Kenichi Ando

System for aerodynamic evaluation was built to understand influences of exterior styling change on aerodynamic performance by computational fluid dynamics, i.e., CFD, at an early concept development stage. Aerodynamic performance effects on fuel efficiency must be cared. It, however, might not be solely pursued since it and other performance requirements have a strong effect on each other, e.g., visibility, livability, engine cooling and so on.

Especially, exterior styling and aerodynamic performance often conflict with each other, that is, high aerodynamic performance does not always result in attractive exterior styling. Aerodynamic engineers and exterior styling designers are, hence, required to spend lots of time to reach their convincing goal. Scale model wind tunnel testing is one method allowing evaluation both aerodynamic performance and exterior styling simultaneously although it might require an arduous process of trial and error. On the contrary, CFD could be an efficient tool though it often requires some specific skills to build a digital model and execute CFD calculation.

The proposed CFD system consists of exterior model morphing, computational mesh generation, flow calculation and result analysis, and the process is successively executed by employing process automation software, i.e., modeFRONTIER. A specialized GUI designed for those lacking specific CFD skills also allows a user to operate the system. Additionally, response surfaces and a multi-dimensional chart allow a user to find the well-balanced aerodynamic styling in a wide design space which is really difficult to be obtained by scale model wind tunnel testing. The system was designed so that three-parameter study was completed within approximately one day. The system has been, as a result, widely applied to aerodynamic styling development at the early concept stage.