Changes between Version 120 and Version 121 of FluxLimitedDiffusion


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Timestamp:
03/30/13 22:37:40 (12 years ago)
Author:
Jonathan
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  • FluxLimitedDiffusion

    v120 v121  
    389389which we can also write as
    390390
    391   [[latex(\frac{\partial e}{\partial t}  = f \left ( e \right ) + g \left (E,\nabla E \right )
    392   [[latex(\frac{\partial E}{\partial t} = \nabla \cdot \frac{c\lambda}{\kappa_{0R}} \nabla E -\nabla \cdot \left ( \frac{3-R_2}{2}\mathbf{v}E  - f \left ( e \right ) - g \left (e,E, \nabla E \right ) \right ) )]] 
     391  [[latex(\frac{\partial e}{\partial t}  = f \left ( e \right ) + g \left ( E,\nabla E \right ) )]]
     392  [[latex(\frac{\partial E}{\partial t} = \nabla \cdot \frac{c\lambda}{\kappa_{0R}} \nabla E -\nabla \cdot \left ( \frac{3-R_2}{2}\mathbf{v}E  \right ) - f \left ( e \right ) - g \left (e,E, \nabla E \right ) )]] 
    393393  where
    394 [[latex( f \left ( e \right ) = - 4 \pi \kappa_{0P} e )]]
     394[[latex( f \left ( e \right ) = - 4 \pi \kappa_{0P} B(T(e)) )]]
    395395 and
    396396  [[latex( g \left (e,E, \nabla E \right ) = \kappa_{0P}(cE) + \lambda \left ( 2 \frac{\kappa_{0P}}{\kappa_{0R}}-1 \right ) \mathbf{v} \cdot \nabla E -\frac{3-R_2}{2}\kappa_{0P}\frac{v^2}{c}E )]]
    397397
    398398Now we can linearize f about e,,0,,
    399 [[latex( f \left ( e \right ) = f \left ( e_0 ) + \partial{f}\partial{e} \left ( e - e_0 \right ) )]]
     399[[latex( f \left ( e \right ) = f \left ( e_0 \right ) + \frac{\partial f}{\partial e} \left ( e - e_0 \right ) )]]
    400400
    401401so that the first equation can be written as
    402402
    403   [[latex(\frac{\partial e}{\partial t}  = f \left ( e_0 \right ) + \partial{f}\partial{e} \left ( e - e_0 \right ) )]]
     403  [[latex(\frac{\partial e}{\partial t}  = f \left ( e_0 \right ) + \frac{\partial f}{\partial e} \left ( e - e_0 \right ) )]]
    404404
    405405and then discretized as
    406406
    407   [[latex(e^{n+1}_i-e^{n}_i = \frac{\Delta t}{\Delta x}  \left ( f \left ( e_n \right ) + g(e_n,E^*,\nabla E^* \right ) + \right ) \left ( \left ( \bar {\psi} - 1 \right ) \phi \right ) e_n +  \psi \phi e^{n+1}_i ]]
    408 
    409 which can be solved for [[latex(e^{n+1} = \frac{1}{1-\psi \phi} \left ( \bar{\psi} \phi e^n_i + f \left ( e^n_i \right ) + g \left ( e^n_i,E^*,\nabla E^* \right ) \right ) )]]
     407  [[latex(e^{n+1}_i-e^{n}_i = \frac{\Delta t}{\Delta x}  \left ( f \left ( e_n \right ) + g \left ( e_n,E^*,\nabla E^* \right ) \right ) + \left ( \left ( \bar{\psi} - 1 \right ) \phi \right ) e_n +  \psi \phi e^{n+1}_i ]]
     408
     409which can be solved for [[latex(e^{n+1} = \frac{1}{1-\psi \phi} \left ( \left ( \bar{\psi} - 1 \right ) \phi e^n_i + f \left ( e^n_i \right ) + g \left ( e^n_i,E^*,\nabla E^* \right ) \right ) )]]
    410410
    411411Then if we take the semi-discretized equation for E