With ever-tighter packaging design of internal engine compartments, increasing use of plastics for lighter-weight products, and an explosion in the use of sensitive electronics, thermal management has become a critical aspect in vehicle design. Components can become so hot that they potentially fail or degrade nearby components, leading to serious safety, durability and warranty issues. Many vehicle systems, such as the engine, transmission, HVAC or power steering, have significant energy requirements, and their thermal efficiency has a direct impact on the vehicle's fuel economy, performance and passenger comfort. Globalization is making the challenges worse with vehicle platforms that must operate in extremely wide temperature ranges. Careful analysis of cooling airflow, component placement and thermal shielding is required to avoid costly late-stage design fixes or, worse, failures when in production.
Traditionally, thermal design depends heavily on prototype testing in thermal wind tunnels or on-road testing with hundreds of thermocouples, which is very expensive, time-consuming and inflexible. Testing with thermocouple instrumentation requires test engineers to a-priori estimate where thermal problems may occur, but the highly turbulent nature of engine compartment and underbody flows makes this very difficult or impossible to predict. Relying on redesign and retesting is an expensive hit-and-miss process that often ultimately fails to identify the highest temperature locations. The inherently transient nature of turbulent flow is almost impossible to visualize in a wind tunnel, yet these complex structures must be understood in order to optimally locate and protect components. In addition, temperature is a function of the complex interaction between conduction, radiation and convection in the surrounding fluid, especially for very hot components. Accurately predicting this is extremely challenging.
Coupled PowerFLOW (right) and PowerTHERM (left) automatically map surface distributions.
PowerTHERM® coupled with PowerFLOW® provides a complete, extensively validated digital thermal management solution. PowerFLOW's unique, inherently transient Lattice Boltzmann-based physics allow thermal simulations to be performed that accurately predict real world transient airflow conditions on the most complex geometry. PowerTHERM is a fully coupled, highly accurate conduction and radiation solver. The combination of PowerFLOW and PowerTHERM enables engineers to accurately predict temperatures and visualize the flow and temperature fields for the entire vehicle. Engineers can then identify problem areas and provide recommendations to improve the design to eliminate problems. Rapid turnaround time for simulation and model setup allows the engineer to quickly make design changes to the baseline and evaluate the improvements in thermal performance.
Learn more about the core CFD technology behind Exa simulation software.
PowerTHERM has been validated to help solve many thermal management problems, including:
BENEFITS OF POWERTHERM FOR THERMAL MANAGEMENT:
• Reduced product development time through early-stage analysis and design improvement
• Reduction of development costs by reducing or eliminating prototype testing
• Improvement in component lifetime and reliability
• Reduction of warranty risks and costs
• Improvement in vehicle efficiency by maintaining optimal thermal operating conditions
• Increased customer satisfaction through analysis of cabin airflow and occupant comfort
PowerTHERM predicts surface temperatures and heat fluxes generated by heat radiation, conduction and convection. Convection is calculated by PowerFLOW and coupled to PowerTHERM via an integrated coupling interface enabling two-way data exchange. The coupled thermal simulation is easily set up as part of a regular PowerFLOW simulation, resulting in a complete flow and heat transfer simulation, enabling the user to efficiently and accurately predict thermal analysis.
Advanced solver for radiation, conduction and convection:
• Multi-bounce radiation
• Shell and solid conduction models
• Convection via coupling with PowerFLOW
• 1-D advection and fluid stream models for modeling coupled internal flows, for example, within an exhaust system
• Temperature-dependent properties including conduction, specific heat and emissivity
• Handles multi-layer parts: solid, air, vacuum or mixed
• Efficient and robust numerical scheme with adaptive solution algorithms
Accurate and efficient over many time scales
• Steady-state or transient
• From a few seconds to hours
High-performance and easy-to-use
• Rapid, easy-to-use thermal model creation and case setup
• Seamless, integrated coupling with PowerFLOW fluid simulation
• Results analyzed in PowerVIZ®, Exa's powerful simulation results visualization & analysis environment – a single environment for analyzing flow results
• Optional parallel processing for reduced simulation time
Battery cell model
• Optional module for coupled thermal-electrical analysis of a battery cell or pack
• Supports both charging and discharging states
• Captures realistic time-varying loads and charges
Natural environment models for accurate climate control analysis
• Solar loading – Direct, Diffuse and Reflected
• Wind loading
Human comfort model
• Optional module for advanced human thermal comfort within complex environments
• Place virtual test dummies with layers of clothes into virtual operating environment and compute comfort indexes
• Full radiant, convective and conductive heat transfer is accounted for
• Computes localized thermoregulatory response such as perspiration, respiration and blood flow changes
• Steady-state or transient localized thermal sensation and comfort analysis
For more information or to see our simulation software in action, visit the Exa Resource library to watch recent demos and interviews with our experts.