“Step-Change” developments in the accuracy and resolution of engine design company Ilmor’s CFD capability have slashed development times by around 50% while reducing prototype build cost for its 2016 Indycar engine development project by 75%.
Ilmor’s engine design consultancy division has been responsible for the design of Chevrolet’s championship-winning Indycar engine that powered Scott Dixon to the 2015 title. Recently, the design team had an opportunity to refine the cylinder head. The engineers turned to Converge, a CFD program that assists engine optimization, performance and efficiency.
Converge software differs from legacy CFD programs as it couples and automates the mesh at runtime, 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 eliminated user-to-user variation inherent in traditional CFD programs that can lead to correlation errors.
The introduction of Converge coincided with a large order for Ilmor in both automotive and motorsport applications. “With over 30 years of experience, our engineers are adept at creating ideas to extract performance from road or race engines,” said Steve O’Connor, chief engineer, Ilmor Racing. “We have always used simulation but to date it has supported our traditional approach of producing a part or concept and then trying it on the dyno. That development method provided accurate, real-world data but was 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.”
This CFD program 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. Users can create larger mesh cells to save time, but accuracy diminishes and runtimes grow longer. With run-time grid generation, the program enabled Ilmor’s engineers to use their time to come up with more creative ideas instead of building meshes.
Underlining the suitability for engine developers, the program also links seamlessly with other software programs, such as GT-Power, making it suitable for other applications such as exhaust after treatment. With opportunities to use it in other applications, such as optimizing flame propagation, Ilmor is keen to blend its knowledge with Converge tools to acquire more OE contracts. “We are known for our motorsport success, but we are doing an increasing amount of automotive and R&D work,” said Ian Whiteside. “Combining our knowledge with the use of Converge to prove our concepts is attracting OEMs looking for novel ideas at the speed that only motorsports know how to deliver.”