one for the aerodynamistists
Discussion
www.seriouswheels.com/2006/2006-Lotus-Sport-Exige-GT3-F-1280x960.htm
relevance to the Sagaris forum?
Note the front splitter is split in half, ie doesn't go right across the front of the car, just like on the Sagaris.
Maybe it's that way on the Sagaris for some reason other than just looking uber cool
while you're at it DJC, what about the little up turned winglets on the front splitters, surely they are just to look cool? Well they succeed in doing that in my opinion. To my knowledge no other road car has 'em.
relevance to the Sagaris forum?
Note the front splitter is split in half, ie doesn't go right across the front of the car, just like on the Sagaris.
Maybe it's that way on the Sagaris for some reason other than just looking uber cool
while you're at it DJC, what about the little up turned winglets on the front splitters, surely they are just to look cool? Well they succeed in doing that in my opinion. To my knowledge no other road car has 'em.
That is the same as the options race splitters on the Noble - Something IIRC to do with getting more air through the rad (if the spliiter jut out a long way on front of the rad it could split the air over the rad or more likely simply reduce the amount of effective surface area of the rad) and presumably in the case of the racecar to have some effect on the air going under the car and making it work harder (the Noble race car had extensions down from either side of the rear venturi to almost touching the floor to make the most of it, not really practical on the road though)
trackcar said:
It could be to allow a managed quantity air under the car, which will get to the rear diffuser and give some rear end downforce .. if no air goes under the car with a full width splitter presumably no air gets to the rear diffuser so giving a front-end biased handling at speed?
As regards Pit's first question, why the split front splitter (as it were), I think the above is roughly where TVR were trying to go. Think Tyrell/Alesi/Monaco. Similar concept.
Right,
Now that Im actually in work at a reasonable time, I havent been up and working for about 20hrs, I can string a cpl of coherent thoughts together.
Simply put:
Traditional thinking...any air under car = bad. Full width front air dam = no/less air = better. Expansion of that...no/little air under car = partial vacuum. Venturi tunnels & rear difuser er, *twist* and funnel the air, squeezing it, making it flow faster. Faster air out = more vacuum under the car, more vacuum = more downforce. With me so far? Good, yer upto about 1980 or so and sliding skirts on F1 cars. Splitters aer a little bit more of a funky thought on the old front air dam. Front air dams are by their very nature ... brick walls. They are there to stop air. Splitters are cleverer air dams. Rather than stop all the air, they try and shove some over the top of the car, thereby not being purely a brick wall and so more efficient. Yes it gets a lot more complex than that but for a QDOS idea of them for you lot, that will do.
So, where are we? Ah yes we now have splitters and venturi diffusers. We are upto about 1990. Front wings on an F1 car are essentially splitters. So, now we get funky with the Tyrell monkeys. Diffusers are centred over the rear of the car, you try and squeeze the air fast out of that centre region. Hmmm...OK raise the nose, shove the splitters either side of it, try and A) block the air/manage the air down the sides/overs the sides/shovel air from the splitters down under the noise, inwards to the centre of the car. By raising the nose, we give the centre air, a relatively unrestricted passage down below the car to our underbody aero effective pieces, i.e. we are giving clean air to more aero parts, in this case the diffusers. Since then of course, F1 teams have spent probably billions of pounds between them playing about with split front splitters, noses, etc. trying to work more efficient ways of doings the job.
The Sagaris/Elise/Exige thingy is as Joo basically said trying to do a little bit of the same as Alesi's Tyrell (out on a limb, was it Barnard design and Postlethwaite aeros?) and manage the air flow down the centre of the car for the rear diffuser.
Those little winglets...OK, Ill give TVR the benefit of the doubt and say they are on there to stop the air over the splitters bleeding away over the edge. They compress the worked air in that gap, keeping it fast and moving over and through the aero appendage and squeezing it to make it go faster.
Right, a 5 minute QDOS answer for you all, I hope its enough as that is probably all Ive got time for today. Er, sorry if anybody wants anything more detailed, in which case you already know the answer....Google Is Your Friend!
Now that Im actually in work at a reasonable time, I havent been up and working for about 20hrs, I can string a cpl of coherent thoughts together.
Simply put:
Traditional thinking...any air under car = bad. Full width front air dam = no/less air = better. Expansion of that...no/little air under car = partial vacuum. Venturi tunnels & rear difuser er, *twist* and funnel the air, squeezing it, making it flow faster. Faster air out = more vacuum under the car, more vacuum = more downforce. With me so far? Good, yer upto about 1980 or so and sliding skirts on F1 cars. Splitters aer a little bit more of a funky thought on the old front air dam. Front air dams are by their very nature ... brick walls. They are there to stop air. Splitters are cleverer air dams. Rather than stop all the air, they try and shove some over the top of the car, thereby not being purely a brick wall and so more efficient. Yes it gets a lot more complex than that but for a QDOS idea of them for you lot, that will do.
