scholarly journals Optimal Control of SiC Crystal Growth in the RF-TSSG System Using Reinforcement Learning

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 791
Author(s):  
Lei Wang ◽  
Atsushi Sekimoto ◽  
Yuto Takehara ◽  
Yasunori Okano ◽  
Toru Ujihara ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Growth Rate ◽  
Reinforcement Learning ◽  
Marangoni Convection ◽  
Three Dimensional ◽  
Development Cost ◽  
Rf Coil ◽  
Melt Flow ◽  
2D Numerical Simulation ◽  
Top Seeded Solution Growth

We have developed a reinforcement learning (RL) model to control the melt flow in the radio frequency (RF) top-seeded solution growth (TSSG) process for growing more uniform SiC crystals with a higher growth rate. In the study, the electromagnetic field (EM) strength is controlled by the RL model to weaken the influence of Marangoni convection. The RL model is trained through a two-dimensional (2D) numerical simulation of the TSSG process. As a result, the growth rate under the control of the RL model is improved significantly. The optimized RF-coil parameters based on the control strategy for the 2D melt flow are used in a three-dimensional (3D) numerical simulation for model validation, which predicts a higher and more uniform growth rate. It is shown that the present RL model can significantly reduce the development cost and offers a useful means of finding the optimal RF-coil parameters.

Numerical simulation and experiment validation of level-pour direct-chill casting of A390 alloy hollow billets under different feeding schemes

2016 ◽  
Vol 26 (6) ◽  
pp. 1871-1888 ◽  
Author(s):  
Kesheng Zuo ◽  
Haitao Zhang ◽  
Ke Qin ◽  
Jianzhong Cui
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Three Dimensional ◽  
Direct Chill ◽  
Melt Flow ◽  
Content Type ◽  
Primary Si ◽  
Hollow Billet ◽  
Dc Casting ◽  
A390 Alloy

Purpose – The purpose of this paper is to study the effect of feeding scheme on melt flow and temperature field during the steady-state of level-pour direct-chill (DC) casting of A390 alloy hollow billet and optimize the design of feeding scheme. Design/methodology/approach – Melt flow and temperature field are investigated by numerical simulation, which is based on a three-dimensional mathematical model and well verified by experiments. Findings – The numerical results reveal that both melt flow and temperature field are obviously affected by the feeding scheme. The homogeneity of melt flow and temperature field in hollow billet with the feeding scheme of modified four inlets are better than the other feeding schemes. Experimental results show that crack can be eliminated by increasing the number of feeding inlets. The primary Si size appears unaffected while the distribution of primary Si particles is highly affected by the change of feeding scheme. Only with the feeding scheme of modified four inlets can fine and uniformly distributed primary Si particles be achieved. Practical implications – The paper includes implications for the design of feeding scheme in level-pour DC casting of hollow billet for practical use. Originality/value – This paper develops different feeding schemes for level-pour DC casting of hollow billet and optimizes the design of feeding scheme.

Three-dimensional numerical simulation of oxide melt flow in Czochralski configuration

2000 ◽  
Vol 216 (1-4) ◽  
pp. 372-388 ◽  
Author(s):  
C.J Jing ◽  
N Imaishi ◽  
T Sato ◽  
Y Miyazawa
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Melt Flow ◽  
Oxide Melt

A Parametric Study of a Three Dimensional Pitching Wing Aerodynamics

2010 ◽  
Author(s):  
M. R. Amiralaei ◽  
H. Alighanbari
Keyword(s):  
Numerical Simulation ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Lift Curve ◽  
Coefficient Versus ◽  
The Mean ◽  
2D Numerical Simulation ◽  
Volume Method

An experimental investigation is conducted to examine the effects of the amplitude of pitching oscillations and mean angle of attack on the aerodynamic behavior of a three-dimensional pitching blade. A 2D numerical simulation is also conducted based on the Unsteady Reynolds Averaged Navier-Stokes (URANS) equations and Finite Volume Method (FVM) and the results are compared with those of the experimental observations. The experimental results show that the investigated parameters affect the peaks of the lift coefficients. The hyteresis loops in the lift coefficient versus the angle of attack curves are also influenced by the variation of these parameters. However, the lift curve slopes are almost unchanged. The onset of flow separation is also dependent on the amplitude of pitching oscillations and the mean angle of attack.

The Effect of Stepped Wall of the Graphite Crucible in Top Seeded Solution Growth of SiC Crystal

2018 ◽  
Vol 924 ◽  
pp. 27-30
Author(s):  
Su Hun Choi ◽  
Young Gon Kim ◽  
Yun Ji Shin ◽  
Seong Min Jeong ◽  
Myung Hyun Lee ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Growth Rate ◽  
Temperature Distribution ◽  
Optical Microscopy ◽  
Single Crystals ◽  
Carbon Concentration ◽  
Graphite Crucible ◽  
Solution Growth ◽  
Metal Addition ◽  
Top Seeded Solution Growth

The crucible design having a stepped wall was introduced for increasing the growth rate of SiC crystal without metal addition in top-seeded solution growth (TSSG) method. The numerical simulation confirmed that new crucible design to increase the solvent-crucible interface could definitely change the temperature distribution and increase the carbon concentration. The simulation result, SiC single crystals were grown with Si solvent at 1900°C using a normal crucible and a stepped crucible to investigate the effect of crucible design having a stepped wall. Grown SiC layers were analyzed using Optical microscopy and Raman spectra. The growth rate in the stepped crucible was finally 66um/h observed.

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