/[MITgcm]/MITgcm/pkg/generic_advdiff/gad_os7mp_adv_r.F
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Revision 1.1 - (hide annotations) (download)
Sat Jan 20 21:20:11 2007 UTC (17 years, 3 months ago) by adcroft
Branch: MAIN
Added new advection scheme, OS7MP, which is seventh order and monotonicity preserving (note: not the same as monotonic!)
 o enabled with advScheme set to "7". (Who chose 77 for Superbee? Oh, that was me ...)
 o scheme requires a halo of 4
   - no error checking for this at the moment
 o scheme is coded for convenience rather than efficiency
   - can easily switch down order or select the TVD limiter by commenting lines
   - the y direction is coded with invert do i; do j loops (for now)

1 adcroft 1.1 C $Header: $
2     C $Name: $
3    
4     #include "GAD_OPTIONS.h"
5    
6     SUBROUTINE GAD_OS7MP_ADV_R(
7     I bi,bj,k,deltaTloc,
8     I wTrans, wFld,
9     I Q,
10     O wT,
11     I myThid )
12     C /==========================================================\
13     C | SUBROUTINE GAD_OS7MP_ADV_R |
14     C | o Compute Vertical advective Flux of tracer Q using |
15     C | 7th Order DST Sceheme with monotone preserving limiter |
16     C |==========================================================|
17     IMPLICIT NONE
18    
19     C == GLobal variables ==
20     #include "SIZE.h"
21     #include "GRID.h"
22     #include "GAD.h"
23    
24     C == Routine arguments ==
25     INTEGER bi,bj,k
26     _RL deltaTloc
27     _RL wTrans(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
28     _RL wFld (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
29     _RL Q (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
30     _RL wT (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
31     INTEGER myThid
32    
33     C == Local variables ==
34     INTEGER i,j,kp3,kp2,kp1,km1,km2,km3,km4
35     _RL cfl,Psi
36     _RL wLoc,Fac,Del,DelIp,DelI,Phi,Eps,rp1h,Msk
37     _RL Qippp,Qipp,Qip,Qi,Qim,Qimm,Qimmm
38     _RL MskIpp,MskIp,MskI,MskIm,MskImm,MskImmm
39     _RL d2,d2p1,d2m1,A,B,C,D
40     _RL dp1h,dm1h,qMD,qUL,qLC,PhiMD,PhiLC,PhiMin,PhiMax
41    
42     Eps = 1. _d -20
43    
44     km4=MAX(1,k-4)
45     km3=MAX(1,k-3)
46     km2=MAX(1,k-2)
47     km1=MAX(1,k-1)
48     kp1=MIN(Nr,k+1)
49     kp2=MIN(Nr,k+2)
50     kp3=MIN(Nr,k+3)
51    
52     DO j=1-Oly,sNy+Oly
53     DO i=1-Olx,sNx+Olx
54    
55     wLoc = wFld(i,j)
56     cfl = abs(wLoc*deltaTloc*recip_drC(k))
