Automotive axial flow fans: design and optimization

Gabriele Milanese

Johnson Electric Asti

Ubaldo Cella

Design Methods


Axial flow fans are typically used within automotive cooling systems controlling temperatures of vehicles engine, passengers compartment and auxiliary systems.
Due to the parallel increase of performance requirements (e.g. efficiency, noise) and installation constraints, the design of this classic application is becoming more and more challenging during last years.
A modern fans designer usually defines a preliminary blade geometry which is than refined by studying complex fluid-dynamic and aero-acoustic interactions with the installation environments. These tasks can be done taking advantage of different computational tools involving self-developed, open source and commercial software. JE Asti develop internally preliminary design tools and currently uses commercial software (ANSYS) for complex 3D analysis. The Scilab platform has been evaluated a suitable tool to support the refinement design phase. A flexible and robust optimization procedure has been developed within Scilab using alternatively the simplex or gradient based routines and driving software devoted to the fan geometry treatment and 3D flow simulations. A proper choice of the geometrical parameters, the objective functions and constraints allows the designer to control the optimization computation. Meta-modeling is used both within the optimization procedure and within the results processing phase.