VitaminJ
Posts: 396
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Dec 15, 2017 3:54 pm

Cool picture! I think you placed those too far forward from the rear trailing edge for starters. Also you have too many and they are too close together from my research. Having them that close will cause the vortices to interfere with eachother and turn turbulent instead of growing the vortex. Lastly, you have staggered the vortex generators which is not recommended.

Based on the Airtab instructions the VGs should be placed as close as possible to the rear trailing edge and have a specific side spacing. Here's an excerpt from the instructions:

Airtabs™ are installed as close as possible to the rear (trailing) edges of the vehicle and with the wide
leading edge vertical. If the Airtabs must be moved forward to avoid rivet heads, obstacles, awning bars
etc., keep the wide ends of the Airtabs within 12-18 inches of the back for optimum performance.

Space Airtabs no closer than 4 inches
(10cm) on center. Increase spacing to avoid rivet heads, lights, grab bars etc. but do NOT decrease spacing as this will
decrease performance. Ensure that they are mounted in a straight vertical line. “Staggering” of the Airtabs to
accommodate body curvature is fine as long as the spacing remains consistent.

Airtabs™ can be spaced farther apart than the recommended 4 inches on center to avoid ribs, rivets, running lights, grab bars, back up lights etc. They should not be placed closer together because the adjacent vortices will interfere with each other and reduce performance. As much as we'd like to sell more, more in this case is not better, and 'shoulder to shoulder' mounting is counterproductive.


I could probably stand to move mine further rearward. In your case, I would recommend you try again if you still have the VGs and place them in a different pattern more inline with the instructions.

Lastly here is a test of vortex generators placed on a Honda Civic hatchback tested in a Lockheed Martin wind tunnel (spoiler: they work!)
http://www.airtab.com/Site/documents/Ho ... portV6.pdf
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- 2lb 5Ah LiFe 12v battery

soldcake
Posts: 61
Joined: Mon Jun 20, 2016 3:47 am
Delivery Date: 19 Jun 2016
Leaf Number: 311414

Re: Aeromod nissan leaf improved aerodynamics increased range

Mon Dec 18, 2017 11:22 am

any idea what is the spacing the vg installed in this civic?
Nov-2017 11043mi 70.4Ahr 88%SOH 82%Hx
May-2017 6866mi 72.9Ahr 91%SOH 87%Hx
Sep-2016 1050mi 74.3Ahr 93%SOH 89%Hx
2016 Leaf White SV + no premium package + rain visor + 40psi :roll:
(BayArea California)

VitaminJ
Posts: 396
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased range

Mon Dec 18, 2017 2:47 pm

No clue! For being the product of NASA and sold all over the world for decades there is surprisingly little documentation. Most of the photos on their website show the "shoulder to shoulder" mounting also.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- 2lb 5Ah LiFe 12v battery

NeilBlanchard
Posts: 617
Joined: Sat Oct 11, 2014 5:02 pm
Delivery Date: 14 Oct 2014
Leaf Number: 306278

Re: Aeromod nissan leaf improved aerodynamics increased range

Tue Dec 19, 2017 9:45 am

VitaminJ wrote:Cool picture! I think you placed those too far forward from the rear trailing edge for starters. Also you have too many and they are too close together from my research. Having them that close will cause the vortices to interfere with eachother and turn turbulent instead of growing the vortex. Lastly, you have staggered the vortex generators which is not recommended.

Based on the Airtab instructions the VGs should be placed as close as possible to the rear trailing edge and have a specific side spacing. Here's an excerpt from the instructions:

Airtabs™ are installed as close as possible to the rear (trailing) edges of the vehicle and with the wide
leading edge vertical. If the Airtabs must be moved forward to avoid rivet heads, obstacles, awning bars
etc., keep the wide ends of the Airtabs within 12-18 inches of the back for optimum performance.

Space Airtabs no closer than 4 inches
(10cm) on center. Increase spacing to avoid rivet heads, lights, grab bars etc. but do NOT decrease spacing as this will
decrease performance. Ensure that they are mounted in a straight vertical line. “Staggering” of the Airtabs to
accommodate body curvature is fine as long as the spacing remains consistent.

Airtabs™ can be spaced farther apart than the recommended 4 inches on center to avoid ribs, rivets, running lights, grab bars, back up lights etc. They should not be placed closer together because the adjacent vortices will interfere with each other and reduce performance. As much as we'd like to sell more, more in this case is not better, and 'shoulder to shoulder' mounting is counterproductive.


I could probably stand to move mine further rearward. In your case, I would recommend you try again if you still have the VGs and place them in a different pattern more inline with the instructions.

Lastly here is a test of vortex generators placed on a Honda Civic hatchback tested in a Lockheed Martin wind tunnel (spoiler: they work!)
http://www.airtab.com/Site/documents/Ho ... portV6.pdf


They were much farther apart than 4", and they were less than 18" from the back. I did lots of mods to my xA, and most of them improved things. These did not.

VitaminJ
Posts: 396
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased range

Tue Dec 19, 2017 2:40 pm

NeilBlanchard wrote:They were much farther apart than 4", and they were less than 18" from the back. I did lots of mods to my xA, and most of them improved things. These did not.

Well I don't think either one of us can come to such a firm conclusion as that :) From reading your old posts you attributed your loss in MPG to rain and carrying passengers. Your VGs are also clearly installed in a non-optimum way. I would say that my positive anecdotal experience should at least cancel out your negative anecdotal experience :mrgreen:
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- 2lb 5Ah LiFe 12v battery

NeilBlanchard
Posts: 617
Joined: Sat Oct 11, 2014 5:02 pm
Delivery Date: 14 Oct 2014
Leaf Number: 306278

Re: Aeromod nissan leaf improved aerodynamics increased range

Thu Dec 21, 2017 1:44 pm

VitaminJ wrote:
NeilBlanchard wrote:They were much farther apart than 4", and they were less than 18" from the back. I did lots of mods to my xA, and most of them improved things. These did not.

