Vortex Generators Really Work . . . . Fact or Fiction ??
Jan 19, 2010, 12:39 PM
#31
Wow, got a chance to read it. They even divulge their optimal findings. They should be 25mm tall, 100mm from the transition of roof to glass, 100mm apart, 5mm thickness, 200mm in length (front to back). They are also supposed to be at a 15 degree attack angle to the direction of flow (so they should not all be pointing directly forward).
I wonder if someone who has them could measure them and compare those measurements to, say, an ebay version. Each of these dimensions is quite important (except for spacing as they note that doesn't change much.)
I wonder if someone who has them could measure them and compare those measurements to, say, an ebay version. Each of these dimensions is quite important (except for spacing as they note that doesn't change much.)
Jan 19, 2010, 01:02 PM
#32
I was poking around after really enjoying that paper, and maybe some of you motorsport and ECU guys can appreciate the root page: http://www.mitsubishi-motors.com/cor...w/e/index.html
They publish lots of their findings including the aero designs, ECU controls, AYC design, and MIVEC.
They publish lots of their findings including the aero designs, ECU controls, AYC design, and MIVEC.
Jan 19, 2010, 03:45 PM
#33
Wow, got a chance to read it. They even divulge their optimal findings. They should be 25mm tall, 100mm from the transition of roof to glass, 100mm apart, 5mm thickness, 200mm in length (front to back). They are also supposed to be at a 15 degree attack angle to the direction of flow (so they should not all be pointing directly forward).
I wonder if someone who has them could measure them and compare those measurements to, say, an ebay version. Each of these dimensions is quite important (except for spacing as they note that doesn't change much.)
I wonder if someone who has them could measure them and compare those measurements to, say, an ebay version. Each of these dimensions is quite important (except for spacing as they note that doesn't change much.)
Jan 19, 2010, 05:57 PM
#34
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In addition to the angle being 15 deg to the local flow, which is the usual practice, the VGs should be thin resulting in somewhat sharp edges. I imagine the mitsu lawyers nixed that!
Also, they would be hard to make out of molded plastic. Pretty easy to make out of aluminum sheet though, trim the shape, bend the foot, and glue them on. That's what is typically done on aircraft.
Also, they would be hard to make out of molded plastic. Pretty easy to make out of aluminum sheet though, trim the shape, bend the foot, and glue them on. That's what is typically done on aircraft.
Jan 19, 2010, 06:01 PM
#35
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In addition to the angle being 15 deg to the local flow, which is the usual practice, the VGs should be thin resulting in somewhat sharp edges. I imagine the mitsu lawyers nixed that!
Also, they would be hard to make out of molded plastic. Pretty easy to make out of aluminum sheet though, trim the shape, bend the foot, and glue them on. That's what is typically done on aircraft.
Also, they would be hard to make out of molded plastic. Pretty easy to make out of aluminum sheet though, trim the shape, bend the foot, and glue them on. That's what is typically done on aircraft.
.
Feb 17, 2012, 07:36 AM
#36
http://www.hotrod.com/techarticles/b...s/viewall.html
Aero Stuff That Doesn't Really Matter
In addition to our list of five tricks that almost always work, here are some things A2 customers might want to try that are really a waste of time.
Wax: Contrary to what you may read on your favorite message board, well-waxed, smooth paint is no more aerodynamic than the worst spray-can, flat-black primer job you can imagine.
Golf-ball dimples: They do not work on cars, regardless of the scale of the dimples, unless your car is a 1.68-inch-diameter sphere spinning through the air with no ground plane.
Taping seams: Rarely if ever are body-panel seams so large and misaligned that smoothing them with duct tape will make a measurable difference in Cd. We tried it on our Camaro, and it did nothing.
Smoothing rivets and hood pins: The removal of minor surface burbles, such as rivets (remember the Howard Hughes movie?) and hairpin-type hood pins shows no measurable improvement in Cd.
Dropping the tailgate: On a pickup, lowering the tailgate does not usually reduce drag. If you are racing a truck, know that extended cabs and crew cabs are more aero than regular cabs.
The biggie: windshield rake: According to Eaker, "Here's a myth I can bust. Once the windshield is past 45 degrees of rake-and many stock cars average like 60 degrees-you will not see an improvement from laying it down at an even steeper angle." We proved this on the Camaro, building a hugely sloped "windshield" out of foam core. It did nothing.
Feb 17, 2012, 07:49 AM
#37
Interesting. Personally I'd take what any hot rod guy said with a grain of salt when it came to aero, but in looking it seems they tested "high speed" aero on a stationary target. Ya non of that will give you downforce, but most of it has been proven to give you MPH because they decrease the resistance against the air, likely not much in a 10 second pass though, but in all other forms it does.
Feb 17, 2012, 08:07 AM
#39
Wow, got a chance to read it. They even divulge their optimal findings. They should be 25mm tall, 100mm from the transition of roof to glass, 100mm apart, 5mm thickness, 200mm in length (front to back). They are also supposed to be at a 15 degree attack angle to the direction of flow (so they should not all be pointing directly forward).
I wonder if someone who has them could measure them and compare those measurements to, say, an ebay version. Each of these dimensions is quite important (except for spacing as they note that doesn't change much.)
I wonder if someone who has them could measure them and compare those measurements to, say, an ebay version. Each of these dimensions is quite important (except for spacing as they note that doesn't change much.)
Mar 1, 2012, 10:02 AM
#40
He's a former senior project engineer from GM's Advanced Aero Group and was later the aerodynamicist for Hendrick Motorsports. He helped develop NASCAR roof flaps, Top Fuel body side deflectors, and the EV-1, with the lowest-ever production-car coefficient of drag (Cd) of 0.19.
His latest project is a wind tunnel known as A2, located alongside his advanced AeroDyn tunnel in Mooresville, North Carolina. AeroDyn operates nearly 24 hours a day with pro race teams, but A2 is a lower-content tunnel without a simulated moving ground plane or the capability of testing a car in yaw, where street-car guys and sportsman race teams can learn lots about their cars.
http://www.hotrod.com/techarticles/b...#ixzz1ntAFuBuk
Oct 25, 2015, 06:11 AM
#43
Newbie
