GasPods: stick on airfoils

[euromodder]

Originally Posted by ConnClark

A simple semi spherical bump is all that is needed to mix the slower boundary layer with the faster moving air above it.

The following report describes boundary layer control using all sorts of techniques. Included are VGs, Arches, Cylindrical posts, and many more.

But whatever sticks out into the airflow, is not very streamlined as a rule.

These gaspods are streamlined shapes, so while they will still push a bit of air up and aside, it won't be much, and it'll be done fairly gently, allowing the air to return to where it was before ... so where would their claimed effect come from ?

[gone-ot]

they "work" on exactly the same principle as VENDOR DECALS do on race cars--they make the cars "go" faster just by being there on the sides of the cars (wink,wink)!

[Piwoslaw]

Originally Posted by Old Tele man

they "work" on exactly the same principle as VENDOR DECALS do on race cars--they make the cars "go" faster just by being there on the sides of the cars (wink,wink)!

So my above-average milage is because of the vendor decal?

[ConnClark]

Originally Posted by euromodder

But whatever sticks out into the airflow, is not very streamlined as a rule.

These gaspods are streamlined shapes, so while they will still push a bit of air up and aside, it won't be much, and it'll be done fairly gently, allowing the air to return to where it was before ... so where would their claimed effect come from ?

The air that gets pushed up gets accelerated by the faster air. When it returns it accelerates the slower air. It may be less effective at re-energizing the boundary layer than other shapes but it does have less drag. Its a trade off. You can however use more of them to get the same effect.

[jalmir]

Originally Posted by Piwoslaw

So my above-average milage is because of the vendor decal?

bingo!

that ecomodder sticker must give you a good 5-6 better MPG!!!

stick a hundred of them on the car and it might just start pumping fuel back in your fuel tank!!!

[broski499]

Suzie should just give use a few free samples to those interested, my humps my humps my lovely gas humps.

[ECONORAM]

I think these pod bumps could possibly work, but I don't see how one could actually get bonafide gains without precise placement on the vehicle. The information I've read about vortex generators and microvanes talks about how they have to be properly placed/positioned, or they'll harm airflow instead of improving it. This is the reason I've not tried any VGs or such stuff; I don't want to do hundreds of miles of tuft testing to see if I got it right or not, when there are several proven items I can install and benefit from...

[razor02097]

Originally Posted by ECONORAM

I think these pod bumps could possibly work, but I don't see how one could actually get bonafide gains without precise placement on the vehicle. The information I've read about vortex generators and microvanes talks about how they have to be properly placed/positioned, or they'll harm airflow instead of improving it. This is the reason I've not tried any VGs or such stuff; I don't want to do hundreds of miles of tuft testing to see if I got it right or not, when there are several proven items I can install and benefit from...

I'm not an aeronautical engineer but I know that if you are going to put VGs on a vehicle they need to not only be placed correctly but scaled to the application. If they are too small they might not affect the air enough and too big they would create more drag than without. That said they probably need to have the shape tweaked depending on where they will be placed and how large they are.

If the company was out to sell a product that reduces your aerodynamic drag there would be testing with many different vehicles. There would be instructions on where to place them and there would be different types of gas pods that are used for different vehicles and the unique shapes found on those vehicles.

Being $30 for a set of 3 my non technical opinion is there is insufficient proof to but 2 or 3 sets to attempt to reduce drag. For $60-$90 one can buy a lot of material for mods or instrumentation that are proven over and over to work.

[Swordsman]

Wouldn't a simple string test show if these did any good? But then, who's going to dump $60+ just to find out? These are the most expensive VGs (oops, non-VGs...?) I've seen on the market. You can make a ton of aircraft-style ones out of a $5 aluminum bar.

~SM

[ChazInMT]

Originally Posted by Swordsman

Wouldn't a simple string test show if these did any good?

No, a string test would only tell you what's going on with the layer of air right next to he car, which can be a helpful tool in some cases, but is only a very small piece of the puzzle.

The best test for these would be a fairly long steep hill where a car can coast at 50-60 mph then time how long it take to go a set distance, while keeping track of your speed, both with and without the aero enhancement. If there is a significant difference, it would show up on this test.

I would be shocked to the core if you could see a 3% variation testing Gaspods by Aerohance using this test.