Wind drag by a solar panel on an RV trailer

Question

I installed my solar panel a couple weeks ago and now I'm not sure if I did it right. The first pic is mine the second is the other guy. it’s what brought up the curiosity, as this guy has the same trailer and the same 200w panel as i do.

See how his panel is sticking out over the front where the teardrop is curved, it seems like it would catch a lot of air like that. So, when I installed mine I did it at a 90 degree rotation to this and installed it lengthwise so its parallel to, and even with the roof bars. My thoughts are since it’s on the flat portion of the trailer by that point it would not catch as much wind as it would facing over the curve and digging into the wind. Also i think i may grab a piece of 30 gauge sheet metal and make a loose curved ramp for the front of mine to make it more smooth by keeping the already curved shape of the trailer going till it gets to the top. but that is a project for a later date. Right now I'm just trying to see which of us installed the panel in a more aerodynamic way

Answer 1

Aerodynamics is a hobby of mine, a holdover from my flying days of the last century. The "other guy" has a great air catcher. It will direct the air under the panel, creating a compression zone and additional drag.

Automobile manufacturers love to close off openings in the front of vehicles and have the minimum area for cooling, as the air coming into an engine bay also suffers from the compression and drag.

On the flip side, your idea of creating a ramp is also valid. Consider how many roof racks you see that have just that ramp to direct air over the first bar. You would also benefit from having the same layout on the rear of the panel, to keep the airflow attached as long as possible, reducing turbulence and drag. Closing in the sides will reduce turbulence just a bit more.

I've seen fairly radical modifications to motor vehicles in which the owner created a tapered back end, running from the roof line to well aft of the bumper. This also allowed the air to remain attached well beyond the normal design considerations, and boosted his fuel economy by more than fifty percent. The creation was a bit of a visual monstrosity, however.

You're on the right track.