Changes between Version 177 and Version 178 of doc/app/initialization_parameters

Timestamp:

Aug 21, 2012 11:35:42 AM (12 years ago)

Author:

fricke

Comment:

--

doc/app/initialization_parameters

@@ -876 +876 @@
 |----------------
 {{{#!td style="vertical-align:top"
+[=#pt_damping_factor '''pt_damping_factor''']
+}}}
+{{{#!td style="vertical-align:top"
+R
+}}}
+{{{#!td style="vertical-align:top"
+0.0
+}}}
+{{{#!td
+Factor for damping the potential temperature.\\\\
+In case of non-cyclic lateral boundary conditions (see [#bc_lr bc_lr] or [#bc_ns bc_ns]), a damping is applied to the potential temperature if a non-zero value is assigned to '''pt_damping_factor'''.
+If switched on, temperature is forced towards the value of their respective basic state (defined by the initial profile of the temperature).
+The intensity of damping is controlled by the value '''pt_damping_factor'''. The damping starts weakly at a distance from the inflow boundary
+defined by [#pt_damping_width pt_damping_width] and rises according to a sin^2^-function to its maximum value at the inflow.\\\\
+
+This method effectively damps gravity waves at the inflow boundary in case of non-cyclic lateral boundary conditions (see [#bc_lr bc_lr] or [#bc_ns bc_ns]).
+If the damping factor is too low, gravity waves can develop within the damping domain and if the damping factor is too high, gravity waves can develop in front of the damping domain. 
+}}}
+|----------------
+{{{#!td style="vertical-align:top"
+[=#pt_damping_width '''pt_damping_width''']
+}}}
+{{{#!td style="vertical-align:top"
+R
+}}}
+{{{#!td style="vertical-align:top"
+0.0
+}}}
+{{{#!td
+Width of the damping domain of the potential temperature (in m).\\\\
+In case of non-cyclic lateral boundary conditions (see [#bc_lr bc_lr] or [#bc_ns bc_ns]), this parameter determines the range where damping of the potential temperature is applied. The damping domain starts at the inflow boundary and ranges to the value of '''pt_damping_width'''. The intensity of the damping is applied by [#pt_damping_factor pt_damping_factor].
+}}}
+|----------------
+{{{#!td style="vertical-align:top"
 [=#pt_reference '''pt_reference''']
 }}}
@@ -1144 +1178 @@
 Boundary condition along x (for all quantities).\\\\
 By default, a cyclic boundary condition is used along x.\\\\
-'''bc_lr''' may also be assigned the values '' 'dirichlet/radiation' '' (inflow from left, outflow to the right) or '' 'radiation/dirichlet' '' (inflow from right, outflow to the left). This requires the multi-grid method to be used for solving the Poisson equation for perturbation pressure (see [#psolver psolver]) and it also requires cyclic boundary conditions along y (see [#bc_ns bc_ns]).\\\\
-In case of these non-cyclic lateral boundaries, a Dirichlet condition is used at the inflow for all quantities (initial vertical profiles - see [#initializing_actions initializing_actions] - are fixed during the run) except u, to which a Neumann (zero gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero gradient) condition is used for the scalars. For perturbation pressure Neumann (zero gradient) conditions are assumed both at the inflow and at the outflow.\\\\
+'''bc_lr''' may also be assigned the values '' 'dirichlet/radiation' '' or '' 'dirichlet/neumann' '' (inflow from left, outflow to the right) or '' 'radiation/dirichlet' '' or '' 'radiation/neumann' '' (inflow from right, outflow to the left). This requires the multi-grid method to be used for solving the Poisson equation for perturbation pressure (see [#psolver psolver]) and it also requires cyclic boundary conditions along y (see [#bc_ns bc_ns]).\\\\
+In case of these non-cyclic lateral boundaries, a Dirichlet condition is used at the inflow for all quantities (initial vertical profiles - see [#initializing_actions initializing_actions] - are fixed during the run) except e, to which a Neumann (zero gradient) condition is applied. At the outflow, a radiation condition (in case of '' radiation '') or a Neumann (zero gradient) condition (in case of '' neumann '') is used for all velocity components, while a Neumann (zero gradient) condition is used for the scalars in both cases. For perturbation pressure Neumann (zero gradient) conditions are assumed both at the inflow and at the outflow.\\\\
 In order to maintain a turbulent state of the flow, it may be neccessary to continuously impose perturbations on the horizontal velocity field in the vicinity of the inflow throughout the whole run. This can be switched on using [../d3par#create_disturbances create_disturbances]. The horizontal range to which these perturbations are applied is controlled by the parameters [#inflow_disturbance_begin inflow_disturbance_begin] and [#inflow_disturbance_end inflow_disturbance_end]. The vertical range and the perturbation amplitude are given by [../d3par#disturbance_level_b disturbance_level_b], [../d3par#disturbance_level_t disturbance_level_t], and [../d3par#disturbance_amplitude disturbance_amplitude]. The time interval at which perturbations are to be imposed is set by [../d3par#dt_disturb dt_disturb].\\\\
 In case of non-cyclic horizontal boundaries [#call_psolver_at_all_substeps call_psolver_at_all_substeps] = ''.T.'' should be used.\\\\
@@ -1164 +1198 @@
 Boundary condition along y (for all quantities).\\\\
 By default, a cyclic boundary condition is used along y.\\\\
-'''bc_ns''' may also be assigned the values '' 'dirichlet/radiation' '' (inflow from rear ("north"), outflow to the front ("south")) or '' 'radiation/dirichlet' '' (inflow from front ("south"), outflow to the rear ("north")). This requires the multi-grid method to be used for solving the Poisson equation for perturbation pressure (see [#psolver psolver]) and it also requires cyclic boundary conditions along x (see
+'''bc_ns''' may also be assigned the values '' 'dirichlet/radiation' '' or '' 'dirichlet/neumann' '' (inflow from rear ("north"), outflow to the front ("south")) or '' 'radiation/dirichlet' '' or '' 'neumann/dirichlet' '' (inflow from front ("south"), outflow to the rear ("north")). This requires the multi-grid method to be used for solving the Poisson equation for perturbation pressure (see [#psolver psolver]) and it also requires cyclic boundary conditions along x (see
 [#bc_lr bc_lr]).\\\\
-In case of these non-cyclic lateral boundaries, a Dirichlet condition is used at the inflow for all quantities (initial vertical profiles - see [#initializing_actions initializing_actions] - are fixed during the run) except u, to which a Neumann (zero gradient) condition is applied. At the outflow, a radiation condition is used for all velocity components, while a Neumann (zero gradient) condition is used for the scalars. For perturbation pressure Neumann (zero gradient) conditions are assumed both at the inflow and at the outflow.\\\\
+In case of these non-cyclic lateral boundaries, a Dirichlet condition is used at the inflow for all quantities (initial vertical profiles - see [#initializing_actions initializing_actions] - are fixed during the run) except e, to which a Neumann (zero gradient) condition is applied. At the outflow, a radiation condition (in case of '' radiation '') or a Neumann (zero gradient) condition (in case of '' neumann '') is used for all velocity components, while a Neumann (zero gradient) condition is used for the scalars in both cases. For perturbation pressure Neumann (zero gradient) conditions are assumed both at the inflow and at the outflow.\\\\
 For further details regarding non-cyclic lateral boundary conditions see [#bc_lr bc_lr].
 }}}