Front Splitter Details

[jonnyd1987]

Hi,

My and my mate were talking about the clio 182 trophy and he said that he thought the front splitter was just for show. Does anyone have a spec sheet or any details saying how much downforce is generated from the front splitter and rear spoiler over a standard renault sport clio without these parts (Small spoiler, no front splitter)? I've tried searching around without any luck.

Thanks

 

[pryor]

Its just for show..?

 

[jonnyd1987]

I understand that its for show, seen as i can see it. But if you understand how front splitters work then you would see that its impossible for it not to affect the downforce. I just wanted to know the figures for how much downforce it creates. Whether its noticable or negligable.........................................................................?

 

[Sam_K]

TBH front splitter is probably extremely minimal gains/downforce. If my wind tunnel was working i would post up the results! :wink:

 

[jonnyd1987]

I think Renault released an info pack or data sheet or something detailing the exact gains that the splitter gave a while ago but i cant find it. I wonder if anyone has that info. My wind tunnel is currently offline due to technical problems, otherwise id do some testing of my own.

 

[Trophy264]

so apparently alot of people own a wind tunnel these days, gone are the days of moldy garden sheds?

 

[Renaultsport]

I think Renault released an info pack or data sheet or something detailing the exact gains that the splitter gave a while ago but i cant find it. I wonder if anyone has that info. My wind tunnel is currently offline due to technical problems, otherwise id do some testing of my own.

Its for styling and adds weight to your car! oh... and if you hit it on a curb it costs you an expensive trip to the dealer.

 

[SharkyUK]

I believe that the downforce / aerodynamic effects of the splitter are negligible. It does look tidy though, especially in carbon fibre. 8)

 

[Cue]

I think Renault released an info pack or data sheet or something detailing the exact gains that the splitter gave a while ago but i cant find it. I wonder if anyone has that info. My wind tunnel is currently offline due to technical problems, otherwise id do some testing of my own.

No they didn't, its a closely guarded secret for some reason... I went down every avenue imagineable to get info on how the airflow worked around the car.... no dice.

I was looking for high and low pressure areas - i was considering a CAF but after a bit of research decided it was worthless, in fact would actually worsen things by increasing drag.

To start with although we all know it as a splitter, it's a very very basic one, normally you would have airflow passing above and below the splitter, still ours do effect/affect airflow, yes... Stay with me on this.....

To understand how a splitter creates downforce you have to know a little bit of fluid mechanics. One should at least be aware of the difference between static pressure and dynamic pressure. It is also instructive to know how dynamic pressure is related to flow velocity. This relationship is given by the well known Bernoulli equation.

The essential point to be taken from Bernoulli's equation is that the pressure inside an air stream is related to the velocity at which the airstream is moving. As the air stream velocity goes up, the dynamic pressure within the air goes down. In the case of an automobile it is instructive to consider the vehicle as stationary, with the air flow moving towards it, as opposed to the other way around. The oncoming air approaches the vehicle at V1, which is the speed of the vehicle, and a pressure P1 which is related to V1 according to Bernoulli's equation. P1 will be somewhat less then atmospheric.

As the incoming air reaches the front of the vehicle it must come to a stop before it turns to move either up and over, down and under, or around the vehicle. The area where the oncoming air flow comes to a stop is termed the "stagnation point". Since the velocity has gone down, the pressure has gone up (the "stagnation pressure). Thus the front of the moving vehicle is an area of relatively high pressure. Most people are well aware of this already.

Since the splitter is close to the tarmac, it creates a restriction to air flowing underneath it (a mini-Venturi if you will). Just as water in a river speeds up when the river narrows, the air that is piled up in front of the spoiler must speed up if it wants to squeeze underneath the splitter. And as we know from the Bernoulli equation, when an airstream speeds up, its pressure goes down. Thus the region between the splitter and the pavement is an area of low pressure. To recap; high pressure exists on top of the splitter, and low pressure exists beneath it. This adds up to a downward force on the splitter. And this downward force is directly proportional to the surface area of the splitter. So, up to a point, the bigger the splitter is, the more downforce it can create.

Plus it would be massively aided from a flat underbody and rear lower wing like the 197 has... (it helps keep the all the extra bulk nailed to the tarmac.)

 

[reboot]

Dear jonnyd1987,

Your mate said he thought they were for show, did he?

Well, how dare he?

Everyone knows that every single part of the Trophy is there to make for the finest driving experience you can have, down to the last nut (including the one behind the wheel).

Nothing on the Trophy is for show, it's all functional perfection.

Yours truly
Defender of the Red Hot Chilli Pepper