First, the computational domain is discretized into a mesh that is suitable for the analysis. In this step the mesh is created and the flow and boundary conditions are defined. In the second step, the discrete problem is solved numerically, usually through the use of a solver package. Finally, the calculated results are analyzed.
From these steps, mesh generation is the most intensive and time consuming.
The airfoil design has a decisive influence on air drag. It is well known that nearly all drag-reducing measures have an influence on lift. Race cars for driving safety and good handling must have negative lift. Therefore, race car wings (airfoil) design must be emphasized that result in negative lift with lowest possible air drag. There are three main sources of negative lift, the basic vehicle configuration, negative inclined wings and the built in ground effect. In this report, main attention will be focused on the ground clearance.
The ground effect uses the airflow between the road surface and the vehicle underbody to create a down force. The ground effect was used for the first time in formula one racing cars where a negative value of Cl = -2.6 is typical. This negative Cl value is reached with the aid of the venture nozzle shape of the underbody of the race car, which helps to maintain the negative pressure, side skirts are designed to prevent air to flow into the low pressure area.
The ground effect is based on the fact that the road surface and the vehicle underbody form a combined nozzle diffuser.
Arturo Guzman
Block B, Flat 3.26
Leodis Flat Complex
Leeds, LS62QE
England.
