Applications of optimization during the aerodynamic development of new vehicles

Enrico Ribaldone, Luca Miretti

Centro Ricerche FIAT


Nowadays CFD simulation is a common tool across automotive industries for the assessment of virtually every car performance related to fluid motion: fuel economy (aerodynamic drag), stability and driveability (lift and lift distribution), acoustic comfort (aerodynamic noise), thermal comfort (air distribution in passenger compartment), visibility (soiling and water management), engine performance (engine cooling flow), etc.
The full power of numerical methods of studying many design variants at a fraction of the cost needed for experimental testing, however, can be fully exploited only when coupled with DOE and optimization techniques. These advanced numerical techniques have recently become determinant as all automotive manufacturers are facing stronger and stronger pressure to optimize all aspects related to fuel consumption of car, and aerodynamic drag makes no exception, due to increasing customer concerns and governments enforcing rules for the reduction of CO2 emissions. This paper presents the deployment of a tool for the coupling modeFrontier and CFD, developed in CRF, for the optimization of several aerodynamic performances of vehicles, in a design environment with many constraints from other disciplines. Applications of this tool will be presented, ranging from the aerodynamic optimization of the overall shape of the vehicle to the optimization of local details of drag reducing devices.