Renault R29

[xpensive]

%#&@!!! Problems with www.f1rejects.com, which is an otherwise most amusing site.

[Fil]

http://www.total-formule1.com/en/#/the-tv-commercial
I stumbled upon this tv ad during last gp,is that an interim car?

Looks like an 08 car minus some of the aero devices with an 09 livery to me.

yep, front wing is 08 width and has the 08 scoop in the middle of it. mirrors are also definitely 08 spec.

[vasia]

This isn't where it's going at all. Don't chicken out now.

The discussion concerns your poor understanding of the aerodynamics involved, and how they apply to a racecar.

Explain how it does or doesn't generate downforce, or how it limits the ability of the rest of the car to do so. Focussing on drag doesn't make sense - ask yourself the 5% question in my last post.

There's no question Renault was around a second off on raw pace at Melbourne - that it's clearly not the fastest car on the grid - or that the nose is part of the aerodynamic solution they've chosen to go with. But there's far more to performance than just aerodynamic performance, and of the aerodynamic systems that aren't working as optimally as those on competing cars it's a joke to suggest the difference is down to any small difference in drag.

This forum is called f1technical after all, right?

As said, don't chicken out now, just give it a second try.

The fat nose definitely generates downforce. Based on the design Renault is trying to send more air over the nose rather than under it. The reason I think the nose is not the most optimal solution in terms of efficient airflow is exactly that; the nose design in tandem with the front wing. The wing does not have enough complexity to it in terms of fences and planes/steps in order to efficiently guide airflow under the nose as well as over/around the front wheels.

Before anybody brings up the Brawn car again, there is no comparison. The Brawn car has a slimmer nose firstly, and also it has a much more complex front wing which works much more efficiently together with the nose. The Brawn design sends more air over the nose rather than under it, but the complex front wing also manages to feed lots of air under the nose at the same time to that splitter sitting under the nose and in front of the sidepods. Contrary to what many people think about the Brawn car, it's strong performance is based fundamentally on very efficient airflow, which thus results in lots of downforce.

Renault's front wing is definitely not as clever or useful as the Brawn wing right now.

The underdeveloped front wing, combined with underdeveloped airflow devices is why the Renault has suboptimal airflow. The fat nose, despite it's advantages, amplifies the problems of the Renault car. The fat nose would work fine if the front wing and airflow devices on the car were more developed and more complex. By airflow devices, I mean under-nose tuning vanes or a front splitter. These will be especially needed if Renault ends up running a double-deck diffuser.

In summation, if Renault wants to keep the fat nose they need a better, more complex front wing and more developed airflow devices. Otherwise, the nose needs to be changed.

Piquet fastest through the speed trap in FP2 @ 308 km/h. The R29 is slow in a what now?

That's irrelevant. Renault is running KERS which gives a big advantage in top speed at the speed traps. Seeing the trap times for the R29 running without KERS would be more accurate. Why don't you look at the apex speeds for the R29? How about the sector times for the R29? The other thing that helps the R29 in top-speed is less downforce than the top cars. The R29 suffers everywhere else though.

[timbo]

but the complex front wing also manages to feed lots of air under the nose at the same time to that splitter sitting under the nose and in front of the sidepods.

Please explain how neutral standard profile can can send more air under the nose on one car than on another. Or you imply that air channel around front tyres can somehow appear under the nose??

[xpensive]

Gaawd, how I love picture-aerodynamics. I can spend hours studying those postings on how the air is derected here, there and everywhere by all sorts of clever little devices.
Hours, no less.

[kilcoo316]

<SNIP>

Shhhhh!

Please.


Its getting painful reading that crap.


Maybe you haven't noticed, but the Renault's nose cone is designed to try and induce some rotation (the bound vortex*) around the centre section of the front wing. Thus, it generates some downforce from a neutral aerofoil section by changing its real angle of incidence to the flow (stagnation points and LE & TE).


*did they teach you about the bound vortex in picture aerodynamics school?

