Changes between Version 253 and Version 254 of doc/app/initialization_parameters

Timestamp:

Mar 5, 2015 5:28:56 PM (10 years ago)

Author:

suehring

Comment:

--

doc/app/initialization_parameters

@@ -1080 +1080 @@
 The user can choose between the following schemes:\\\\
 '' 'ws-scheme' ''\\\\
-      The 5th order upwind scheme of Wicker and Skamarock (2002, Mon. Wea. Rev, 130, 2088-2097) is used. The dispersion error is     much smaller than the dispersion error of '' 'pw-scheme' ''. The 5th order scheme implies a small numerical dissipation that stabilizes the solution. To assure a stable numerical solution the time integration has to be carried out with [#timestep_scheme timestep_scheme] = '' 'runge-kutta-3' '' . This scheme is based on a formulation of the advection term in flux form, which requires a vanishing divergence of the flow field, else a stable numerical solution is not given. So [#call_psolver_at_all_substeps call_psolver_at_all_substeps] = '' .T. '' has to be used. 
+      The 5th order upwind scheme of Wicker and Skamarock (2002, Mon. Wea. Rev, 130, 2088-2097) is used. The dispersion error is much smaller than the dispersion error of '' 'pw-scheme' ''. The 5th order scheme implies a small numerical dissipation that stabilizes the solution. To assure a stable numerical solution the time integration has to be carried out with [#timestep_scheme timestep_scheme] = '' 'runge-kutta-3' '' . This scheme is based on a formulation of the advection term in flux form, which requires a vanishing divergence of the flow field, else a stable numerical solution is not given. So [#call_psolver_at_all_substeps call_psolver_at_all_substeps] = '' .T. '' has to be used. 
 '''Note''': Due to the larger stencil of this scheme vertical grid stretching should be handled with care.
 The computation of turbulent fluxes takes place inside the advection routines to get a statistical evaluation consistent to the numerical solution. 
 
 '''Important''': The number of ghost layers for 2d and 3d arrays changed. This affects also the user interface. Please adapt the allocation of 2d and 3d arrays in your user interface like [../userint/output#Allocate here]. Furthermore the exchange of ghost layers for 3d variables changed, so calls of exchange_horiz in the user interface have to be modified. Here an example for the potential temperature: CALL exchange_horiz( pt , nbgp ). \\\\
+'' 'ws-scheme-mono' ''\\\\
+      Monotone scheme combining the 5th order upwind scheme of Wicker and Skamarock with 1st order upwind scheme using a monotonic limiter. Please note that this monotone scheme can are very diffusive. Even though this scheme prevents non-physical numerical oscillations at large gradients, the numerical dispersion might be very large, particularly at large gradients. Moreover, it should be noted that in contrast to 'ws-scheme', the computation of turbulent fluxes '''does not''' take place inside the advection routines, resulting in possible kinks in the near-surface profiles of vertical fluxes.\\\\
 '' 'pw-scheme' ''\\\\
       The scheme of Piacsek and Williams (1970, J. Comp. Phys., 6, 392-405) with central differences in the form C3 is used.\\\\