57    
58     IF (wLoc.lt.0.) THEN
59     Qippp = Q(i,j,kp2)
60     Qipp = Q(i,j,kp1)
61     Qip = Q(i,j,k)
62     Qi = Q(i,j,km1)
63     Qim = Q(i,j,km2)
64     Qimm = Q(i,j,km3)
65     Qimmm = Q(i,j,km4)
66    
67     MskIpp = maskC(i,j,kp2,bi,bj) * float(kp2-kp1)
68     MskIp = maskC(i,j,kp1,bi,bj) * float(kp1-k)
69     MskI = maskC(i,j,k,bi,bj) * float(k-km1)
70     MskIm = maskC(i,j,km1,bi,bj) * float(km1-km2)
71     MskImm = maskC(i,j,km2,bi,bj) * float(km2-km3)
72     MskImmm = maskC(i,j,km3,bi,bj) * float(km3-km4)
73     ELSEIF (wLoc.gt.0.) THEN
74     Qippp = Q(i,j,km3)
75     Qipp = Q(i,j,km2)
76     Qip = Q(i,j,km1)
77     Qi = Q(i,j,k)
78     Qim = Q(i,j,kp1)
79     Qimm = Q(i,j,kp2)
80     Qimmm = Q(i,j,kp3)
81    
82     MskIpp = maskC(i,j,km2,bi,bj) * float(km2-km3)
83     MskIp = maskC(i,j,km1,bi,bj) * float(km1-km2)
84     MskI = maskC(i,j,k,bi,bj) * float(k-km1)
85     MskIm = maskC(i,j,kp1,bi,bj) * float(kp1-k)
86     MskImm = maskC(i,j,kp2,bi,bj) * float(kp2-kp1)
87     MskImmm = maskC(i,j,kp3,bi,bj) * float(kp3-kp2)
88     ENDIF
89    
90     IF (wLoc.ne.0.) THEN
91     Phi = 0.
92     C 2nd order correction [i i-1]
93     Fac = 1.
94     Del = Qip-Qi
95     Msk = MskI
96     Phi = Msk * Fac * Del
97     C 3rd order correction [i i-1 i-2]
98     Fac = Fac * ( cfl + 1. )/3.
99     Del = Del - ( Qi-Qim )
100     Msk = Msk * MskIm
101     Phi = Phi - Msk * Fac * Del
102     C 4th order correction [i+1 i i-1 i-2]
103     Fac = Fac * ( cfl - 2. )/4.
104     Del = ( Qipp-2.*Qip+Qi ) - Del
105     Msk = Msk * MskIp
106     Phi = Phi + Msk * Fac * Del
107     C 5th order correction [i+1 i i-1 i-2 i-3]
108     Fac = Fac * ( cfl - 3. )/5.
109     Del = Del - ( Qip-3.*Qi+3.*Qim-Qimm )
110     Msk = Msk * MskImm
111     Phi = Phi + Msk * Fac * Del
112     C 6th order correction [i+2 i+1 i i-1 i-2 i-3]
113     Fac = Fac * ( cfl + 2. )/6.
114     Del = ( Qippp-4.*Qipp+6.*Qip-4.*Qi+Qim ) - Del
115     Msk = Msk * MskIpp
116     Phi = Phi + Msk * Fac * Del
117     C 7th order correction [i+2 i+1 i i-1 i-2 i-3 i-4]
118     Fac = Fac * ( cfl + 2. )/7.
119     Del = Del - ( Qipp-5.*Qip+10.*Qi-10.*Qim+5.*Qimm-Qimmm )
120     Msk = Msk * MskImmm
121     Phi = Phi - Msk * Fac * Del
122    
123     DelIp = ( Qip - Qi ) * MskI
124     Phi = sign(1.,Phi)*sign(1.,DelIp)*abs(Phi+Eps)/abs(DelIp+Eps)
125    
126     DelI = ( Qi - Qim ) * MskIm
127     rp1h =sign(1.,DelI)*sign(1.,DelIp)*abs(DelI+Eps)/abs(DelIp+Eps)
128    
129     C TVD limiter
130     ! Phi = max(0., min( 2./(1-cfl), Phi, 2.*rp1h/cfl ) )
131    
132     C MP limiter
133     d2 = ( ( Qip + Qim ) - 2.*Qi ) * MskI * MskIm
134     d2p1 = ( ( Qipp + Qi ) - 2.*Qip ) * MskIp * MskI
135     d2m1 = ( ( Qi + Qimm ) - 2.*Qim ) * MskIm * MskImm
136     A = 4.*d2 - d2p1
137     B = 4.*d2p1 - d2
138     C = d2
139     D = d2p1;
140     dp1h = max(min(A,B,C,D),0.)+min(max(A,B,C,D),0.)
141     A = 4.*d2m1 - d2
142     B = 4.*d2 - d2m1
143     C = d2m1
144     D = d2;
145     dm1h = max(min(A,B,C,D),0.)+min(max(A,B,C,D),0.)
146     qMD = 0.5*( ( Qi + Qip ) - dp1h )
147     qUL = Qi + (1.-cfl)/cfl*( Qi-Qim )
148     qLC = Qi + 0.5*( 1.+dm1h/(Qi-Qim+Eps) )*(qUL-Qi)
149     PhiMD = 2./(1.-cfl)*(qMD-Qi+Eps)/(Qip-Qi+Eps)
150     PhiLC = 2.*rp1h/cfl*(qLC-Qi+Eps)/(qUL-Qi+Eps)
151     PhiMin = max(min(0.,PhiMD),min(0.,2.*rp1h/cfl,PhiLC))
152     PhiMax = min(max(2./(1.-cfl),PhiMD),max(0.,2.*rp1h/cfl,PhiLC))
153     Phi = max(PhiMin,min(Phi,PhiMax))
154    
155     Psi = Phi * 0.5 * (1. - cfl)
156     wT(i,j) = wTrans(i,j)*( Qi + Psi*DelIp )
157     ELSE
158     wT(i,j) = 0.
159     ENDIF
160    
161     ENDDO
162     ENDDO
163    
164     RETURN
165     END

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