Theseus-FE Module
: Heat Transfer Analysis
3D Heat Transfer Simulation & Thermal Analysis Software
Heat Conduction
multi-layered composite shell elements
solid elements
connectivity elements and thermal contact definitions
temperature-dependent material properties
anisotropic heat conduction
internal heat generation
phase-changes
Thermal Convection
simple and advanced analytic models for convective heat transfer
air zones with degrees of freedom for bulk temperature and humidity
user-defined mass & volume transfer
ventilation objects to model HVAC systems
coupling to external fluid dynamics solver possible
coupling to various fluid network solvers via coupling software TISC
Thermal Radiation
models for solar radiation and all sorts of other sources of light and thermal radiation
material properties depending on wavelength and angle of incidence
intra-model surface-to-surface radiation
considers absorption, reflection and transmission as well as refraction
diffuse and specular reflection
tool for generating representative solar and cloudiness environmental data for any place and time on earth
Software for Heat Transfer Analysis
The thermal solver at the core of THESEUS‑FE can look back on a successful history of over 30 years. This makes THESEUS‑FE one of the oldest and most mature CAE tools in the field of numerical thermal simulations.
At the center of our software portfolio THESEUS‑FE is the tool chain for thermal analysis simulations suitable for solving a wide range of heat transfer problems. The tools include
a highly efficient numerical solver
a powerful and intuitive graphical user interface (GUI)
the Coupler module to quickly and robustly set up complex coupled simulations with external tools
the Transformer utility to convert results of THESEUS‑FE to various other formats as well as preparing field results from other sources as boundary conditions in a THESEUS‑FE case
THESEUS‑FE is always a first-choice candidate whenever the transient thermal development of a component has to be analyzed. The application range of THESEUS‑FE encompasses but is not limited to:
simple cases, e.g. heating of individual components for performing virtual thermal endurance studies
advanced cases including the heat exchange with human thermal models
highly complex simulations fully coupled with external fluid dynamics simulations
Overview of Thermal Analysis features
Core numerical thermal solver
Formulas related to the finite element method used in THESEUS‑FE
THESEUS‑FE offers a steady-state and transient solver based on the Finite Element Method (FEM) for solving heat transfer problems. Different types of thermal boundary conditions can be applied such as:
heat exchange by convection at surfaces
thermal radiation between surfaces and external solar loads
direct spatial contact of surface areas
various types of heat sources and sinks
coupling of component part temperatures to adjacent air
Most boundary conditions can be time-dependent or temperature-dependent. For full flexibility the user can import element-wise values from result files.
The numerical solver itself allows for
fixed and adaptive time stepping for efficient solution progress
restarting a simulation based on previous results
a wide range of expert solver options for fine-tuning of result precision and convergence behaviour
Thermal manikin FIALA-FE
FIALA-FE, a virtual human thermal model based on latest research results in the area of thermophysiology, is included as well. Its purpose is the simulation of the temperature distribution of the human body on the surface as well as internally. Life-like simulations can be performed taking into account aspects as blood flow, respiration, evaporation, metabolic responses, sweating, shivering, cardiac output and local heat exchange between the manikin and its environment. The thermal manikin FIALA-FE is fully integrated in our solver THESEUS‑FE. It is a powerful tool providing both local and global thermal comfort indices. FIALA-FE is commonly used for determining optimal settings for automotive HVAC systems while maintaining passenger comfort. For electric vehicles an additional objective is maximizing vehicle range by reducing the HVAC energy consumption.
Thermal analysis results on car driver
Graphical User Interface
The easy-to-learn and clearly structured graphics user interface (GUI) of THESEUS‑FE is a highly valuable tool for reducing model building time. To further minimize model setup time, a vast material database including thermal properties of the most common materials is readily available. Default clothing datasets for typical summer and winter clothing settings are available as well. All simulation results are written to a single output file in the publicly documented HDF format which is perfectly suitable for storing numerical results. These simulation results can be visualized within the GUI at any time during and after the simulation. Various ways of displaying and interpreting results are possible, ranging from simple 2d plots to fully-featured 3d views. Results from THESEUS‑FE can be exported or mapped to various formats for use in third-party CAE simulation software and post-processing tools.
Heat Transfer simulation model opened in THESEUS‑FE GUI
Simulate Thermal Conduction
Simulation of heat transfer by conduction is done within THESEUS‑FE using established Finite Element approaches. The thermal conduction solver offers all features necessary for modelling highly complex cases of thermal conduction:
multi-layered composite shell elements with 1D and 3D conduction representing sheet-like parts with uniform thickness
solid elements for modelling massive volumes
connectivity elements, e.g. bars and DOF coupling constraints
temperature-dependent and time-dependent thermal material properties
phase changes are possible
internal heat generation within shell and solid elements
vacuum and air layers within composite shells
anisotropic heat conduction, e.g. for representing fibre-reinforced materials
various techniques for modelling direct contact between different parts, including tied contact and conductive contact
Results from heat transfer simulation on brake disc
Simulate Convective Heat Transfer
Thermal convection can be modelled using various means within THESEUS‑FE. For prescribing convective heat transfer, analytical models are available as well as direct user-input to apply heat transfer coefficients, fluid velocities or temperature value for each element individually. Special entities called 'Ventilation', 'Volumes' and 'Airzones' can be used to model ventilation systems and regions of air flow such as vehicle cabins.
For modelling heat transfer by convection, the following features are at hand:
general gas regions with temperature-dependent properties
special air regions offering bulk temperature and humidity as additional degrees of freedom
advanced convection laws for forced and free convection, analytically modelling laminar and turbulent flow
user-defined mass/volume transfer between regions of air, e.g. to model exhaust gas systems
automatic detection of small, nearly encapsulated regions to simplify the process of assigning suitable convection boundary conditions to all surfaces
Coupled simulation with CFD results and thermal results of car cabin
Simulate Radiative Heat Transfer
THESEUS‑FE comprises many different mathematical models for representing energy exchange by thermal radiation. The overall spectrum of thermal radiation is separated into two bands, the so-called short-wave and long-wave radiation ranges.
Short-Wave Radiation
The short-wave range includes all wavelengths below the ultraviolet spectrum, the entire spectrum of visible light and higher-frequency parts of the infrared spectrum. This is the typical domain of energy sources dominated by radiative energy exchange, including solar energy, domestic light sources and infrared radiators. This kind of radiation exchange usually takes place in a highly directional manner. Within the radiation solver, material parameters and interaction effects such as specular and diffuse reflection, transmission and absorption can be treated in a physically correct manner as a function of wavelength. Major effects covered by the short-wave radiation solver include:
diffuse and specular reflection
opaque and transmitting materials
transmittance depending on the angle of incidence
refraction in transparent materials, e.g. to model optical lenses in automotive headlights
wave-length dependent material properties for absorption, transmission and reflection
various specialized sources of radiative energy, e.g. to model the sun, point-sources or generally radiating surfaces
Solar radiation simulation results on airplane
Long-wave radiation
The long-wave range is used to model intra-model thermal radiation energy exchange based on the current part temperature. Depending on the temperature, this type of thermal radiation can reach into the visible spectrum but is usually maximal in the non-visible, deep infrared range. The intra-model radiative exchange is modelled in a highly efficient manner using view factors calculated between all the surfaces of the finite element mesh.