Red Bull Rake 2012 without EBD

[aterren]

Haha....yeah... you know what I meant. Fluid...can't believe I did that. I'm going to blame the coffee. I also got verticle and horizontal mixed up regarding some structural steel here at work. So sad...

Hurry and answer your phone. HRT wants to offer you a job.

[godlameroso]

1) I believe that earlier in the season there were cars designed without EBD. Why did none of these cars make use of the ideas you are proposing?

2) Regardless of the quality of your diffuser edge/skirt sealing, why would you not want the largest possible diffuser exit volume? May I assume that a larger exhaust volume means the potential for greater low pressure?

Brian

It's all about where you place the exhausts, in nature vortecies are created when cold and hot air masses slam into each other. By heating the edge of the outer part of the diffuser you create a large temperature difference between the air going over the diffuser, and the air going through it, precisely where the pressure differential is the highest. The exhaust doesn't add much to pressure(aerodynamic effects add substantially more), yet it does add a lot of temperature and it's this difference that causes vortecies to form. I'm sure other teams knew this, but just could not get it to work as well as Red Bull. McLaren came closest, however, I feel they dropped the ball when it came to using the cooling exits. Aside from this, there are some other details the RB7 does better. Like using the cascades on the rear tires to help tune the vortecies they produce. I imagine the large cooling hole aids in this effect as well, it's not improbable that the effect also extends to the beam wing.

In any case having a larger volume allows for potentially more flow, although if the diffuser isn't designed properly then the turbulence will stagnate and therefore limit your flow. As long the flow stays laminar across the diffuser then yes bigger is better.

[shelly]

ògodlameros: I think temperature has less infleunce then speed in vortex formation with the exhausts. Where did you get the info on temperature influence from?

[Sonic59]

It's all about where you place the exhausts, in nature vortecies are created when cold and hot air masses slam into each other. By heating the edge of the outer part of the diffuser you create a large temperature difference between the air going over the diffuser, and the air going through it, precisely where the pressure differential is the highest. The exhaust doesn't add much to pressure(aerodynamic effects add substantially more), yet it does add a lot of temperature and it's this difference that causes vortecies to form.

In any case having a larger volume allows for potentially more flow, although if the diffuser isn't designed properly then the turbulence will stagnate and therefore limit your flow. As long the flow stays laminar across the diffuser then yes bigger is better.

Can u draw a picture what u talking about?

[godlameroso]

ògodlameros: I think temperature has less infleunce then speed in vortex formation with the exhausts. Where did you get the info on temperature influence from?

From a book on tornadoes, most theories with tornadoes have one thing in common: a mass of cold air and a mass of hot air colliding. Which is why you don't usually see tornadoes in places where the weather is pretty much constant. However in places in the U.S. where cold air from the north meets the much warmer temperature in, say the south east, you get tornadoes.

It's not the difference in temperature by itself that causes vortex formation, however, said difference increases the probability of vortex formation. Pressure, Volume, and Temperature are all intimately related. Change one and the others change with it. So think about it, you have a given volume, dictated by the aerodynamics, a given pressure differential, also directed by aerodynamics, and along with all that you also create a (massive) temperature differential, which also changes the pressure differential(slightly), as well as volume(slightly, remember hotter air is less dense air). The bodywork is responsible for the generation of vortex, the exhausts just make sure it happens more often, and at lower speeds.

[shelly]

Yes I Thought you got it from meteorology. Though the basic laws are the same, I think in f1 application is high speed and low pressure of the exhaust which play the major role, even if temeprature has an influence.
It is way different form tornadoes

[MIKEY_!]

I think they will go for some radiator gases through where the exhausts go now. They could increase the flow by using a venturi on the exits (i think) and maybe some Meredith effect too (if its allowed). That could give a similar (although lesser) effect to what they have now.

[Sonic59]

I think they will go for some radiator gases through where the exhausts go now. They could increase the flow by using a venturi on the exits (i think) and maybe some Meredith effect too (if its allowed). That could give a similar (although lesser) effect to what they have now.

First of all Meredith effect is about creating a thrust. And i think most of teams already use it. Secondly on exit we need a high temperature gas about 700-1000 celsius degrees. And i dont think radiator can give such a high temperature.

[MIKEY_!]

I know thats, why i said 'lesser'. And i know the meredith effect is for thrust which is kind of what the high speed exhaust gasses produce, and again 'lesser'.

Any advantage is an advantage worth taking (so long as it doesn't compromise the overall design somewhere else)

Could this along with the vortex generators mentioned earlier work together.

[Sonic59]

I know thats, why i said 'lesser'. And i know the meredith effect is for thrust which is kind of what the high speed exhaust gasses produce, and again 'lesser'.

Any advantage is an advantage worth taking (so long as it doesn't compromise the overall design somewhere else)

Could this along with the vortex generators mentioned earlier work together.

Well the biggest broblem here is numbers. All we talking about is suggestions and ideas, but any idea without mathematical backup is fake. Your idea may work or may not - I dont know.
Temperarute is not the only problem here. Engine needs correct flow spreading because of overheating. If the flow doestnt reach some engine zones, those zones will crack earlier than expected.
The meredith effect may affect flow spreading. The question is by how much?

[godlameroso]

Apparently the air that travels through the chassis has a lot of pressure, I remember a chunk of engine cover flying off the Sauber during winter testing. I think that's why most cars have extra orifices and vents at the leading and trailing edge of the sidepods, to relieve some of the pressure that builds up, most notably the w02.

[Dragonfly]

Isn't the air flow through the radiator boxes conditioned and slowed down by means of size, shape and additional elements in front of them?

[Sonic59]

Isn't the air flow through the radiator boxes conditioned and slowed down by means of size, shape and additional elements in front of them?

Partly. For subsonic flow the elements behind can affect elements in front. A simple example:

As u can see on a picture, high pressure zone (caused by a sharp angle on the ground) speads forward for subsonic flow. But for supersonic flow in has no inflence (although there is still pressure difference before and arter sharp angle).

[Dragonfly]

Thanks Sonic59, I read your posts and illustrations with great interest.

[dren]

remove post please