MFP: Additional viscosity model #158
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temperature and concentration dependency of viscosity as presented in Chierici (1994)
FEM/rf_mfp_new.cpp
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| if (viscosity_model == 10) // my(C,T), | ||
| { | ||
| in >> C_0; | ||
| in >> viscosity_T_shift; |
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This is not need. Temperature is changed to Kevin one during the computation.
There is a keyword in pcs: $TEMPERATURE_UNIT for input data.
The default temperature unit for input is Celsius.
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Thanks for the comment. I will adapt this
Do I understand correctly that internally the temperature is always considered in Kelvin?
I rebased this changes from a quite old version of ogs5 we used for a project and think we received temperature values in celsius then as input for this function
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You are right that the internal internally the temperature is always considered in Kelvin. The Celsius can be used for input and output (see PR. #115). By default, the temperature unit for input and output is Celsius.
If you have to read a temperature value, e.g a reference temperature, for a material model, you can do like the following
in >> T_0;
T_0 += TemperatureUnitOffset();
(see https://github.com/ufz/ogs5/blob/master/FEM/rf_mfp_new.cpp#L363-L364)
In your case, the input of in >> viscosity_T_shift is unnecessary.
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Thanks for referencing the PR. We hadn't noticed that change. I will adapt the changes accordingly
FEM/rf_mfp_new.cpp
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| if (!T_Process) | ||
| primary_variable[1] = T_0 + viscosity_T_shift; | ||
| else | ||
| primary_variable[1] += | ||
| viscosity_T_shift; // JM if viscosity_T_shift==273 (user | ||
| // defined), Celsius can be used within | ||
| // this model |
FEM/rf_mfp_new.h
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| @@ -228,6 +228,7 @@ class CFluidProperties | |||
| double viscosity; | |||
| double viscosity0; | |||
| double viscosity_T_star; | |||
| double viscosity_T_shift; // for viscosity model =10 | |||
|
looks ok, except for the part of temperature shifting as Wenqing commented. |
Add viscosity model with dependency on temperature and concentration as presented in
Chierici (1994)