Multi-Scale Modeling of Industrial Crystallization Process

2013 ◽  
Vol 295-298 ◽  
pp. 3062-3066 ◽  
Author(s):  
Bao Liang Fang ◽  
Xue Kui Wang ◽  
Peng Jiang ◽  
Zuo Liang Sha
Keyword(s):  
Crystallization Process ◽  
Volume Fraction ◽  
Balance Model ◽  
Scale Problem ◽  
Dynamics Model ◽  
Industrial Crystallization ◽  
Multi Scale ◽  
Scale Modeling ◽  
Multi Phase ◽  
Crystal Volume

The multi-scale method was applied to solve the multi-phase multi-scale problem in the industrial crystallization process. The fluid dynamics model was considering under the grid scale, and the population balance model was considering under subsystem scale. The macro model was used to interact with the environment. The crystallization process of potassium chloride was simulated by CFD and MATLAB. The result of the simulation shows the distribution of the supersaturation is strongly affected by the distribution of the suspended crystal volume fraction.

scholarly journals Temperature Resistance of Mo3Si: Phase Stability, Microhardness, and Creep Properties

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 564 ◽  
Author(s):  
Olha Kauss ◽  
Susanne Obert ◽  
Iurii Bogomol ◽  
Thomas Wablat ◽  
Nils Siemensmeyer ◽  
...  
Keyword(s):  
Power Law ◽  
Phase Stability ◽  
Gas Turbines ◽  
Constitutive Models ◽  
Creep Properties ◽  
Multi Scale ◽  
Scale Modeling ◽  
Significant Difference ◽  
Before And After ◽  
Multi Phase

Mo-Si-B alloys are one of the most promising candidates to substitute Ni based superalloys in gas turbines. The optimization of their composition can be achieved more effectively using multi-scale modeling of materials behavior and structural analysis of components for understanding, predicting, and screening properties of new alloys. Nevertheless, this approach is dependent on data on the properties of the single phases in these alloys. The focus of this investigation is Mo3Si, one of the phases in typical Mo-Si-B alloys. The effect of 100 h annealing at 1600 °C on phase stability and microhardness of its three near-stoichiometric compositions—Mo-23Si, Mo-24Si and Mo-25Si (at %)—is reported. While Mo-23Si specimen consist only of Mo3Si before and after annealing, Mo-24Si and Mo-25Si comprise Mo5Si3 and Mo3Si before annealing. The latter is then increased by the annealing. No significant difference in microhardness was detected between the different compositions as well as after annealing. The creep properties of Mo3Si are described at 1093 °C and 1300 °C at varying stress levels as well as at 300 MPa and temperatures between 1050 °C and 1350 °C. Three constitutive models were used for regression of experimental results—(i) power law with a constant creep exponent, (ii) stress range dependent law, and (iii) power law with a temperature-dependent creep exponent. It is confirmed that Mo3Si has a higher creep resistance than Moss and multi-phase Mo-Si-B alloys, but a lower creep strength as compared to Mo5SiB2.

APPLICATION OF REED-VIBRATION MECHANICAL SPECTROSCOPY FOR LIQUIDS IN STUDYING LIQUID CRYSTALLIZATION

2013 ◽  
Vol 27 (21) ◽  
pp. 1350080 ◽  
Author(s):  
HENG-WEI ZHOU ◽  
LI-NA WANG ◽  
LI-LI ZHANG ◽  
YI-NENG HUANG
Keyword(s):  
Glass Transition ◽  
Room Temperature ◽  
Crystallization Process ◽  
Volume Fraction ◽  
Supercooled Liquid ◽  
Avrami Exponent ◽  
Dimethyl Phthalate ◽  
Mechanical Spectroscopy ◽  
Crystal Volume ◽  
Complex Young’S Modulus

By using the reed-vibration mechanical spectroscopy for liquids (RMS-L), we measured the complex Young's modulus of dimethyl phthalate (DP) during a cooling and heating circulation starting from room temperature at about 2 KHz. The results show that there is no crystallization in the cooling supercooled liquid (CSL) of DP, but a crystallization process in the heating supercooled liquid (HSL) after the reverse glass transition. Based on the measured modulus, crystal volume fraction (v) during the HSL crystallization was calculated. Moreover, the Avrami exponent (n) was obtained according to the JJMA equation and v data. In view of n versus temperature and v, the nucleation dynamics was analyzed, and especially, there has already existed saturate nuclei in DP HSL before the crystallization. Furthermore, the authors inferred that the nuclei are induced by the random frozen stress in the glass, but there is no nucleus in CSL. The above results indicated that RMS-L might provide a new way to measure and analyze the crystallization of liquids.

A Simple Procedure for Measuring Magma Rheology

2019 ◽  
Vol 14 (4) ◽  
pp. 616-622 ◽  
Author(s):  
Aika K. Kurokawa ◽  
Takahiro Miwa ◽  
Hidemi Ishibashi ◽  
◽  
Keyword(s):  
Volume Fraction ◽  
Simple Procedure ◽  
Reliable Data ◽  
Entire Sample ◽  
The Mean ◽  
Crystal Arrangement ◽  
Multi Phase ◽  
Oxide Crystals ◽  
Crystal Volume ◽  
Magma Rheology

In this study, a procedure to measure the viscosity of multi-phase magma at high temperatures (>1000°C) was developed by using a simple apparatus comprising a commercially available desktop furnace and viscometer. In particular, the use of a disposable container enabled observations of the microstructure of an entire sample. The procedure was applied to basaltic andesite magma of the 1986 Izu–Oshima fissure eruption, Japan. The results show that reliable data, consistent with previous studies, were obtained and that the magma rheology became non-Newtonian with decreasing temperature, showing clear shear-thinning behavior. The rheological properties of the magma at 1180°C are quantitatively described as a function of shear rate based on three simple non-Newtonian fluid models. Sectional views of the sample confirm that plagioclase and Fe–Ti oxide crystals were nearly uniformly dispersed in the sample. The mean crystal volume fraction of 0.14 enabled crystal interactions inducing changes in crystal arrangement, affecting the rheology.

