OSBC.DAT

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For each border or river declared in OSB.DAT, OSBC.DAT describe how to treat them.

For each border it give for each variables the boundary condition indentifier ( IBC ), the number of parameters for this boundary condition and those parameters, (and filename of data if needed by the boundary condition).

Some boundaries can have 2 condition : one passive and one active. The (optionnal) passive one is used to condition the application of the active one (for example OS*501.F is used to apply the active conditions through a relaxation time)

all files os*###.f are different boudary conditions options, such as zero grdient, constant values, values from files, etc.. the first number (*) is for the variable

0 -> scalar
1 -> Normal speed
2 -> tangential speed
3 -> mean Normal speed
4 -> mean  tangential speed

the other three is for the specific conditions..

001 -> constant value
002 -> ancient value
003 -> nul gradient
008 -> constant value for specified layer and zero gradients elsewhere
078 -> value from file
 etc...




example of osbc.DAT

'DANUBE' 'T' 'ACTIVE'
3                         --> going to call os0003.f (impose nul gradients)
0                         --> there is no parameters  
'*'                       --> BCF is '*', meaning there is no file 
'DANUBE' 'S' 'ACTIVE'
8                         --> going to call os0008.f (impose constant value (BC(3)) between layer BC(1) and BC(2)
3                         --> there is 3 parameters  
22                        --> BC (1) is 22  
31                        --> BC (2) is 31 
0                         --> BC (3) is 0 
'*'                       --> BCF is '*', meaning there is no file 
'DANUBE' 'E' 'ACTIVE'
3 
0                           etc...
'*'
'DANUBE' 'VN' 'ACTIVE'
1008
2
22
31
'*'
'DANUBE' 'VT' 'ACTIVE'
2001
1
0
'*'
'DANUBE' 'VNM' 'ACTIVE'
3078  
3
-1297000
2592000
1
'/u/acapet/riverdata/danube_1992.RIV'
'DANUBE' 'VNM' 'PASSIVE'
3501
1
1000000
'*'
'DANUBE' 'VTM' 'ACTIVE'
4001
1
0
'*'

Contents

Some specific conditions

Scalars

active

  • os0001 -> IMPOSE CONSTANT VALUE
  • os0002 -> IMPOSE ANCIENT VALUE
  • os0003 -> IMPOSE ZERO NORMAL GRADIENT
  • os0004 -> zero normal gradient for outflow, old value for inflow
  • os0008 -> IMPOSE CONSTANT VALUE WHERE INPUT (between Kinf and Ksub), IMPOSE ZERO NORMAL GRADIENT FOR THE REST TO INSURE NO FLUX
  • os0052 -> IMPOSE INITIAL VALUE
  • os0069 -> COMPUTES CONSTANT VALUE (between Kinf and Ksub) TO BE GIVEN TO open boundary condition os0096 IMPOSE ZERO NORMAL GRADIENT TO INSURE NO FLUX
  • os0096 -> IMPOSE IMPOSED INCREASE OF THE SCALAR PROVIDED BY os0069.f WHERE INPUT (between Kinf and Ksub) IMPOSE ZERO NORMAL GRADIENT TO INSURE NO FLUX
  • os0077 -> IMPOSE VERTICAL PROFILE IN TIME
  • os0078 -> IMPOSE A GIVEN FLUX READ FROM A FILE and Interpolate in time
  • os0088 -> PERIODICITY

passive

  • os0501 -> " Memory" : Time relaxation . The bigger the parameter,the slower is the application of the ACTIVE part. This passive B.C. allows thus an easy implementation of parts like dY/dt = -(Y -YB)/T
  • os0502 -> TWO-DIMENSIONAL ADVECTION :
  • os0503 -> TWO-DIMENSIONAL ORLANSKI
  • os0512 -> TWO-DIMENSIONAL ADVECTION FOR OUTFLOW ONLY (one-dimensional for base and top) FOR INFLOW THE ACTIVE PART IS RETAINED
  • os0513 -> ONE-DIMENSIONAL ADVECTION FOR OUTFLOW ONLY FOR INFLOW THE ACTIVE PART IS RETAINED
  • os0552 -> WHEIGHT INITIAL VALUE WITH ACTIVE B.C.
  • os0999 -> the user-defined parameter : this b.c. calls the function OSUSER for each mesh of the boundary.

Mean Normal velocity

compute the total flux.

active

  • OS3001 -> IMPOSE CONSTANT VALUE ON VNM2D
  • OS3001 -> IMPOSE ANCIENT VALUED
  • OS3003 -> zero normal gradient
  • OS3004 -> zero normal gradient for outflow, old value for inflow, filtering of outflow values by y <- y * (1-BC(1))+ (y+ + y-)/2*BC(1)
  • OS3005 -> IMPOSE GEOSTROPHIC EQUILIBRIUM ON VNM2D
  • OS3006 -> IMPOSE GEOSTROPHIC EQUILIBRIUM ON VNM2 WITH A GIVEN FLUX
  • OS3007 -> IMPOSE CONSTANT MEAN VELOCITY WITH A GIVEN FLUX
  • OS30010 -> IMPOSE TIDE DZETA= BC(1)*SIN( BC(2)*T-BC(3) )
  • OS3011 -> Impose barotropic flux for given sea surface elevation

passive

  • OS3501 -> "Memory"

Normal velocity

compute the vertical repartition of the total flux given by VNM condition

active

  • os1001 -> IMPOSE CONSTANT VALUE ON VN
  • os1002 -> IMPOSE ANCIENT VALUE
  • os1003 -> zero normal gradient
  • os1004 -> IMPOSE zero gradient on baroclinic transport
  • os1008 -> IMPOSE CONSTANT VALUE ON VN between Kinf and Ksup, zero values outside WARNING: The constant value is computed from the current transport value at the boundary. The boundary condition on the mean normal velocity must thus impose the flux
  • os1009 -> same as 1008 but the current decrease linearly from Ksup to Kinf. The boundary condition on the mean normal velocity must thus impose the flux
  • os1052 -> IMPOSE INITIAL VALUE
  • os1088 -> PERIODICITY

passive

  • os1501 -> (PASSIVE) memory = time relaxation
  • os1503 -> TWO-DIMENSIONAL ORLANSKI
  • os1552 -> WHEIGHT INITIAL VALUE WITH ACTIVE B.C.
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