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Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 16 May 2011, 22:40
by shelly
n smikle wrote:
I think the whole point of this is say whether his CFD is accurate? The question is how accurate do we need it to be to show that the Renault exaust is meant to form a skirt? That is the whole crux of the argument right?
Yep.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 17 May 2011, 21:30
by strad
DOesn't matter much now. :lol:

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 17 May 2011, 21:37
by malcolm
It does when they're on throttle. Blown diffusers aren't banned... just the off-throttle over-run.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 17 May 2011, 22:07
by marekk
flyboy2160 wrote:I've been able to see vortex swirling / reversed / separated flow running on an HP workstation with the results verified/matched against zillion dollar wind tunnel data and flight data. The fine meshing went as small as ~.02" to .03"

I admit I've never run adaptive mesh CFD a car - only aero-optical distortion - but I don't see why this revolutionary technique wouldn't work on an F1 model.
It would work. But you need F1 model and very fine grid for almost whole volume around the car. It won't fit into HP workstation. Not to mention we don't have the model.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 17 May 2011, 23:10
by hardingfv32
Here is my issue with the CFD presentations:

When someone presents his thoughts/theories on a subject AND supports then with some form of logic, then this logic can be challenged.

When a CFD is presented there is an assumption that it uses an accurate model of the item being discussed. How can we judge this accuracy when we know little about the actual design. In this case no statement of total accuracy was made, but how do we know where we are along accuracy scale and what are the consequences? How can any of the results be challenge?

Brian

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 17 May 2011, 23:16
by marekk
As one (well, 3 in this case) picture says more than milion words, quick summary of our 650 posts long thread:

ringo 1:
Image

scarbs:
Image

Toyota, ringo & myself :)
Image

Seems we are all just few cm apart. Thats F1 :D

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 18 May 2011, 00:00
by hardingfv32
"As one (well, 3 in this case) picture says more than milion words, quick summary of our 650 posts long thread:"

Yes, these illustrations summarize what are the general conclusions of this thread. But they lack any standing without the logic that has been agreed on in the body of this thread.

Brian

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 18 May 2011, 03:08
by ringo
Marek cherry picking the pictures. :P
That was the first iteration. It was amended to something else, which in in the thrread, but i get what you are saying.
Scarbs idea was also amended from his original concept. His amendment somewhat of a reaction to what was being discussed in this thread.

In case the question was overlooked, what if Renault change to the redbull solution?

Or will the new restriction on off throttle engine maps give the r31 solution a slight advantage?

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 21 May 2011, 12:30
by godlameroso
Image

No more speculating, now we can see what is going on..sucks for Heidfield though. It seems ringo was right, it's shoots under the floor, but some of it still goes on top. It's probably what that little crease on the edge of the floor is for.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 21 May 2011, 12:42
by Richard
If only he hadn't stopped, the we could see the high speed flow as well!

Ideally we need an internal engine failure to send smoke out the exhaust during a race so we can see the flow at high speed.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 21 May 2011, 15:44
by ringo
I looks like it's moving outside of the floor, which would agree with the skirt theory, but i must say This evidence is worse than the rain shots. Engine speeds are probably bellow 2000rpm right there, The engine could even be off.

The video in the rain shows what happens at low speeds like this.
An engine fire such as this one is not very representative.


Would be nice to see how it looks right as it happened.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 21 May 2011, 17:51
by finishline
ringo wrote: Would be nice to see how it looks right as it happened.
Unfortunately you only see flames at the front after he's slowed down an awful lot and is almost to the grass verge.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 21 May 2011, 18:58
by hardingfv32
What is the flow mechanism that improves the skirt function of this design? Does it have something to do with decreasing or increasing vortex formation, for example.

Brian

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 21 May 2011, 20:50
by godlameroso
Maybe by bleeding some of the airflow under the car creates more distributed downforce as opposed to just running the gases to the back of the car.

Re: Exhaust Blown Floor - Forward Exhaust Exit

Posted: 22 May 2011, 03:11
by strad
I captured the video (can post) and watched frame by frame and I have to agree there's not much here. It's much like the shot in the wet that only shows that they have the exhaust angled to the outside...Which does re-enforce the skirt/seal theory