Estimation of Interfacial Heat Transfer Coefficient for Horizontal Directional Solidification of Sn-5 wt%Pb Alloy Using Genetic Algorithm as Inverse Method

2018 ◽  
pp. 447-459
Author(s):  
P. S. Vishweshwara ◽  
N. Gnanasekaran ◽  
M. Arun
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Directional Solidification ◽  
Inverse Method ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer

Effect of Interfacial Heat Transfer Coefficient on Dendritic Growth and Microhardness during Horizontal Directional Solidification of an Aluminum-Copper Alloy

2016 ◽  
Vol 367 ◽  
pp. 10-17 ◽  
Author(s):  
A.S. Barros ◽  
Adrina P. Silva ◽  
Ivaldo Leão Ferreira ◽  
O.L. Rocha ◽  
A.L. Moreira
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Directional Solidification ◽  
Numerical Technique ◽  
Thermal Parameter ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer ◽  
Cu Alloy ◽  
The Heat Transfer Coefficient

This paper presents a theoretical-experimental study for the prediction of the interfacial heat transfer coefficient during the horizontal directional solidification of an Al-3wt.%Cu alloy on water cooled stainless steel chill under transient heat flow conditions. Eight thermocouples were connected with the casting and the time-temperature data were recorded automatically. The thermocouples were placed at 5, 10, 15, 20, 30, 50, 70 and 90 mm from the metal-mold interface. A numerical technique which compares theoretical and experimental thermal profiles was used to measure the heat transfer coefficient values. This has permitted the evaluation of the variation of this thermal parameter along the solidification which is represented by a power equation that shows the time dependence during the process given by hi = constant (t)-n, which represents the best fit between the experimental and calculated curves. The obtained results also include the variation of both primary and secondary dendritic arm spacings of alloy analyzed as a function of heat transfer coefficient. These dendrite arm spacings were found to decrease as the values of this coefficient are increased. Finally, an experimental law of the Hall-Petch type is proposed relating the resulting microhardness to the heat transfer coefficient investigated.

From Experimentation to Analysis: Considerations for Determination of the Metal/Mold Interfacial Heat Transfer Coefficient via Solution of the Inverse Heat Conduction Problem

2006 ◽  
Author(s):  
Jonathan W. Woolley ◽  
Michal Pohanka ◽  
Keith A. Woodbury
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Inverse Method ◽  
Heat Conduction Problem ◽  
Inverse Heat Conduction Problem ◽  
Transfer Model ◽  
Interfacial Heat Transfer Coefficient ◽  
Metal Mold ◽  
Interfacial Heat Transfer

Casting solidification simulation has been established as an effective tool used to improve the efficiency of the casting design process. Knowledge of the interfacial heat transfer coefficient at the metal/mold interface of metal castings is crucial to the simulation of casting solidification. The characterization of the heat transfer from metal to mold has been the focus of many researchers. The solution of the inverse method has been used to determine the interfacial heat flux and/or the interfacial heat transfer coefficient (IHTC) and has been applied to a variety of casting techniques and geometries. While the inverse method is a legitimate technique to determine the metal/mold interfacial heat transfer coefficient, there are a number of important issues to consider before applying the method to actual castings. The present work is a discussion of practical and important issues related to various common casting techniques that must be considered when collecting temperature measurements to be used in an inverse calculation and when developing a heat transfer model of the system.

A Correlation for Interfacial Heat Transfer Coefficient for Turbulent Flow Over an Array of Square Rods

2005 ◽  
Vol 128 (5) ◽  
pp. 444-452 ◽  
Author(s):  
Marcelo B. Saito ◽  
Marcelo J. S. de Lemos
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Heat Transfer Coefficient ◽  
Turbulent Flow ◽  
Transfer Coefficient ◽  
Energy Equation ◽  
Local Thermal Equilibrium ◽  
Equation Modeling ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer

Interfacial heat transfer coefficients in a porous medium modeled as a staggered array of square rods are numerically determined. High and low Reynolds k-ϵ turbulence models are used in conjunction of a two-energy equation model, which includes distinct transport equations for the fluid and the solid phases. The literature has documented proposals for macroscopic energy equation modeling for porous media considering the local thermal equilibrium hypothesis and laminar flow. In addition, two-energy equation models have been proposed for conduction and laminar convection in packed beds. With the aim of contributing to new developments, this work treats turbulent heat transport modeling in porous media under the local thermal nonequilibrium assumption. Macroscopic time-average equations for continuity, momentum, and energy are presented based on the recently established double decomposition concept (spatial deviations and temporal fluctuations of flow properties). The numerical technique employed for discretizing the governing equations is the control volume method. Turbulent flow results for the macroscopic heat transfer coefficient, between the fluid and solid phase in a periodic cell, are presented.

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