So, where are we? Ah yes we now have splitters and venturi diffusers. We are upto about 1990. Front wings on an F1 car are essentially splitters. So, now we get funky with the Tyrell monkeys. Diffusers are centred over the rear of the car, you try and squeeze the air fast out of that centre region. Hmmm...OK raise the nose, shove the splitters either side of it, try and A) block the air/manage the air down the sides/overs the sides/shovel air from the splitters down under the noise, inwards to the centre of the car. By raising the nose, we give the centre air, a relatively unrestricted passage down below the car to our underbody aero effective pieces, i.e. we are giving clean air to more aero parts, in this case the diffusers. Since then of course, F1 teams have spent probably billions of pounds between them playing about with split front splitters, noses, etc. trying to work more efficient ways of doings the job.
The Sagaris/Elise/Exige thingy is as Joo basically said trying to do a little bit of the same as Alesi's Tyrell (out on a limb, was it Barnard design and Postlethwaite aeros?) and manage the air flow down the centre of the car for the rear diffuser.
Those little winglets...OK, Ill give TVR the benefit of the doubt and say they are on there to stop the air over the splitters bleeding away over the edge. They compress the worked air in that gap, keeping it fast and moving over and through the aero appendage and squeezing it to make it go faster.
Right, a 5 minute QDOS answer for you all, I hope its enough as that is probably all Ive got time for today. Er, sorry if anybody wants anything more detailed, in which case you already know the answer....Google Is Your Friend!
I just thought it interesting that the full race GT3 Lotus Exige gets a front end treatment similar to the standard road design of the Sagaris. I unfairly assumed it was like that on the 'gris just to look cool. Who knows, maybe a GT3 racer Sagaris (there's a thought....
) would have a similar front splitter design to the road Exige!
Please, someone with more spare cash and sponsorship connections than me, please start racing the Sagaris!
) would have a similar front splitter design to the road Exige! Please, someone with more spare cash and sponsorship connections than me, please start racing the Sagaris!
There seem to be two approaches to underbody aerodynamics. The safe approach is to put an airdam/splitter at the front to reduce the underbody air flow as far as possible, connect the whole underbody to the low pressure area at the back of the car and get downforce over the whole plan area. It's hard to go far wrong with this, it'll always more or less work.
The other approach is to open up the front of the car to get as much flow underneath as possible, put an extractor at the back of the car to create a dynamic pressure rise, connect the free end of this to the low pressure area at the back and let the venturi effect pull the pressure down over the rest of the underbody area. If you get this right you can get far more downforce, but it relies on keeping the air flow smooth and attached over the length of the car. It's quite a fragile approach and if anything goes wrong and the air flow gets disrupted you can end up with loats of lift and drag instead of downforce.
The front splitter design with a gap in the middle looks like an attempt to get smooth underbody flow down the center of the car which would make sense if you have a venturi which didn't extend the whole width of the car. I don't know if this is what the Saggy actually has though. Last time I looked at one there were loads of aerodynamic features that didn't look right and I was left with the impression that it had been styled rather than designed, so I'm not particularly optimistic. More likely IMO somebody thought it would look nice and sporty. But you never know.
The other approach is to open up the front of the car to get as much flow underneath as possible, put an extractor at the back of the car to create a dynamic pressure rise, connect the free end of this to the low pressure area at the back and let the venturi effect pull the pressure down over the rest of the underbody area. If you get this right you can get far more downforce, but it relies on keeping the air flow smooth and attached over the length of the car. It's quite a fragile approach and if anything goes wrong and the air flow gets disrupted you can end up with loats of lift and drag instead of downforce.
The front splitter design with a gap in the middle looks like an attempt to get smooth underbody flow down the center of the car which would make sense if you have a venturi which didn't extend the whole width of the car. I don't know if this is what the Saggy actually has though. Last time I looked at one there were loads of aerodynamic features that didn't look right and I was left with the impression that it had been styled rather than designed, so I'm not particularly optimistic. More likely IMO somebody thought it would look nice and sporty. But you never know.
Well, at least they succeeded in that. Thanks for the very interesting post though.
DJC, it looks like you have competition!
Is this consistent with the theory above?
www.seriouswheels.com/2006/2006-Lotus-Sport-Exige-GT3-R-1024x768.htm
>> Edited by the pits on Wednesday 15th February 13:23
DJC, it looks like you have competition!
Is this consistent with the theory above?
www.seriouswheels.com/2006/2006-Lotus-Sport-Exige-GT3-R-1024x768.htm
>> Edited by the pits on Wednesday 15th February 13:23
the pits said:
Well, at least they succeeded in that. Thanks for the very interesting post though.
DJC, it looks like you have competition!
Is this consistent with the theory above?
www.seriouswheels.com/2006/2006-Lotus-Sport-Exige-GT3-R-1024x768.htm
>> Edited by the pits on Wednesday 15th February 13:23
Er he basically said more or less what I did, and as I have said quite a few times in the past about some of the Sag's aero features being of the more artisitc than functional variety
Aerodynamics is to be on honest relatively easy, its only once you want to start really start fine tuning stuff that you get funky with the number monkeys. Even then we usually just go for a cup of coffee or the loo for 5 minutes, have a bit of a thunk, toddle back to the computer, throw in the ROM figures we came up and wait for the puter to tell us we were right in the first place, but now a bit more accurate out to few millionths. Occasionally we are wrong, but then we just blame it on the Requirements folk
Gassing Station | Tamora, T350 & Sagaris | Top of Page | What's New | My Stuff