Browsing by Author "Hung, Chieh-Tsan"

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Development of a parallel implicit solver of fluid modeling equations for gas discharges
(2011-01-01)
Hung, Chieh-Tsan
;
Chiu, Yuan-Ming
;
Hwang, Feng-Nan
;
Wu, Jong-Shinn
;
機械工程學系
A parallel fully implicit PETSc-based fluid modeling equations solver for simulating gas discharges is developed Fluid modeling equations include the neutral species continuity equation the charged species continuity equation with drift-diffusion approximation for mass fluxes the electron energy density equation and Poisson s equation for electrostatic potential Except for Poisson s equation all model equations are discretized by the fully implicit backward Euler method as a time integrator and finite differences with the Scharfetter-Gummel scheme for mass fluxes on the spatial domain At each time step the resulting large sparse algebraic nonlinear system is solved by the Newton-Krylov-Schwarz algorithm A 2D-GEC RF discharge is used as a benchmark to validate our solver by comparing the numerical results with both the published experimental data and the theoretical prediction The parallel performance of the solver is investigated (C) 2010 Elsevier B V All rights reserved
Development of a semi-implicit fluid modeling code using finite-volume method based on Cartesian grids
(2011-01-01)
Smith, Matthew R.
;
Hung, Chieh-Tsan
;
Lin, Kun-Mo
;
Wu, Jong-Shinn
;
Yu, Jen-Perng
Presented is the HLLG (Harten Lax and van Leer with Gradient inclusion) method for application to the numerical solution of general Partial Differential Equations (PDEs) in conservation form The HLLG method is based on the traditional HLL method with formal mathematical inclusion of gradients of conserved properties across the control volume employed for flux derivation The simple extension demonstrates that conventional higher extensions of the HLL method are mathematically inconsistent and produce various numerical instabilities The HLLG method with higher order extensions consistent with the flux derivation is absent of (or less affected by) the said numerical instabilities The HLLG method is then applied to solutions of the Euler Equations and the simulation of ID argon RF plasma simulation (C) 2010 Elsevier B V All rights reserved
Fluid Modeling of a Nitrogen Atmospheric-Pressure Planar Dielectric Barrier Discharge Driven by a Realistic Distorted Sinusoidal Alternating Current Power Source
(2012-11-01)
Cheng, Kai-Wen
;
Hung, Chieh-Tsan
;
Lin, Kun-Mo
;
Chiu, Yuan-Ming
;
Wu, Jong-Shinn
One-dimensional self-consistent simulations of a parallel-plate atmospheric-pressure nitrogen dielectric barrier discharge (DBD) are presented. The DBD was driven by a realistic distorted-sinusoidal voltage power source with a frequency of 60 kHz. The simulated discharge currents are in quantitative agreement with experimental measurements. N-4(+) ions gain more of the input electric power than electrons, which is unlike most glow discharges. The densities of all charged and neutral species increase exponentially with increasing applied peak voltage in the range of 6.2-8.6 kV. The higher the permittivity of the dielectric material, the larger the discharge current and the longer the period of gas breakdown. In addition, the quantity of accumulated charges at each electrode increases with increasing permittivity of the dielectric material. Finally, the increase in dielectric thickness from 1.0 to 2.0mm greatly reduces the densities of all species and also the plasma absorbed by the power. (C) 2012 The Japan Society of Applied Physics
Numerical Investigation on Ion Inertia Force in Low-Temperature Plasma Using Fluid Model Considering Ion Momentum Equation
(2016-12-01)
Chen, Kuan-Lin
;
Tseng, Meng-Fan
;
Gu, Bi-Ren
;
Hung, Chieh-Tsan
;
Wu, Jong-Shinn
In this paper, we would like to numerically investigate the effect of ion inertia force in a typical argon gas discharge using fluid model considering the ion momentum equation, which becomes important under various operating conditions. The proposed self-consistent fluid model consists of the electron continuity equation with the drift-diffusion approximation, the ion continuity equation, the electron energy density equation, the ion momentum equation, and the Poisson equation for electric potential. We studied the plasma properties affected by the inertia force by comparing between the use of momentum equation and drift-diffusion approximation for ion momentum. The results show that the ion inertia force is significant under the low-pressure conditions (<100 mtorr) as expected, e.g., for plasma etching and radio frequency magnetron sputtering plasma. In addition, we also found when the pressure is higher than 100 mtorr, the inertia force becomes important (e.g., more than 15%) in the sheath region when the driving frequency is high enough (e.g., 60 MHz), e.g., for high-frequency plasma-enhanced chemical vapor deposition. Thus, inclusion of inertia force in the modeling of momentum equation becomes necessary under these operating conditions.
Numerical Investigation on Ion Inertia Force in Low-Temperature Plasma Using Fluid Model Considering Ion Momentum Equation
(2016-12)
Chen, Kuan-Lin
;
Tseng, Meng-Fan
;
Gu, Bi-Ren
;
Hung, Chieh-Tsan
;
Wu, Jong-Shinn
In this paper, we would like to numerically investigate the effect of ion inertia force in a typical argon gas discharge using fluid model considering the ion momentum equation, which becomes important under various operating conditions. The proposed self-consistent fluid model consists of the electron continuity equation with the drift-diffusion approximation, the ion continuity equation, the electron energy density equation, the ion momentum equation, and the Poisson equation for electric potential. We studied the plasma properties affected by the inertia force by comparing between the use of momentum equation and drift-diffusion approximation for ion momentum. The results show that the ion inertia force is significant under the low-pressure conditions (<100 mtorr) as expected, e.g., for plasma etching and radio frequency magnetron sputtering plasma. In addition, we also found when the pressure is higher than 100 mtorr, the inertia force becomes important (e.g., more than 15%) in the sheath region when the driving frequency is high enough (e.g., 60 MHz), e.g., for high-frequency plasma-enhanced chemical vapor deposition. Thus, inclusion of inertia force in the modeling of momentum equation becomes necessary under these operating conditions.
Parallel 2D Axisymmetric Fluid Modeling of CF4 Discharge in an Inductively Coupled Plasma Source During SiO2 Etching
(2014-04-01)
Chiu, Yuan-Ming
;
Chiang, Chung-Hua
;
Hung, Chieh-Tsan
;
Hu, Meng-Hua
;
Wu, Jong-Shinn
A parallel 2D axisymmetric plasma fluid modeling for an inductively coupled plasma source with tetrafluoromethane precursor is reported. In total, 32 species with 96 gas-phase and 27 surface reactions with site-balance equations are considered. The predicted results of major species densities are in reasonable agreement with reported experiments. The etching products, e.g. SiFx and O-2, are found to be appreciable (approximate to 10%) compared to the precursor near the substrate. The predicted density trends, such as CFx+ and CFx (x=1-3), are also consistent with reported experiments. Finally, the predicted etching rate on the SiO2 substrate is presented and discussed in detail.