Stochastic Subspace Projection Methods for Efficient Multiphase Flow Uncertainty Assessment

2006 ◽  
Author(s):  
H. M. Klie ◽  
M. F. Wheeler ◽  
G. Liu ◽  
D. Zhang
Keyword(s):  
Multiphase Flow ◽  
Uncertainty Assessment ◽  
Projection Methods ◽  
Subspace Projection

An Efficient Algorithm to Construct an Orthonormal Basis for the Extended Krylov Subspace

2014 ◽  
Vol 4 (3) ◽  
pp. 267-282
Author(s):  
Akira Imakura
Keyword(s):  
Efficient Algorithm ◽  
Orthonormal Basis ◽  
Krylov Subspace ◽  
Computational Cost ◽  
Projection Methods ◽  
Matrix Equations ◽  
Subspace Projection ◽  
Matrix Computations ◽  
Large Matrix ◽  
Traditional Algorithm

AbstractSubspace projection methods based on the Krylov subspace using powers of a matrix A have often been standard for solving large matrix computations in many areas of application. Recently, projection methods based on the extended Krylov subspace using powers of A and A−1 have attracted attention, particularly for functions of a matrix times a vector and matrix equations. In this article, we propose an efficient algorithm for constructing an orthonormal basis for the extended Krylov subspace. Numerical experiments indicate that this algorithm has less computational cost and approximately the same accuracy as the traditional algorithm.

Investigation on the control of multiphase flow behavior in a continuous casting tundish during ladle change

2020 ◽  
Vol 117 (6) ◽  
pp. 619
Author(s):  
Rui Xu ◽  
Haitao Ling ◽  
Haijun Wang ◽  
Lizhong Chang ◽  
Shengtao Qiu
Keyword(s):  
Multiphase Flow ◽  
Flow Behavior ◽  
Rolled Strip ◽  
Impact Zone ◽  
Steel Cleanliness ◽  
Carry Over ◽  
Slag Carry Over ◽  
Hot Rolled ◽  
Turbulence Inhibitor ◽  
The Impact

The transient multiphase flow behavior in a single-strand tundish during ladle change was studied using physical modeling. The water and silicon oil were employed to simulate the liquid steel and slag. The effect of the turbulence inhibitor on the slag entrainment and the steel exposure during ladle change were evaluated and discussed. The effect of the slag carry-over on the water-oil-air flow was also analyzed. For the original tundish, the top oil phase in the impact zone was continuously dragged into the tundish bath and opened during ladle change, forming an emulsification phenomenon. By decreasing the liquid velocities in the upper part of the impact zone, the turbulence inhibitor decreased considerably the amount of entrained slag and the steel exposure during ladle change, thereby eliminating the emulsification phenomenon. Furthermore, the use of the TI-2 effectively lowered the effect of the slag carry-over on the steel cleanliness by controlling the movement of slag droplets. The results from industrial trials indicated that the application of the TI-2 reduced considerably the number of linear inclusions caused by ladle change in hot-rolled strip coils.

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