koenkai Rombunshu, 2(1), p.109 - 112, 1997/05

no abstracts in English

Performance estimation of a vector parallel calculation for short-range molecular dynamics

*; ; Yokokawa, Mitsuo

JAERI-Data/Code 96-011, 32 Pages, 1996/03

JAERI-Data-Code-96-011.pdf:0.87MB

no abstracts in English

Parallel simulation on Rayleigh-Benard convection in 2D by the direct simulation Monte Carlo method

Yokokawa, Mitsuo; D.Schneider*; Watanabe, Tadashi;

Parallel Computational Fluid Dynamics; Implementations and Results Using Parallel Computers, 0, p.75 - 80, 1995/00

no abstracts in English

Moessbauer spectroscopic study of frozen solutions of Co using a specially designed cryostat for time differential coincidence emission Moessbauer spectroscopy of Np

Saeki, Masakatsu; Nakada, Masami; ; Yoshida, Zenko; *; *; Yamashita, Toshiyuki; ;

Hyperfine Interactions, 92, p.1177 - 1181, 1994/00

https://doi.org/10.1007/BF02065752

no abstracts in English

Separation characteristics of cryogenic distillation column with a feedback strem for separation of protium and tritium

; Naruse, Yuji

Nucl.Technol./Fusion, 2, p.410 - 425, 1982/00

no abstracts in English