TAITherm™

POWERFUL THERMAL SIMULATION FOR DIVERSE INDUSTRIES

OVERVIEW

Since 1996ThermoAnalytics TAITherm® software is the leading transient thermal simulation code for solving complex heat transfer problems. Corporations and laboratories around the globe rely on TAITherm’s accuracy, powerful features, and computation speed to deliver system-level thermal analysis.

The Choice of Global LeadersThermoAnalytics’ software is a central tool for achieving heat management at many of the world’s leading manufacturers. Feedback from these elite engineering teams defines our future development and performance benchmarks.

• BAE Systems

• BMW

• Boeing

• Bentley

• Chrysler/FIAT

• EADS

• Ford

• Foster + Partners

• GM/Opel

Advancing InnovationBecause rapid time-to-market yields a competitive advantage, our customers rely on the unequaled speed and features of TAITherm to solve system-scale transient problems. The GUI integrates geometry import and editing, assignment of boundary conditions, setting simulation parameters, and post-processing of results. The intuitive user interface design means engineers and analysts can become effective users with little or no software training.

Accelerating SolutionsThe TAITherm solver is parallelized to allow for multiprocessor workstations to quickly solve large models. TAITherm is also run on HPC systems at many of our customers’ locations, and features a robust command line mode that can be managed with job scheduling systems.

• Harley-Davidson

• Honda

• Hyundai

• Jaguar/Land Rover

• John Deere

• MAN Truck

• Mercedes-Benz

• Peugeot Citroen

• Porsche

• Renault

• Rolls-Royce

• TATA Motors

• Volkswagen

• Volvo

• Westinghouse

Leading Thermal SolverTAITherm is written in modern, object-oriented C++ with an optimized architecture. It performs a multimode energy balance on each thermal node in a simulation, simultaneously computing heat transfer rates for conduction, convection, and radiation. The finite difference solution and numerical methods used by TAITherm are unconditionally stable and second order accurate in time and space. Models with millions of elements are routinely solved on workstations and HPC systems.

APPLICATIONS & INDUSTRIES

UNDERHOOD • Heat Protection

• Component Modeling

• Key-Off/Hot Shut Down

• Dynamic Driving Profiles

EXHAUST • Heat Shield Design

• Transient Drive Cycles

• Hot Spot Analysis

• Thermomechanical Fatigue

HVAC & CLIMATE CONTROL• Occupant Thermal Sensation

& Comfort

• Heated/Cooled Seats

• HVAC System Sizing

• Body Insulation & Window Glazing

ELECTRONICS• Heat Sink Design

• Chassis Analysis

• Enclosure Design

• Passive Cooling Optimization

OFF-HIGHWAY EMISSIONS • Underhood/Exhaust Systems

• Insulation/Heat Protection

• Muffler & Catalyst

• Turbochargers

ARCHITECTURE• HVAC System Analysis

• Passive Design Studies

• Building Energy Modeling

• Natural Environment Simulation

AEROSPACE • Environmental Control Systems (ECS)

• Fuselage Thermal Insulation Design

• FAA Thermal Certification

• Composite Material Optimization

BATTERIES • Cell or Pack Level Analysis

• Thermal Management (Passive & Active)

• Transient Drive Cycles

• Hot Soak

BRAKES & CLUTCHES • Transient Brake Cooling Analysis

• Composite Design Evaluation

• Transient Braking Cycle

• Interface with FEA for Stress Analysis

BOUNDARY CONDITIONS

Importing GeometryIn addition to basic geometry creation and editing tools, TAITherm can directly read native geometry from meshing tools, such as ANSA and Hypermesh, or import neutral file formats including Nastran, Patran, and STL. The user can quickly modify designs within TAITherm, e.g. shield position, without returning to the original CAD file. Boundary conditions are easily assigned using our TAITherm’s tabbed user interface, which guides the user through the model hierarchy.

ConvectionTAITherm allows the user to choose from several different methods of computing convection, based on the system requirements and available data:

• Fixed or time-dependent convection coefficient

• Library convection for use with 1D fluid nodes & automatically calculated convection coefficients

• Fluid streams for interior convection along ducts & pipe systems using easily-configured flows

• Wind convection for modeling natural environments

• CFD results can be imported & mapped to model geometry along a transient TAITherm timeline

RadiationTAITherm has comprehensive physics models to accurately simulate large and complex radiation problems. Users can select from a wide range of fixed or temperature-dependent surface conditions from the standard TAITherm database. TAITherm uses the net-radiation equation for computing radiant heat transfer between surfaces. Because the net-radiation solution is integrated into the thermal and radiometric solutions, TAITherm can account for temperature-varying surface conditions.

