/[MITgcm]/MITgcm/pkg/generic_advdiff/gad_dst3fl_impl_r.F
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Revision 1.1 - (show annotations) (download)
Sat Oct 22 20:17:44 2005 UTC (18 years, 6 months ago) by jmc
Branch: MAIN
CVS Tags: checkpoint57w_post
add code to solve implicitly vertical advection using
 DST2, 1rst.O.Upwind, DST3 or DST3_Flux-Limit advection schemes

1 C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_u3c4_impl_r.F,v 1.5 2005/06/22 00:27:47 jmc Exp $
2 C $Name: $
3
4 #include "GAD_OPTIONS.h"
5
6 CBOP
7 C !ROUTINE: GAD_DST3FL_IMPL_R
8 C !INTERFACE:
9 SUBROUTINE GAD_DST3FL_IMPL_R(
10 I bi,bj,k, iMin,iMax,jMin,jMax,
11 I deltaTarg, rTrans, tFld,
12 O a5d, b5d, c5d, d5d, e5d,
13 I myThid )
14
15 C !DESCRIPTION:
16
17 C Compute matrix element to solve vertical advection implicitly
18 C using 3rd order Direct Space and Time (DST) advection scheme
19 C with Flux-Limiter.
20 C Method:
21 C contribution of vertical transport at interface k is added
22 C to matrix lines k and k-1
23
24 C !USES:
25 IMPLICIT NONE
26
27 C == Global variables ===
28 #include "SIZE.h"
29 #include "GRID.h"
30 #include "EEPARAMS.h"
31 #include "PARAMS.h"
32 #include "GAD.h"
33
34 C !INPUT/OUTPUT PARAMETERS:
35 C == Routine Arguments ==
36 C bi,bj :: tile indices
37 C k :: vertical level
38 C iMin,iMax :: computation domain
39 C jMin,jMax :: computation domain
40 C deltaTarg :: time step
41 C rTrans :: vertical volume transport
42 C tFld :: tracer field
43 C a5d :: 2nd lower diag of pentadiagonal matrix
44 C b5d :: 1rst lower diag of pentadiagonal matrix
45 C c5d :: main diag of pentadiagonal matrix
46 C d5d :: 1rst upper diag of pentadiagonal matrix
47 C e5d :: 2nd upper diag of pentadiagonal matrix
48 C myThid :: thread number
49 INTEGER bi,bj,k
50 INTEGER iMin,iMax,jMin,jMax
51 _RL deltaTarg(Nr)
52 _RL rTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
53 _RL tFld (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
54 _RL a5d (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
55 _RL b5d (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
56 _RL c5d (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
57 _RL d5d (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
58 _RL e5d (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
59 INTEGER myThid
60
61 C == Local Variables ==
62 C i,j :: loop indices
63 C kp1 :: =min( k+1 , Nr )
64 C km2 :: =max( k-2 , 1 )
65 C wCFL :: Courant-Friedrich-Levy number
66 C lowFac :: low order term factor
67 C highFac :: high order term factor
68 C rCenter :: centered contribution
69 C rUpwind :: upwind contribution
70 C rC4km, rC4kp :: high order contributions
71 LOGICAL flagC4
72 INTEGER i,j,kp1,km2
73 _RL wCFL, rCenter, rUpwind
74 _RL lowFac (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
75 _RL highFac(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
76 _RL rC4km, rC4kp
77 _RL mskM, mskP, maskM2, maskP1
78 _RL Rj, Rjh, cL1, cH3, cM2, th1, th2
79 _RL deltaTcfl
80 CEOP
81
82 C-- process interior interface only:
83 IF ( k.GT.1 .AND. k.LE.Nr ) THEN
84
85 km2=MAX(1,k-2)
86 kp1=MIN(Nr,k+1)
87 maskP1 = 1. _d 0
88 maskM2 = 1. _d 0
89 IF ( k.LE.2 ) maskM2 = 0. _d 0
