Many components in an aircraft have to safely operate in a wide range of thermal and flow conditions. Ensuring that design temperature ranges are not exceeded and that hot components do not degrade nearby components is a key challenge that should be addressed as early as possible in the detail design phase to avoid serious safety, durability, and certification issues. Careful and detailed analysis of component placement and thermal shielding is required to avoid costly late-stage design fixes. This type of analysis is required for many different systems of the aircraft, such as APU compartments, Nacelle, wheel wells, and many more.
Systems thermal design traditionally depends heavily on prototype testing - a process that is very expensive, time consuming, and inflexible. Testing involves thermocouple instrumentation that requires test engineers to a-priori estimate where thermal problems may occur - but the highly turbulent nature of flows in complex systems makes this very difficult or impossible to predict. Redesign and retesting is an expensive hit or 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 an experiment, 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.
Exa's solutions are uniquely suited to address aircraft systems thermal protection issues. PowerFLOW's unique, inherently transient Lattice Boltzmann-based physics allows it to perform simulations that accurately predict real-world transient 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 aircraft. This enables the engineer to 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.
Measurements can evaluate systems thermal performance and locate potential hot spots. Exa’s simulation solution can be used not only to predict the location of these hot spots; it can also identify the physical causes behind them. These insights allow much quicker design and better thermal solutions. It is a common experience that the use of Exa thermal solution significantly reduces the number of thermal failures observed in the first prototypes or even completely eliminates them. All this can be achieved at significant reduction of the design costs.
Application areas for PowerFLOW thermal systems analysis capabilities:
- Auxiliary power unit compartment and boiler rooms
- Nacelle thermal management
- Brake cooling and wheel well thermal analysis
Benefits of the Exa solution for thermal protection:
- Identification of hot spots
- Improvement of component lifetime and reliability
- Optimum placement, or even elimination, of heat shields
- Optimization of component layout
- Reduction of development costs by eliminating prototype testing
EXA SOFTWARE USED FOR THIS APPLICATION