|
||||||||||
|
||||||||||
3 Mar 2008, 21:34 (Ref:2143600) | #1 | ||
Rookie
Join Date: Dec 2007
Posts: 89
|
Aerodynamic surfaces...
Here's one to get yer teeth into.
I was thinking about aerodynamics on my way home from work (as you do!) and had a thought - why don't F1 cars use dimpled surfaces to reduce drag, in the same way as dimples are used on a golf ball to reduce drag? I find it hard to believe that I'm the first to think of it, so is there a specific rule banning dimpled surfaces, or is there some aspect of the physics behind it which means it simply wouldn't work? |
||
|
3 Mar 2008, 22:11 (Ref:2143622) | #2 | ||
14th
1% Club
Join Date: Jul 2001
Posts: 42,598
|
Interesting first post calibrax.
Here are a few threads on this subject in the racing technology sub-forum of 10-10ths: What would you do to your own car to decrease drag? Dimples are not zits Amongst some other in this sub forum and some kicking around elsewhere. |
||
__________________
Seriously not taking motorsport too seriously. |
3 Mar 2008, 22:23 (Ref:2143627) | #3 | ||
Veteran
Join Date: Jul 2002
Posts: 6,704
|
read the article I wrote on the subject - its on the racecar site. F1 teams have tested it.
Just realised Trikes never sent me that vee pic... Look at Zipp Speed cycle wheels Last edited by ss_collins; 3 Mar 2008 at 22:26. |
||
__________________
Chase the horizon |
3 Mar 2008, 23:52 (Ref:2143701) | #4 | |||
Veteran
Join Date: Jul 2006
Posts: 4,418
|
Quote:
Then let us know how much faster you go with all the dimples.... Oh and Welcome to 10/10ths |
|||
__________________
"When the fear of death out weighs the thrill of speed, brake." LG |
4 Mar 2008, 09:38 (Ref:2143963) | #5 | ||
Nature's servant
Veteran
Join Date: May 2000
Posts: 4,380
|
My car's full of little dents.. Don't think it goes any faster though
|
||
__________________
This planet is mildly noted for its hoopy casinos. |
4 Mar 2008, 10:20 (Ref:2144006) | #6 | ||
Veteran
Join Date: Dec 2005
Posts: 1,164
|
Is this why acne riddled teenagers with craters in their skin are usually faster than me?
|
||
__________________
Dallara F307 Toyota, MSV F3 Cup - Class and Team Champion 2012 Monoposto Champion 2008, 2010 & 2011. |
5 Mar 2008, 01:30 (Ref:2144598) | #7 | ||
Veteran
Join Date: Apr 2006
Posts: 1,910
|
I would bet my right one on the fact that it has been tested
My guess is that high speed vs low speeds would be the reason it is not done if the dimples can't trap the air to cause the boundry layer then you are just generating drag. Even though Bike wheels go fast 40 mph ground speed (less at the rim) is nothing like 120 mph, like wise boat use dimples, but the are also slow. (Also note not all manufactures use dipples, Zipp are the highest profile maker of TT equipment in the world, but other, well resoured organisations do not see the value in it, like Mavic) |
||
__________________
Contrary to popular opinion, I do have mechanical sympathy, I always feel sorry for the cars I drive. |
5 Mar 2008, 13:31 (Ref:2144920) | #8 | |
Racer
Join Date: Apr 2006
Posts: 185
|
There are a couple more things to add to this.
Currently F1 cars are developed in low-turbulence tunnels (~0.1%) at 50-60% scale and 50-60m/sec wind speeds. This means they are optimised for Reynolds numbers less than those experienced at normal racing speeds and that there will be no wing or diffuser stalls at anything but the lowest speeds on track, where the aero input to grip is minimal. One of the reasons the dimple / boundary layer trip approach tends not to work on track is because the ambient wind (in the UK at least) typically has a turbulent intensity of around %5. This means that boundary layers become turbulent a lot sooner than they would in a typical wind tunnel and so these sorts of boundary layer techniques become almost completely redundant. Somewhat ironically the road car industry is leading the way on this one, with a lot of focus being put on simulating 'realistic' on-road/track aerodynamic conditions in the wind tunnel, as it tends to lead to different optimal solutions than if you develop in a super-smooth low turbulence facility (the aeronautical ideal, but less so for ground vehicles). F1 would benefit a lot from this, particularly with respect to the aerodynamic aspect of the overtaking problem. |
|
|
6 Mar 2008, 01:32 (Ref:2145327) | #9 | ||
Veteran
Join Date: Apr 2006
Posts: 1,910
|
Intersting stuff,
Question, do they (both F1 and Road) test with various degrees of yaw as well? |
||
__________________
Contrary to popular opinion, I do have mechanical sympathy, I always feel sorry for the cars I drive. |
6 Mar 2008, 05:18 (Ref:2145383) | #10 | ||
Rookie
Join Date: Feb 2004
Posts: 81
|
Yes. They all test at different yaw angles.
