How much lift?

[Geokilroy]

Is there any info on the amount of lift we are dealing with on the roof of an RV?

My thought is that the lack of aerodinamics of a motorhome would lead the air up over the solar panels and not affect them. Possibly creating a dead air space. If anything, a piece of flat aluminum sheet down from the leading edge of a panel would deflect most of the problem air eliminating any lift of the panels.

Any ideas?

 

[WinnieView1]

Is the front cap sloped? A piece of flat aluminum sheet on the leading edge couldn't hurt.

 

[eXodus]

Is there any info on the amount of lift we are dealing with on the roof of an RV?

My thought is that the lack of aerodinamics of a motorhome would lead the air up over the solar panels and not affect them. Possibly creating a dead air space. If anything, a piece of flat aluminum sheet down from the leading edge of a panel would deflect most of the problem air eliminating any lift of the panels.

Any ideas?

lookup pictures of "bus aerodynamics"

an Class A behaves like a Bus.

You got a lot of lift in the front - and less in the rear of the RV. So it depends where you mount the panels.

 

[HRTKD]

Something I read about this topic was that the solar panel is flat, unlike a wing, which is curved. You shouldn't get any lift from air flowing over a flat solar panel. Pretty sure I read that on the Internet, so it must be true.

Placing a diverter on the leading edge of the panel would also prevent cool air from flowing from that end of the panel when parked. If the diverter isn't solidly attached to both the solar panel frame and the roof, then it's likely to vibrate or flap in the wind.

I do a lot of traveling through Wyoming. The winds are notoriously strong there. I've had no issues with the panels mounted on the top of my RV trailer which tops out at almost 13'.

 

[Short_Shot]

Something I read about this topic was that the solar panel is flat, unlike a wing, which is curved. You shouldn't get any lift from air flowing over a flat solar panel. Pretty sure I read that on the Internet, so it must be true.

Placing a diverter on the leading edge of the panel would also prevent cool air from flowing from that end of the panel when parked. If the diverter isn't solidly attached to both the solar panel frame and the roof, then it's likely to vibrate or flap in the wind.

I do a lot of traveling through Wyoming. The winds are notoriously strong there. I've had no issues with the panels mounted on the top of my RV trailer which tops out at almost 13'.

In fact any time you accelerate air under the panels, if anything, it will pull them down by creating a pressure drop underneath.

Either way it can be detrimental without proper mounting and if they are mounted properly then you should be able to ignore either case anyways.

Assuming the panels can handle the wind load at speed plus gusts of wind added to that.

 

[alfaeric]

The problem with panels on your roof isn't lift, it's drag. And you can put an air diverter in front and even along the sides, that will not seal the undersides of the panels.

Where this may get mixed up a little is when the airflow makes a lot of disturbance which will shake the panels- and the only direction they can go is up.... By managing the air going under the panel, the mixing of the flows will be greatly reduced.

(again, it's easy to direct the air and not seal off the bottom.)

 

[circus]

Building a roof mounted fairing is difficult so I simply screwed an air dam to the bottom of the leading edge of the panel out of roof fascia aluminum I had laying around. It reduced the gap between the panel and roof from 3" to about half an inch. To my surprise, made it quieter too.