[vasia]

but the complex front wing also manages to feed lots of air under the nose at the same time to that splitter sitting under the nose and in front of the sidepods.

Please explain how neutral standard profile can can send more air under the nose on one car than on another. Or you imply that air channel around front tyres can somehow appear under the nose??

Wing fences can shape and guide the airflow to different places. The BMW and Brawn wings are more complex than the Renault front wing in terms of fences. The neutral standard profile does not really matter here.

<SNIP>

Shhhhh!

Please.


Its getting painful reading that crap.


Maybe you haven't noticed, but the Renault's nose cone is designed to try and induce some rotation (the bound vortex*) around the centre section of the front wing. Thus, it generates some downforce from a neutral aerofoil section by changing its real angle of incidence to the flow (stagnation points and LE & TE).


*did they teach you about the bound vortex in picture aerodynamics school?

Yes I have noticed that, and are you saying that is the most efficient design in terms of sending airflow under the nose, beneath the floor, and subsequently around the sidepods and to the diffuser?

Since it's been concluded I don't know anything about aerodynamics, is it not the front end of the car where airflow management starts? Is airflow management around the nose and front wing not important to guiding the flow to the rest of the car?

Are you going to tell me inducing rotation at the center section of the front wing is most efficient for accelerating and managing airflow through the rest of the car?

What good is Renault's fat nose right now if they don't have a front wing or airflow management devices to take full advantage of it?

[kilcoo316]

Wing fences can shape and guide the airflow to different places. The BMW and Brawn wings are more complex than the Renault front wing in terms of fences. The neutral standard profile does not really matter here.

No-one has wing fences (bar the mouting pylons) in the region of the standard profile, as it is a regulation definition.


And of course, knowing all about aerodyanmics, you'll know the transverse flow effects are zero at a wing centre, and minimal immediately either side of.

Yes I have noticed that, and are you saying that is the most efficient design in terms of sending airflow under the nose, beneath the floor, and subsequently around the sidepods and to the diffuser?

Under the nose, to beneath the floor... to around the sidepods?

Since it's been concluded I don't know anything about aerodynamics, is it not the front end of the car where airflow management starts?

In subsonic aerodynamics, not necessarily. What you do downstream can shape the flow upstream.

Is airflow management around the nose and front wing not important to guiding the flow to the rest of the car?

Of course it is.


But I've found people that use word like "management" and "condition" don't have a clue what they are talking about as they cannot even specify what is desired in the target area.

Are you going to tell me inducing rotation at the center section of the front wing is most efficient for accelerating and managing airflow through the rest of the car?

Are you going to tell me it isn't?

Tell me - why did all the teams have non-symmetrical wing profiles in the front wing centre last year... and the year before, and the year before (continue ad nauseum)


Clue: It might be something to do with a wing's centre being the most efficient place to generate downforce for minimal drag. With you on your drag crusade, I thought you'd know that. It might also be to do with the wing centre being unaffected by the front wheels.

What good is Renault's fat nose right now if they don't have a front wing or airflow management devices to take full advantage of it?

So you know the actual performance curves of Renault's front end aerodynamics?



Something for you to think about:

Often, the designer can get around having to define every aspect of the flow with fences and endplates by being clever, by using otherwise present pressure and flow gradients to manipulate the flow as desired. Simple can often be better.

The region around the front wheel stagnation point is a very complex flow area.

I would never be stupid enough to try and quantify performance of a component in this area based on photographs. I can easily state what they are trying to do - quantifying how good they are doing it is a different story. I strongly suggest you start to do the same, otherwise you'll just continue to make yourself look very stupid. If you have just started studying fluid mechanics, in a few years time you will look back on these posts and cringe.

[slimjim8201]

Had just about enough of this...

No one here can honestly say how good or bad ANY of the aero solutions really are. It's all speculation and engineering-based guesses at this point.

