Browsing by Author "Yu, Jen-Perng"

Now showing 1 - 3 of 3

Development of a semi-implicit fluid modeling code using finite-volume method based on Cartesian grids
(2011-01-01)
Smith, Matthew R.
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Hung, Chieh-Tsan
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Lin, Kun-Mo
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Wu, Jong-Shinn
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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
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Hung, Chieh-Tsan
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Lin, Kun-Mo
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Chiu, Yuan-Ming
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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
Rapid optimization of blast wave mitigation strategies using Quiet Direct Simulation and Genetic Algorithm
(2010-06-01)
Smith, Matthew R.
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Kuo, Fang-An
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Hsieh, Chih-Wei
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Yu, Jen-Perng
;
Wu, Jong-Shinn
Presented is a rapid calculation tool for the optimization of blast wave related mitigation strategies The motion of gas resulting from a blast wave (specified by the user) is solved by the Quiet Direct Simulation (QDS) method - a rapid kinetic theory-based finite volume method The optimization routine employed is a newly developed Genetic Algorithm (GA) which is demonstrated to be similar to a Differential Evolution (DE) scheme with several modifications lit any Genetic Algorithm, individuals contain genetic information which is passed on to newly created individuals in successive generations The results from unsteady QDS simulations are used to determine the individual's "genetic fitness" which is employed by the proposed Genetic Algorithm during the reproduction process The combined QDS/GA algorithm is applied to various test cases and finally the optimization of a non-trivial blast wave mitigation strategy Both QDS and the proposed GA are demonstrated to perform with minimal computational expense while accurately solving the optimization problems presented (C) 2010 Elsevier BV All rights reserved