godlameroso wrote: ↑07 Apr 2018, 23:36
It occurred to me why you'd want to have slots on the bargeboards. You want to turn the air as that creates downforce on it's own, but you also want to let some slip by to interact with the sidepod undercut. That alone would shed some drag and it's probably why teams either load the bargeboard with slots, or use capes, and all sorts of nose devices and mostly solid bargeboards, to force channel air behind the bargeboards to interact with the sidepod undercut.
Are you talking about vertical barge board pieces (big ones, actual boards) or horizontal ones? Barge boards on these cars are completely different from the first ones to be put on open wheel cars some 20+ years ago.
Vertical slots are there to move high pressure and high energy air from front side to back side. Most of the air in front of barge boards goes outboard and doesn't come back to the car any more. It's also used by horizontal pieces in front of barge boards (I'd like to call them barge board foot plates) to create some downforce. This uses the energy (brings down total pressure) in the air, so that air is not as useful. This whole area, by the looks of it, works with Y250 vortex in moving front tyre wake outboard as soon as possible.
Obviously, teams don't use upper layers of air going by barge boards to make downforce, so these can be used to energize airflow passing between the tub and barge boards. This is also increasing drag (by increasing pressure difference on front and back sides), but it's increasing the amount of air going around side pods and above diffuser as well. Needless to say, this improves diffuser performance.
Different teams use different amounts of air for different purposes, so we still have very different (but all of them very complex) barge board designs.
Basically, in this area around and in front of side pods every slot on upper surface says downforce (and sometimes vortex induction).
godlameroso wrote: ↑07 Apr 2018, 23:36
Anyone want to take a guess how the side pod end plates work with the rest of the car? Are they for both front and rear tire wake control? Do they serve a greater purpose? Are they a test item and are they eventually just going to copy Haas?
Deflectors seem to be "catching" cleaner air behind the front tyre wake. Obviously, that air can't be completely clean (ie non-turbulent) but 5% turbulence intensity is quite okay to work with and a lot better than 50% or 100% in the turbulent core behind front wheels.
Because of convergent slots (vertical flaps in this area) this cleaner air is compressed and that remaining turbulence is compressed as well and it's bad effect is mitigated. However, as on barge boards, these slots induce drag. Horizontal instead of vertical pieces (like on Haas) are probably used to exploit this area for some more downforce.
Seems to me that without these deflectors a lot of air that could be used in the rear end would be wasted. So, as ringo said, it's strange seeing so small pieces in this area. Maybe McLaren MCL33 is making a lot of drag in some other area, so the team can't afford too much more of it.
Now, the top of the barge boards and subsequent cut downstream is a very interesting area. RB14 and W09 have a flat and straight vertical board first, to minimize spillage induced by pressure difference. MCL33 has barge boards connected to the tub, to eliminate it altogether. My guess is all those teams want to have that vortex made by barge-board cut and height reduction as strong as possible. This vortex probably passes between side pods and deflectors and who knows where it could end up without deflectors. The top and side surface of side pods behind this area is low pressure and in front of rear tyre you have a large high pressure zone, so it's very likely these create a tunnel for all that air caught by deflectors to go above diffuser and help it.
godlameroso wrote: ↑08 Apr 2018, 04:33
What do you suppose that wavy wing connected to the barge board does? It's connected to the barge boards, the wavy wing basically channels air to the undercut right?
The wing-shaped strut for deflector looks to be creating a bit of downforce and aiding to move that air (coming at a steeper angle downward) to the rear, while also giving it some "upwash". "upwash" because it's more likely straightening it towards the rear, rather than sending it up.