Renault's front end may be the best in the field. Or it may be the worst. No real way to prove it. Perhaps Renault is struggling with a mechanical grip issue? Perhaps there is some other combination of factors that are coming together to result in a medium-paced car. It's all conjecture and it may be far more complicated than we understand.

The only real fact that we know from the first two races is a rough running order of the cars. BrawnGP, for whatever combination of reasons, has the fastest package and Renault, for whatever combination of reasons, does not.

It's one thing to speculate as to why Renault is off the pace (I'm all for it). It's another to state unfounded reasons...and this thread is full of those...

[slimjim8201]

In subsonic aerodynamics, not necessarily. What you do downstream can shape the flow upstream.

A good point to remember. Lets assume that all the cars are mechanically equal and that their performance differences rest solely on their respective aerodynamic designs. I would venture a guess that the BrawnGP simply functions better as a package. I'm not really convinced that any one aero element is superior to that of any other team. Their front wing is pretty complex, but others may produce more downforce with less drag. The rear diffuser is unique, but exactly how much performance does is gain? Impossible to say.

When I look at the Brawn, the two things that stand out the most are the underbody entrance and exit. It's fair to say that they spent a great deal of time optimizing the underbody, namely the entrance "shovel" and the exit diffuser. Renault's car looks so much simpler in comparison. It's looks aerodynamically "smooth" to me, but maybe that's just the thing? Not enough flow conditioning going on? Front wing not working with the underbody? Underbody not working with the diffuser?

[kilcoo316]

No one here can honestly say how good or bad ANY of the aero solutions really are. It's all speculation and engineering-based guesses at this point.

Exactly.

We can all say what design features x, y and z are trying to do.

We don't have a clue how well they are doing it.

[jon-mullen]

No one here can honestly say how good or bad ANY of the aero solutions really are. It's all speculation and engineering-based guesses at this point.

Engineering-based if we're lucky. Can't we all just face the fact that Renault went with the fat nose on cause it's sexy?

The only real fact that we know from the first two races is a rough running order of the cars. BrawnGP, for whatever combination of reasons, has the fastest package and Renault, for whatever combination of reasons, does not.

Renault does not have the fastest package, and outside of the diffuser cars it's hard to say who does. Australia was hard to judge (although Alonso and Hamilton were the highest-finishing of the non-diffuser cars) and Malaysia was slop. Judging the R29's performance is made even more difficult by the fact that Alonso can usually score a points finish riding a donkey. So we'll have to wait and see.

[PlatinumZealot]

No one here can honestly say how good or bad ANY of the aero solutions really are. It's all speculation and engineering-based guesses at this point.

Exactly.

We can all say what design features x, y and z are trying to do.

We don't have a clue how well they are doing it.

Praise heee the Lord!! Amen =D>

[vasia]

Renault does not have the fastest package, and outside of the diffuser cars it's hard to say who does. Australia was hard to judge (although Alonso and Hamilton were the highest-finishing of the non-diffuser cars) and Malaysia was slop. Judging the R29's performance is made even more difficult by the fact that Alonso can usually score a points finish riding a donkey. So we'll have to wait and see.

Exactly. The pace of the R29 is better judged looking at Piquet, and so far he's been fairly slow. Even in the hands of Alonso the R29 has looked slow both at Australia and Malaysia. Bob Bell talks about how the R29 has plenty of pace, but they haven't been able to show that on track. I hope for Renault's sake Bell is not just spouting hot air.

[Metar]

Exactly. The pace of the R29 is better judged looking at Piquet, and so far he's been fairly slow. Even in the hands of Alonso the R29 has looked slow both at Australia and Malaysia. Bob Bell talks about how the R29 has plenty of pace, but they haven't been able to show that on track. I hope for Renault's sake Bell is not just spouting hot air.

Better look at an average between them. You shouldn't judge the Williams solely by Nakajima, nor the Renault be Piquet. While Alonso is a step above the "average", and indeed overperforms for the car - Piquet does the exact opposite.