Bipe Wings

[jdcook54]

Are Biplane wings usually set at the same incidence, another words both wings parallel to each other?:confused:

[Marion]

I understand they are not usually at the same angle. Which is at a higher angle is dependent on your airplane and wing arrangement. Try a post on the Science group.

[farnboro flyer]

I would like to know the answer to this one...........My plan shows the top wing at 2 degrees postive to the datam line........but does that mean all bipes are the same?

Ian

[steve lewin]

I'll move this to Modeling Science where the serious aerodynamics buffs hang out ;).

My take is that it depends on the type of plane. Aerobatics bipes like Pitts, Christens etc are usually set zero/zero. Slower flying bipes have the incidences adjusted in an attempt to improve the stall characteristics. The logic for higher incidence on the top wing is to ensure that it stalls first. Assuming forward stagger i.e. top wing in front of bottom, with only the bottom wing lifting the centre of lift moves rearward and that tends to tip the nose down, pulling it out of the stall ;).

Or, as that's guesswork from first principles, I could easily be completely wrong :(.

Steve

[jdcook54]

Thanks Steve I think my question was a bit complicated, and there probably is too many factors involved to get an answer, ie cord, stagger, airfoil type, sweep, purpose, movement, wing loading, ect ect anyway Im sure someone in the Science forum could probably supply a mathematical formula, it will probably be easier to just experiment a little, however your answer will give me something to look for during flight testing.

Thanks all

[Ollie]

I think Steve has hit the nail on the head. The biplane wing incidences should be designed to meet the purpose of the plane and the priorities of the designer as well as harmonize with the over all configuration. There is no such thing as a universally correct answer for all biplanes.