| 1 | SUBROUTINE timestep_scheme_steering |
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| 2 | |
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| 3 | !------------------------------------------------------------------------------! |
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| 4 | ! Current revisions: |
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| 5 | ! ----------------- |
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| 6 | ! |
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| 7 | ! |
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| 8 | ! Former revisions: |
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| 9 | ! ----------------- |
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| 10 | ! $Id: timestep_scheme_steering.f90 484 2010-02-05 07:36:54Z raasch $ |
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| 11 | ! RCS Log replace by Id keyword, revision history cleaned up |
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| 12 | ! |
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| 13 | ! Revision 1.2 2005/03/26 21:17:06 raasch |
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| 14 | ! No pressure term for Runge-Kutta-schemes (tsc(4)=0.0) |
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| 15 | ! |
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| 16 | ! Revision 1.1 2004/01/28 15:34:47 raasch |
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| 17 | ! Initial revision |
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| 18 | ! |
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| 19 | ! |
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| 20 | ! Description: |
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| 21 | ! ------------ |
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| 22 | ! Depending on the timestep scheme set the steering factors for the prognostic |
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| 23 | ! equations. |
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| 24 | !------------------------------------------------------------------------------! |
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| 25 | |
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| 26 | USE control_parameters |
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| 27 | |
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| 28 | IMPLICIT NONE |
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| 29 | |
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| 30 | |
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| 31 | IF ( timestep_scheme(1:5) == 'runge' ) THEN |
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| 32 | ! |
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| 33 | !-- Runge-Kutta schemes (here the factors depend on the respective |
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| 34 | !-- intermediate step) |
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| 35 | IF ( timestep_scheme == 'runge-kutta-2' ) THEN |
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| 36 | IF ( intermediate_timestep_count == 1 ) THEN |
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| 37 | tsc(1:5) = (/ 1.0, 1.0, 0.0, 0.0, 0.0 /) |
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| 38 | ELSE |
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| 39 | tsc(1:5) = (/ 1.0, 0.5, -0.5, 0.0, 1.0 /) |
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| 40 | ENDIF |
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| 41 | ELSE |
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| 42 | IF ( intermediate_timestep_count == 1 ) THEN |
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| 43 | tsc(1:5) = (/ 1.0, 1.0/3.0, 0.0, 0.0, 0.0 /) |
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| 44 | ELSEIF ( intermediate_timestep_count == 2 ) THEN |
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| 45 | tsc(1:5) = (/ 1.0, 15.0/16.0, -25.0/48.0, 0.0, 0.0 /) |
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| 46 | ELSE |
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| 47 | tsc(1:5) = (/ 1.0, 8.0/15.0, 1.0/15.0, 0.0, 1.0 /) |
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| 48 | ENDIF |
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| 49 | ENDIF |
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| 50 | |
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| 51 | ELSE |
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| 52 | |
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| 53 | IF ( .NOT. dt_fixed ) THEN |
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| 54 | ! |
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| 55 | !-- Leapfrog and Euler schemes |
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| 56 | !-- Determine whether after the time step adjustment the Euler- or the |
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| 57 | !-- leapfrog scheme will be applied. The very first time step must always |
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| 58 | !-- be an Euler step. |
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| 59 | IF ( dt_changed ) THEN |
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| 60 | IF ( timestep_scheme == 'leapfrog+euler' .OR. & |
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| 61 | timestep_scheme == 'euler' .OR. simulated_time == 0.0 ) THEN |
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| 62 | tsc(1:5) = (/ 1.0, 1.0, 0.0, 1.0, 1.0 /) |
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| 63 | ELSE |
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| 64 | tsc(1:5) = (/ 0.0, 2.0, 0.0, 1.0, 2.0 /) |
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| 65 | ENDIF |
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| 66 | ELSE |
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| 67 | ! |
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| 68 | !-- No time step change, hence continue with the scheme set by the |
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| 69 | !-- user. |
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| 70 | IF ( timestep_scheme == 'euler' ) THEN |
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| 71 | tsc(1:5) = (/ 1.0, 1.0, 0.0, 1.0, 1.0 /) |
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| 72 | ELSE |
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| 73 | tsc(1:5) = (/ 0.0, 2.0, 0.0, 1.0, 2.0 /) |
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| 74 | ENDIF |
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| 75 | ENDIF |
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| 76 | |
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| 77 | ELSE |
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| 78 | |
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| 79 | ! |
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| 80 | !-- Fixed time step: |
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| 81 | ! |
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| 82 | !-- In any case, the very first time step must always be an Euler step. |
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| 83 | timestep_reason = 'F' |
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| 84 | IF ( simulated_time == 0.0 ) THEN |
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| 85 | dt_changed = .TRUE. |
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| 86 | tsc(1:5) = (/ 1.0, 1.0, 0.0, 1.0, 1.0 /) |
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| 87 | ELSE |
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| 88 | dt_changed = .FALSE. |
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| 89 | IF ( timestep_scheme == 'euler' ) THEN |
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| 90 | tsc(1:5) = (/ 1.0, 1.0, 0.0, 1.0, 1.0 /) |
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| 91 | ELSE |
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| 92 | tsc(1:5) = (/ 0.0, 2.0, 0.0, 1.0, 2.0 /) |
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| 93 | ENDIF |
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| 94 | ENDIF |
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| 95 | |
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| 96 | ENDIF |
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| 97 | |
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| 98 | ENDIF |
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| 99 | |
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| 100 | |
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| 101 | END SUBROUTINE timestep_scheme_steering |
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