Solar "Hump" for aerodynamics for Class A RV

Bugwubber

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Mid-engine Diesel. i can‘t say I noticed any change. There is a satellite dish dome right in front of the panels, two acs and two vents etc so it was fairly turbulent anyway. 6.5mpg before and after. The panels are more “knife edge” and present a smaller edge than the panels I had puzzle pieced around the ac units. First photo shows the difference as I began installing them. I have thought about a dam, but mainly to keep branches etc from getting caught under.
 

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eXodus

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Mid-engine Diesel.
What chassis?
6.5mpg before and after.
for a Diesel that's not good.
The panels are more “knife edge”
You got panels above a roof - the space between those two channels air. Since you got a bunch of obstacles underneath their my guess would be that the air slow down - so that is potentially creating a low pressure zone - which increases drag.

I like that you got a ton of panels up there. Very clean install - but the leading edge looks dangerous for anything to get caught.
Try to find a large deflector. Looks like an upside down Tub or kiddie pool cut in half could do the trick.

Imagine when you look from the front towards the RV - you don't want to see any jagged edges.
 

Bugwubber

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What chassis?

for a Diesel that's not good.

You got panels above a roof - the space between those two channels air. Since you got a bunch of obstacles underneath their my guess would be that the air slow down - so that is potentially creating a low pressure zone - which increases drag.

I like that you got a ton of panels up there. Very clean install - but the leading edge looks dangerous for anything to get caught.
Try to find a large deflector. Looks like an upside down Tub or kiddie pool cut in half could do the trick.

Imagine when you look from the front towards the RV - you don't want to see any jagged edges.
It’s a Spartan ATME 400 ISL (pre def)- Newmar’s toyhauler line for awhile
 

WYtreasure

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Just FYI - look what I saw in the wild - a Fleetwood Axon - notice the Aerodynamic hump above the front cap?
Fleetwood calls that feature "Aero-Glide"

Much more pronounced then the solar spoiler I've built - but when a mass market RV builder starts offering that feature it must have some merit.
It sure looks pretty BUT that "Next Generation Feature: Aero-Glide (Aerodynamic Design Front Cap)" could direct even more smooth flowing air under solar panels, trying to push them up. Maybe the flow will be nice and smooth over the top of the panels which will create lift.

Try to find a large deflector.
A bug deflector may work.
 

Bugwubber

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It sure looks pretty BUT that "Next Generation Feature: Aero-Glide (Aerodynamic Design Front Cap)" could direct even more smooth flowing air under solar panels, trying to push them up. Maybe the flow will be nice and smooth over the top of the panels which will create lift.


A bug deflector may work.

Probably could just add more solar lol (just angled down to be flush to the roof)
 
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Bugwubber

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eXodus

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could direct even more smooth flowing air under solar panels, trying to push them up.
My panels are directly attached to the front cap. No gap where air could get in between.

Probably could just add more solar lol (just angled down to be flush to the roof)
Please read the remainder of this thread

That's what I did. The first panel at the front is a spoiler. It angles from the front cap up.
 

12VoltInstalls

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Maybe the flow will be nice and smooth
Or not:
Please read the remainder of this thread
 

eXodus

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PXL_20220418_231624808.MP.jpgPXL_20220418_231707992.jpgScreenshot_20220510-135453.png

Even with my 5500lbs horse trailer attached I'm still around 10mpg for most of my trips,

The trailering MPG is actually a lot better then the pre-Hump mpg (8->10mpg), but I'm only on my second gas tank with that. So could be just a random climate occurrence.

Next steps, front Air Dam :)
 

Kcdaniels

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When I added another 80" x40" panel it had to be mounted further forward than I wanted...Found these on Amazon and they work great...

I would not Rely on these for just for mounts but just for air foil effects...
 

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eXodus

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When I added another 80" x40" panel it had to be mounted further forward than I wanted...Found these on Amazon and they work great...

I would not Rely on these for just for mounts but just for air foil effects...
Nice job! great creative use of the standardized material.

I had those also looked up - but found that I can mount the front panel flatter on the roof without - so my front panels is laying directly on the roof in the middle (mounted with a simple L-Angle), and has only spacer brackets on both sides.
I've tried to create very low profile.
 

NPhil

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What about the trailing edge? I think what I have read about aerodynamics implies that a longer, smoother transition on the trailing edge is as important, or even more important, than smoothing the leading edge.
 

Bobert

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What about the trailing edge? I think what I have read about aerodynamics implies that a longer, smoother transition on the trailing edge is as important, or even more important, than smoothing the leading edge.
I’m interested in learning about how to improve wind resistance at the tail of a vehicle. I have a 38’ travel trailer that I installed 10 solar panels with a 8” lift the front panels are to code to the edge and the path of the wind would obviously try to lift the panels and cause excessive wind resistance. I built a airfoil on the front to divert the wind over the panels as wel as giving a bit more strength to the front pane’s attachment. I’m curious if there is anything practical that could be done minimize the effect of the fact that the back of the trailer is completely flat.
 

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WYtreasure

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As far as the trailing edge goes, the top of a raindrop worked well about 80 years ago. That was Mother Earth's design, if I'm not mistaken. 😁

I have to wonder how much things have changed.
 

eXodus

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What about the trailing edge? I think what I have read about aerodynamics implies that a longer, smoother transition on the trailing edge is as important, or even more important, than smoothing the leading edge.
that would be a interesting topic to explore. But I want to get a lower profile A/C unit first. You can see that it's rather close the the Panels - so I would have to integrate that with the trailing edge fairing.
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when you look at the simulation (around post 100 in this threat) that only the angle of the panel in the front is already reducing the high pressure air zone above the RV.
I’m interested in learning about how to improve wind resistance at the tail of a vehicle. I have a 38’ travel trailer that I installed 10 solar panels with a 8” lift the front panels are to code to the edge and the path of the wind would obviously try to lift the panels and cause excessive wind resistance. I built a airfoil on the front to divert the wind over the panels as wel as giving a bit more strength to the front pane’s attachment. I’m curious if there is anything practical that could be done minimize the effect of the fact that the back of the trailer is completely flat.
very impressive install. pretty nice integration, I like the tent shape of the panels. You should share that somewhere in Show and Tell.

you could try posting a picture directly from the side like perfectly parallel to the RV. Some of the Simulation Wizards here could create a black and gray model and run it through the fluid dynamic flow simulation and try various tweaks.
 

Supervstech

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I’m interested in learning about how to improve wind resistance at the tail of a vehicle. I have a 38’ travel trailer that I installed 10 solar panels with a 8” lift the front panels are to code to the edge and the path of the wind would obviously try to lift the panels and cause excessive wind resistance. I built a airfoil on the front to divert the wind over the panels as wel as giving a bit more strength to the front pane’s attachment. I’m curious if there is anything practical that could be done minimize the effect of the fact that the back of the trailer is completely flat.
Truckers use a fold out panel to draw air from the sides of the trailer, I wonder if something is available like that for rv's
 
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