This example makes use of the facility in order to print out integrated values of a user-defined Additional Variable that measures the residence time distribution in the flow domain. It uses the facilities to loop over all domains and all boundary condition patches, and it prints out the integrated residence time distribution on each of these locales. For details, see:
It also uses the facilities to look up the fluid name on each domain. Hence, it should work generically for any single phase problem. For details, see:
Before creating the domains, define the Additional Variable
representing Residence Time Distribution.
Create an Additional Variable called
RTDof Type Volumetric.Set Units of time
[s].
Create one or more single phase domains. On each domain, include the Additional Variable RTD.
Declare
RTDof Type Transport Equation.Set its kinematic diffusivity equal to zero.
On each domain, create a subdomain that encompass the entire domain.
On each such subdomain, for the Additional Variable RTD, set Option to
Source, and set the dimensionless source term identically equal to unity.
This ensure that the Additional Variable obeys the transport equation:
 | (19–5) |
Hence, integrated along stream lines RTD, measure the residence time of fluid particles along streamlines.
In CFX-Pre, you should create a User Routine with the following settings:
Routine Name:
User OutputOption: Junction
Box RoutineCalling Name:
user_outputLibrary Name:
user outputLibrary Path:
/home/user/Shared_LibrariesJunction Box Location:
End of Run
In order to ensure that the solver calls the declared Junction Box routine, you should:
Go to the Solver Control panel in CFX-Pre. For details, see Basic Settings Tab in the CFX-Pre User's Guide.
Select the Junction Box Routines box, and select the Junction Box User Output.
This routine looks up the number of domains, and loops over
them. On each domain, it computes and prints out the arithmetic average
and maximum values of the Residence Time Distribution. Additionally, on each domain, it looks up the number of boundary
condition patches, and loops over them. On each BCP, it also computes
and prints the arithmetic average Residence Time Distribution. Some of the comment lines are omitted. This routine user_output.F is supplied in the
<CFXROOT>/examples/UserFortran/ directory of your Ansys CFX installation.
#include "cfx5ext.h"
dllexport(user_output)
SUBROUTINE USER_OUTPUT (CZ, DZ, IZ, LZ, RZ)
C
C Routine called at end of run
C
C Preprocessor includes
#include "MMS.h"
#include "cfd_constants.h"
C
C Arguments
CHARACTER*(1) CZ(*)
DOUBLE PRECISION DZ(*)
INTEGER IZ(*)
LOGICAL LZ(*)
REAL RZ(*)
C
C External routines
CHARACTER*15 CFROMR
INTEGER LENACT
EXTERNAL CFROMR, LENACT
C
C Local parameters
CHARACTER*(*) ROUTIN
PARAMETER (ROUTIN = 'USER_OUTPUT')
C Local variables
CHARACTER*4 CRESLT
CHARACTER*(MXDNAM) CDIR_GLOB, CDIR_ZONE, CDIR_PHYS,
& CZONE, CBCP, CPHASE
CHARACTER*120 User_Domain_Name, User_BCP_Name,
& User_Phase_Name, User_Var_Name
INTEGER NZN,IZN, NBCP,IBCP
REAL VAR
C
C Executable statements
CALL MESAGE( 'WRITE', ' ')
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', 'Start USER_OUTPUT')
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', ' ')
C
C---- Obtain global meshdata
CDIR_GLOB = ' '
CALL USER_GET_MESH_INFO (ROUTIN,'GET','STOP','LATEST',
& ' ',' ',CDIR_GLOB,CRESLT, CZ,DZ,IZ,LZ,RZ)
C---- Look up number of domains, and loop over domains
CALL PEEKI ('/USER/'//CDIR_GLOB//'/NZN',IONE,NZN,
& 'STOP',CRESLT, IZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
DO IZN = 1, NZN
C
C---- CZONE = solver domain name
CALL PEEKCA ('/USER/'//CDIR_GLOB//'/CZONE',IZN,CZONE,
& 'STOP',CRESLT, CZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
C
C---- Convert to user domain name
CALL CONVERT_NAME_S2U ('Domain',CZONE,' ',User_Domain_Name,
& CRESLT, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
CALL MESAGE( 'WRITE', ' ')
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', 'Domain: '//User_Domain_Name)
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', ' ')
C
C---- Get physics info.
