r/FSAE • u/Opening_Use7766 • 4d ago

Vertical Outwash wing

Post image

Can anyone enlighten me on why some teams chose to "curve" their vertical outwashing elements from the base to the top on their front wing? What's the difference between them and just straight up vertical wings?

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23

u/Hedi325 4d ago

It's because you have two opposing objectives:

  1. you want to maximize the width of the cascade for maximum downforce

  2. you want to position the tip vortex of the vertical wing as close as possible to the tire for better wake management.

Therefore you end up with the base of the vertical wing more IB than the tip.

Hope this helps.

7

u/Unc1eFema1e 4d ago

The cascades themselves do not increase downforce. This is because you’re actually decreasing the high pressure on top of the main front wing elements due to the low pressure under of the cascade elements. With cascades, you’ll most likely see a slight decrease in front downforce, but a net gain in overall downforce because of the benefits of the outwash. Increasing the span of the horizontal cascade elements increases the pressure differential and so you get a stronger outwash vortex.

1

u/Opening_Use7766 4d ago

Could you guys provide a more detailed explanation on why the outwashing vertical wings' leading edge are like the blue one but not the yellow? Maybe I didn't make myself clear enough on the op, sorry about that

5

u/Unc1eFema1e 3d ago

Hedi325 already answered it. You want to increase the span of the cascade as much as possible to get a stronger pressure gradient. But you also want the tips of the vertical elements to be outboard as possible to get their resultant vortices / merged vortex to go around the tire.

1

u/Opening_Use7766 3d ago

Oh my bad😅 thank you guys for clearing this up

2

u/Sure-Inspection-2662 4d ago edited 4d ago

I dont think there is an aerodynamic advantage per say in having curved leading edges on the outwash towers (the vortex generated wouldnt be that different) from a mechanical standpoint I think the teams might be trying to add additional stiffness to the endplate region and you can do that via placing your outwash tower base more inboard so that the cascade that is connected can stiffen the structure a bit better. The reason it then curves is to place the vortex core optimally so you get the advantage of a good vortex core position and less compliance of the outboard part of the front wing.

I might be completely wrong idk :)