Thread: Vortex Generators

Should I correct the spelling in the Fuelsavers website?

Ron

As the original inventor comments - the cars they were tested on were not a very good test vehicle - the parasitic drag of the vortex generators will be nearly as high as the improvement.

Where I would expect them to work best is on vehicles with poor streamlining to start with - i.e. Landrovers (most of them, anyway). I haven't tried them myself, but I have thought about it! To be successful I think you would have to understand the airflow on the vehicle, and the tufting tell tales used in the tests are a good way of doing this.

John

Originally Posted by JDNSW

As the original inventor comments - the cars they were tested on were not a very good test vehicle - the parasitic drag of the vortex generators will be nearly as high as the improvement.

Where I would expect them to work best is on vehicles with poor streamlining to start with - i.e. Landrovers (most of them, anyway). I haven't tried them myself, but I have thought about it! To be successful I think you would have to understand the airflow on the vehicle, and the tufting tell tales used in the tests are a good way of doing this.

John

Thanks John, It isn't an expensive experiment so I may give them a try it would just be good to hear some first hand experiences.
If and when I do I will post my results.

Streamlining has negligible affect under about 60mph/100kph. Something to do with the immutable laws of physics and the speed at which air behaves as a liquid. ask an engineer.

I reakon with all of the fuel saving thingys available to fit, by the time them all fuel should flow out of your filler as you drive.
They all seem to claim 6 to 10% savings on fuel.

RHJSTR runs them on the roofline of his discovery.

We were discussing the benefits etc... of them...

He was happy with them.

Hopefully he'll pipe up soon!!!!!

Originally Posted by Hymie

I reakon with all of the fuel saving thingys available to fit, by the time them all fuel should flow out of your filler as you drive.
They all seem to claim 6 to 10% savings on fuel.

Absolutely. The calculation you need to do is whether the fuel savings will eventually negate the cost of the tank trailer you will need to tow to catch all the fuel spilling out of your vehicles storage.

I made some of my own (as close as i could approximate to an airtab. And put them on a Subaru 1800 wagon I had at the time. I was unable to notice the difference in drag with fuel consumption measurements, however i believe it was due to the fact id was petrol engine and not running particularly efficiently at highway speeds that a few percent just wasn't noticeable.

I considered putting them on the county wagon i had (due to the gearing of the 5 speed i reckon that the difference would have been noticeable. If not in fuel consumption in acceleration and hill climbing performance). I sold it before i got a chance. My dad put some on the roof section of his county however the was no effect as the county has the ribs on the roof on the outside. And so the VGs (vortex generators) sat down between them. The defender would be a lot better. VG's need smooth flowing air to work with. If the air has gone its own way VG's wont bring it back. If you put them just before the problem area (back of car) they feed energy in to the air so that rather than separating willy nilly it tries to follow the surface in an ordered way. I have to say that in the rain the airtabs completely changed the rain pattern on the rear wind of the subaru. The stantard series/110 the front of the car (windscreen and mudguards) send the air out just about sideways. I can stick my arm out straight out the window to reach fast air at 100. So the air has to rejoin the body to make the airtabs or VGs work. I don't believe it does. So to get the full benifit of VG's you would have to do something about the front. Range Rovers and Discoverys would be much better. Would be worth a try putting them straight on. On my 120" the airflow just catches the rear edge of the canopy. Adds about 0.5L/100km to my fuel consumption. Semi trailers have the entire length of the trailer for air to re attach to the sides before it gets to the airtabs. (And even the Cab over primemoves today are more streamlined than they look)

I am planing to modify the canopy and have a play with the aerodynamics on mine. Just that i have to get the winch finished first. Priorities.

Aerodynamics can be a bit of a black art, trying is the only sure way to find out.

Hope this isn't to disjointed.

WR.