Begell House Inc.
Computational Thermal Sciences: An International Journal
CTS
1940-2503
5
3
2013
PREFACE: INTERNATIONAL CONFERENCE ON HEAT TRANSFER, FLUID MECHANICS AND THERMODYNAMICS 2012
ix
10.1615/ComputThermalScien.v5.i3.10
Josua Petrus
Meyer
Department of Mechanical and Mechatronic Engineering, Stellenbosch University, Banghoek Rd, Stellenbosch Central, Stellenbosch, 7600, South Africa
NUMERICAL SIMULATION OF THE DEPOSITION PROCESS AND THE EPITAXIAL GROWTH OF CADMIUM TELLURIDE THIN FILM IN A MOCVD REACTOR
177-188
10.1615/ComputThermalScien.2013006321
Xiaogang
Yang
Institute for Arts, Science and Technology, Glyndwr University, Wrexham LL11, 2AW, United Kingdom
Yiyi
Wu
Institute for Arts, Science and Technology, Glyndwr University, Wrexham LL11, 2AW, United Kingdom
Xiaobing
Huang
Institute for Arts, Science and Technology, Glyndwr University, Wrexham LL11, 2AW, United Kingdom
Vincent
Barrioz
CSER, Glyndwr University, OpTIC Glyndwr, St. Asaph, LL17 0JD, United Kingdom
Giray
Kartopu
CSER, Glyndwr University, OpTIC Glyndwr, St. Asaph, LL17 0JD, United Kingdom
Shafiul
Monir
CSER, Glyndwr University, OpTIC Glyndwr, St. Asaph, LL17 0JD, United Kingdom
Stuart J. C.
Irvine
CSER, Glyndwr University, OpTIC Glyndwr, St. Asaph, LL17 0JD, United Kingdom
thin film
chemical vapor deposition
CFD
MOCVD reactor
Metalorganic chemical vapor deposition (MOCVD) is an attractive method for depositing thin films of cadmium telluride (CdTe) and other group II−VI compound materials. It has been known that the growth rate of CdTe thin film is sensitive to the substrate temperature and the reactant partial pressures, indicating that the deposition process is kinetically controlled and affected by many conditions. In the deposition process, heterogeneous reactions play an important role in film formation, and the process is further complicated by the coupling of gas and surface reactions via desorption
of the reactive intermediates. A detailed understanding of the deposition mechanism and kinetics will be crucial for the design, optimization, and scaling up of II−VI MOCVD reactors. This paper presents the results of computational fluid dynamics (CFD) modeling of the deposition process in an inline MOCVD reactor, taking into account the heat transfer and mass transport of the chemical species. The numerical simulations have been conducted using the CFD code, ANSYS FLUENT. The influence of the process controlling parameters such as the total flow rate, reactor pressure, and substrate temperature on the deposition behavior has been assessed. In the present study, dimethylcadmium and diisopropyltelluride have been used as precursors while H2 acts as the carrier gas and N2 as the flushing gas. The capabilities of using the developed CFD models for revealing the deposition mechanisms in MOCVD have been demonstrated. The simulations have been conducted in both mass transport and kinetics regimes at the temperature range of 355−455° to match the experimental conditions.
THE STATISTICAL THEORY OF MONOMOLECULAR FULLERENE FILM FORMATION ON THE CRYSTAL SURFACE
189-194
10.1615/ComputThermalScien.2013006342
Svetlana Yu.
Zaginaichenko
Institute for Problems of Materials Science of NAS of Ukraine, Krzhyzhanovsky strasse 3, 03142 Kiev, Ukraine
Zinaida A.
Matysina
Dnepropetrovsk National University, 72 Gagarin strasse, Dnepropetrovsk, 49000 Ukraine
Dmitry
Schur
Institute for Problems of Materials Science of NAS of Ukraine, Krzhyzhanovsky strasse 3, 03142 Kiev, Ukraine
Aleksey D.
