Computational Study of High Temperature Liquid Metal Infusion

2017 ◽  
Author(s):  
Arturo Schiaffino ◽  
Ashesh Chattopadhyay ◽  
Shaikh Tanveer Hossain ◽  
Vinod Kumar ◽  
V. M. K. Kotteda ◽  
...  
Keyword(s):  
Porous Media ◽  
Liquid Metal ◽  
Molten Metal ◽  
Multiple Scales ◽  
Computational Study ◽  
Interface Energy ◽  
Network Simulator ◽  
Void Space ◽  
Infiltration Process ◽  
Viscous Forces

Liquid metal infiltration, or liquid method infusion, consists of impregnating porous media composed of woven, ceramic particles, or fibers with a molten metal matrix, which fills the pores and occupies the void space within. Understanding the infiltration process is crucial to optimize the properties of the recently formed material and avoid or minimize the formation of fabrication defects. Given the fact that the flow of molten metal differs from organic flows, since molten metal possess a higher interface energy than organic flows, and modifies the wetting dynamics of the molten metal over surfaces, creating a flow driven by capillary and viscous forces. In addition, flow through porous media presents an extraordinary challenge to simulate efficiently, due to the presence of multiple scales far apart participating in the governing dynamics. For this reason, an in-house pore network simulator (EXPNS) was used. EXPNS was designed on a next generation computing framework using Sandia National Lab’s Trilinos and Kokkos library to perform high-resolution computing to generate data for the infiltration model and improve the general understanding of this process.

A Pore-Network Study of Bubble Growth in Porous Media Driven by Heat Transfer

1996 ◽  
Vol 118 (2) ◽  
pp. 455-462 ◽  
Author(s):  
C. Satik ◽  
Y. C. Yortsos
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Vapor Phase ◽  
Network Models ◽  
Pore Network ◽  
Network Simulator ◽  
Invasion Percolation ◽  
Viscous Forces ◽  
Theoretical Investigations ◽  
Visualization Experiments

We present experimental and theoretical investigations of vapor phase growth in pore-network models of porous media. Visualization experiments of boiling of ethyl alcohol in horizontal etched-glass micromodels were conducted. The vapor phase was observed to grow into a disordered pattern following a sequence of pressurization and pore-filling steps. At sufficiently small cluster sizes, growth occurred “one pore at a time,” leading to invasion percolation patterns. Single-bubble (cluster) growth was next simulated with a pore-network simulator that includes heat transfer (convection and conduction), and capillary and viscous forces, although not gravity. A boundary in the parameter space was delineated that separates patterns of growth dictated solely by capillarity (invasion percolation) from other patterns. The region of validity of invasion percolation was found to decrease as the supersaturation (heat flux), the capillary number, the thermal diffusivity, and the vapor cluster size increase. Implications to continuum models are discussed.

Resonance-like dynamics in radial cyclic injection flows of immiscible fluids in homogeneous porous media

2017 ◽  
Vol 819 ◽  
pp. 713-729 ◽  
Author(s):  
T. F. Lins ◽  
J. Azaiez
Keyword(s):  
Porous Media ◽  
Flow Instability ◽  
Physical Phenomenon ◽  
Resonance Effect ◽  
Level Set Methods ◽  
Immiscible Fluids ◽  
Interfacial Instabilities ◽  
Viscous Forces ◽  
Homogeneous Porous Media ◽  
Abrupt Changes

Interfacial instabilities of immiscible radial displacements in homogeneous porous media are analysed in the case of sinusoidal injection flows. The analysis is carried out through numerical simulations based on the immersed interface and level set methods. Investigations of the effects of the period of the sinusoidal injection flows revealed a novel resonance effect where, for a critical period, the number of fingers as well as their structures are considerably changed. The resonance in the flow development is clearly identified through the abrupt changes in the Fourier spectrum of the interface as well as quantitative characteristics of the flow in the form of the minimum and maximum radii of the interface. For the range of parameters examined in this study that correspond to instabilities dominated by viscous forces, the resonance period was found to correlate with a characteristic time of the flow and the fluids mobility ratio. This new physical phenomenon offers new perspectives for using the flow instability to determine important physical properties such as the viscosity and the surface tension of fluids.

