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【期刊论文】Numerical analysis of LEC growth of GaAs with an axial magnetic field
李明伟, Mingwei Li a, *, Wenrui Hu b, Nuohu Chen c, Danling Zeng a, Zemei Tang b
International Journal of Heat and Mass Transfer 45(2002)2843-2851,-0001,():
-1年11月30日
A set of numerical analyses for momentum and heat transfer for a 3 in. (0.075m) diameter Liquid Encapsulant Czochralski (LEC) growth of single-crystal GaAs with or without an axial magnetic field was carried out using the finite-element method. The analyses assume a pseudosteady axisymmetric state with laminar flows. Convective and conductive heat transfers, radiative heat transfer between diffuse surfaces and the Navier-Stokes equations for both melt and encapsulant and electric current stream function equations for melt and crystal are considered together and solved simultaneously. The effect of the thickness of encapsulant, the imposed magnetic field strength as well as the rotation rate of crystal and crucible on the flow and heat transfer were investigated.
Liquid Encapsulant Czochralski (, LEC), , Growth of GaAs, Magnetic field, Finite-element method, Boron oxide
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【期刊论文】微重力下两同轴液柱内的热毛细对流的渐近解及数值模拟
李明伟, LI Mingwei, ZENG Danling
工程热物理学报,1997,18(2):177~180,-0001,():
-1年11月30日
A mathematical model describing the thermocapillary convection in two immiscible coaxial liquid columns is proposed. An approximate analytical solution is obtained by asymptotical way. The results of numerical simulation show that effective reduction of ther-mocapillary convection in the inner liquid layer can be reached by properly selecting the encapsulation which has a reasonable match relation with the encapsulated fluid.
热毛细对流, 液封, 渐近线方法
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李明伟, Mingwei Li*, Danling Zeng, Tingxia Zhu
International Journal of Heat and Mass Transfer 45(2002)157-164,-0001,():
-1年11月30日
Linear stability theory is used to analyze the stability of the basic state solution of Marangoni convection in a liquid bridge with liquid encapsulation. By processing the linear disturbance equations numerically, stability analysis can be evolved to a complex general eigenvalue problem. Inverse iteration algorithm combined with LZ algorithm is employed to solve the complex generalized eigenvalue problem. The results show that the stability of the system can be enhanced greatly by choosing reasonable matching parameters of the two fluid layers. The preferred mode of instability is axial wave number α=2, 3 and 4, which means that the system is more sensitive to the disturbance with larger wave lengths.
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【期刊论文】Global simulation of a silicon Czochralski furnace
李明伟, Mingwei Li a, YourongLi a, Nobuyuki Imaishi a, *, Takao Tsukada b
Journal of Crystal Growth 234(2002)32-46,-0001,():
-1年11月30日
To understand the characteristics of the Czochralski (Cz) furnace for the single-crystal growth of silicon, a set of global analyses of momentum, heat and mass transfer in small Cz furnaces (crucible diameter: 7.2cm, crystal diameter: 3.5cm, operated in a 10 Torr argon flow environment) is carried out using the finite-element method. The global analysis assumes a pseudosteady axisymmetric state with laminar flow, equilibrium relations at the melt/silica interface and vapor-liquid chemical equilibrium at the melt/gas interface, as well as the segregation coefficient of unity at the melt/crystal interface. Convective and conductive heat transfers, radiative heat transfer between diffuse surfaces and the Navier-Stokes equations for gas and melt phases are all combined and solved together. Thus, the velocities and temperatures obtained are used to calculate the oxygen concentrations. The global analysis code is effectively used to discuss the influences of the Marangoni effect and a gas guide (or a heat shield) placed between the crucible and the crystal. The results indicate that the gas guide reduces the heater power and changes the melt flow pattern and oxygen transport. The melt flow pattern is strongly dependent on the Marangoni effect and gas flow near the surface, and changes the oxygen concentration significantly. This analysis reveals the importance and effectiveness of global analysis.
A1., Computer simulation, A1., Fluid flows, A1., Heat transfer, A1., Mass transfer, A2., Czochralski method, B2., Semiconducting silicon
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【期刊论文】Suppression of Marangoni convection of silicon melt by a non-contaminating method
李明伟, Jie Li a, Mingwei Li a, *, Wenrui Hu b, Danling Zeng a
International Journal of Heat and Mass Transfer 46(2003)4969-4973,-0001,():
-1年11月30日
A set of numerical simulation of the effect of the gas shearing flow over a silicon melt free surface on Marangoni convection under microgravity condition was conducted by using finite element method. For given gas channel width, Marangoni number and aspect ratio a remarkable reduction of Marangoni convection in silicon liquid bridge can be achieved by choosing the optimal gas velocity in accordance with the correlation proposed in the paper. The effectiveness of the reduction of the gas flow under different conditions shows that, in some cases, Marangoni convection reduction of 99% can be realized by this non-contaminating method.
Marangoni convection, Silicon, Non-contamination method, Finite-element method
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