Shoulder wings
10-01-2003, 04:54 AM
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Shoulder wings
I just recently completed an old hobbico viper kit. I don't have plans to race it, I just wanted a FAST plane. One question though, why are all the new style planes shoulder wings? There must be some sort of advantage right?
Mike
Mike
10-01-2003, 07:08 AM
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RE: Shoulder wings
Not only are they all high wing they also have vee tails. You know how it works Mike. Somebody wins a major contest with a certain style of airplane and everybody wants one.
There is some logic to it actually. The high wing airplane is more stable. The wing is easier to build there being no dihedral (Not that too many racers build anymore). The Vee tail configuration is supposed to create less drag than a conventional tail. With computer radios Vee tail mixing is not a problem. And, the most important thing of all they just seem to go faster.
Ed S
There is some logic to it actually. The high wing airplane is more stable. The wing is easier to build there being no dihedral (Not that too many racers build anymore). The Vee tail configuration is supposed to create less drag than a conventional tail. With computer radios Vee tail mixing is not a problem. And, the most important thing of all they just seem to go faster.
Ed S
10-01-2003, 08:18 AM
#3
RE: Shoulder wings
There is actually more to it than just someone's design flew fast.
There is drag created at each joint to the fuse and there is more drag created the more acute the angle of the joint. So, if you have a mid-wing there is a joint at the fuse at the top and the bottom of the wing, four areas, creating drag, thus the fillet (not allowed in Q500). Now if you move the wing down to the bottom, you have only one on each side of the fuse, but the air flow over the top of the wing is faster than the flow over the bottom. This means that the drag will be greater than if the wing is a shoulder wing with no upper joint and the slower air flow under the wing creating less drag.
Many of the low wing designs have dihedral which decreases the angle to the fuse at the wing upper surface to less than 90 degrees causing more drag in that faster air than a wing with no dihedral and a 90 degree connection to the fuse.
Now we move to the v-tail. With a conventional tail with the horizontal stab in the middle of the fuse you have the same situation as the mid wing plus you add two more drag areas at the vertical stab for a total of six drag areas. with a v-tail at the middle of the fuse you reduce that to four. Now move the v-tail up so it's a shoulder v-tail and you have only three areas of drag; two under the tail and one at the 110 degree dihedral point. But look what else has happened, the angles have been reduced to 125 degrees at the two undersides and is 110 at the top. These greater angles are less draggy.
That's the theory as I know it, of course then we hang an antenna 12 inches out the tail negating any gains.
Stan Douglas
There is drag created at each joint to the fuse and there is more drag created the more acute the angle of the joint. So, if you have a mid-wing there is a joint at the fuse at the top and the bottom of the wing, four areas, creating drag, thus the fillet (not allowed in Q500). Now if you move the wing down to the bottom, you have only one on each side of the fuse, but the air flow over the top of the wing is faster than the flow over the bottom. This means that the drag will be greater than if the wing is a shoulder wing with no upper joint and the slower air flow under the wing creating less drag.
Many of the low wing designs have dihedral which decreases the angle to the fuse at the wing upper surface to less than 90 degrees causing more drag in that faster air than a wing with no dihedral and a 90 degree connection to the fuse.
Now we move to the v-tail. With a conventional tail with the horizontal stab in the middle of the fuse you have the same situation as the mid wing plus you add two more drag areas at the vertical stab for a total of six drag areas. with a v-tail at the middle of the fuse you reduce that to four. Now move the v-tail up so it's a shoulder v-tail and you have only three areas of drag; two under the tail and one at the 110 degree dihedral point. But look what else has happened, the angles have been reduced to 125 degrees at the two undersides and is 110 at the top. These greater angles are less draggy.
That's the theory as I know it, of course then we hang an antenna 12 inches out the tail negating any gains.
Stan Douglas
10-01-2003, 02:33 PM
#5
RE: Shoulder wings
I don't, I was making a ha ha. Although I do see it done by others. It makes for a real interesting first turn at pylon one when your caller steps on it during launch.
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