Barge boards and sealing the floor

[johnbeamer]

My understanding is that barge boards have a couple of roles. One is to tidy up the flow around the side of the car, indeed I think this was the original idea. Additionally all the sawtooth edges were designed to create vortices.

My understanding was that these vortices were mainly designed to sweep under the floor, providing higher energy flow to the diffuser, hence creating more downforce.

However, I was intrigued by what Scarbs wrote in this post: viewtopic.php?f=6&t=5388

He said:

"Later teams adopted bargeboards one use of which was to create a vortice to help seal the floor".

This implies that some of the vortices seal the floor. I guess this could happen by sending a clockwise vortice (looking from the car's nose) down the side of the car, whose turning action could prevent a seal.

Is this possible? Are both effects in play?

Thanks
John

[scarbs]

I understand from F1 aerodynamicists that the sealing effect is less of a priority than it used to be, that is not to say some effort is directed that way.

[johnbeamer]

Thanks Scarbs, that is helpful knowledge.

One question though: what is the mechanism that a vortex would "seal the floor"?

My understanding (which stands to be corrected) is that the energy from a vortex directed at the sides of the floor will sweep higher pressure flow into the vortex structure thereby sealing the floor?

Is that right?

[taku]

bargeboards produce two vortices one from the bottom edge and one from the top edge.

the bottom one makes its way under the floor giving lots of nice low pressure and i believe the top one helps to seal the floor as follows:

looking down the car from the nose to the rear wing, the top vortex is rotating clockwise from the left side bargeboard (counter-clockwise from the right side bargeboard). this passes around the outside of the sidepod and the rotation pushes the higher pressure air away from the edge of the floor. i think this is the reason teams have gone for the heavily sculpted sidepods (narrower at the bottom to allow more room for this vortex to develop)

anyone else?