scholarly journals On the Transition From Creeping to Inertial Flow in Arrays of Cylinders

2010 ◽  
Author(s):  
K. Yazdchi ◽  
S. Srivastava ◽  
S. Luding
Keyword(s):  
Porous Media ◽  
Darcy’S Law ◽  
Computational Study ◽  
Darcy's Law ◽  
Natural Processes ◽  
Inertial Flow ◽  
Flow Through ◽  
High Reynolds ◽  
An Array Of Cylinders ◽  
Element Method

Many important natural processes involving flow through porous media are characterized by large filtration velocity. Therefore, it is important to know when the transition from viscous to the inertial flow regime actually occurs in order to obtain accurate models for these processes. In this paper, a detailed computational study of laminar and inertial, incompressible, Newtonian fluid flow across an array of cylinders is presented. Due to the non-linear contribution of inertia to the transport of momentum at the pore scale, we observe a typical departure from Darcy’s law at sufficiently high Reynolds number (Re). Our numerical results show that the weak inertia correction to Darcy’s law is not a square or a cubic term in velocity, as it is in the Forchheimer equation. Best fitted functions for the macroscopic properties of porous media in terms of microstructure and porosity are derived and comparisons are made to the Ergun and Forchheimer relations to examine their relevance in the given porosity and Re range. The results from this study can be used for verification and validation of more advanced models for particle fluid interaction and for the coupling of the discrete element method (DEM) with finite element method (FEM).

Uncertainty Quantification of Molten Hafnium Infusion Into a B4C Packed-Bed

2019 ◽  
Author(s):  
Arturo Schiaffino ◽  
V. M. Krushnarao Kotteda ◽  
Vinod Kumar ◽  
Arturo Bronson ◽  
Sanjay Shantha-Kumar
Keyword(s):  
Uncertainty Quantification ◽  
High Performance Computing ◽  
Molten Metal ◽  
High Performance ◽  
Control Volume ◽  
Packed Bed ◽  
Network Simulator ◽  
Matrix Composites ◽  
Formidable Challenge ◽  
Performance Computing

Abstract In the manufacturing of metal matrix composites (MMC), liquid-metal reactive infusion with a solid mesh or particles composed of ceramic or metal may be used. The objective of this study is to determine the uncertainty quantification of the modeling of liquid hafnium infusion to expedite the processing and improve properties of MMCs ultimately. Uncertainty quantification (UQ) characterized the uncertainty scientifically especially for high-performance computing with observed physics and/or chemistry of the phenomena and predicted from estimated parameters. In this work, molten hafnium infusing through a boron carbide packed bed is modeled to optimize the manufacturing of components used for a hypersonic vehicle. The creation of molten matrix composites by the infiltration of molten metal represents a formidable challenge to be accurately modeled. First, the structural randomness associated with porous mediums complicates the prediction of the flow passing through it. Secondly, the properties of the molten metal could vary inside our control volume, since the temperature inside the control volume is not constant. Also, there are several chemical reactions and solidification rates occurring in during the impregnation. Given the recent advances in high-performance computing, an in-house pore network simulator are implemented along with Dakota, an open-source, exascale software, to determine the optimal parameters (e.g., porosity and temperature) and uncertainty quantification for the modeling.

A Numerical Study of a Molten Aluminum for Investment Casting of 3D Cellular Metals

2013 ◽  
Author(s):  
Jiwon Mun ◽  
Jaehyung Ju ◽  
Byoung-Gwan Yun ◽  
Byung-Moon Chang ◽  
Doo-Man Kim
Keyword(s):  
Liquid Metal ◽  
Velocity Profile ◽  
Molten Metal ◽  
Investment Casting ◽  
Metal Flow ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Dependent Viscosity ◽  
Analytical Approaches ◽  
Numerical Approaches