CDIR_PHYS = ' '
CALL USER_GET_PHYS_INFO (ROUTIN,'GET','STOP','LATEST',
& CZONE,' ',CDIR_PHYS,CRESLT, CZ,DZ,IZ,LZ,RZ)
C
C---- CPHASE = solver phase name (assumes single phase)
CALL PEEKCA ('/USER/'//CDIR_PHYS//'/CPHASE',IONE,CPHASE,
& 'STOP',CRESLT, CZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
C
C---- Convert to user phase name
CALL CONVERT_NAME_S2U ('Phase',CPHASE,' ',User_Phase_Name,
& CRESLT, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
C
C---- Set User Variable Name = User_Phase_Name.RTD
C---- (RTD = Residence Time Distribution).
User_Var_Name = User_Phase_Name(1:LENACT(User_Phase_Name))
& // '.RTD'
CALL MESAGE( 'WRITE', ' ')
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', 'Variable: '//User_Var_Name)
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', ' ')
C
C---- Obtain global values on domain
CALL USER_GET_GVAR (User_Var_Name, User_Domain_Name,
& 'ave', CRESLT, VAR, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
CALL MESAGE( 'WRITE', 'RDT Mean Value = '//CFROMR(VAR))
C
CALL USER_GET_GVAR (User_Var_Name,User_Domain_Name,
& 'maxVal', CRESLT, VAR, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
CALL MESAGE( 'WRITE', 'RDT Max Value = '//CFROMR(VAR))
C
C---- Obtain zonal meshdata
CDIR_ZONE = ' '
CALL USER_GET_MESH_INFO (ROUTIN,'GET','STOP','LATEST',
& CZONE,' ',CDIR_ZONE,CRESLT,
& CZ,DZ,IZ,LZ,RZ)
C
C---- Look up number of Boundary Condition Patches (BCP's),
C---- and loop over BCP's.
CALL PEEKI ('/USER/'//CDIR_ZONE//'/NBCP',IONE,NBCP,
& 'STOP',CRESLT, IZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
DO IBCP = 1, NBCP
C
C---- CBCP = solver BCP name
CALL PEEKCA ('/USER/'//CDIR_ZONE//'/CBCP',IBCP,CBCP,
& 'STOP',CRESLT, CZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
C
C---- Convert to user BCP name
CALL CONVERT_NAME_S2U ('Bcp',CBCP,' ',User_BCP_Name,
& CRESLT, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
CALL MESAGE( 'WRITE', ' ')
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', 'Boundary: '//User_BCP_Name)
CALL MESAGE( 'WRITE', '-----------------')
CALL MESAGE( 'WRITE', ' ')
C
C---- Obtain global values on BCP
CALL USER_GET_GVAR (User_Var_Name,User_BCP_Name,
& 'ave', CRESLT, VAR, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
CALL MESAGE( 'WRITE', 'RDT Mean Value = '//CFROMR(VAR))
C
CALL USER_GET_GVAR (User_Var_Name,User_BCP_Name,
& 'maxVal',CRESLT, VAR, CZ,DZ,IZ,LZ,RZ)
IF (CRESLT .NE. 'GOOD') GOTO 999
CALL MESAGE( 'WRITE', 'RDT Max Value = '//CFROMR(VAR))
C
C---- End Loop Over BCP's
END DO
C
C---- End Loop Over Zones
END DO
C
C---- Delete Mesh Data
CALL USER_GET_MESH_INFO (ROUTIN,'DELETE','STOP','LATEST',
& ' ',' ',CDIR_GLOB,CRESLT,
& CZ,DZ,IZ,LZ,RZ)
C
999 CONTINUE
IF (CRESLT .NE. 'GOOD') THEN
CALL MESAGE( 'WRITE', 'User abort, CRESLT = '//CRESLT)
CALL CFXSTP (ROUTIN)
ENDIF
C
END