<simulation>

For thermal simulations, the <simulation> category contains additional parameters describing thermal method, thermal wall model, initialization of temperature field, setup of gravity, surface mesh and the fluid material.

<simulation>- <general>

The <general> category contains the parameters for specifying thermal model used in the simulation. Currently, ultraFluidX supports the following options for thermal model:

<thermal_method>: With the thermal method option, you can either disable the thermal solver or enable thermal solver using either a Boussinesq model or passive scalar transport.; <thermal_method> (off / passive_scalar_transport / Boussinesq); Default: off; off: No thermal simulation will be performed.; passive_scalar_transport: Unidirectional coupling from velocity to temperature field: this method does not consider buoyancy forces.; Boussinesq: Bidirectional coupling between temperature and velocity field on basis of buoyancy forces due to heating. This method allows you to describe natural convection.
<gravity>: Specifies the gravity as a vector via the child parameters.; <x_dir>; <y_dir>; <z-dir>; If <thermal_method> is set to Boussinesq, the default value for the gravity vector is (0, 0, -9.816).; If <thermal_method> is set to off or passive_scalar_transport the gravity vector is not considered.

<simulation>- <material>

For thermal simulations, the <material>category contains the following parameters:

<temperature>: Temperature [in K] at which material properties are estimated. This temperature is used to initialize flow field unless you specify a file or fallback temperature in the <initialization> section. Temperature value is also used as inlet/outlet/wall temperature if you do not specify a temperature when using temperature boundary condition.
<thermal_conductivity>: Thermal conductivity of the fluid material. Default value is set to 0.025 W/m-K.
<thermal_expansion>: Thermal expansion coefficient. Default is 0.00341 1/K.
<density>: Density of the material at specified temperature in .
<dynamic_viscosity>: Specifies dynamic viscosity of the material at specified temperature.
<specific_heat_capacity>: Allows you to specify the specific heat capacity of the fluid material. The default value is set to 1006.0 J/kg-K.
<specific_heat_ratio>: Allows you to set the specific heat ratio of the material. The default value is set to 1.4.
<specific_gas_constant>: Allows you to set the specific gas constant of the material. The default value is set to 287.058 J/kg-K.

<simulation> <thermal_wall_modeling>

This section enables the thermal wall model in a thermal simulation. If <thermal_method> is set to either Boussinesq or passive_scalar_transport, <thermal_wall_model> is activated by default.

<thermal_wall_modeling>: <wall_model> (TLW, off); default: TLW; TLW refers to thermal law of the wall, a function that describes the near wall temperature slope.
<coupling> adaptive_two-way: The thermal adaptive_two-way wall model imposes the appropriate near wall slope of the temperature as well as the right wall eddy diffusivity based on different information collected in the wall vicinity and the chosen thermal law of the wall.