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sunfluidh:new_numerical_methods_setup_namelist

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sunfluidh:new_numerical_methods_setup_namelist [2017/09/28 18:13]
yann [Poisson_NumericalMethod]
sunfluidh:new_numerical_methods_setup_namelist [2017/09/28 18:13]
yann [Simulation control]
Ligne 140: Ligne 140:
 For more information on this data set, [[sunfluidh:simulation_management_setup_namelist|click here]]. For more information on this data set, [[sunfluidh:simulation_management_setup_namelist|click here]].
  
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 Keep in mind the time step must be chosen with caution because it can generate numerical instabilities when it is too much large. The numerical stability depends on the property of the numerical methods used for solving the conservation equations It often relies on the CFL criterion which have not to exceeded a reference value. This value depends on the numerical scheme properties as well as the computational problem. Keep in mind the time step must be chosen with caution because it can generate numerical instabilities when it is too much large. The numerical stability depends on the property of the numerical methods used for solving the conservation equations It often relies on the CFL criterion which have not to exceeded a reference value. This value depends on the numerical scheme properties as well as the computational problem.
    * For semi-implicit schemes proposed here, a maximum CFL-value about 0.5 is generally prescribed for usual computations, but it could be smaller for problems with strong gradients.    * For semi-implicit schemes proposed here, a maximum CFL-value about 0.5 is generally prescribed for usual computations, but it could be smaller for problems with strong gradients.
    * For explicit schemes, the CFL criterion also depends on the viscous/diffusive time scales as well as the space dimension of the problem. As a consequence, the CFL value prescribed is generally between $0.5^{n-1}$ and $0.5^n$, where n is the dimension of the problem.    * For explicit schemes, the CFL criterion also depends on the viscous/diffusive time scales as well as the space dimension of the problem. As a consequence, the CFL value prescribed is generally between $0.5^{n-1}$ and $0.5^n$, where n is the dimension of the problem.
 When the time-step value is constant, the user can verify if the CFL criterion is respected by checking regularly the file checkcalc_xxxxx.d When the time-step value is constant, the user can verify if the CFL criterion is respected by checking regularly the file checkcalc_xxxxx.d
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sunfluidh/new_numerical_methods_setup_namelist.txt · Dernière modification: 2018/05/29 15:06 de witko