The Effect of Nanotube Specifications on Multi-Scale Modeling of Nanocomposites

2011 ◽  
Vol 110-116 ◽  
pp. 1237-1244 ◽  
Author(s):  
Seyyed Mohammad Reza Khalili ◽  
A. Haghbin
Keyword(s):  
Volume Fraction ◽  
Elastic Continuum ◽  
Atomic Structures ◽  
Linear Elastic ◽  
Multi Scale ◽  
Beam Elements ◽  
Scale Modeling ◽  
Inverse Effect ◽  
Lower Accuracy ◽  
Multi Scale Modeling

The effect of diameter, chirality and volume fraction of SWCNTs on the tensile behavior of nanocomposites is studied. Multi-scale material modeling is applied to assemble different RVEs composed of various SWCNTs embedded in polymer. Nanotubes are modeled in continuum mechanics, based on their atomic structures as space frame structures. Beam elements in this structure are defined based on carbon bonds characteristics in molecular mechanics. Polymer portion of the RVE is modeled as a linear elastic continuum material, with lower accuracy regarding to the multi-scale modeling technique. Attained stress-strain curves obtained from modeled nanocomposites revealed that using Armchair SWCNTs in RVEs makes nanocomposites tougher rather than Zigzags. Also, diameter of CNT has an inverse effect on the curves level. Moreover, the effect of diameter is more obvious at higher volume fraction of CNTs.

Influence of microstructure morphology on multi-scale modeling of low-alloyed TRIP-steels

2018 ◽  
Vol 35 (2) ◽  
pp. 499-528 ◽  
Author(s):  
Stefan Prüger ◽  
Ashutosh Gandhi ◽  
Daniel Balzani
Keyword(s):  
Volume Fraction ◽  
Measurement Techniques ◽  
Content Type ◽  
Systematic Assessment ◽  
Microstructural Parameters ◽  
Multi Scale ◽  
Scale Modeling ◽  
Macro Scale ◽  
Microstructure Morphology ◽  
The Impact

Purpose The purpose of this study is to quantify the impact of the variation of microstructural features on macroscopic and microscopic fields. The application of multi-scale methods in the context of constitutive modeling of microheterogeneous materials requires the choice of a representative volume element (RVE) of the considered microstructure, which may be based on some idealized assumptions and/or on experimental observations. In any case, a realistic microstructure within the RVE is either computationally too expensive or not fully accessible by experimental measurement techniques, which introduces some uncertainty regarding the microstructural features. Design/methodology/approach In this paper, a systematical variation of microstructural parameters controlling the morphology of an RVE with an idealized microstructure is conducted and the impact on macroscopic quantities of interest as well as microstructural fields and their statistics is investigated. The study is carried out under macroscopically homogeneous deformation states using the direct micro-macro scale transition approach. Findings The variation of microstructural parameters, such as inclusion volume fraction, aspect ratio and orientation of the inclusion with respect to the overall loading, influences the macroscopic behavior, especially the micromechanical fields significantly. Originality/value The systematic assessment of the impact of microstructural parameters on both macroscopic quantities and statistics of the micromechanical fields allows for a quantitative comparison of different microstructure morphologies and a reliable identification of microstructural parameters that promote failure initialization in microheterogeneous materials.

scholarly journals Multi-scale modeling of the lamellar unit of arterial media

2019 ◽  
Vol 8 (1) ◽  
pp. 539-547
Author(s):  
Hozhabr Mozafari ◽  
Lulu Wang ◽  
Yuguo Lei ◽  
Linxia Gu
Keyword(s):  
Structural Variation ◽  
Volume Fraction ◽  
Collagen Fibers ◽  
Scale Model ◽  
Ground Substance ◽  
Fiber Architecture ◽  
Aging Effects ◽  
Structural Variations ◽  
Multi Scale ◽  
Scale Modeling

AbstractThe heterogeneity of the lamellar unit (LU) of arterial media plays an important role in the biomechanics of artery. Current two-component (fibrous component and a homogenous matrix) constitutive model is inappropriate for capturing the micro-structural variations in the LU, such as contraction/relaxation of vascular smooth muscle cells (VSMCs), fragmentation of the elastin layer, and deposition/disruption of the collagen network. In this work, we developed a representative volume element (RVE) model with detailed micro-configurations, i.e., VSMCs at various phenotypes, collagen fibers, and elastin laminate embedded in the ground substance. The fiber architecture was generated based on its volume fraction and orientations. Our multi-scale model demonstrated the relation between the arterial expansion and the micro-structural variation of the lamellar unit. The obtained uniaxial response of the LU was validated against the published experimental data. The load sharing capacity of fibrous component and VSMCs of the LU were obtained. We found that the VSMC could take 30% of the circumferential load when contracted until the collagen fibers were recruited, while this value was less than 2% for the relaxed VSMC. In addition, the contribution of collagen fibers at low stretch levels was negligible but became predominant when straightened in high stretches.Moreover, aging effects by collagen deposition was modeled to estimate the arterial stiffening. It was revealed that the aortic stiffness is mainly controlled by collagen fibers, instead of VSMCs. Our findings could shed some light about the contribution of VSMCs in arterial stiffness which has been under debate in recent years.

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