Changeset 3083 for palm/trunk/SOURCE/timestep.f90

Timestamp:

Jun 19, 2018 2:03:12 PM (6 years ago)

Author:

gronemeier

Message:

merge with branch rans

Location:

palm/trunk

Files:

• . (modified) (1 prop)
• SOURCE (modified) (1 prop)
• SOURCE/timestep.f90 (modified) (8 diffs)

palm/trunk/SOURCE/timestep.f90

@@ -25 +25 @@
 ! -----------------
 ! $Id$
+! limit dt_3d to be at maximum 2*old_dt; define old_dt at beginning of routine
+! Add km/kh_max
+! 
+! 3049 2018-05-29 13:52:36Z Giersch
 ! Error messages revised
 ! 
@@ -161 +165 @@
     INTEGER(iwp) ::  j !< 
     INTEGER(iwp) ::  k !< 
+    INTEGER(iwp) ::  km_max_ijk(3) = -1  !< index values (i,j,k) of location where km_max occurs
+    INTEGER(iwp) ::  kh_max_ijk(3) = -1  !< index values (i,j,k) of location where kh_max occurs
 
     LOGICAL ::  stop_dt_local !< local switch for controlling the time stepping
@@ -173 +179 @@
     REAL(wp) ::  dt_w              !< 
     REAL(wp) ::  dt_w_l            !< 
+    REAL(wp) ::  km_max            !< maximum of Km in entire domain
+    REAL(wp) ::  kh_max            !< maximum of Kh in entire domain
     REAL(wp) ::  u_gtrans_l        !< 
     REAL(wp) ::  u_max_l           !< 
@@ -190 +198 @@
 
 
-
     CALL cpu_log( log_point(12), 'calculate_timestep', 'start' )
+!
+!--    Save former time step as reference
+       old_dt = dt_3d
 
 !
@@ -318 +328 @@
 !--    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.
+!--    The time step must not exceed the maximum allowed value and must not
+!--    increase by more than a factor of 10.
        dt_3d = cfl_factor * MIN( dt_diff, dt_u, dt_v, dt_w, dt_precipitation )
-       dt_3d = MIN( dt_3d, dt_max )
+       dt_3d = MIN( dt_3d, dt_max, 2.0_wp * old_dt )
 
 !
@@ -334 +345 @@
        IF ( dt_3d < ( 0.00001_wp * dt_max ) )  THEN
           stop_dt = .TRUE.
+
+!
+!--       Determine the maxima of the diffusion coefficients, including their
+!--       grid index positions.
+          CALL global_min_max( nzb, nzt+1, nysg, nyng, nxlg, nxrg, km, 'abs',  &
+                               0.0_wp, km_max, km_max_ijk )
+          CALL global_min_max( nzb, nzt+1, nysg, nyng, nxlg, nxrg, kh, 'abs',  &
+                               0.0_wp, kh_max, kh_max_ijk )
 
           WRITE( message_string, * ) 'Time step has reached minimum limit.',   &
@@ -342 +361 @@
                '&dt_w            = ', dt_w, ' s',                              &
                '&dt_diff         = ', dt_diff, ' s',                           &
-               '&u_max           = ', u_max, ' m/s   k=', u_max_ijk(1),        &
+               '&u_max           = ', u_max, ' m/s    k=', u_max_ijk(1),       &
                '  j=', u_max_ijk(2), '  i=', u_max_ijk(3),                     &
-               '&v_max           = ', v_max, ' m/s   k=', v_max_ijk(1),        &
+               '&v_max           = ', v_max, ' m/s    k=', v_max_ijk(1),       &
                '  j=', v_max_ijk(2), '  i=', v_max_ijk(3),                     &
-               '&w_max           = ', w_max, ' m/s   k=', w_max_ijk(1),        &
-               '  j=', w_max_ijk(2), '  i=', w_max_ijk(3)
+               '&w_max           = ', w_max, ' m/s    k=', w_max_ijk(1),       &
+               '  j=', w_max_ijk(2), '  i=', w_max_ijk(3),                     &
+               '&km_max          = ', km_max, ' m2/s2  k=', km_max_ijk(1),     &
+               '  j=', km_max_ijk(2), '  i=', km_max_ijk(3),                   &
+               '&kh_max          = ', kh_max, ' m2/s2  k=', kh_max_ijk(1),     &
+                '  j=', kh_max_ijk(2), '  i=', kh_max_ijk(3)
           CALL message( 'timestep', 'PA0312', 0, 1, 0, 6, 0 )
 !
@@ -388 +411 @@
        dt_3d = NINT( dt_3d * 100.0_wp / div ) * div / 100.0_wp
 
-!
-!--    Adjust the time step
-       old_dt = dt_3d
-
     ENDIF