Spyker Cars NV

Project: Aerodynamics C8 Spyder

Aerodynamics is of great importance in order to reach well balanced vehicle dynamics and low air resistance. Basically research in this area can be performed in two ways: measurements (wind tunnel tests or driving tests) and simulations (CFD). Measurements are very well suitable for quick and reliable answers about drag and lift. However the drawback remains that a physical model of the vehicle and its different configurations is needed for these tests.

For flow simulations, called Computational Fluid Dynamics (CFD), a CAD model of the vehicle is enough to start investigating the aerodynamics. This way it is possible to optimise the shape at an early design stage, when adjustments are still feasible. Furthermore it is possible to extensively analyse the behaviour of airflow around the vehicle, engine cooling and passenger comfort.

In this study for Spyker Cars a few simulations of the air flow around the Spyker C8 Spyder have been made. The study was a first acquaintance with CFD for Spyker with the objective to show the capabilities of flow simulations as a design tool and to identify car parts that could be optimised. The results of the CFD study and wind tunnel measurements formed the input for further optimisation of the new C8 Spyder series and other developments in the near future. The new C8 Spyder, having body panels built by Karmann, will be launched by the end of 2005.

For the aerodynamics study Modesi made a simplified variant of the model created in the reverse engineering project. This way it was possible to generate a high quality hybrid mesh, consisting of approximately 8 million cells. To take into account the influence of the internal channels and the radiator on the external flow, these parts were modelled and meshed as well.

In order to get a quick impression of the aerodynamic characteristics and to locate the points of special attention, a 2D investigation has been performed. This investigation has given us enough insight in the flow to create a 3D mesh that resulted in reliable answers regarding the behaviour of the flow around the vehicle.

An analysis of the simulations of the different configurations clearly showed the added value of CFD to Spyker. Furthermore it turned out that the driving behaviour of the car could be optimised by a few simple modifications to the vehicle.