The Society of Automotive Engineers (SAE) recently hosted their automotive-centric 2019 World Congress Experience (WCX) April 9-11 at the Cobo Center in Detroit, Michigan. This conference is the premier automotive technology event, providing a platform to acquire critical knowledge as well as share new ideas proliferating the rapidly changing automotive technology environment.
While the focus remained on self-driving vehicles and other forms of automotive-autonomy, a noticeably concerted effort towards integrating computational fluid dynamics (CFD) into the heart of the design optimization process dominated the proceedings. As evident by the many “break-out” sessions, CFD has become a useful tool in many areas including external aerodynamics, valve design and optimization, Lithium-Ion battery design, and combustion.
Conducting real-world, physical experiments can be invaluable, but in many cases are cost prohibitive. Enter stage left – CFD. Over the last 20 years, as computational performance has rapidly increased and model verification/validation (V&V) has become more systematic, CFD has become the de facto tool in research and design. At present, and moving forward, a significant emphasis on speed and efficiency shapes the development path for many of these tools. With nearly unimaginable speed, once thought to be impossible, modeling and simulation have given rise to design optimization workflow processes, providing the design engineer with the ability to expeditiously iterate through prototypes (Figure 1).
One particularly interesting optimization example presented at WCX involved intake and exhaust port design to improve gasoline engine tumble and mass flow rate. Worldwide automotive manufacturers continuously research suitable technical solutions to meet ever increasingly stringent carbon dioxide emission regulations. The author’s work utilized different geometries designed and analyzed by means of CFD simulation. Using a parameter space which included, port shape, flow separation edge, port top profile angles, port side profile angle, and valve angle – a 45% improvement in tumble coupled with a 36% increase in mass flow rate demonstrated the power of design optimization via simulation. The final design can then be manufactured and tested.
The project life cycle for the automotive industry is extremely rapid. Automotive manufacturers make minor changes to their vehicles year-to-year and major design changes follow every three to four years. To keep pace, the automotive engineer has developed an affinity for end-to-end simulation environments where automation and speed are critical. As a result, many self-contained tools have been developed and provide an automated computational framework requiring very little user interaction. However, shifting to a modular optimization loop methodology provides the engineer with the ability to leverage the best tools available for specific tasks, while maintaining speed and efficiency.
Often the optimization bottleneck, grid generation historically has been a time-consuming, yet critical part of the process. So when considering the modular approach, each tool must be flexible, have robust I/O capabilities, work well with the other modules, and the process must be entirely scriptable. Enter stage right – Pointwise.
An example of this modular approach was utilized for a parametric optimization study for vertical axis wind turbines. In this approach, Pointwise was used for both geometry and mesh generation and then tied together with the remaining modules using Glyph scripting – allowing hundreds of simulations to be run in a relatively short period. Glyph scripting is native to Pointwise and built on top of Tcl, which is a mature, dynamic, and robust programming language. Glyph and Tcl functionalities for Pointwise extend far beyond requirements needed for integration into optimization processes. Pointwise engineers and developers have developed a wealth of useful scripts designed to increase the speed and efficiency of mesh generation and have made them publically available on our Glyph Script Exchange.
Conferences similar to the SAE World Congress provide opportunities to perpetuate best practices and exchange information in such a way, which nurtures the immense technological evolution as we speed through yet another decade. Like the examples highlighted demonstrate, Pointwise is a flexible tool that can be incorporated and tailored to fit within any design optimization process. As a standalone tool, Pointwise is extremely powerful and designed to meet your meshing needs. For more information about how Pointwise is used within the automotive industry, please visit the link below.