View FactorsThermoAnalytics has pioneered the use of high speed voxel-based ray tracing algorithms, which compute both radiation view factors and solar projected (apparent) areas. The voxel method is exceptionally fast and accurate. The user can dynamically set the accuracy of the view factor computation, and utilize radiation patches to accelerate the thermal solution of large models or simulate rotating components.

Conduction TAITherm supports using 1D links, 2D shell meshes, and 3D volume meshes for accurate conduction calculations. By using the most appropriate methods for each model, the user gains the maximum engineering insight with minimal computation time. TAITherm has many specialized shell mesh part types, including multi-layer parts where the user can define up to 25 layers of solids, air gaps, vacuum gaps, or porous media, each having a parametric thickness. Heat rates can be dynamically imposed on external or internal layers.

Boundary Condition SetsExperienced users creating large models with hundreds or thousands of parts can manage and document models using TAITherm’s spreadsheet-style model summary table. Boundary condition sets can be imported from one model to another, and applied to matching part numbers or names.

Integrated Modeling ParadigmsBy supporting several methods of representing both solids and fluids, TAITherm allows the user to integrate the most suitable paradigm for each component or sub-system. Integrating these empirical and mechanistic models enables TAITherm to deliver transient simulations of actual tests, such as a sequence of hill climb, key-off, and hot soak.

Curves & ScriptsTAITherm supports curves to define many system variables. Users can import curves or generate and edit curves directly in the GUI. Scripts and user routines allow for querying model data and integrating external controls with the overall thermal simulation.

Programmer’s APIAdvanced users can access the full power of TAITherm with the TDFIO C++ API. This library allows the development of advanced programming functions to create or modify model settings or extract results from a model. This extends the power of TAITherm and enables customized and integrated solutions to be designed and implemented by our customers.

Property DatabasesTAITherm’s material database includes substances with temperature-dependent properties. Fluids, solids, transparent

solids, and anisotropic solids are supported. These materials can be assigned to each part in a model, or combined to define a composite or layered component while using a planar mesh. A user can add/edit materials through the user interface. Surface conditions are also included in the database and define the thermal emissivity and solar absorptivity of common substances. The local database can be imported, exported, or linked to a central material database.

Thermal LinksMany simulations require the use of geometry for various CAD or vendor sources. TAITherm’s powerful thermal links feature allows the user to easily set up conduction paths between arbitrary elements, parts, or surfaces that face each other. Elements that are within a user-defined threshold are identified by TAITherm and highlighted on the geometry to confirm the correct contact patch. In the example at right, the basketball elements highlighted in blue are in face to face contact with the hand.

Fluid NetworksMany systems involve liquids or gasses that play a vital role in heat transfer and thermal management. TAITherm’s 1D fluid parts and fluid stream parts provide a rapid solution to convection within volumes and through pipes. Flow rates can be defined via curves or managed with scripts and routines that match real-world controls.

Layered Anisotropic CompositesCarbon fiber composites can be accurately represented using TAITherm’s layered part type with anisotropic materials. The user can easily set the preferred conduction direction of each carbon fiber layer, yielding an accurate 3D conduction network. The preferred direction is displayed on the mesh.

RAPID SETUP

Climate Chamber SimulationVehicle testing in climate chambers that mimic outdoor environments can also be simulated in TAITherm with environmental inputs. This allows manufacturers to validate their model with the controlled test conditions of a climate chamber before analyzing vehicle performance at specific global locations.

Natural EnvironmentsMany systems operate in outdoor or partially enclosed environments and TAITherm has advanced algorithms to calculate environmental loads. Actual or averaged weather data is used to define local conditions. Terrain temperatures are computed based on first principles physics to predict soil, concrete, asphalt, or foliage temperatures. Faceted terrain will accurately simulate solar shadowing effects and solve for reflected solar and thermal radiation. TAITherm can utilize weather data for wind speed and direction to compute convection values using the wind vector and planar orientation of each element.

Solar Loading & TransparencyWhen using natural environments, TAITherm computes multi-bounce direct, diffuse, and reflected solar loading based on global location, altitude, cloud cover, and date/time. Transparent glass is supported to capture the greenhouse effect through single pane, multi-pane, or layered glass. A full energy balance is computed on transparent layers with reflected, absorbed, and transmitted solar values.

REFLECTED

DIRECTINFRARED

DIFFUSE

WIND

NATURAL ENVIRONMENTS & DATA REPORTING

Thermal ReportsTAITherm’s innovative reporting feature enables the user to define the production of specific images, plots, data exports, or animations before or after simulation. This allows the export of matching data sets or graphics from a series of thermal models and provides effective comparison of specific performance metrics. Report templates can be exported and re-used in future projects.

Post ProcessingThe engineering value of TAITherm simulations is enhanced by providing effective tools for communicating results to engineers and managers. TAITherm offers clear insight to the root cause of hot spots or heat management problems. More importantly, engineers can use TAITherm to test various solutions and select the most cost effective option. Transient solutions can be animated and exported as AVI files, along with plot graphics. Raw data on a part- or element-level can be written out as CSV files for documentation or further computations in custom tools.

