Air intake manifold design: 1D-3D fluid-dynamic multi-objective engine performances optimization

Assunta Teducci, M. Di Paola -Magneti Marelli
Francesco Franchini, Marco Accarino - EnginSoft

The task of the air intake manifold is to provide the air that satisfies the requirements of the engine over its operating regime. Intake manifolds consist typically of a plenum with individual runners feeding branches which lead to each cylinder: as consequence, the engine performances as power, torque and efficiency are strictly connected to the geometry and behavior of our products.
The design process is a complex flow where different tools work together to reach the geometry of the air intake manifold that lead to the engine performances required by the customers: it is not a simple process due to the different fluid dynamics needs, to the geometrical constraints and to the conflicting target of performances.
In order to reach the optimal solution, a completely parameterized CAD model has been developed, so that it could interact with both 1D CFD software and 3D CFD software; using Ansys Workbench Design Modeler module, the CAD model has been created starting from the initial air intake configuration, parameterizing all the geometrical entities, which could lead to a performance increase, so that they could be automatically updated by the optimization software, modeFRONTIER.
A multi-objective optimization with modeFRONTIER has been carried out, by integrating in the design workflow a 1D CFD software, to optimize the main engine performances (torque and power), and a 3D CFD software, in order to further improve the best solutions optimizing pressure drop, flux homogeneity, etc.