Analysis Led Design Using CFD
Computational Fluid Dynamics (CFD) is the method of calculating fluid flow, either internally or externally around a component. At Cummins Turbo Technologies, this involves using modeling software that measures and tracks gas passage within the turbocharger.
Similar to finite element analysis, which breaks a model into many parts and assigns 'elements' to a number of locations and positions, the engineers at Cummins Turbo Technologies identify anywhere from two to 15 million elements, depending on the model’s geometry and complexity. A typical Holset VGTTM requires 12 to 14 million elements. The model is then passed through “meshing” software, which essentially wraps a mesh around the intricate parts of the model such as the turbine or compressor wheel blades. With this, flow data is captured around these components in as much detail as possible.
With Holset turbochargers, accuracy is paramount for CFD analysis, seeking to produce an error-free model in terms of gas flow, heat transfer, radiation, turbulence and combustion. Backed by a powerful computing environment, engineers work within an extremely small error threshold (1.00E-6) between model iterations. Attention to accuracy and efficiency affects product development in profound ways. The software techniques used in the past would take a week per iteration – it now takes just an hour per iteration. Faster development equates to faster to-market product for the customer.