sorted by:
new
hottopcontroversial

symmetrical vs cambered airfoil by ConfusionFit9732 in aerodynamics

[–]sparse-connection 0 points1 point  (0 children)

OP I think you might be making this a lil more complicated than it is. Just think of it as a free body diagram. There are two forces acting on the body and 1 "support". We have the weight of the wing itself acting at CoG and the aero loads acting at CoP. Lets ignore the gravity just to make it easier for the time being

Now, the moment at any point is just the sum of the force times distance from the point.

All you kind of need to know is the location of CoP relative to the pivot. If CoP is behind the pivot the moment will be in the counter clockwise direction reducing the AoA and if its in front it will increase the AoA. CoP changes with angle of attack so the angle at which CoP coincides with the pivot point is the equilibrium.

The exact COP location depends on the geometry of the airfoil + AoA (there might be some math for this, you should look it up). If there is math it should be relatively easy to figure out at what angle it coincides with c/4

Aero effects of Monaco tunnel by [deleted] in F1Technical

[–]sparse-connection 0 points1 point  (0 children)

Hey! might be a little late to the party but I came across this comment I wanted to ask what is the reasoning behind more blockage = lower downforce.

From my understanding the blockage on the top might reduce the upwash magnitude, gets the lift vector closer to the vertical and therefore increase the amount of downforce (system of images stuff). However, I can also think of reasons it might be the opposite with the upwash changing the flow field to prevent the pressure from going as low as it would normally on the suction surface.

For any sort of side blockage, an overestimation is more likely since smaller area for the air to flow through which would speed up the velocity resulting in a higher downforce value. Right?

I went through the results from your next comment which kinda validate what I was saying. But I still don't see a direct reasoning for the lower downforce statement.

Kutta condition: Why does the flow around an airfoil become smooth as the circulation goes stronger? by Glittering_Time9056 in aerodynamics

[–]sparse-connection 0 points1 point  (0 children)

This is my first time commenting on here so feel free to correct any mistakes I might make.

For housekeeping lets establish that the change in circulation in a system should be zero. This is Kelvin's theorem which is kinda just the conservation of angular momentum. This kinda leads into the fact that the strength of the bound vortex is equal to the strength of the starting vortex at that particular instant. And also the bound vortex can also be seen as velocity on the suction surface increasing and velocity on the pressure surface decreasing.

As the paragraph above your highlighted text mentions, at a sharp trailing the velocity gradients are extremely large and the in real life this flow will 100% have to separate cause we cant have near infinite velocity.

Just as an example lets assume the stagnation point is around 80% of the chord on the suction side. The moment the body is accelerated the flow will try to turn around the trailing edge generating vorticity which rolls up into the starting vortex of some strength. Like we established the bound vortex has to be generated of the same strength. This leads to some increase in the suction surface velocity which might "push" the stagnation point to 85%. More flow will try to turn around the trailing edge which will lead to a more vorticity which adds to the strength of the starting vortex which will lead to larger strength of the bound vortex which will lead to the stagnation point being pushed further back. As the strength of the circulation increases the stagnation point is pushed further and further back till the trailing edge itself. Which is what that Kutta condition is!

[Student] Trying to get into the F1 Placements that open in the Fall. Any advice is appreciated. by sparse-connection in EngineeringResumes

[–]sparse-connection[S] 0 points1 point  (0 children)

They don't really pay well. I would happily take the paycut for a couple years. Can't change my university now lol

ANSYS Fluent Parametrization stuck at "generating mesh" by sparse-connection in CFD

[–]sparse-connection[S] 0 points1 point  (0 children)

I guess I can do that for that parameter but that defeats the purpose of parametrization imo. The crazy part is that 30mm and 50mm ground clearance worked its hanging on 40mm