Atomic theory

Our Ariel Atom study concludes with tweaks to the mudguards and some intriguing tests involving the engine cover and the rear wing

- SIMON MCBEATH

The 2019 Javelin Trackdays Sprint Series-winning Ariel Atom of owner/driver Stuart Drewell featured wide span dual-element wings front and rear but, apart from extra cooling capacity and associated ducting, was otherwise fairly standard in the aerodynamics department. Having seen how the wings reversed the car’s natural positive lift and enabled a well-balanced downforce distribution in our previous two issues, we round off the project this month by examining other aspects of this quirky car’s aerodynamics.

Guard duty

It was evident from the smoke plume that the Atom’s short mudguards would have been creating aerodynamic lift, partly from attached flow over the concave upper surface creating reduced pressure. It wasn’t practically possible to remove the mudguards during our session because of time constraints, and cutting holes was not desired either, so we were restricted to fitting small Gurneys just behind the top of the front mudguards to try to reduce the upper surface suction. Table 1 shows these devices had very modest effects, but this does suggest that a more radical rethink of mudguard shape, along with the arc of coverage, could bring further benefits. It’s interesting that modifying the flow over the front mudguards and achieving a small increase in front downforce had almost as much effect on rear downforce. The changes are given in counts, where one count is a coefficient change of 0.001.

Cover up