A new section named Ambient Settings is now available in the settings of the heat transfer interfaces, for the definition of ambient variables (temperature, relative humidity, absolute pressure, wind velocity, and solar irradiance). These variables are defined once and available as inputs from several features for all of the interfaces in the Heat Transfer Module.
By default, the ambient variables are User defined. With the Heat Transfer license, the ambient variables can also be defined from typical time-dependent meteorological data (Ashrae, 2013). Several settings for the choice of location (among 6000+ stations worldwide), the time, and the ambient conditions are available.
The ambient variables are available as inputs in several features. For example, in the Heat Flux feature, the ambient temperature, ambient absolute pressure, and wind velocity can be used in the correlations defining the heat transfer coefficient of external forced convection over a plate.
The Heat and Moisture Transport interface is found under the Heat Transfer branch in the model wizard. It adds the Heat Transfer in Building Materials interface, the Moisture Transport interface, and the
Heat and Moisture multiphysics node.
The Building Material model is the default domain feature of the
Heat Transfer in Building Materials interface. It is also available in any heat transfer interface when the
Heat transfer in porous media property is selected.
The Moisture Transport interface models moisture transfer. The default domain feature, Porous Medium, accounts for the moisture storage, capillary suction forces, and convective transport of vapor. Similarly to the
Building Material feature, it implements partial derivative equations derived from
EN 15026.
They have the Thin Film and
Fracture features as default boundary feature and have the same features available as the Heat Transfer in Thin Shells interface.
A new option, the General thin film model, is available in the
Thin Film feature. It provides a discretization of the temperature field through the film thickness. This new option defines an extra dimension to account for the temperature variations through the film thickness.
A new option, Sector of symmetry, is now available for 2D and 3D models in the
Symmetry for Surface-to-Surface Radiation feature. It supports an arbitrary number of sectors and provides an option to define a reflection plane in each sector.
The Opaque subfeature (used for surface-to-surface radiation) available in previous versions under a restricted list of domain features —
Solid (formerly
Heat Transfer in Solids),
Porous Medium (formerly
Heat Transfer in Porous Media), and
Biological Tissue — has been replaced by the
Opacity feature under all main domain features. This includes
Fluid (formerly
Heat Transfer in Fluids),
Phase Change Material (formerly
Heat Transfer with Phase Change),
Building Material, and
Isothermal Domain.
The opacity is set by selecting either Transparent or
Opaque in the settings of the feature.
The Gravity property is available in the Single Phase Flow interface. When selected, it adds the
Gravity feature to the application where it is possible to edit the
Acceleration of the gravity definition. The
Gravity feature defines a volume force due to the gravity in all the domains where the interface is active.
When the Incompressible flow option is selected, the incompressible version of the flow equation, assuming that the velocity field is divergence free, is used. With this option, the density is evaluated at the
Reference pressure level and at the
Reference temperature defined in the fluid flow interface, which guarantee that the density is correct in most cases. The dynamic viscosity is also evaluated at the reference temperature. In addition, when a
Non-Isothermal Flow multiphysics feature couples a heat transfer interface and a flow interface using the
Incompressible flow option, the thermal material properties are also evaluated at the reference temperature.
When the Weakly compressible flow option is selected, the compressible version of the flow equation is used. However, the density is evaluated at the
Reference pressure level defined in the fluid flow interface. The temperature dependency of the density is considered. This option is recommended in cases where the density has a very small dependency on the pressure, which does not significantly affect the results but may significantly increase the computational cost.
The Compressible flow (Ma<0.3) corresponds to the general formulation of the fluid flow equations. It does not assume any hypothesis on the density property.