Vehicle Aerodynamic Shape Optimization

Author(s): 
Robert Louis Lietz (Ford Motor Co.)

Recent advances in morphing, simulation, and optimization technologies have enabled analytically driven aerodynamic shape optimization to become a reality. This paper will discuss the integration of these technologies into a single process which enables the aerodynamicist to optimize vehicle shape as well as gain a much deeper understanding of the design space around a given exterior theme.

Efforts are made periodically to understand the aerodynamic potential of a given vehicle theme using designed experiments and physical wind tunnel testing.The physical model is typically constructed from a number modules, in order to support the multiple configurations within the designed experiment. 


Example of a dynamic image generated during a truck DOE

A region such as the greenhouse might be represented by two or more modules. For example, one module representing various windshield angles, a second module to account for modified tumble home, and a third module representing different rear header, rear pillar and backlight angles. This type of physical experiment also requires the multiple variations of each module in order to evaluate different levels of each factor in the design.

The design and fabrication of these multiple modules is costly and time consuming. The number of factors that can be evaluated is normally limited by the complexity of the modules and interfaces between modules. These constraints and the cost of wind tunnel test time often limit the extent of the investigation. (i.e.: two level vs. multiple level factor evaluation). 

 

Overall process integration and optimization algorithms are provided by the modeFRONTIER software application.