Changeset 3084 for palm/trunk/SOURCE/timestep.f90

Timestamp:

Jun 19, 2018 3:30:55 PM (6 years ago)

Author:

gronemeier

Message:

bugfix: limit increase of dt_3d only in case of RANS mode

File:

• palm/trunk/SOURCE/timestep.f90 (modified) (3 diffs)

palm/trunk/SOURCE/timestep.f90

@@ -25 +25 @@
 ! -----------------
 ! $Id$
+! limit increase of dt_3d only in case of RANS mode
+! 
+! 3083 2018-06-19 14:03:12Z gronemeier
 ! limit dt_3d to be at maximum 2*old_dt; define old_dt at beginning of routine
 ! Add km/kh_max
@@ -128 +131 @@
     USE control_parameters,                                                    &
         ONLY:  cfl_factor, coupling_mode, dt_3d, dt_fixed, dt_max,             &
-               galilei_transformation, old_dt, message_string,                 &
+               galilei_transformation, old_dt, message_string, rans_mode,      &
                stop_dt, terminate_coupled, terminate_coupled_remote,           &
                timestep_reason, u_gtrans, use_ug_for_galilei_tr, v_gtrans
@@ -328 +331 @@
 !--    The time step is the minimum of the 3-4 components and the diffusion time
 !--    step minus a reduction (cfl_factor) to be on the safe side.
-!--    The time step must not exceed the maximum allowed value and must not
-!--    increase by more than a factor of 10.
+!--    The time step must not exceed the maximum allowed value.
        dt_3d = cfl_factor * MIN( dt_diff, dt_u, dt_v, dt_w, dt_precipitation )
-       dt_3d = MIN( dt_3d, dt_max, 2.0_wp * old_dt )
+       dt_3d = MIN( dt_3d, dt_max )
+!
+!--    In RANS mode, the time step must not increase by more than a factor of 2
+       IF ( rans_mode )  dt_3d = MIN( dt_3d, dt_max, 2.0_wp * old_dt )
 
 !