Front tracking based modeling of the solid grain growth on the adaptive control volume grid

2017 ◽  
Author(s):  
Mirosław Seredyński ◽  
Piotr Łapka
Keyword(s):  
Adaptive Control ◽  
Grain Growth ◽  
Control Volume ◽  
Front Tracking

scholarly journals X3D Moving Grid Methods for Semiconductor Applications

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 117-121 ◽  
Author(s):  
Andrew Kuprat ◽  
David Cartwright ◽  
J. Tinka Gammel ◽  
Denise George ◽  
Brian Kendrick ◽  
...  
Keyword(s):  
Grain Growth ◽  
Unstructured Grids ◽  
Optimization Algorithms ◽  
Front Tracking ◽  
Adaptive Refinement ◽  
Moving Grid ◽  
Los Alamos ◽  
Adaptive Smoothing

The Los Alamos 3D grid toolbox handles grid maintenance chores and provides access to a sophisticated set of optimization algorithms for unstructured grids. The application of these tools to semiconductor problems is illustrated in three examples: grain growth, topographic deposition and electrostatics. These examples demonstrate adaptive smoothing, front tracking, and automatic, adaptive refinement/derefinement.

Adaptive Control of Rubbing Rotor under Flow Induced Force

2013 ◽  
Vol 365-366 ◽  
pp. 800-804
Author(s):  
De Chen Yao ◽  
Li Min Jia ◽  
Yong Qin ◽  
Yun Yun Zhao
Keyword(s):  
Adaptive Control ◽  
Adaptive Algorithm ◽  
Control Method ◽  
Control Volume ◽  
Structural Parameters ◽  
Rotor System ◽  
Rotary Machine ◽  
Volume Model ◽  
Chaotic Response ◽  
Nonlinear Dynamic Equation

Along with the increasing of structural parameters of a rotary machine, the flow induced excitation on the rotor will significantly increase. By taking two-control-volume model for sealing force, the nonlinear dynamic equation of rubbing rotor foundation was derived. Then, the problem of controlling the chaotic response of the nonlinear rubbing rotor was studied by the adaptive control theory. Numerical simulations on the rotor system were performed with a multi-parameter adaptive algorithm. The numerical results show that the parametric adaptive control method is effective to suppress a chaotic response once happened into a required steady state periodic response. This control strategy is helpful to rotor system design and maintenance.

Front Tracking Based Macroscopic Calculations of Columnar and Equiaxed Solidification of a Binary Alloy

2010 ◽  
Vol 132 (10) ◽  
Author(s):  
M. Seredyński ◽  
J. Banaszek
Keyword(s):  
Binary Alloy ◽  
Control Volume ◽  
Simulation Models ◽  
Front Tracking ◽  
Transport Processes ◽  
Thermosolutal Convection ◽  
Alloy Solidification ◽  
Tracking Method ◽  
Front Tracking Method ◽  
The Impact

The paper explores the potential of a recently developed special front tracking method in the identification of the interface between columnar and equiaxed structures formed during a binary alloy solidification, driven by thermosolutal convection. The method, based on theoretical and experimental dendrite tip kinetics, is capable of directly distinguishing between the columnar mush and the undercooled liquid/equiaxed region developing ahead of the dendrite tip curve. A new numerical model and its computational algorithm are proposed, where the classical Eulerian volume averaged description of the transport processes is coupled with the Lagrangian front tracking method on a fixed control-volume grid. Having thus distinguished zones of different dendrite structures, distinct simulation models are used within each of the zones, e.g., the Darcy’s porous medium model in the stationary dendrite region, and a model of slurry with floating dendrites in the equiaxed part of the mush. The calculated temperature and solute concentration fields are compared with the relevant results of the classical enthalpy-porosity model, for an example problem of Pb-48 wt % Sn alloy solidification driven by diffusion and thermosolutal convection. And a good match with both solutions is exhibited. A preliminary validation study is also presented by comparing the available experimental data with the model predictions. Possible reasons for some observed discrepancies between the calculations and the experimental findings are discussed. Finally, the proposed front tracking approach is used to address the question of the impact of dendrites floating in the liquid on the flow pattern and macrosegregation in the solidifying alloy.

scholarly journals A 2D Front-Tracking Lagrangian Model for the Modeling of Anisotropic Grain Growth

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4219
Author(s):  
Sebastian Florez ◽  
Julien Fausty ◽  
Karen Alvarado ◽  
Brayan Murgas ◽  
Marc Bernacki
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Grain Growth ◽  
Boundary Migration ◽  
Boundary Energy ◽  
Front Tracking ◽  
Intersection Point ◽  
Lagrangian Model ◽  
Polycrystalline Materials ◽  
Computational Performance

Grain growth is a well-known and complex phenomenon occurring during annealing of all polycrystalline materials. Its numerical modeling is a complex task when anisotropy sources such as grain orientation and grain boundary inclination have to be taken into account. This article presents the application of a front-tracking methodology to the context of anisotropic grain boundary motion at the mesoscopic scale. The new formulation of boundary migration can take into account any source of anisotropy both at grain boundaries as well as at multiple junctions (MJs) (intersection point of three or more grain boundaries). Special attention is given to the decomposition of high-order MJs for which an algorithm is proposed based on local grain boundary energy minimisation. Numerical tests are provided using highly heterogeneous configurations, and comparisons with a recently developed Finite-Element Level-Set (FE-LS) approach are given. Finally, the computational performance of the model will be studied comparing the CPU-times obtained with the same model but in an isotropic context.

Grain Refinement in Titanium-Erbium Alloys

1974 ◽  
Vol 32 ◽  
pp. 522-523
Author(s):  
B. B. Rath ◽  
J. E. O'Neal ◽  
R. J. Lederich
Keyword(s):  
Electron Microscopy ◽  
Size Distribution ◽  
Grain Refinement ◽  
Grain Growth ◽  
Volume Fraction ◽  
Pure Titanium ◽  
Systematic Investigation ◽  
Second Phase ◽  
Titanium Matrix ◽  
Average Size

Addition of small amounts of erbium has a profound effect on recrystallization and grain growth in titanium. Erbium, because of its negligible solubility in titanium, precipitates in the titanium matrix as a finely dispersed second phase. The presence of this phase, depending on its average size, distribution, and volume fraction in titanium, strongly inhibits the migration of grain boundaries during recrystallization and grain growth, and thus produces ultimate grains of sub-micrometer dimensions. A systematic investigation has been conducted to study the isothermal grain growth in electrolytically pure titanium and titanium-erbium alloys (Er concentration ranging from 0-0.3 at.%) over the temperature range of 450 to 850°C by electron microscopy.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

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