Zolotarenko
Institute for Problems of Materials Science of NAS of Ukraine, Krzhyzhanovsky strasse 3, 03142 Kiev, Ukraine
monomolecular film
statistical theory
metallic substrate
adsorption
fullerene concentration
temperature
The theoretical study of fullerene film production on the crystal faces of (100)-type crystals with simple cubic (sc), body-centered cubic (bcc), and face-centered cubic (fcc) lattices is the subject of this paper. The calculation of equilibrium concentration of fullerenes C60, C70 and its dependence on temperature has been carried out. Adsorption-desorption
processes of fullerenes on the crystal surface and possible special features of these processes have been investigated. The developed statistical theory of the process of fullerene deposition on the metallic substrate provides an explanation and justification of the possibility of manifestation of these processes, revealing that each is defined to a large extent by the character and degree of interaction between the fullerenes and atoms of the metallic substrate.
A COMPUTATIONAL FLUID DYNAMICS STUDY OF ELASTOHYDRODYNAMIC LUBRICATION LINE CONTACT PROBLEM WITH CONSIDERATION OF SURFACE ROUGHNESS
195-213
10.1615/ComputThermalScien.2013006347
Sutthinan
Srirattayawong
Department of Engineering, University of Leicester, Leicester LE1 7RH, United Kingdom
S.
Gao
Department of Engineering, University of Leicester, Leicester LE1 7RH, United Kingdom
elastohydrodynamic
surface roughness
lubrication
Newtonian
Traditionally, the Reynolds equation is widely used to describe the flow of lubricants for the elastohydrodynamic lubrication (EHL) problem, though there are a number of limitations for this approach. In this work an advanced computational fluid dynamics (CFD) model has been developed for such EHL problem. The CFD model developed can predict the characteristics of fluid flow in the EHL problem, taking into consideration the pressure distribution, minimal film thickness, viscosity, and density changes. The cylinder is considered to be an elastic deformation which is a function of the generated
pressure and the elasticity of the material. Above all, the surface of the cylinder is defined to have an arbitrary
roughness, though only the cases with moderate roughness are reported in this paper. Reconstructing the object geometry, meshing and calculation of the conservation of mass and momentum equations are carried out by using the
commercial software packages ICEMCFD and ANSYS Fluent. In addition, the user-defined functions for density, viscosity, and elastic deformation of the cylinder as the function of pressure need to be defined for this particular work. A number of simulation cases have been investigated, and detailed results of velocity, pressure distribution, and film thickness are obtained. In particular, the effects of surface roughness on the EHL line contact problem are compared to the smooth surface case when the applied load is varied. It is found that the pressure profile at the center of the contact area
directly relates to the roughness amplitude and the applied load. The surface roughness influences the fluctuated shape of pressure distribution. The pressure and the effect of surface roughness increase when the applied load is increased.
WATER DROPLET EVAPORATION AT HIGH GAS PRESSURE AND TEMPERATURE LEVELS − COMPARISON OF EXPERIMENTAL RESULTS WITH A ONE-DIMENSIONAL SIMULATION
215-226
10.1615/ComputThermalScien.2013006358
Botond
Barabas
Department of Mechanical Engineering, University of Duisburg-Essen
A.
Kefalas
Department of Mechanical Engineering, University of Duisburg-Essen
J. P.
Schnitzler
Department of Mechanical Engineering, University of Duisburg-Essen
A.
Rossetti
Department of Mechanical Engineering, University of Duisburg-Essen
F.-K.
Benra
Department of Mechanical Engineering, University of Duisburg-Essen
H. J.
Dohmen
Department of Mechanical Engineering, University of Duisburg-Essen
two-phase-flow
droplet breakup
numerical model
Water injection into gas turbines has been the subject of investigations for decades, due to a high power and efficiency augmentation potential compared to the simple gas turbine cycle. Based on former research at ambient injection conditions, some technologies have already been realized, e.g., inlet fogging. Further applications of water injection at higher temperature and pressure levels are limited because of few experimental data. In order to gain fundamental understanding of these boundary conditions, a novel test facility for droplet evaporation investigations has been built up at the Department of Mechanical Engineering at University of Duisburg-Essen. The resulting spray patterns are recorded by a laser-based measuring technology, phase Doppler particle analyzer. In this paper, experimental results from the test facility are compared to simulation results of a one-dimensional model for droplet evaporation. The focus of this
investigation is on the accordance of the simulation results with the experimental data at high pressure and temperature levels.
