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ANHEDRAL angle effects

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ANHEDRAL angle effects

Old 03-04-2002, 09:46 PM
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F86_SABRE
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Default ANHEDRAL angle effects

Hi,

Can anybody please informme what the effects does an anhedral angle on the wing position would be?
I am currently building a Mig-15 and the plane has a 2 degree anhedral (as opposed to dihedral) and would wish to know
what the likelhood effects (if any) of such a position.

Thanks for any help you may provide.

Regards

Reuben Saliba
Malta (Europe)
Old 03-12-2002, 05:24 AM
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aerotow1
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Default ANHEDRAL angle effects

This is not in response to your question, but I noticed that you are in Malta. How is the RC flying down there? I have family in Malta and am looking forward to visiting sometime!!!!!

Dan Borg
Old 03-12-2002, 01:54 PM
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Ollie
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Default Anhedral

The anhedral causes adverse yaw at roll coupling which is more than offset by rhe sweepback's proverse yaw to roll coupling.
Old 03-12-2002, 05:42 PM
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F86_SABRE
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Default ANHEDRAL

To OLLIE:
First of all thanks for answering. Would a gyro solve the problem of adverse yaw?
Thanks.

To DAN BORG:

Hi Dan...very nice to hear from a fellow maltese in the States.
Yes we have a thriving r/c community here. We have two clubs on the island with a total membership of around 150 members each club. Both sites are hard surface. The one I am member at is around 700 feet long by 550 feet (the largest flying field).
Just in case you come and visit us let me know you are coming so that we can make arrangements to meet but in case you wish to make your own arrangements our flying field is situated at the place called TA' QALI.
There are various r/c interests including pattern, funfly, scale and sunday flying. There are also around 20 turbines, both commercial and homebuilt types, in both clubs.

Well this seems to be a short round-up of the local scene.
My email address is [email protected] should you any further information.

Keep in touch.

Regards

Reuben Saliba
Malta
Old 03-12-2002, 08:57 PM
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gubbs3
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Default ANHEDRAL angle effects

What I have heard in other threads on this topic is it gives the opposite effect as dihedral. If you equip a high wing plane with anhedral it would feel more like and act more like a low wing plane.
Old 03-12-2002, 09:13 PM
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djlyon
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Default ANHEDRAL angle effects

Reuben
The effect will be as follows for the Mig 15 I suspect.
When you apply right rudder, with the migs high vertical tail, the plane will tend to roll left. The anhedral will also tend to roll the plane left. The sweep back of the wing will have a right roll forse. So you don't know where it will go till you try it. If you do wind up with adverse roll and don't like it you can program it out with a programmable radio. In the mix mode of your radio slave your ailerons to rudder so that you get some aileron input in the direction of the rudder when you move the rudder. This way you can null out the adverse roll when flying upright. The mix function is on anon/off switch so you can switch it off for contineous inverted flight or take-off.
Old 03-12-2002, 09:20 PM
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Ollie
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Default Anhedral

The dihedral effect of the generous sweepback overcomes the effect of the slight anhedral so that the net result is the opposite of adverse yaw. Adverse yaw will probably not show up except, possibly at very slow speeds and can be controlled by applying compensating rudder. With intermediate flying skills or better a gyro would be wasted money in my opinion. This is a scale model and shouldn't be expected to maneuver with the same precision as an aerobatic model. You should be satisfied if it is fully controllable over its entire flight envelop.
Old 03-12-2002, 11:20 PM
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Johng
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Default sweepback = dihedral

Ollie is completely right, but maybe stating it so boldly that some are missing the point.

Swept wings give the same effect as dihedral. The highly swept wings of the Mig give ALOT of dihedral effect. The anhedral helps negate this so you could maybe do a knife edge without spraining your thumbs. This thing will not show any adverse roll except maybe at landing speeds. Activate an aileron-rudder mix with your landing gear deployment and you will be more than fine.
Old 03-14-2002, 07:12 PM
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F86_SABRE
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Default ANHEDRAL EFFECTS

Hi,

I wish to thank you all for the very informative discussion...
thanks folks....really appreciated!

Regards

Reuben Saliba
Malta

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