Location: Covilhã, Portugal (and sometimes in Évora)
Post
Well in the article I suggest they actually do prove that too much air is a disadvantage! The article is written by Simon McBeath with Advantage CFD giving all the data!
The thing is that with too much air due to viscous effects air stalls under the car...removing all downforce.
Ok, too much is bad but here it was suggested by some that sidepods just ride along without much influence on DF because the main action takes place only in plank zone.
It was suggested that since that there are no skirts and the floor is stepped airflow under sidepods isn't affecting downforce in amount done by plank-to-diffuser flow which actually doesn't exists since it is sidepods-to-diffuser flow.
Much of the aero discussion has been based upon Bernoulli's Principle, where higher air velocity results in lower pressure. But there is another factor to be considered, basic Newtonian physics. And for example, that's how a simple kite flies. It just presents a flat surface to the airflow, and the resulting force pushes against the kite. So although air flow is required to make Bernoulli's Principle work, too much results in Newtonian physics coming into effect.
The sidepod skirts are still there, we just don't see them anymore. Instead of physical sliding skirts, the goal is to have a low pressure area along the side of the sidepods. If you can have a low pressure area there, then there won't be any (maybe minimal trickle) airflow from the side of the sidepods to under the car. This is achieved by two methods. The side of undertray is sharp, it does not have rounded edges. And the undercuts on the sidepod make this area a low pressure zone.