CFD FLOW DOMAIN

SUBVOLUME 1D FLUID NETWORK IN TAITHERM

Model Inputs & Measurements

CFD CFD CFD CFD

TAITherm Transient Simulation “A”

TAITherm Transient Simulation “B”

TIME

EXAMPLE COUPLED TAITHERM CFD PROCESS

COUPLED SIMULATIONS

Linking TAITherm with Other SoftwareTAITherm is the choice of leading engineering teams because it can share data as inputs and outputs, enabling co-simulation and optimization throughout the product development cycle.

Co-Simulation with 1D System ToolsTAITherm links with 1D system tools to provide 3D geometry-based radiation, conduction, and convection coupled with parametric 1D representations of complex objects like radiators and heat exchangers. TAITherm can be linked with AMESim, Flowmaster®, and MATLAB®. Other software can be linked using our Solver API.

Product Optimization SoftwareEngineers and analysts must often solve a range of problems with a single, final design—weight reduction must be balanced with thermal performance, acoustic behavior, and prevention of thermomechanical fatigue. TAITherm models can be operated in batch mode by an optimization code, such as Isight, modeFRONTIER, or Optimus®.

Exporting to FEA for Stress/StrainThermal results can be exported to FEA codes to determine the distortion and stress caused by steady or transient temperature distributions. TAITherm exports results natively to Nastran and Abaqus.

Coupling with CFDTAITherm computes total system energy balance combining one or more data sets of 3D convection data from CFD (Computational Fluid Dynamics) software. For example, HVAC flow data for inside a vehicle can be combined with external flow data to compute exhaust loading to the floor pan and the effects on passenger comfort.

Converting CFD Flow Data to 1D SubvolumesCFD can effectively characterize the flow patterns and mixing inside enclosures. An effective system approach for transient analysis, such as AC pull-down of a hot vehicle cabin, can be achieved by slicing the cabin domain into subvolumes and computing mixing flow rates between regions. CFD data is used to generate mass flow rates between the zones, and powerful 1D fluid nodes are used to solve the transient, localized air temperatures.

Advanced Transient WorkflowsDue to thermal mass and complex heat transfer, many systems, such as vehicle hot shut-down, need to be analyzed under long time scale transient conditions. These systems are well-suited to TAITherm as the primary system-level tool but may also require a CFD code to capture various 3D flow phenomena. As shown in the diagram at left, advanced teams usually begin such an analysis using TAITherm’s internal convection options based on known inputs, such as flow speed. Once the initial transient TAITherm’s run is completed, surface temperatures are exported from TAITherm’s at various points in time and read into a CFD code to compute pseudo-steady-state snapshots of convective flows. Flow simulation results are then imported back to TAITherm’s for a subsequent transient analysis over the same timeline. This process can be iterated, and is considered the state-of-the-art method for a complete thermal analysis.

Human PhysiologyBuilding upon the past decade of research, ThermoAnalytics has developed the most accurate model of human physiology available. Our human thermal module supports male and female physiologies from 1st to 99th percentile, and any body mass index. Human models can be situated in natural or engineered environments, with layered clothing applied to each body segment. Applications for the human thermal module include design of clothing, furniture/seats, HVAC, architecture, and safety.

Sensation & ComfortTAITherm outputs a complete temperature profile of each human model, along with thermal sensation and comfort for each body segment, as computed by the Berkeley Comfort Model. Engineers can accurately develop localized heating, cooling, or clothing designs.

HEAT TRANSFER ANALYSIS SOFTWARE

Battery ModuleThe Battery Module performs a bidirectionally coupled thermal-electrical analysis of a battery cell or pack and supports both charging and discharging states to capture realistic time-varying loads and charges.

The charge state of the battery is computed over time as the load varies with demand. Because the battery module supports both cell and pack-level behaviors, optimization of battery cells can be achieved by varying cell geometry, tab location, and number of cells in a pack.

An equivalent circuit model allows rapid analysis of integrated cooling systems and packaging into a full vehicle or subsystem model. Virtual driving schedules can be imposed and matched to track global location and weather data.

TAITherm and ThermoAnalytics are trademarks of ThermoAnalytics, Inc. All other product names are trademarks of their respective owners.

BATTERY MODULE APPLICATIONS• Validation & test method implementation

• Optimized simulation process for cell & pack level studies

• Cooling, insulation, & heat protection studies

• Vehicle drive cycle model: heat up & cool down

• Electrical drive cycle power profile

ThermoAnalytics’ experienced team will work with you to develop efficient and effective solutions to your thermal and infrared challenges. Contact us today to schedule an engineering review of your analysis needs.

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