Exhaust Blown Floor - Forward Exhaust Exit

[n smikle]

I don't spend any time discussing technical stuff as I value my job far too much. I have spent most of my working life in Defence so know how expensive a few loose words can be.

And yes I know teams read these sites. Nobody is as good at spotting changes in cars like you guys are; and you always seem to get pictures.

I would gladly talk about any technical query as long as its not using an F1 car as an example. I am reasonably active on a Defence forum and I have to go to great lengths to discuss technology through quoting 3rd parties. Its just not worth the effort in F1 as there are so many more rumour mills in Defence.

My general area of work is Composites.

So go into the scarbs T-tray thread and tell them the proposal is rubbish!

And while you are at it.. give a sample of your knowledge. tell us about the carbon fibre used near the Exhaust blown diffusers.

[malcolm]

Ok, Brother, I have a few questions.

1) Would a diffuser on an LMP car draw in air from the sides?

2) If a flow from a laterally-facing jet exiting at roughly 500 mph exited a car travelling 150 mph, would that jet arc backward significantly toward longitudinal within two feet?

3) In this humourous thread, have there been any posters that have been close to the mark? Or any specific ones that have been way far off?

And finally, a comment: It's fun for us to try to reverse-engineer F1 cars, given the challenge it faces. All we have are a few videos and pictures, a few of us have access to some small CFD packages, and we're trying to figure out how all of these things work on something that is the target of the most intense engineering in the world. Given that, is it any surprise that a few of us (or even all of us) are at least a little wide of the mark when postulating how various parts work?

[shelly]

I have added an approximative path to the image I posted some time ago in another thread.
This explains my view on diffuser - floor pressure field in a non blown case. Could be a starting point for discussing blowing effects and vortices, and general diffuser functions also.

@malcom: I think that engineers' knowledge has a very narrow focus, so it is unlikely that brother, being a composite specialist, does know about specific aero topics. But maybe he can ask for hints to a colleague of his, or give us his opinion anyway.

[ringo]

It's not correct. Don't want to be blunt or anything but that is not natural.
It goes against the universal law of a system tending to a state of as low an energy as possible.
You'll never observe a flow like that in reality. The flow wont come from underneath the floor and go back in.
It wouldn't leave in the first place. If it did leave, it would be gone.

[shelly]

I think the picture is packed with information. Let us not start from the pathline, but from the pressure field.
Do you see the barge board vortex?

[PNSD]

Top picture Shelly. Where did you get it may I ask?

[shelly]

I have just made it with ms paint to explain myself better, as more than one has suggested