Emad Elnajjar¹, Mohammad O. Hamdan, Yousef Haik

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 77-89, 2013, DOI:10.3970/fdmp.2013.009.077

Abstract In this paper, two heat transfer configurations (central-jet and side-jet) of jet impinging on a semicircular surface are experimentally studied. The internal channel is formed using flat insulated wall and a semi-circular surface using a curved flexible heater with a uniform heat flux. A set of experiments have been performed for the purpose of assessing the heat augmentation and pressure drop between the two jet configurations. The measurements include the inlet and outlet flow temperatures using thermocouples, the temperature map of the flexible heater using thermal infra-red camera, the flow rates using rotary meter and More >

S. Aggoune¹, E.H. Amara¹, M. Debiane²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 61-75, 2013, DOI:10.3970/fdmp.2013.009.061

Abstract The effects of inert assisting gas nature and velocity on laser cut quality are investigated. A pure fusion cutting process just above melting point is considered, where the molten steel velocity is given as a function of the two acting forces represented by the pressure gradient and the frictional forces applied by the laminar gas flow. In the case of nitrogen assisting gas, the stainless steel melt film exhibits a visible separation point. The point where the melt flow is separated out from the solid wall depends strongly on the gas velocity. It is pushed… More >

A. Maougal¹, R. Bessaïh²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 35-59, 2013, DOI:10.3970/fdmp.2013.009.035

Abstract The present study is a numerical investigation of the irreversibility and heat transfer properties of a steady laminar mixed flow in a square cavity, filled with a saturated porous medium and heated by a discrete set of heat sources. The continuity, Navier-Stokes, energy and entropy generation equations have been solved by a finite volume method. Both heat transfer irreversibility and fluid friction irreversibility have been taken into account in the computations of entropy generation. Simulations have bee carried out for Reynolds number Re=20, 40, 80, 100, 200, Darcy number, Da=10^-5-10^-1, Prandtl number, Pr=0.015, 0.7, 10, 103, More >

E. Gedik¹, H.Kurt², Z.Recebli¹

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 23-33, 2013, DOI:10.3970/fdmp.2013.009.023

Abstract In this paper, the steady, laminar, incompressible viscous flow of an electrically conducting liquid-metal fluid is investigated numerically in a circular non-conducting pipe. The considered work fluid is Galinstan (GaInSn, i.e. Gallium-Indium-Tin). Such a liquid metal is subjected to a constant pressure gradient along the axial direction and a uniform transverse magnetic field in the spanwise direction. Numerical simulations are performed by means of the Fluent commercial software (used to solve the governing three dimensional fluid dynamics and electromagnetic field partial differential equations iteratively). The magnetic field induction, B, takes values between 0 and 1.5 More >

M. M. Shemirani¹, M. Z. Saghir²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 11-21, 2013, DOI:10.3970/fdmp.2013.009.011

Abstract Producing homogeneous single bulk crystals requires a good understanding of the thermo-solutal behavior in the solvent region. This study explores simulation of the growth of large diameter single bulk crystals of silicon and germanium alloy from its melt utilizing Bridgman method. Both thermal and solutal diffusion of silicon and germanium in the molten SiGe alloy are of interest. It was observed that the diffusion dominates the transport phenomenon in the solvent region especially in the first 25 mm of the model due to having a Pe_T <<1. It was also found that the control of both More >

A. Balbay¹, H. Ülker², Ö. Şahin³

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 1-10, 2013, DOI:10.3970/fdmp.2013.009.001

Abstract In this study, drying behaviours of the outer shell peeled Bittim (Pistacia terebinthus) with initial moisture content of 42.2% (dry basis (d.b)) was investigated in a novel fixed bed drying system. The drying experiments were performed at different temperatures (40 °C, 60 °C and 80 °C), air velocities (0.5 m/s and 1 m/s) and weights (30 g and 40 g). A constant rate period was not observed in the drying of bittims; all the drying process occurred in falling rate period. Three models in literature were selected to fit the experimental data. The fit quality of models More >

Kyong Pil Jang¹, Je kuk Son², Seung Hee Kwon^1,3

CMC-Computers, Materials & Continua, Vol.38, No.3, pp. 155-173, 2013, DOI:10.3970/cmc.2013.038.155

Abstract In a precast shell pier cap, cracking at the interface between the precast shell and the cast-in-place concrete may happen due to differences between the drying shrinkage of the inner and the outer concrete. The objective of this study is to establish a prediction method for interfacial cracking that will consider the real mechanism of differential drying shrinkage and creep. The main parameters used in the analysis were determined from experiments for a concrete mix that is applied to the manufacturing of pier caps. The variation of internal relative humidity over time was first calculated More >

Hsien-Chie Cheng^1,2, Chien-Hao Ma¹, Ching-Feng Yu³, Su-Tsai Lu⁴, Wen-Hwa Chen^2,3

CMC-Computers, Materials & Continua, Vol.38, No.3, pp. 129-154, 2013, DOI:10.3970/cmc.2013.038.129

Abstract User experiences for electronic devices with high portability and flexibility, good intuitive human interfaces and low cost have driven the development of semiconductor technology toward flexible electronics and display. In this study proposes, an advanced flexible interconnect technology is proposed for flexible electronics, in which an ultra-thin IC chip having a great number of micro-bumps is bonded onto a very thin flex substrate using an epoxy-based anisotropic conductive film (ACF) to form fine-pitch and reliable interconnects or joints (herein termed ACF-typed thin-flip-chip-on-flex (TFCOF) technology). The electrical and thermal -mechanical performances of the micro-joints are the… More >

Aurora Costales¹, C. J. F. Solano², E. Francisco¹, A. Martín Pendás¹

CMC-Computers, Materials & Continua, Vol.38, No.2, pp. 105-128, 2013, DOI:10.3970/cmc.2013.038.105

Abstract An extension of our previously reported periodic cluster model (J. Phys. Chem. C 2008, 112, 6667-6676 ) to nanorings and nanobelts is presented. This new scheme allows for accurately calculating reasonably large nanostructures while preserving a very small number of optimization parameters. The model has been applied to a number of AlN semiconducting structures using ab initio pair potentials. Attention has been paid to the variation of the B1-B4 phase transition pressure as the the size of the structures is varied. More >

Efraín Hernández-Rivera^1,2, Veena Tikare¹, Lumin Wang²

CMC-Computers, Materials & Continua, Vol.38, No.2, pp. 91-103, 2013, DOI:10.3970/cmc.2013.038.091

Abstract We present the development of a hybrid Monte Carlo-phase field model that is able to simulate radiation induced chemical segregation and the corresponding phase transformation and nano-structure evolution. Under irradiation by a lowenergy ion beam, defects (vacancies) are created and accumulate. In a binary crystalline material, AB, studied in this work, these defects are of the two types A and B and diffuse at different rates. These differential diffusivities are sufficient driving mechanisms for the formation of chemically distinct regions with accompany changes in phases and nano-structure. In this work, we present a model that More >