37 |
INTEGER I, J, K |
INTEGER I, J, K |
38 |
real faceArea |
real faceArea |
39 |
_RL myNorm |
_RL myNorm |
40 |
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_RL aC, aCw, aCs |
41 |
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|
42 |
C-- Initialise laplace operator |
C-- Initialise laplace operator |
43 |
C aW2d: integral in Z Ax/dX |
C aW2d: integral in Z Ax/dX |
111 |
CcnhDebugEnds |
CcnhDebugEnds |
112 |
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|
113 |
C-- Initialise preconditioner |
C-- Initialise preconditioner |
114 |
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C Note. 20th May 1998 |
115 |
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C I made a weird discovery! In the model paper we argue |
116 |
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C for the form of the preconditioner used here ( see |
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C A Finite-volume, Incompressible Navier-Stokes Model |
118 |
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C ...., Marshall et. al ). The algebra gives a simple |
119 |
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C 0.5 factor for the averaging of ac and aCw to get a |
120 |
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C symmettric pre-conditioner. By using a factor of 0.51 |
121 |
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C i.e. scaling the off-diagonal terms in the |
122 |
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C preconditioner down slightly I managed to get the |
123 |
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C number of iterations for convergence in a test case to |
124 |
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C drop form 192 -> 134! Need to investigate this further! |
125 |
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C For now I have introduced a parameter cg2dpcOffDFac which |
126 |
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C defaults to 0.51 but can be set at runtime. |
127 |
DO bj=myByLo(myThid),myByHi(myThid) |
DO bj=myByLo(myThid),myByHi(myThid) |
128 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
DO bi=myBxLo(myThid),myBxHi(myThid) |
129 |
DO J=1,sNy |
DO J=1,sNy |
130 |
DO I=1,sNx |
DO I=1,sNx |
131 |
pC(I,J,bi,bj) = 1. _d 0 |
pC(I,J,bi,bj) = 1. _d 0 |
132 |
IF ( |
aC = -( |
133 |
& aW2d(I,J,bi,bj) + aW2d(I+1,J,bi,bj) |
& aW2d(I,J,bi,bj) + aW2d(I+1,J ,bi,bj) |
134 |
& +aS2d(I,J,bi,bj) + aS2D(I,J+1,bi,bj) |
& +aS2d(I,J,bi,bj) + aS2D(I ,J+1,bi,bj) |
135 |
& .EQ. 0. |
& ) |
136 |
& ) pC(I,J,bi,bj) = 0. _d 0 |
aCs = -( |
137 |
pW(I,J,bi,bj) = 0. |
& aW2d(I,J-1,bi,bj) + aW2d(I+1,J-1,bi,bj) |
138 |
pS(I,J,bi,bj) = 0. |
& +aS2d(I,J-1,bi,bj) + aS2d(I ,J ,bi,bj) |
139 |
|
& ) |
140 |
|
aCw = -( |
141 |
|
& aW2d(I-1,J,bi,bj) + aW2d(I ,J ,bi,bj) |
142 |
|
& +aS2d(I-1,J,bi,bj) + aS2d(I-1,J+1,bi,bj) |
143 |
|
& ) |
144 |
|
IF ( aC .EQ. 0. ) THEN |
145 |
|
pC(I,J,bi,bj) = 0. _d 0 |
146 |
|
ELSE |
147 |
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pC(I,J,bi,bj) = 1. _d 0 / aC |
148 |
|
ENDIF |
149 |
|
IF ( aC + aCw .EQ. 0. ) THEN |
150 |
|
pW(I,J,bi,bj) = 0. |
151 |
|
ELSE |
152 |
|
pW(I,J,bi,bj) = |
153 |
|
& -aW2d(I ,J ,bi,bj)/((cg2dpcOffDFac *(aCw+aC))**2 ) |
154 |
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ENDIF |
155 |
|
IF ( aC + aCs .EQ. 0. ) THEN |
156 |
|
pS(I,J,bi,bj) = 0. |
157 |
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ELSE |
158 |
|
pS(I,J,bi,bj) = |
159 |
|
& -aS2d(I ,J ,bi,bj)/((cg2dpcOffDFac *(aCs+aC))**2 ) |
160 |
|
ENDIF |
161 |
ENDDO |
ENDDO |
162 |
ENDDO |
ENDDO |
163 |
ENDDO |
ENDDO |
168 |
_EXCH_XY_R4(pS, myThid) |
_EXCH_XY_R4(pS, myThid) |
169 |
|
|
170 |
C-- Set default values for initial guess |
C-- Set default values for initial guess |
171 |
DO bj=myByLo(myThid),myByHi(myThid) |
IF ( startTime .EQ. 0 ) THEN |
172 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
DO bj=myByLo(myThid),myByHi(myThid) |
173 |
DO J=1,sNy |
DO bi=myBxLo(myThid),myBxHi(myThid) |
174 |
DO I=1,sNx |
DO J=1,sNy |
175 |
cg2d_x(I,J,bi,bj) = 0. _d 0 |
DO I=1,sNx |
176 |
|
cg2d_x(I,J,bi,bj) = 0. _d 0 |
177 |
|
ENDDO |
178 |
ENDDO |
ENDDO |
179 |
ENDDO |
ENDDO |
180 |
ENDDO |
ENDDO |
181 |
ENDDO |
C-- Update overlap regions |
182 |
C-- Update overlap regions |
_EXCH_XY_R8(cg2d_x, myThid) |
183 |
_EXCH_XY_R8(cg2d_x, myThid) |
ENDIF |
184 |
|
|
185 |
RETURN |
RETURN |
186 |
END |
END |