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Table des matières
Examples of data set related to the namelist "Fluid_Properties".
The user finds here some examples illustrating different configurations related to the namelist "Fluid_Properties". The data initialized by default, and not explicitly required, are generally not present for a sake of clarity.
Data values are showed for equations used in dimensional form.
Usual incompressible Flows
Here, the physical properties are constant.
One fluid is considered.
Isotherm flows
&Fluid_Properties Reference_Dynamic_Viscosity = 1.84D-05 , Reference_Density = 1.2058789 /
Example of isothermal and axisymmetrical flows
&Fluid_Properties Axisymmetric_Case_3D_Enabled= .true. , Reference_Dynamic_Viscosity = 1.84D-05 , Reference_Density = 1.20 /
Flows with Boussinesq's hypothesis
Here Heat transfer are considered.
The physical properties are constant.
The buoyancy effect are related to the temperature variation.
&Fluid_Properties Heat_Transfer_Flow = .true. , Reference_Dynamic_Viscosity = 1.84D-05 , Prandtl = 0.71 , Reference_Temperature = 300.0 , Reference_Density = 1.20 , Thermal_Expansion_Coefficient= 0.033 Reference_Heat_Capacity = 1004.50 /
Don not forget also to define the gravity constant in the namelist "Gravity". Thermal_Expansion_Coefficient= 0.0 involves that it is automatically calculated as the inverse of the “Reference_Temperature”.
The “Reference_Heat_Capacity” is only useful when the simulation must explicitly take into account the heat flux (i.e. a heat flux boundary condition or heat exchange between the fluid and a thermal conductive material). In these cases, the equation of enthalpy is globally considered and not its simplified version that leads to the equation of temperature.
Incompressible two phase flows
No heat transfer.
The physical properties of each fluid are constant.
&Fluid_Properties Incomp_MultiFluids= .true. , Reference_Dynamic_Viscosity = 1.84D-05 , Reference_Dynamic_Viscosity_2 = 1.00D-03 , Reference_Density = 1.2 , Reference_Density_2 = 1000. , Interface_Thickness_Scale = 1.e-2 /
Low Mach-number Flows
The fluid is a perfect gas.
Example of flow with heat transfer
One species only (or homogenous species gas).
The viscosity and the thermal conductivity depend on the Sutherland's law.
When the buoyancy/gravity force is considered, it is directly related to the density variation.
&Fluid_Properties Variable_Density = .true. , Heat_Transfer_Flow = .true. , Reference_Dynamic_Viscosity = 1.84D-05 , Reference_Temperature = 300.0 , Reference_Density = 1.20 , Prandtl = 0.71 , Heat_Capacity_Ratio = 1.4 , Molecular_Mass = 2.9D-02 , Reference_Heat_Capacity = 1004.50 , Sutherland_Law_Enabled = .true. /
In the dimensionless form, the specific gas constant is generally equal to unity and the heat capacity is $C_p= \frac{\gamma}{\gamma -1}$. The reference value of the molecular mass must be set to the constant of perfect gas $R$.
If gravity/buoyancy effects must be considered, they are directly bounded to the density variation. The variable “Thermal_Heat_Expansion” can be omitted and the gravity source term can be defined in the namelist "Gravity".
Multi-species flows
Heat transfer is activated.
Multi-species component gas .
Physical properties depend on the gas components.
When the buoyancy/gravity force is considered, it is directly related to the density variation.
&Fluid_Properties Variable_Density = .true. , Heat_Transfer_Flow = .true. , MultiSpecies_Flow = .true. , Reference_Dynamic_Viscosity = 1.84D-05 , Reference_Temperature = 300.0 , Reference_Density = 1.20 , Prandtl = 0.71 , Heat_Capacity_Ratio = 1.4 , Molecular_Mass = 2.9D-02 , Reference_Heat_Capacity = 1004.50 , Sutherland_Law_Enabled = .true. Multi_Species_Mixture_Law_for_Viscosity_Enabled = .true. , Multi_Species_Mixture_Law_for_Thermal_Conductivity_Enabled= .true. , Multi_Species_Mixture_Law_for_Mass_Diffusion_Enabled = .true. , Soret_Effect_Enabled = .false. //
In this example, the physical properties are not constant depend on the gas mixture and the temperature. They are calculated in each cell for each time step by means of formulations coming from the kinetic theory of gas.
The gas properties bounded to each species are provided by the namelist "Species_Properties".
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