The document summarizes research on simulating hydrogen dispersion using the ADVENTURE_sFlow solver. It describes modeling hydrogen dispersion as an analogy to thermal convection problems. Two models are analyzed: a hallway model and a car garage model. The hallway model analyzes hydrogen dispersion from inlet, door, and roof vents in an empty volume. The car garage model analyzes hydrogen leakage from a fuel cell car in a full-scale garage. The objective is to demonstrate the feasibility of using the ADVENTURE_sFlow solver, which uses a hierarchical domain decomposition method, to efficiently solve large-scale problems like hydrogen dispersion in engineering facilities.
The document summarizes research on simulating hydrogen dispersion using the ADVENTURE_sFlow solver. It describes modeling hydrogen dispersion as an analogy to thermal convection problems. Two models are analyzed: a hallway model and a car garage model. The hallway model analyzes hydrogen dispersion from inlet, door, and roof vents in an empty volume. The car garage model analyzes hydrogen leakage from a fuel cell car in a full-scale garage. The objective is to demonstrate the feasibility of using the ADVENTURE_sFlow solver, which uses a hierarchical domain decomposition method, to efficiently solve large-scale problems like hydrogen dispersion in engineering facilities.
Stationary Incompressible Viscous Flow Analysis by a Domain Decomposition MethodADVENTURE Project
This document describes an iterative domain decomposition method for analyzing large-scale stationary incompressible viscous flow problems using finite element analysis. The method decomposes the domain into subdomains and solves the inner degrees of freedom using a skyline solver. Interface degrees of freedom are solved using preconditioned BiCGSTAB or GPBiCG iterative solvers. Numerical examples are provided to demonstrate the method on problems with over 1 million degrees of freedom and compare results to a monolithic finite element method solver.
19. 流体解析 流体解析
時刻 t 時刻 t+Δt
構造解析 構造解析
圧力 圧力
t
p tt
p
分離型連成解析法の分類
片方向連成(流体 → 構造)/Off-line vs. On-line
多段遠心ポンプの流体誘起固体伝播音の高精度計算法と騒音発生機構の解明、
日本機械学会論文集C編、Vol.72, No.719, pp.2065-2072, (2006.7)
(姜玉雁、吉村忍、今井隆太、桂裕之、吉田哲也、加藤千幸)
19
20. 流体解析 流体解析
時刻 t 時刻 t+Δt
構造解析 構造解析
構造予測子
構造予測子
圧力 圧力
変位
tt
d
ttttt
dtdtdd 2
)(
2
1
t
p tt
p
分離型連成解析法の分類
双方向連成(流体 → 構造):単純互い違い法の場合
Simple Staggered Method
20
21. )1()()(
)1(
ititit
ddd
流体解析 流体解析
時刻 t 時刻 t+Δt
構造解析 構造解析
圧力 圧力
変位
)(it
d
)1( it
p
)1( itt
p
変位
)(itt
d
反復計算
分離型連成解析法の分類
双方向連成(流体 ⇔ 構造):分離反復法の場合
(1) Line Search Partitioned Approach for Fluid-Structure Interaction Analysis of Flapping Wing,
Computer Modeling in Engineering and Sciences, Vol.24, No.1, pp.51-60, (2008)
(Tomonori Yamada, Shinobu Yoshimura)
(2) Performance Evaluation on Nonlinear Algorithms with Line-Search for Partitioned Coupling
Techniques for Fluid-Structure Interactions”, International Journal for Numerical Methods in
Fluids, Vol.64, Nos.10-12, pp. 1129-1147, (2010)
(Satsuki Minami, Shinobu Yoshimura) 21
22. 音響流体構造連成解析の支配方程式
F
s
surfacefree
FSI
FSI
nd
Fρn/p
surfacefree
F Fluid domain
S Structure domain surfacefree Free surface
FSI Interface of fluid and structure
p pressure
d displacement of structure
流体領域:低速, 非粘性, 非圧縮F
s
0cρ SSS fσdd
動弾性体領域
0p
0p
自由表面
流体構造連成界面の連続条件
Fρ Density of fluid Sρ Density of structure
Sc damping 22
29. x y
z
bottom fixed
ux=uy=uz=0
0.25
0.125
fluid model structure model
Free surface condition
pressure = 0
25柱列モデル
X方向にステップ状の体積力を負荷
自由表面条件, p=0
流体モデル 構造モデル
構造の底面を完全固定 時間加速度
29
Ex. 現実の大型原子炉では燃料集合体数は900
30. One fixed point iteration
性能試験
TEST1 プロセッサ数を16に固定
柱列数を1から16に変更(10万自由度から240万自由度)
TEST2 柱列数を64に固定 (500万自由度)
プロセッサ数を1から16に変更
ADVENTURE
Solid
ADVENTURE
Thermal
Socket
Broyden
Mapping
communication
Socket
Mapping
Socket
30
31. 計算機環境
PC cluster (16ノード)
Intel Core i7-870 (Nehalem) 2.93 GHz
Giga-bit Ethernet
Nノード, マルチコアは使用せず
structure
process
Fluid
process
Coupler
process
Coupler
process
4ノード計算機環境の場合
31
32. Test 1 モデルサイズの依存性
0.1
1
10
100
1000
1.E+04 1.E+05 1.E+06 1.E+07 1.E+08
averagetime(sec)
degrees of freedom in each domain/ both domain
ADVENTURE_Thermal ADVENTURE_Solid
Coupled analysis
0.001
0.01
0.1
1
1.E+04 1.E+05 1.E+06 1.E+07
averagetime(sec)
degrees of freedom on interface
ADVENTURE_Coupler Socket Mapping Broyden
Time for each fixed
point iteration
カプラの処理時間は、各ソルバでの解析時間よりもはるかに小さい
カプラの処理時間は、通信レイテンシに支配されている
32