Ilmor’s engine design consultancy division is responsible for designing Chevrolet’s championship-winning Indycar engine that powered Scott Dixon to the 2015 title. With 2016 homologation opening the opportunity to find refinements in the cylinder head, Ilmor’s engineers turned to Converge, a CFD programme specifically created to assist engine designers to optimise engine design, performance and efficiency.
According to its creators Convergent Science, Converge software differs from legacy CFD programmes as it fully couples and automates the mesh at runtime, significantly reducing the time taken to calculate flow. This feature, once thought difficult to achieve in CFD, saved Ilmor eight weeks in development time on its 2016 Indycar engine update. Generating the mesh also crucially eliminates user-to-user variation inherent in traditional CFD programmes that can lead to correlation errors.
The introduction of Converge has coincided with a burgeoning order book for Ilmor in both automotive and motorsport applications. “With over 30 years’ of experience, our engineers are incredibly adept at creating ideas to extract performance from road or race engines,” says Steve O’Connor – chief engineer, Ilmor Racing. “We have always used simulation but to date it has supported our traditional approach of us actually producing a part or concept and then trying it on the dyno. That development method obviously provided accurate, real world data but was more costly and time consuming. Now Converge has improved our understanding of the complex mechanisms that occur within the combustion chamber without cutting metal and has guided us along new avenues of development for both the road and track. With complex issues such as combustion system development now critical for road car emissions, it enables engineers to test more ideas without the need to manufacture each time. It marks a step-change in how we manage our entire development process.”
“Converge was created by engine specialists to address the deficiencies of other CFD codes in their field and to focus on the areas that really mattered to them. Factors such as flame propagation and knocking can be a real problem,” adds Rob Kaczmarek, director of global marketing at Convergent Science. “You can of course create larger mesh cells to save time but your accuracy diminishes and invariably you find your runtimes extended. With run-time grid generation Converge means Ilmor’s engineers can use their time to come up with more creative ideas instead of building meshes.”
Underlining the suitability for engine developers, Converge also links seamlessly with other software programs such as GT-Power making it suitable for other applications such as exhaust aftertreatment. With opportunities to use Converge in other applications such as optimising flame propagation, Ilmor is keen to blend its knowledge with Converge tools to acquire more OE contracts.
