A Computer Modeling of the Czochralski Growth of Bismuth Silicon Oxide With Free Surface

1991 ◽  
Author(s):  
G. S. Liaw ◽  
Y. M. Zheng ◽  
J. D. Mo ◽  
L. C. Chou
Keyword(s):  
Free Surface ◽  
Flow Field ◽  
Silicon Oxide ◽  
Surface Effect ◽  
Czochralski Growth ◽  
Bismuth Silicon Oxide ◽  
Thermal Buoyancy ◽  
Czochralski Crystal Growth ◽  
Steady State Model ◽  
Growth System

Abstract A comprehensive numerical modeling of the Czochralski crystal growth system has been conducted for the growth of Bismuth Silicon Oxide (BSO). Both the thermal buoyancy and the surface tension effects are taken into account in the convective flow field. A pressure-based numerical algorithm in conjunction with an algebraic adaptive grid procedure is employed for the simultaneous solution of the melt flow field and the global melt/solid temperature distribution. The free surface effect is treated by coupling the Young-Laplace equation with the flow field along the interface. The results of the quasi-steady-state model at three different stages are presented, they agree with the experimental observations qualitatively.

scholarly journals Vortex-Induced Vibration Characteristics of a PTC Cylinder with a Free Surface Effect

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 907
Author(s):  
Dahai Zhang ◽  
Lei Feng ◽  
Hao Yang ◽  
Tianjiao Li ◽  
Hai Sun
Keyword(s):  
Free Surface ◽  
Flow Field ◽  
Surface Effect ◽  
Amplitude Ratio ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Water Tunnel ◽  
Vortex Induced Vibration ◽  
Turbulence Control ◽  
Moving Cylinder

The experimental study of vortex induced vibration needs to be carried out in water tunnel, but in previous associated simulation work, the water tunnel was treated as an infinite flow field in the depth direction with the effect of the free surface neglected. In the paper, the dynamic characteristics and physical mechanisms of a passive turbulence control (PTC) cylinder in a flow field with a free surface is studied, and the combined technique of a volume of fluid (VOF) method and vortex-induced vibration (VIV) was realized. In the range of Reynolds number studied in this paper (3.5 × 104 ≤ Re ≤ 7.0 × 104), the dynamic parameters (lift and drag coefficients), vortex structures, VIV response (amplitude and frequency ratios), and energy harvesting characteristics of a PTC cylinder under different flow conditions were obtained. The study found that: (1) the shear layer was made more unstable behind the cylinder by the free surface, which made it quicker to reach periodic stability, and the asymmetry shortened the initial stage of vibration of the oscillator, which made it easier to produce dynamic control of the motion of the oscillator; (2) the presence of the free surface only affected the positive amplitude ratio, but had almost no effect on the negative amplitude ratio; (3) the frequency ratio in the free surface flow was closer to the experimental data; (4) the presence of the free surface did not affect the detached vortex pattern in the flow around the stationary cylinder, but in the VIV, the lower the free surface height Z, the more vortices that were shed from the moving cylinder.

Boundaries Influence on the Flow Field Around an Oscillating Sphere

2013 ◽  
Author(s):  
Domenica Mirauda ◽  
Antonio Volpe Plantamura ◽  
Stefano Malavasi
Keyword(s):  
Free Surface ◽  
Flow Field ◽  
Boundary Conditions ◽  
Damping Ratio ◽  
Water Channel ◽  
Open Water ◽  
Free Surface Flows ◽  
The Body ◽  
Sphere Diameter ◽  
Oscillating Sphere

This work analyzes the effects of the interaction between an oscillating sphere and free surface flows through the reconstruction of the flow field around the body and the analysis of the displacements. The experiments were performed in an open water channel, where the sphere had three different boundary conditions in respect to the flow, defined as h* (the ratio between the distance of the sphere upper surface from the free surface and the sphere diameter). A quasi-symmetric condition at h* = 2, with the sphere equally distant from the free surface and the channel bottom, and two conditions of asymmetric bounded flow, one with the sphere located at a distance of 0.003m from the bottom at h* = 3.97 and the other with the sphere close to the free surface at h* = 0, were considered. The sphere was free to move in two directions, streamwise (x) and transverse to the flow (y), and was characterized by values of mass ratio, m* = 1.34 (ratio between the system mass and the displaced fluid mass), and damping ratio, ζ = 0.004. The comparison between the results of the analyzed boundary conditions has shown the strong influence of the free surface on the evolution of the vortex structures downstream the obstacle.

InSb Czochralski Growth Single Crystals for InGaSb Substrates

2014 ◽  
Vol 1616 ◽  
Author(s):  
J. E. Flores Mena ◽  
R. Castillo Ojeda ◽  
J. Díaz Reyes
Keyword(s):  
Low Cost ◽  
Electronic Devices ◽  
Czochralski Method ◽  
Liquid Nitrogen Temperature ◽  
Longitudinal Optical ◽  
Czochralski Growth ◽  
Etch Pit ◽  
Growth System ◽  
Radiation Sensors ◽  
Made In

ABSTRACTThe massive crystal growth of single crystal semiconductors materials has been of fundamental importance for the actual electronic devices industry. As a consequence of this one, we can obtain easily a large variety of low cost devices almost as made ones of silicon. Nowadays, the III-V semiconductors compounds and their alloys have been proved to be very important because of their optical properties and applications. It is the case of the elements In, Ga, As, Sb, which can be utilized for the fabrication of radiation sensors. In this work we present the results obtained from the ingots grown by the Czochralski method, using a growth system made in home. These results include anisotropic chemical attacks in order to reveal the crystallographic orientation and the possible polycrystallinity. Isotropic chemical attacks were made to evaluate the etch pit density. Metallographic pictures of the chemical attacks are presented in this work. Among the results of these measurements, the best samples presented in this work showed mobilities of 62.000 cm2/V*s at room temperature and 99.000 cm2/V*s at liquid nitrogen temperature. Typical pit density was 10,000/cm2. The Raman spectra present two dominant peaks associated at Transversal Optical (TO)- and Longitudinal Optical (LO)-InSb, the first vibrational mode is dominant due to the crystalline direction of the ingots and second one is associated to high defects density.

Irreversible Adsorption Erases the Free Surface Effect on the Tg of Supported Films of Poly(4-tert-butylstyrene)

2017 ◽  
Vol 6 (4) ◽  
pp. 354-358 ◽  
Author(s):  
Natalia G. Perez-de-Eulate ◽  
Michele Sferrazza ◽  
Daniele Cangialosi ◽  
Simone Napolitano
Keyword(s):  
Free Surface ◽  
Surface Effect ◽  
Irreversible Adsorption

Bismuth silicon oxide as a holographic storage medium

1992 ◽  
Author(s):  
Charles L. Eads ◽  
Azad Siahmakoun ◽  
Arthur B. Western
Keyword(s):  
Silicon Oxide ◽  
Storage Medium ◽  
Holographic Storage ◽  
Bismuth Silicon Oxide
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