Well I don't think either one of us can come to such a firm conclusion as that :) From reading your old posts you attributed your loss in MPG to rain and carrying passengers. Your VGs are also clearly installed in a non-optimum way. I would say that my positive anecdotal experience should at least cancel out your negative anecdotal experience :mrgreen:


I have a record of every fillup for almost 10 years. And with all the aeromods I did (including side video mirrors for about 5 years), I averaged more the 50% above EPA Combined rating over that time. So, I have much more than an anecdotal account.

I don't think I had the VG's installed wrong, or sub-optimally. They are not doing things that are particularly helpful - and I don't think they can fix the drag at the back of a bluff body. A Kamm back or a boattail can fix this, though. I had a pretty large Kamm back, with wheel strakes at the end.

VitaminJ
Posts: 396
Joined: Tue Jan 03, 2017 11:46 am
Delivery Date: 07 Jan 2017
Leaf Number: 415775
Location: Morrison, CO
Contact: YouTube

Re: Aeromod nissan leaf improved aerodynamics increased range

Thu Dec 21, 2017 4:52 pm

NeilBlanchard wrote:I have a record of every fillup for almost 10 years. And with all the aeromods I did (including side video mirrors for about 5 years), I averaged more the 50% above EPA Combined rating over that time. So, I have much more than an anecdotal account.

I don't think I had the VG's installed wrong, or sub-optimally. They are not doing things that are particularly helpful - and I don't think they can fix the drag at the back of a bluff body. A Kamm back or a boattail can fix this, though. I had a pretty large Kamm back, with wheel strakes at the end.

Now you're just being stubborn :D

I have read your blog. I read it when I was still driving an ICE many years ago on ecomodder. Recently, I read the posts you wrote about your VGs. You only had them on your car for a short time and in that same time period, in your own words, was rainier than usual and you also were carrying passengers. Now if you have another blog post you want to point me to I'll gladly read that :lol:

Secondly, you clearly have not installed them correctly. Based on that your results are, in the nicest possible way, garbage.

Thirdly, VGs are most definitely intended for this type of use which is why they are marketed specifically for things like tractor trailers, horse trailers, box trailers, etc. They have also been scientifically tested by NASA and have proven to be worth several % in fuel savings.

Lastly, this morning we received some snow that was very light and dry. I was watching in my rear-view the snow coming off the roof, going abruptly down, and then swirling behind the car in a rotating mass. Doing exactly what they are supposed to do, keeping the flow attached further down the rear of the car and leaving a smaller wake. I'm going to try mounting my GoPro to watch it the next time we get snow.
2013 Ocean Blue SV w/ QC and LED
- +0.2 mi/kwh Aeromods
- 2lb 5Ah LiFe 12v battery

hornstudio
Posts: 21
Joined: Tue Jan 22, 2013 4:02 pm
Delivery Date: 01 Jul 2013
Leaf Number: 010852

Re: Aeromod nissan leaf improved aerodynamics increased range

Wed Dec 27, 2017 3:58 pm

no aerodynamics but saving fuel. i dont know if that has been postet yet: on a 2013+ leaf isolating the naked aluminium tubes that lead from the compressor of the heat pump at the bottom of the engine bay to the cabin interior at the fire wall can make the leaf feel more like fall than winter and decide earlier and more often to use the heat pump instead of the ptcs to heat and cut energy consumption a lot. ptcs are 1,5kW around and the heat pump is at 0,5kW consumption. this is an efficient 2US$ mod, especially when preheating the cabin. remember i did this first on my blue 2011 leaf in stuttgart/germany, which had the liquid heating system.

LeftieBiker
Posts: 8420
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 31 May 2013
Location: Upstate New York, US

Re: Aeromod nissan leaf improved aerodynamics increased range

Wed Dec 27, 2017 4:17 pm

hornstudio wrote:no aerodynamics but saving fuel. i dont know if that has been postet yet: on a 2013+ leaf isolating the naked aluminium tubes that lead from the compressor of the heat pump at the bottom of the engine bay to the cabin interior at the fire wall can make the leaf feel more like fall than winter and decide earlier and more often to use the heat pump instead of the ptcs to heat and cut energy consumption a lot. ptcs are 1,5kW around and the heat pump is at 0,5kW consumption. this is an efficient 2US$ mod, especially when preheating the cabin. remember i did this first on my blue 2011 leaf in stuttgart/germany, which had the liquid heating system.


If you can post photos and more detailed instructions I'll add this to my Tips & Tricks FAQ. Please post them in that topic.

http://www.mynissanleaf.com/viewtopic.php?f=38&t=23297
2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

mux
Posts: 65
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Aeromod nissan leaf improved aerodynamics increased range

Fri Mar 23, 2018 7:55 am

Well, count me in with trying out a bunch of aeromods. I've just 'finished' (i.e.: good enough for now) my extender battery project, so just before I'm heading off for a short holiday 200mi over in Germany, I'm trying out some simple aeromods.

Today I did a 5-minute (really more like 15) grill block:

Image

Just stuffed a piece of styrofoam in the hole and taped it down. It is that simple. It doesn't look half bad until you look at it really closely.

I'm also going to try and remove the antenna today, but I have no idea how that's fastened. Unfortunately we don't have a place to buy cheap 16" pizza trays, so no moonies for me yet.

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