Vanja #66 wrote: ↑
Tue Feb 22, 2022 7:59 pm
As promised, here are the results for W13-like sidepods as well. Once again, I opted mostly for comparisons, that's really the most interesting and the most relevant for us. To avoid any confusion, as we can discuss these concepts only to an extent - since we don't have actual geometries with all the details - let's call them tub-pods and micro-pods.
Both simulations had their problems with various eddies and separations where probably there isn't any. With that in mind, I'm happy that both had roughly the same amount of problematic areas. Micro-pods are really slim and really low drag altogether, lot less than tub-sidepods percentage wise. I've added the rear part of engine cover to sidepod surface to have a better comparison base, I think it can be seen easily.
As can be seen on iso views, the rear tyre of micro-pods has a larger stagnation zone. It naturally had comparatively more drag as well. This was unexpected for me, as micro-pods, just like W13, feature an outwash "flick" along the inlet and I expected this is used to throw the air out and let it hit the tyre. It might as well be that other W13 elements help with this and the overall effect is better, but this is what we have. Sidepod and rear-tyre mixed together - tub-pods are slightly less draggy.
From the top view, the difference is astonishing and one could easily confuse these two cars for completely different series. Micro-pods, being micro, leave a large floor surface exposed, where the air can slow down a bit and build up some pressure to add to the overall downforce. And this is not insignificant over such a large surface.
However, for some reason the top surface of the rear wing generates less downforce, being "less red" This was also unexpected for me and I couldn't find the proper reason for this. Seeing these results gives another angle at why W13 has such a huge rear wing angle over the entire span, along with the huge airbox.
This is a velocity plot at 0.3m above ground, just like before. The difference is huge and very telling on just how different these cars actually are. The way the slow air hits the rear tyre affects a lot of different areas as well, such as diffuser sealing, diffuser and floor overall, maybe even rear wing to some extent.
Overall, micro-pods-car generated more downforce and more drag, for those who believe this information might be valuable. I won't mention downforce and drag percentages and such, but I think it could be noted that the difference in drag is twice as big as the downforce difference - meaning micro-pods-car generated more downforce but with lower downforce/drag ratio.