Aeromodifications for large motorhome

[aerohead]

Originally Posted by botsapper

The usual boat tail (folding) wings @ recommended taper angles. While we're at it, shallower nosecones & boat tails on the AC units. (Optional: awnings removed). Front & rear wheel well covers. Just the start...

botsapper,I hope Coleman can get a look at your image of their AC units.According to Hoerner,the fairings would drop their drag to Cd 0.09,from maybe Cd 0.45 now.With that you could just leave 'em in place.Ditto for the Weingard satellite antenna housings.all that stuff could benefit.
As always,your Photo Shop skills are exemplary! You the Man!

[orbywan]

I have a question for everyone if I may; does anyone know of a mileage calculator that works on OBD1 vehicles? Checking my VIN, my RV is actually a 95 Ford cab, which means the system is OBD1, and most mileage calculators, i.e. ScanGauge, etc., are for OBDII only I believe.

This would make short term testing for results way easier.

[Weather Spotter]

Alternative fuel consumption instruments - EcoModder

[orbywan]

Great information Weather Spotter, thank you very much. When I have time to breathe I'll sit down and check it out.

[Weather Spotter]

You may also wan to look through the wiki, it has lots of good mods and results in it.

[orbywan]

I have a question regarding boat tails for everyone if I may. I'm building a 5 foot boat tail for the back of my RV. My question is; over the 5 foot length of the tail, how much bow should the sides have?

I'm guessing from my flying days that the best shape for the sides of the boat tail should be shaped very much like a wing, bowed in the tightest arc possible, or close to it, that will allow the air to adhere to the curve, ala the Coriolis effect, without having separation of airflow on the boat tail surface.

If that is true, can anyone tell me how much curve to put in the tail surfaces?
Thanks. I thought I was going to whip up a quick test cone to see what the results were. Ah, grasshopper, you have much to learn.

[Weather Spotter]

it sounds like you are on the right path.

[euromodder]

Search EM for the aerodynamic template, and follow its curved lines.

Flat panels would be a lot easier to make though, and you'd essentially get the same results.

[basjoos]

I used the tailcone of a Questair Venture kitplane, nicknamed "the flying egg" for its short fat fuselage, as a template when building my boattail. A line drawing of the Venture is at:

http://img.photobucket.com/albums/v417/MikeMariettaSC/80MPG%20Honda%20Civic/Venture_s_th.jpg

[crmears]

Originally Posted by orbywan

I have a question regarding boat tails for everyone if I may. I'm building a 5 foot boat tail for the back of my RV. My question is; over the 5 foot length of the tail, how much bow should the sides have?

I'm guessing from my flying days that the best shape for the sides of the boat tail should be shaped very much like a wing, bowed in the tightest arc possible, or close to it, that will allow the air to adhere to the curve, ala the Coriolis effect, without having separation of airflow on the boat tail surface.

If that is true, can anyone tell me how much curve to put in the tail surfaces?
Thanks. I thought I was going to whip up a quick test cone to see what the results were. Ah, grasshopper, you have much to learn.

I do not think that we should attempt to copy the shape of a wing. Wings are designed to use airflow to create lift. The action of creating lift with a wing induces drag. The best thing to copy is the fuseloge of an airplane. Euromodder might be correct. Flat panels might give you the same basic result. Of course you would need to round the corners where the top and sides meet.
Randy