Sauber C32 Ferrari

[bhall]

---, I guess I did sorta forget to "bring it all home" in a tidy fashion.

The point about the airflow over the car being an incompressible fluid was to underline the fact that it always has somewhere to go before it's ever remotely constricted, ergo no Venturi as was stated in the original thought.

But, you get it. You always do.

[ringo]

there are drastic density changes around an F1 car. The air is not considered incompressible.

[bhall]

Please correct me if I'm wrong, but I don't think that's the case everywhere around an F1 car. I mean, If any of my ideas about choked flow on the car are correct, like at the various narrow-throated inlets, those instances would be the result of "local" compressible flow. Over the sidepods, however, or over the chassis and wings, the changes in pressure aren't anywhere near that drastic, because airflow has somewhere to escape, if you will, before its pressure can build to that point. Were that not the case, the cars would have to be shaped like bullets to escape the enormous drag penalty incurred by such pressure if it was allowed to accumulate on the nose, wings, sidepods faces and whatnot, as compressible flow would tend to do.

EDIT: Grammar. OCD is a ---. Fo' real, yo.

[Raptor22]

there are drastic density changes around an F1 car. The air is not considered incompressible.

F1 cars are not approaching transonic let alone supersonic speeds so the air flowing around it is not considered to be compressible. Its treated as IMCOMPRESSIBLE FLOW.

There are compressiblity effects but they are so small that they are considered negligible.
If you have a super computer the small changes in psi / bar around the car can be considered but it hardly alters the flow patterns.

[bhall]

Indeed, "incompressible flow," as opposed to "incompressible fluid," was definitely the term I should have used before.

[Raptor22]

even so if we are dealing in absolutes then even water or oil are compressible, just not by very much are one needs a lot more gravity available here on earth.

Within the boundaries of relativity in the Solar system we live in and more specifically the neutonian physics that governs motion and other physical and chemical laws on Earth, air moving sub sonic is considered an impressible fluid in a flow environment. Add boundaries, and its compressible and will obey Boyles law. A liquid could also be compressed but its bulk modulus means we can consider it incompressible under dynamic or static conditions.

Its important for everyone to understand these laws and constructs.
Boundaryless flow, gases are incompressible
Bounded flow (like in pneumatics) , then gases are considered compressible

[Artur Craft]

I posted the rake comparison made by RaceCar engineering on the appropriate thread, and now I wonder what is the disadvantadge of rake?

I know the benefit of if, it makes the whole floor work as a diffuser, which will increase downforce. Red Bull have been using it for a very long time, why doesn't the others do the same? or why not to the same extent, to put it better?

The comparison was posted here:
http://www.f1technical.net/forum/viewto ... 45#p416445

Why would have Williams opted for almost no rake at all, Sauber for a little of it and Red Bull a lot of it?

Isn't this something that C32 could improve on? The rake would bring the car even more downforce with no, at first sight, significant increase in drag

There must be a downside of rake, anybody knows it, if it really exists?

[Owen.C93]

You can't run a lot of rake without good diffuser seal and strong flow under the floor. Otherwise you start getting separation and stalling issues.

[Drewd11]

You can't run a lot of rake without good diffuser seal and strong flow under the floor. Otherwise you start getting separation and stalling issues.

This is why people were commenting positively on the rake of the W04. It implies that the exhaust and therefore the diffuser seal is performing well.
Further running a lot of rake is only possible when you can run a low tea tray, implying well sorted front suspension settings (so that the tea tray will not impact under braking).

[bhall]

even so if we are dealing in absolutes then even water or oil are compressible, just not by very much are one needs a lot more gravity available here on earth.

Within the boundaries of relativity in the Solar system we live in and more specifically the neutonian physics that governs motion and other physical and chemical laws on Earth, air moving sub sonic is considered an impressible fluid in a flow environment. Add boundaries, and its compressible and will obey Boyles law. A liquid could also be compressed but its bulk modulus means we can consider it incompressible under dynamic or static conditions.

Its important for everyone to understand these laws and constructs.
Boundaryless flow, gases are incompressible
Bounded flow (like in pneumatics) , then gases are considered compressible

Just for the sake of clarification, are you implying that the laws of physics themselves are location-dependent variables, i.e. Event-A occurs at Location-X and only at Location-X, because other locations have altogether different rules? Or have you said that any practical application of the laws of physics is environmentally-dependent, i.e. Event-A, which in the context of this discussion is incompressible flow, occurs at Location-X (Earth), and it can occur anywhere else provided environmental factors at that location are the same as those on Earth? I can get behind the latter, not so much the former.

Otherwise, I think we've expressed identical views here. But, the way you've phrased that last bit has confused me.

[Raptor22]

The latter.

Also remember that a lot of the newtonian laws are based on observations on Earth and will be slightly different on Jupiter due to difference in Gravity which can influence the local speed of light.

However if we were in a solar system in a different part of the galaxy where there is generally more gravity i.e. orbiting a more massive star, the newtonian laws would not apply without some serious revision, hence I stated that its all relative.

back to F1 cars,

[Nando]

Edit: lol at YOU, you know who you are.

[aral]

http://eoimages.gsfc.nasa.gov/images/im ... 52_lrg.jpg

What on earth has this meteorology got to do with the Sauber C32?

[Richard]

What on earth has this meteorology got to do with the Sauber C32?

Look at the caption - it shows the variation in gravity around the earth.

Raptor & bhallg2k - Thanks for reminding us that air should be considered incompressible in the context of air flow over an F1 car. It's nice to have the occasional interlude while we wait for more pictures of the car.

Back to Sauber - I am curious about the lift on the pods. Sending flow sideways on each side results in equal and opposite forces. The sloping Sauber pod sends air over the top so that would create a bit of lift. Obviously they perceive the overall benefits outweigh that notional lift.

How much lift is created? Is it significant or is this an angels on the head of a pin debate? http://en.wikipedia.org/wiki/How_many_a ... f_a_pin%3F

[Nando]

What on earth has this meteorology got to do with the Sauber C32?

Did you bother reading the text in the picture?
It´s off topic but i posted it because of the conversation above.
But of course when i post then all of a sudden we are off topic..