|
||
|
6 Mar 2008, 13:06 (Ref:2145607) | #11 | |
Racer
Join Date: Apr 2006
Posts: 185
|
^What he said^
Plus the racing guys will do some steering and roll work too. There are some people currently working on a kind of lap simulation system, which will drive the wind tunnel model through a virtual lap. This is the next step on from the heave / pitch / yaw / roll / steer maps they do currently in that it will take into account the transient responses (such as those behind 'porpoising'). The measurement and analysis side of this is an absolute nightmare though! |
|
|
6 Mar 2008, 13:15 (Ref:2145613) | #12 | |||
Veteran
Join Date: Jul 2006
Posts: 4,418
|
Quote:
|
|||
__________________
"When the fear of death out weighs the thrill of speed, brake." LG |
6 Mar 2008, 13:42 (Ref:2145631) | #13 | |||
Veteran
Join Date: Jul 2002
Posts: 6,704
|
Quote:
see here (I know bad form but...) http://www.racecar-engineering.com/a...-surfaces.html I also know that Hendrick uses rough surfaces on its CoT's to cut drag. |
|||
__________________
Chase the horizon |
7 Mar 2008, 07:55 (Ref:2146182) | #14 | ||
Veteran
Join Date: Apr 2006
Posts: 1,910
|
Ok, but previously HED had a system on their wheels where they had dimples on part of the wheel (edges of low spoke wheels, can't remember if it was trailing or leading) and they abandoned it. Admit it not the rim like Zipp, but the same concept, indeed it should be more significant because the spokes are trying to "break" the air each time, and there are 3 of them
Look at how many track bikes use Zipp wheels... not many, and that is not a sponsorship thing, like it is in the protour. Don't get me wrong, I use 60mm deep Reynolds Wheels and pay a weight penalty over a shallower section, because aero is more important than weight in overall performance (and with wheels it is reciprocating as well) but personal experiance didn't see Zipp 303's living up to the hype |
||
__________________
Contrary to popular opinion, I do have mechanical sympathy, I always feel sorry for the cars I drive. |
7 Mar 2008, 09:29 (Ref:2146216) | #15 | ||
Veteran
Join Date: Jul 2002
Posts: 6,704
|
look om the protour - you will see Zipp wheels badged as botrangers or whatever rather a lot.
|
||
__________________
Chase the horizon |
8 Mar 2008, 01:54 (Ref:2146665) | #16 | ||
Veteran
Join Date: Apr 2006
Posts: 1,910
|
Agree the badge mean nothing. If you want to know who really uses what look that cyclingnews.com, they review actual protour bikes, and they list riders because the spec can change within the same team, both TT and road, and let you know about the "discrepancies".
Also note that nearly all of the high profile US brands are owned buy about 3 companies |
||
__________________
Contrary to popular opinion, I do have mechanical sympathy, I always feel sorry for the cars I drive. |
18 Mar 2008, 11:42 (Ref:2155524) | #17 | ||
Veteran
Join Date: Jun 2005
Posts: 508
|
The most famous example being Lance Armstrong's 1999 "Trek" TT bike that was of course a Litespeed Blade sprayed blue with a Trek sticker :-)
Ben |
||
|
18 Mar 2008, 12:23 (Ref:2155556) | #18 | |||
Veteran
Join Date: Jul 2006
Posts: 4,418
|
Quote:
The Great Eddie Merckx's bicycles said Peugeot in his early days, then Colnogo. His early Peugeots were built by Masi, and his Colnogos were built by Kessels in Belgium. Kinda Like ther GT1 an GT2 race cars. PPL think they are converted road going off the show room floor cars, but they aren't. They just LOOK like road going cars. |
|||
__________________
"When the fear of death out weighs the thrill of speed, brake." LG |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Indicating slippery surfaces | Locost47 | Marshals Forum | 13 | 30 Aug 2006 19:43 |
Tony's Homebush Street Race Fantasy Surfaces Again | Alan 52 | Australasian Touring Cars. | 184 | 27 Jul 2006 21:02 |
Aerodynamic Questions | Armco Bender | Racing Technology | 10 | 11 Feb 2003 13:35 |
Any aerodynamic experts here?? | steve nielsen | Formula One | 5 | 14 Jul 2001 15:09 |
Aerodynamic Stagger | Niall | Racing Technology | 15 | 26 Jun 2001 23:35 |