NUMERICAL SIMULATION OF PHASE CHANGE MATERIALS MELTING PROCESS
227-237
10.1615/ComputThermalScien.2013006360
Giuseppe
Petrone
Department of Industrial Engineering − University of Catania Viale A. Doria, 6 − 95125 Catania, ITALY
Giuliano
Cammarata
Department of Industrial Engineering − University of Catania Viale A. Doria, 6 − 95125 Catania, ITALY
phase change
rectangular enclosure
enthalpy method
natural convection
This study deals with a numerical investigation on the melting process of a phase change material (PCM) in a differentially heated rectangular enclosure. A finite-element-based software is used in order to solve Navier–Stokes and energy equations in the considered system. Adopting the enthalpy formulation, one single equation is used to solve transient conduction and convection heat transfer in both the solid and liquid phase. The liquid flow patterns during the melting process have been captured and the instantaneous marching of the liquid–solid interface is presented. In addition, the
temperature distributions in the PCM are reported. A successful comparison between obtained numerical results with experimental ones found in the literature is presented.
TWO-EQUATION TURBULENCE MODEL FOR SUPERSONIC FLOWS BASED ON MODELING OF PRESSURE–STRAIN CORRELATION
239-248
10.1615/ComputThermalScien.2013006435
Alexander M.
Molchanov
Aerospace Heating Engineering Department,Moscow Aviation Institute (National Research
University) "MAI", Volokolamskoe shosse, d. 4, 125993, Moscow, Russia
turbulence
high-speed flows
pressure-strain correlation
turbulent Mach number
supersonic
A new turbulence model K − ε − Vn for high-speed compressible flows is developed. It is based on the modeling of the rapid part of pressure–strain correlation depending on turbulent Mach number and on the assumption that the velocity fluctuations normal to streamline play the key role in the turbulent mixing process. Simulations of plane supersonic mixing layers and axisymmetrical high-speed jets were performed and comparison with the experimental data showed reasonable agreement.
A CONTROL-VOLUME FINITE ELEMENT METHOD FOR THE PREDICTION OF THREE-DIMENSIONAL DIFFUSION-TYPE PHENOMENA IN ANISOTROPIC MEDIA
249-260
10.1615/ComputThermalScien.2013006532
Simon
Kattoura
Heat Transfer Laboratory, Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada
Alexandre
Lamoureux
Heat Transfer Laboratory, Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada
Bantwal R. (Rabi)
Baliga
Department of Mechanical Engineering, McGill University, Montreal, Quebec H3A 0C3, Canada
diffusion-type phenomena
anisotropic media
irregular domains
control-volume finite element method
tetrahedral elements
vertex-centered polyhedral control volumes
element-based interpolation functions
sequential iterative variable adjustment procedure
The formulation and testing of a control-volume finite element method (CVFEM) for the prediction of 3D, linear and
nonlinear, diffusion-type phenomena in anisotropic media in irregular calculation domains are presented. The calculation domain is discretized into four-node tetrahedral elements. Contiguous, nonoverlapping, polyhedral control volumes are then associated with each node, and the governing differential equation is integrated over these control volumes. In each tetrahedral element, the dependent variable is interpolated linearly, centroidal values of the diffusion coefficients are assumed to prevail, and nodal values of the coefficients in the linearized source term are assumed to prevail over
the polyhedral sub–control volumes. These interpolation functions are used to derive the discretized equations, which, in general, are nonlinear and coupled, and are solved using an iterative procedure. Comments are provided on the sufficient conditions for ensuring positive coefficients in the discretized equations. The proposed CVFEM appears to be the first numerical method for the solution of anisotropic diffusion-type problems that is based on tetrahedral elements and vertex-centered polyhedral control volumes. These features make it particularly attractive for amalgamation with
adaptive-grid schemes and applications to problems with complex irregular geometries. The proposed 3D CVFEM and
its computer implementation were tested using several steady conduction–type problems, for which analytical solutions were constructed using a special technique. In all cases, the agreement between the numerical and analytical solutions was excellent.