A Unified Workflow
The Heat Transfer Module is unique to the world of modeling as it is a dedicated tool for simulating thermal effects in your manufacturing processes and product designs. COMSOL takes a unified approach to both the model set-up and operation of your simulations for heat transfer and all other physical phenomena involved in your applications. You are thereby empowered with a standard tool for communicating with other engineers and engineering departments looking at alternate phenomena to yours. Irrespective of which physics you or your colleagues are working on within a particular application, your workflow is uniform and straightforward, and occurs as follows:
- Import or draw the device or system geometry in question
- Select material data or relations from the same files using constant or temperature-dependent properties
- Decide the best description of the heat transfer of your system from a range of tailor-made interfaces that may or may not depend on other physics coupled to your system
- Include any other physical effects that are coupled with the effects of heat transfer
- Define conditions and constraints on your system’s boundaries
- Mesh your system, then use the same or derived meshes between different simulations
- Run the solving process, with an appropriate solver and settings for the analysis being performed
- Process and visualize your results, and present these on the same graphs and figures even if from different simulations
Unified Platform for Simulating Thermal Effects on Manufacturing Processes and Product Designs
Together with COMSOL Multiphysics and the wealth of add-on modules, COMSOL provides you with a unified tool for all facets of your processes and designs, regardless of the physical phenomena you are studying. You can be modeling the joule heating of your system’s devices one day, the cooling of them by passing air through your system the next, and the thermal stresses your devices incur because of it the day after that. Or model all effects at once.
Heat transfer is an important physical effect that is mostly taken into consideration with other physical effects. Temperature fields lead to thermal stresses, while electromagnetic fields create resistive, induction, microwave, and RF heating. Fluid flow over different components and parts is essential for cooling them, while temperature variations have a very large impact on the material properties and their physical behavior when being thermally processed, such as casting or welding. The Heat Transfer Module includes a number of user interfaces for easy modeling of heat transfer coupled with other phenomena, and can be integrated into any of the other modules in the COMSOL® Product Suite.
The Mechanisms of Heat Transfer
Fundamental to the Heat Transfer Module is the ability to perform computations relating to the conservation of heat, or energy balances, where a variety of phenomena such as mechanical losses, latent heats, joule heating, or heat of reaction are available. The Heat Transfer Module provides ready-made interfaces, known as physics interfaces, that are configured to receive model inputs via the graphical user interface (GUI), and to use these inputs to formulate your energy balances. As with all physics interfaces within the software from the COMSOL Product Suite, you can manipulate the underlying equations to provide flexibility for modifying the transfer mechanisms, defining specific heat sources, or coupling to other physics.
The Heat Transfer Module helps you investigate the effects of heating and cooling in devices, components, or processes. The software furnishes you with simulation tools to study the mechanisms of heat transfer – conduction, convection, and radiation – often in collaboration with other physics, such as structural mechanics, fluid dynamics, electromagnetics, and chemical reactions. In this context, the Heat Transfer Module acts as a platform for all possible industries and applications where the creation, consumption, or transfer of heat or energy is the focus of or contributes significantly to the studied process.
Support for modeling radiation is provided for a number of scenarios in the Heat Transfer Module, which includes specialized solvers to model the phenomenon and couple it with convection and conduction. The Heat Transfer Module provides tools for modeling surface-to-ambient radiation, ambient-to-surface radiation, and surface-to-surface radiation in transparent, opaque, and participating media.
The module uses the radiosity method to model surface-to-surface radiation, and accounts for surface-properties dependent on the wavelength where you can simultaneously consider up to five spectral bands in the same model. This is appropriate for modeling sun radiation, where the surface absorptivity for short wavelengths (solar spectral band) may differ from the surface emissivity for the longer wavelengths (ambient spectral band). In addition, transparency properties can be defined for each spectral band. The Heat Transfer Module also models radiative heat transfer in participating media, which accounts for the absorption, emission, and scattering of heat radiation in such media.
The presence of fluids in your systems invariably introduces convection to your heat transfer applications and energy contributions, through pressure work and viscous effects. The Heat Transfer Module easily supports these processes and accounts for both forced and free or natural convection. It includes a specific physics interface for conjugate heat transfer, where solid and fluid materials are modeled in one and the same system. To account for fluid flow, the Heat Transfer Module contains physics interfaces to model laminar flow and turbulent flow through using high-Reynolds and low-Reynolds k-ε turbulent models. In all flow cases, natural buoyancy effects occurring due to differences in temperature are respected by assuming nonisothermal flow. Integrating your heat transfer models with the CFD Module allows for further simulations of the fluid flow, including alternate turbulence models, porous media flow, and two-phase flow.
Additionally, the Heat Transfer Module provides features for simplifying modeling of convection, where fully modeling the fluid dynamics does not provide extra accuracy or is computationally prohibitive. The features are available through a built-in library of heat transfer coefficients, and can be used to simulate the transfer of heat between the surroundings of your systems and your boundaries through either forced or natural convection. The module also contains relations for different types of geometric configurations, like chimneys or plates (vertical, inclined, or horizontal), and different external fluids (air, water, and oil).