The Building Materials Version of the Heat and Moisture Transport Multiphysics Interface
When the Building Materials version of the predefined Heat and Moisture Transport interface () is added (found under the Heat Transfer branch () of the Model Wizard or Add Physics windows), it combines the Heat Transfer in Building Materials and the Moisture Transport in Building Materials interfaces to model coupled heat and moisture transport in building materials, by taking into account heat and moisture storage, latent heat effects, and liquid and diffusive transport of moisture.
Stationary, time-domain, and frequency-domain modeling are supported in all space dimensions.
On the Constituent Physics Interfaces
As a predefined multiphysics coupling, Heat Transfer in Building Materials and Moisture Transport in Building Materials interfaces are added to the Model Builder. In addition, a Multiphysics node is added, which automatically includes the Heat and Moisture multiphysics coupling feature.
The Heat Transfer in Building Materials interface provides features for modeling heat transfer by conduction, convection, and radiation. The Building Material model, active by default in all domains, provides in addition the functionality for moisture content dependency of thermodynamics properties and latent heat effects.
The Moisture Transport in Building Materials interface provides features for modeling moisture transfer by liquid transport (capillary flow) and vapor diffusion. A Building Material model is active by default on all domains.
As an Add-on Multiphysics Coupling
The Heat and Moisture multiphysics coupling is also available when there is at least one of each of the following interfaces with the specified model activated:
•
Any version of the Heat Transfer interface, with Building Material model
•
Any version of the Moisture Transport interface, with Building Material model
See Building Material Library in the COMSOL Multiphysics Reference Manual for a description of materials containing the thermal and hygroscopic properties to be used with the Building Materials version of the Heat and Moisture Transport multiphysics interface.
Settings for the Physics Interfaces and Coupling Features
When physics interfaces are added using the predefined couplings, specific settings are included with the physics interfaces and the coupling feature.
Table 8-10: Modified Settings for the Building Materials Version of the Heat and Moisture Transport interface
Physics or Coupling Interface
Modified Settings (if Any)
Heat Transfer in Building Materials
In the Model Input section of the Building Material default feature, the Relative humidity, , is automatically set to the variable from the Heat and Moisture multiphysics coupling feature.
Moisture Transport in Building Materials
In the Model Input section of the Building Material default feature, the Temperature, T, is automatically set to the variable from the Heat and Moisture multiphysics coupling feature.
Heat and Moisture
The Heat Transfer and Moisture Transport interfaces are preselected.
Note that these settings may be overridden if another predefined coupling is added.