This Heat Transfer Module User’s Guide gets you started with modeling heat transfer using COMSOL Multiphysics. The information in this guide is specific to this module. Instructions on how to use COMSOL in general are included with the COMSOL Multiphysics Reference Manual.

The Modeling with the Heat Transfer Module chapter includes the following topics:

The Theory for the Heat Transfer Module chapter includes the theory related to the heat transfer and moisture transport interfaces and multiphysics interfaces, and also to some nodes.

After the establishment of the heat balance equation from the energy conservation laws in Foundations of the General Heat Transfer Equation, the various versions of the heat equation solved in COMSOL Multiphysics are presented in the following sections:

Then the theory related to multiphysics interfaces is described in the section Theory for the Heat Transfer Multiphysics Couplings.

Finally, topics related to specific features or variables are treated in the sections Theory for Thermal Contact, Moist Air Fluid Type, Out-of-Plane Heat Transfer, The Heat Transfer Coefficients, Equivalent Thermal Conductivity Correlations, Temperature Dependence of Surface Tension, Heat Flux and Heat Balance, and Frames for the Heat Transfer Equations.

The chapter The Heat Transfer Module Interfaces describes the main Heat Transfer interface (ht) that forms the backbone for all the fundamental interfaces in this module, and the other interfaces (Heat Transfer in Shells (htlsh), Radiation in Participating Media (rpm), Radiation in Absorbing-Scattering Media (rasm), Radiative Beam in Absorbing Media (rbam), Surface-to-Surface Radiation (rad), and Moisture Transport (mt)).

The sections The Heat Transfer in Solids Interface, The Heat Transfer in Fluids Interface, and The Heat Transfer in Solids and Fluids Interface discuss modeling heat transfer in solids and fluids.

The section The Heat Transfer in Porous Media Interface discusses modeling heat transfer in porous media.

The particular case of heat transfer in moist air and building materials is considered in the sections The Heat Transfer in Moist Air Interface and The Heat Transfer in Building Materials Interface.

The section The Bioheat Transfer Interface discusses modeling heat transfer within biological tissue using the Bioheat Transfer interface.

The sections The Heat Transfer in Shells Interface, The Heat Transfer in Films Interface, and The Heat Transfer in Fractures Interface describe the physics interfaces which are suitable for solving thermal conduction, convection, and radiation problems in layered materials defined on boundaries.

The section The Lumped Thermal System Interface describes the modeling of heat transfer in a system using a thermal network representation.

The sections The Surface-to-Surface Radiation Interface, The Radiation in Participating Media Interface, The Radiation in Absorbing-Scattering Media Interface, and The Radiative Beam in Absorbing Media Interface discuss the modeling of radiative heat transfer in transparent and participating media.

Finally, the sections The Moisture Transport in Building Materials Interface and The Moisture Transport in Air Interface describe the modeling of moisture transfer in a porous medium through moisture storage, vapor diffusion and capillary moisture flows; or in air, through convection and diffusion.

The chapter The Heat Transfer Features describes the Domain Features, Boundary Features, Edge Features, Point Features, and Global Features available with the Heat Transfer interfaces.

The Moisture Transport Features chapter describes the Domain Features and Boundary Features available with the Moisture Transport interface.

The Multiphysics Interfaces chapter describes the predefined multiphysics interfaces.

The chapter The Nonisothermal Flow and Conjugate Heat Transfer Interfaces describes the multiphysics versions of both the Nonisothermal Flow Laminar Flow and Turbulent Flow interfaces found under the Fluid Flow branch, which are identical to the Conjugate Heat Transfer interfaces. Each section describes the applicable physics interfaces in detail and concludes with the underlying theory.

The section The Heat Transfer with Surface-to-Surface Radiation Interface describes the predefined multiphysics interface used to model heat transfer by conduction, convection, and radiation in a transparent media.

The sectio nThe Heat Transfer with Radiation in Participating Media Interface describes the predefined multiphysics interface used to model heat transfer by conduction, convection, and radiation in semi-transparent media. The radiative intensity equations are approximated by the Discrete Ordinates Method or the P1 Approximation. When no emission should be considered, see the section The Heat Transfer with Radiation in Absorbing-Scattering Media Interface.

The section The Heat Transfer with Radiative Beam in Absorbing Media Interface describes the predefined multiphysics interface used to model heat transfer by conduction, convection, and radiation in semi-transparent media. The Beer-Lambert law is used for the approximation of the radiative intensity.

The section The Thermoelectric Effect Interface describes the predefined multiphysics interface used to model the Peltier-Seebeck-Thomson effect.

The section The Local Thermal Nonequilibrium Interface describes the predefined multiphysics interface used to model heat transfer in porous media when there is no thermal equilibrium between porous and fluid phases.

The section The Heat and Moisture Transport Interfaces describes the predefined multiphysics interfaces used to model coupled heat and moisture transport either in building materials, by taking into account heat and moisture storage, latent heat effects, and liquid and convective transport of moisture; or in moist air by convection and diffusion of moisture and heat.

The section The Moisture Flow Interfaces describes the predefined multiphysics interfaces used to model moisture transport in air by laminar and turbulent flows.

The section The Heat and Moisture Flow Interfaces describes the predefined multiphysics interfaces used to model heat transfer and moisture transport in air by laminar and turbulent flows.

The Multiphysics Couplings chapter describes the Domain Multiphysics Couplings and the Boundary Multiphysics Couplings available with the predefined multiphysics interfaces.