Changes between Version 126 and Version 127 of FluxLimitedDiffusion
- Timestamp:
- 03/30/13 23:14:34 (12 years ago)
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FluxLimitedDiffusion
v126 v127 405 405 and then discretized as 406 406 407 [[latex(e^{n+1}_i-e^{n}_i = \frac{ \Delta t}{\Delta x} \left ( f \left ( e^n_i \right ) + g \left (E^*,\nabla E^* \right ) \right ) + \left ( \left ( \bar{\psi} - 1 \right ) \phi \right ) e^n_i + \psi \phi e^{n+1}_i )]]407 [[latex(e^{n+1}_i-e^{n}_i = \frac{1}{\Delta t} \left ( f \left ( e^n_i \right ) + g \left (E^*,\nabla E^* \right ) \right ) + \left ( \left ( \bar{\psi} - 1 \right ) \phi \right ) e^n_i + \psi \phi e^{n+1}_i )]] 408 408 409 409 which can be solved for 410 [[latex(e^{n+1}_i = e^{n}_i + \frac{ 1}{1 - \psi \phi} \left ( f \left ( e^n_i \right ) + g \left ( e^n_i,E^*,\nabla E^* \right ) \right ) )]]410 [[latex(e^{n+1}_i = e^{n}_i + \frac{\Delta t}{1 - \psi \phi} \left ( f \left ( e^n_i \right ) + g \left (E^*,\nabla E^* \right ) \right ) )]] 411 411 412 412 Then if we take the semi-discretized equation for E 413 413 414 [[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^n_i \right ) + g \left (e^n_i,E, \nabla E \right ) + \bar{\psi}\phi e^n_i - \psi \phi e^{n+1}_i )]]414 [[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^n_i \right ) - g \left (E, \nabla E \right ) - \left ( \left ( \bar{\psi} - 1 \right ) \phi \right ) e^n_i - \psi \phi e^{n+1}_i ) ]] 415 415 416 416 and then plugin the solution for e^n+1^,,i,, we get 417 417 418 [[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 _0,E, \nabla E \right ) - \bar{\psi}\phi e^n_i - \frac{\psi \phi }{1-\psi \phi} \left ( \bar{\psi} \phi e^n_i + f \left ( e_0,E,\nabla E\right ) \right ) )]]418 [[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^n_i \right ) - g \left (E, \nabla E \right ) - \frac{1}{\Delta t} \left ( \left ( \left ( \bar{\psi} - 1 \right ) \phi \right ) e^n_i - \psi \phi e^n_i - \frac{\psi \phi }{1-\psi \phi} \left ( f \left ( e^n_i \right ) + g \left (E,\nabla E \right ) \right ) \right ) )]] 419 419 420 420 which simplifies to