90 IF ( k.GE.Nr) maskP1 = 0. _d 0
91
92 C-- Compute the low-order term & high-order term fractions :
93 deltaTcfl = deltaTarg(k)
94 C DST-3 Flux-Limiter Advection Scheme:
95 C- Limiter: Psi=max(0,min(1,cL1+theta*cH1,theta*(1-cfl)/cfl) )
96 C with theta=Rjh/Rj ;
97 C is linearize arround the current value of theta(tFld) & cfl:
98 C lowFac & highFac are set such as Psi*Rj = lowFac*Rj + highFac*Rjh
99 DO j=jMin,jMax
100 DO i=iMin,iMax
101 wCFL = deltaTcfl*ABS(rTrans(i,j))
102 & *recip_rA(i,j,bi,bj)*recip_drC(k)
103 cL1 = (2. _d 0 -wCFL)*(1. _d 0 -wCFL)*oneSixth
104 cH3 = (1. _d 0 -wCFL*wCFL)*oneSixth
105 c cM2 = (1. _d 0 - wCFL)/( wCFL +1. _d -20)
106 cM2 = (1. _d 0 + wCFL)/( wCFL +1. _d -20)
107
108 Rj =(tFld(i,j,k) -tFld(i,j,k-1))
109 IF ( rTrans(i,j).GT.0. _d 0 ) THEN
110 Rjh = (tFld(i,j,k-1)-tFld(i,j,km2))*maskC(i,j,km2,bi,bj)
111 ELSE
112 Rjh = (tFld(i,j,kp1)-tFld(i,j,k) )*maskC(i,j,kp1,bi,bj)
113 ENDIF
114 IF ( Rj*Rjh.LE.0. _d 0 ) THEN
115 C- 1rst case: theta < 0 (Rj & Rjh opposite sign) => Psi = 0
116 lowFac(i,j) = 0. _d 0
117 highFac(i,j)= 0. _d 0
118 ELSE
119 Rj = ABS(Rj)
120 Rjh = ABS(Rjh)
121 th1 = cL1*Rj+cH3*Rjh
122 th2 = cM2*Rjh
123 IF ( th1.LE.th2 .AND. th1.LE.Rj ) THEN
124 C- 2nd case: cL1+theta*cH3 = min of the three = Psi
125 lowFac(i,j) = cL1
126 highFac(i,j)= cH3
127 ELSEIF ( th2.LT.th1 .AND. th2.LE.Rj ) THEN
128 C- 3rd case: theta*cM2 = min of the three = Psi
129 lowFac(i,j) = 0. _d 0
130 highFac(i,j)= cM2
131 ELSE
132 C- 4th case (Rj < th1 & Rj < th2) : 1 = min of the three = Psi
133 lowFac(i,j) = 1. _d 0
134 highFac(i,j)= 0. _d 0
135 ENDIF
136 ENDIF
137 ENDDO
138 ENDDO
139
140 C-- Add centered & upwind contributions
141 DO j=jMin,jMax
142 DO i=iMin,iMax
143 rCenter= 0.5 _d 0 *rTrans(i,j)*recip_rA(i,j,bi,bj)*rkSign
144 mskM = maskC(i,j,km2,bi,bj)*maskM2
145 mskP = maskC(i,j,kp1,bi,bj)*maskP1
146 rUpwind= (0.5 _d 0 -lowFac(i,j))*ABS(rCenter)*2. _d 0
147 rC4km = highFac(i,j)*(rCenter+ABS(rCenter))*mskM
148 rC4kp = highFac(i,j)*(rCenter-ABS(rCenter))*mskP
149
150 a5d(i,j,k) = a5d(i,j,k)
151 & + rC4km
152 & *deltaTarg(k)
153 & *recip_hFacC(i,j,k,bi,bj)*recip_drF(k)
154 b5d(i,j,k) = b5d(i,j,k)
155 & - ( (rCenter+rUpwind) + rC4km )
156 & *deltaTarg(k)
157 & *recip_hFacC(i,j,k,bi,bj)*recip_drF(k)
158 c5d(i,j,k) = c5d(i,j,k)
159 & - ( (rCenter-rUpwind) + rC4kp )
160 & *deltaTarg(k)
161 & *recip_hFacC(i,j,k,bi,bj)*recip_drF(k)
162 d5d(i,j,k) = d5d(i,j,k)
163 & + rC4kp
164 & *deltaTarg(k)
165 & *recip_hFacC(i,j,k,bi,bj)*recip_drF(k)
166 b5d(i,j,k-1) = b5d(i,j,k-1)
167 & - rC4km
168 & *deltaTarg(k-1)
169 & *recip_hFacC(i,j,k-1,bi,bj)*recip_drF(k-1)
170 c5d(i,j,k-1) = c5d(i,j,k-1)
171 & + ( (rCenter+rUpwind) + rC4km )
172 & *deltaTarg(k-1)
173 & *recip_hFacC(i,j,k-1,bi,bj)*recip_drF(k-1)
174 d5d(i,j,k-1) = d5d(i,j,k-1)
175 & + ( (rCenter-rUpwind) + rC4kp )
176 & *deltaTarg(k-1)
177 & *recip_hFacC(i,j,k-1,bi,bj)*recip_drF(k-1)
178 e5d(i,j,k-1) = e5d(i,j,k-1)
179 & - rC4kp
180 & *deltaTarg(k-1)
181 & *recip_hFacC(i,j,k-1,bi,bj)*recip_drF(k-1)
182 ENDDO
183 ENDDO
184
185 C-- process interior interface only: end
186 ENDIF
187
188 RETURN
189 END

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