Q. How does one implement the Herschel-Bulkley dynamic viscosity model in CFX 11.0?
A. The RULES file for CFX 11.0 allows the use of these models, but CFX-PRE does not recognize them. So the input must be included in a CCL file and the case run from the Command line in the Solver manager.
One exports the original CCL file from a DEF file and replaces the DYNAMIC VISCOSITY section with something like this:
DYNAMIC VISCOSITY:
Option = Herschel Bulkley
Power Law Index = 1.0
Minimum Shear Strain Rate = 1.E-7 [s^-1]
Maximum Shear Strain Rate = 1.E-3 [s^-1]
Viscosity Consistency = 0.4 [kg m^-1 s^-1]
Yield Stress = 1.0 [Pa]
END
If the existing DEF file had viscosity defined, it must be removed, as reading in the above CCL will not get rid of it. An error message will occur.
In CFX-PRE go to the material of interest and replace the value of viscosity with a blank value and then uncheck thebox for viscosity.
Then in the SOLVER manager, execute on the command line, using your own file names,
cfx5solve -def mydefile.def -ccl mynewcclfile.ccl
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Q. How does one implement the Herschel-Bulkley dynamic viscosity model in CFX 11.0? A. The RULES file for CFX 11.0 allows the use of these models, but CFX-PRE does not recognize them. So the input must be included in a CCL file and the case run from the Command line in the Solver manager. One exports the original CCL file from a DEF file and replaces the DYNAMIC VISCOSITY section with something like this: DYNAMIC VISCOSITY: Option = Herschel Bulkley Power Law Index = 1.0 Minimum Shear Strain Rate = 1.E-7 [s^-1] Maximum Shear Strain Rate = 1.E-3 [s^-1] Viscosity Consistency = 0.4 [kg m^-1 s^-1] Yield Stress = 1.0 [Pa] END If the existing DEF file had viscosity defined, it must be removed, as reading in the above CCL will not get rid of it. An error message will occur. In CFX-PRE go to the material of interest and replace the value of viscosity with a blank value and then uncheck thebox for viscosity. Then in the SOLVER manager, execute on the command line, using your own file names, cfx5solve -def mydefile.def -ccl mynewcclfile.ccl |
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