Investment casting processes are influenced by a variety of parameters. Many researches considering viscosity as a constant have been conducted up to this point. In particular, however, viscosity with temperature change has not been much accounted for solidification and heat transfer simulation of molten metal in the investment casting process. In addition, analysis of behavior of metal flow as well as air gap problems for complex network structures have not been investigated much. The aim of this study is to build transient metal flow and velocity profile models considering temperature dependent viscosity in investment casting processes of cellular structures. In this study, a Computational Fluid Dynamics (CFD) modeling tool was used for metal flow and velocity profile in investment casting processing using User Defined Function (UDF) for temperature dependent viscosity. The results of the metal flow and velocity profile inside of the simple cylindrical geometry are represented. It is shown that for the validation of the numerical simulation, the velocity profile between analytical and numerical approaches showed very good agreement. Analytical approaches showed that velocity was reduced with the increase in viscosity, which is applied as a function of temperature. In particular, rapid decreasing in velocity was shown from under the melting temperature of the molten metal. There was no movement on metal flow at the room temperature. Numerical approaches showed that the liquid metal began to be solidified from the wall surface inside of the mold. For the same simulation time, it was shown that the metal flow in a cylinder that has 1mm diameter showed better fluidity rather than that of the cylinder that has 2mm diameter due to the increase in adhesion between liquid metal and the surface of the mold and surface tension between molten metal and air. The effective diameter by solidification is decreased with the time change.

scholarly journals A homogenised model for flow, transport and sorption in a heterogeneous porous medium

2021 ◽  
Vol 932 ◽  
Author(s):  
L.C. Auton ◽  
S. Pramanik ◽  
M.P. Dalwadi ◽  
C.W. MacMinn ◽  
I.M. Griffiths
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Multiple Scales ◽  
Effective Diffusivity ◽  
Rectangular Lattice ◽  
Mathematical Framework ◽  
Anisotropic Flow ◽  
Flow And Transport ◽  
Soft Porous Media ◽  
The Impact

A major challenge in flow through porous media is to better understand the link between microstructure and macroscale flow and transport. For idealised microstructures, the mathematical framework of homogenisation theory can be used for this purpose. Here, we consider a two-dimensional microstructure comprising an array of obstacles of smooth but arbitrary shape, the size and spacing of which can vary along the length of the porous medium. We use homogenisation via the method of multiple scales to systematically upscale a novel problem involving cells of varying area to obtain effective continuum equations for macroscale flow and transport. The equations are characterised by the local porosity, a local anisotropic flow permeability, an effective local anisotropic solute diffusivity and an effective local adsorption rate. These macroscale properties depend non-trivially on the two degrees of microstructural geometric freedom in our problem: obstacle size and obstacle spacing. We exploit this dependence to construct and compare scenarios where the same porosity profile results from different combinations of obstacle size and spacing. We focus on a simple example geometry comprising circular obstacles on a rectangular lattice, for which we numerically determine the macroscale permeability and effective diffusivity. We investigate scenarios where the porosity is spatially uniform but the permeability and diffusivity are not. Our results may be useful in the design of filters or for studying the impact of deformation on transport in soft porous media.

Oxidation Effect on the Monosized Droplets Generation of the Liquid Metal Jet

2003 ◽  
Vol 125 (3) ◽  
pp. 595-596
Author(s):  
Wei-Hsiang Lai ◽  
Chia-Chin Chen
Keyword(s):  
Liquid Metal ◽  
Molten Metal ◽  
Oxygen Concentration ◽  
Formation Process ◽  
Droplet Formation ◽  
Transition Regime ◽  
Oxide Formation ◽  
Drastic Effect ◽  
Metal Jet ◽  
Oxidation Effect

The oxide formation on the surface of the molten metal jet was shown to have a drastic effect on the droplet formation process according to the description of some publication. Thus, the main objective of this research is to investigate the influence of oxygen concentration on the breakup and the monosized droplets generation of molten metal jet (Sn63 Pb37 alloy). The breakup phenomena of molten metal jet can be approximately divided into three regimes. They are “breakup regime” for oxygen concentration below C1, “transition regime” for oxgyen concentration between C1 and C2, and “breakup failing regime” for oxygen concentration beyond C2, respectively.

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