Exhaust Blown Floor - Forward Exhaust Exit

[ringo]

volarchico

I understood you statement and was not disturbed by it. I just thought a more detailed comment about one member of this forum was in order.

In this case Ringo has voiced a theory which he cannot translate to actual physical traits on the R31.
This is not unusual.

Brian

I said it already! It's in the middle of thread and it's already in the ferrari thread.
It speaks to the traits of the R31.

let me go back and find it.

[MIKEY_!]

At least ringo has been able to provide some sort of evidence, unlike most of us. CFD will not be truly accurate unlit we have a really powerful computer (or lots of time), a top notch CFD program and a comprehensive model of the R31 + internals to some extent (or accurate information regarding pressure, speed and temperature of exhaust and maybe even radiator outlets).

Until someone comes up with that lot we can only speculate/guess/experiment with known concepts and tools that we have at our disposal.

[PNSD]

And saying homemade CFD is not accurate.
As said earlier the only limitation is the calculation time.
I didn't create a program for it to be homemade. I can't create these wonderfull software.
Secondly i'm just as qualified to run an accurate CFD as any other F1 engineer out there. I just don't have the work experience.

It would be nice if you could prove that "homemade" CFD is inaccurate.
So far it's holding up nicely.

A few things;

Only limiting factor calculation time? Im not so sure. My issue with the whole the subject is the accuracy flow works can provide for this application.

You say it's holding up nicely, but there is no possible way to determine this unless you have a batch of comparison data?

[shelly]

ringo, for your last post I see that I have not explained myself better, or that you do not want to understand.

When you says that cfd is holding up, you do not take into account thta what you bring in as evidence of this is nt a valid proof. So you have no proof or data to validate anything, you just have a embedded cfd software (which is not on par with proper cfd software), run on model without anything but rough estimates of the boundary conditions, with limited computing power that does not allow for a detailed enough mesh. So it does not add up anything to the discussion.

So stating that your opinion stands untouchable because this kind of cfd tells so, is not constructive, nor it is refusing to discuss.

[Sonic59]

ringo, for your last post I see that I have not explained myself better, or that you do not want to understand.

When you says that cfd is holding up, you do not take into account thta what you bring in as evidence of this is nt a valid proof. So you have no proof or data to validate anything, you just have a embedded cfd software (which is not on par with proper cfd software), run on model without anything but rough estimates of the boundary conditions, with limited computing power that does not allow for a detailed enough mesh. So it does not add up anything to the discussion.

So stating that your opinion stands untouchable because this kind of cfd tells so, is not constructive, nor it is refusing to discuss.

Ofcourse even using industrial CFD and supercomputer u can not be sure in result (Virgin is a living proof). But I didnt noticed any arguments added by you. Ringo may be going the wrong way, but at least he is trying. While all u do is saying he is wrong.

[shelly]

sonic59, I disagree with you. When ringo says "it is like that because cfd tells so", I say that you can not trust cfd and the discussion should go on differently, for example estimating effect fo side car flow on deflection of exhaust path etc.

There have been some side issues like the dust trajectory (which again I tried to explain), and the discussion about flow coming in the floor from the sides, which some poster think harmful for downforce.
I have taken Allison words and corrected my point of view by taking into consideration the barg board vortex,for which I had to write n times tht i was reffering to the vortex generated by the bargeboard and not to another.

So I explained my views, introduced ideas and motivated them and got almost no answer for that, except "cfd does not lie".

I think that you should read this loong thread to get a better idea.

[Sonic59]

Well, Shelly, I made a quick look through the thread. I want to say that all your posts have one big problem - you trying to talk about geometry without actually posting a single picture. Its really difficult to follow your logic path. So dont be surprised many people will argue your statements.
So please people - post pictures. One picture sometimes can substitute pages of text.

[shelly]

This is a fair point, and from now I will begin to include some sketches.
Till now I have always taken other poster' drawing as good representatio of what I was saying.

[ringo]

sonic59, I disagree with you. When ringo says "it is like that because cfd tells so", I say that you can not trust cfd and the discussion should go on differently, for example estimating effect fo side car flow on deflection of exhaust path etc.

There have been some side issues like the dust trajectory (which again I tried to explain), and the discussion about flow coming in the floor from the sides, which some poster think harmful for downforce.
I have taken Allison words and corrected my point of view by taking into consideration the barg board vortex,for which I had to write n times tht i was reffering to the vortex generated by the bargeboard and not to another.

So I explained my views, introduced ideas and motivated them and got almost no answer for that, except "cfd does not lie".

I think that you should read this loong thread to get a better idea.

I'm witholding any details, until i see other images as sonic says.
It's funny you say that the CFD can't be trusted, yet you want people to trust what they cannot see or can't quantify.
I'll get into detail if you generally want to inquiry about a specific aspect.
Doent make sense killing out my self, only to have it pushed aside becuase it's homemade hill billy CFD.
If you understood the maths behind the CFD, you would agree that it is pretty difficult for it to get this r31 simulation inccorect; providing the geometry is accurate.
The level of accuracy we need at the moment is where it flows, and no CFD package out there is so incompetent that it will completely throw off a calculated flow by a few feet.
As sonic says a few images would be good, so it can either be supported or shot down.

[hardingfv32]

Ringo,

A very narrow and specific request:

Please define what parts of the R31 mimic those of the ejector example. For instance what do you consider to be the chamber and inlet port? Is there a choke point just after the two flows mix and go out the diffuser?

Brian

[Sonic59]

I'm witholding any details, until i see other images as sonic says.
It's funny you say that the CFD can't be trusted, yet you want people to trust what they cannot see or can't quantify.
I'll get into detail if you generally want to inquiry about a specific aspect.
Doent make sense killing out my self, only to have it pushed aside becuase it's homemade hill billy CFD.
If you understood the maths behind the CFD, you would agree that it is pretty difficult for it to get this r31 simulation inccorect; providing the geometry is accurate.
The level of accuracy we need at the moment is where it flows, and no CFD package out there is so incompetent that it will completely throw off a calculated flow by a few feet.
As sonic says a few images would be good, so it can either be supported or shot down.

Shelly's opinion about CFD u use is based on very low accuracy of SolidWorks flowsimulation. As I said before in another thread, its really a big problem about FlowSimulation and some other CFD. Accuracy may vary a lot. So, ringo, if u want shelly believe your calculation, make a very-very simplified model, leaving only important details. On a simplified 3d model with high resolution mesh results may be acceptable (but still accuracy +-20%). What you trying to calculate(the whole car) is almost impossible to do even on supercomputer.

[shelly]

ringo, do you really need a picture to understand that cement dust is much heavier than air?
Let us start from that.

[Brother]

As somebody who used to work with Renault on these floors I find this thread absolutely amazing.

As an office we have not enjoyed a thread this much since the R30 thread in the days of the diffuser rows.

Making this grey Saturday behind our screens just about bearable, Thanks

[hollus]

Would you then bother to comment on what Allison said?

[PNSD]

As somebody who used to work with Renault on these floors I find this thread absolutely amazing.

As an office we have not enjoyed a thread this much since the R30 thread in the days of the diffuser rows.

Making this grey Saturday behind our screens just about bearable, Thanks

Used to work with Renault on these floors?

Your using the past tense, and present tense in this post. You say used to work with Renault, then say making this saturday bearable. So still with Renault, different dept?

Rather than being an arrogant tw*t about it (pardon myself) why not tell us why you find it amazing. Afterall is not life about learning? Excuse what may seem like poor attitude but I find it just as amazing that you've bothered to post only an insult without enlightening us all with an apparent superior knowledge .