Dual function air outlet numerical optimization

Fabrizio Mattiello (Centro Ricerche Fiat, Engine & Thermal Systems Innovation)

CHALLENGE - The thermal comfort in the standard vehicles is reached passing through a series of thermal transient conditions where jet air ejected by the common dashboard outlets produces high thermal asymmetry, always perceived as annoying. The ways to achieve the passengers’ comfort are particularly difficult and even maintaining comfort might be problematic in some cases.

SOLUTION - The integration into the cabin of systems that improve the thermal comfort, able to reduce the fluiddynamic resistances of the HVAC system and simplify its geometry at the same time, allows to reach in advance both the thermal comfort itself and to decrease the cabin thermal transient. These solutions give the possibility to set forward the thermal stationary system condition of the A/C system with a consequent energy demand reduction and fuel saving too. In this activity an enhanced geometry of an air outlet with a double function (jet and diffuse air) has been developed coupling the CFD numerical simulations with modeFRONTIER multi-objective optimization platform. The experimental tests on rapid prototyping components had as results the validation of both the air outlet geometry and the numerical methodology accuracy.


BENEFITS - The 3D CFD virtual and test validation of the selected optimal result has shown that selected 2D virtual CFD approach can be used to obtain reliable results in short a time, which is necessary for the optimization process. It has also been proved that starting with base validated model and applying to it geometry changes (e.g. morphing) it is possible to obtain the optimal solution within multiobjective optimization approach even if the objectives remain in conflict. Such an approach allows to decrease developing costs and time.