Frontal aerodynamics

The area in front of the sidepods is messy as a result of the dimensional regulations rather than an attempt at forming the ideal shape.

The main cause for the awkward layout is the regulation for the stepped underfloor (red), leaving the splitter (dark grey) at the lowest (reference plane) level and the sidepods being a little higher in line with the step plane. The splitter needs to extend to the front of the flat floor area (behind the front wheels) and provide amount for the plank (brown). The modern design preference for Raised noses require some shaping under the raised section to accommodate the drivers hips (bum…?) and the join the flow under the nose to the splitter, the resulting snowplough shape (Yellow) directs air either side of the car. Then the requirement for forward placed side impact protection in the form of carbon fibre spars (green) mounted just inside the upper and lower leading edges of the sidepod, makes the sidepods boxy and moves the inlet vertically into the middle of the sidepod.


Different aerodynamicists have different approaches to the treatment of this area. Most form the splitter into a wedge shape to rise up to meet the step plane, this allows for a hollow splitter to create space to place ballast, it also creates a neat join between the two levels. The point where the stepped side of the splitter meets the sidepods and the snowplough shape under the chassis, is a difficult area to manage the various flows. Bargeboards play a key role in directing the flow around the front of the car, the effectively route the flow between the front wheels around the car, flow inside (green) of the boards is routed into the sidepod intakes and around the outside of the sidepods, while the dirtier flow (brown) on the outside of the bargeboards is kept clear of critical aerodynamic surfaces. This shaping of the flow inside the barge boards helps the flow negotiate the tricky interface between the step and sidepods.


Flow over the top of the splitter and around the snowplough tries to go under the floor this would ruin the flow to the diffuser. Instead the try to channel it either; into the sidepod intake sor around the flanks of the sidepods, Jordan use the latter philosophy and scallop out an area below the sidepod intake to encourage the flow around the sidepod.


Flow along the step under the floor is of low quality being slow with low energy, this affects the flow into the centre of the diffuser. To improve this many teams place a small fin (blue) on the step plane to act as a vortex generator to get the flow (green) moving more quickly along the step


The other approach to managing flow at the step interface with the sidepods was first adopted by Geoff Willis when at Williams and since on his redesign of the 2002 BAR, recent Jordans and at the end of the season at Toyota. Each of these teams use a pair of smaller bargeboards placed forward towards the front wing and act in the same way as conventional bargeboards. As the smaller bargeboards are placed so far forward of the step\sidepod interface the flow here more treatment to prevent dirty airflow going under the floor. To manage this a full width fin (blue) is placed across the front of the sidepods at the step plane level and serves two purposes.


Firstly it prevents too much flow coming off the snowplough and under the floor (Light Green) at the same time it also creates a smoother flow for the flow that does go under the floor. Gavin Fisher, Geoff Willis’ ex colleague explained to me that it makes the flow under floor more laminar (Dark green) than if left unmanaged. The second use of the fin is to use the outer tip, sometimes with a vertical lip to create a vortex (red) to keep air from going under the floor along the flanks of the sidepods.