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Old 10th January 2013, 07:34 AM   #121
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Originally Posted by ynot View Post
FanWing not only claims high lift at low speeds but also lift at no speed! Apparently their model will hover from a tether. In other words merely by way of the wind created by the fans flowing over the top of the wings. So multiple wings opposing each other should mean it would hover without a tether. Not sure how well it would work at human scale however.
In theory, a cycloidal wing like the FanWing should be able to hover, since you can direct the lift vector at any angle perpendicular to the rotational axis.
The limit of torque you can apply to a single rotor pair would be the weight of the fuselage times the distance of the CG below the axis, though.
As you point out, two counter rotating sets should solve that problem.

At human scale, it's not at all clear to me how autorotation would work, although vertical axis windmills turn, so it's probably not impossible. Just tilt the lift vector forward enough, I guess.
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Old 10th January 2013, 11:17 AM   #122
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Originally Posted by TjW View Post
In theory, a cycloidal wing like the FanWing should be able to hover, since you can direct the lift vector at any angle perpendicular to the rotational axis.
The limit of torque you can apply to a single rotor pair would be the weight of the fuselage times the distance of the CG below the axis, though.
As you point out, two counter rotating sets should solve that problem.

At human scale, it's not at all clear to me how autorotation would work, although vertical axis windmills turn, so it's probably not impossible. Just tilt the lift vector forward enough, I guess.
Intuitively (to me) they seem to have the configuration up-side-down. I would have expected it to work better if the fan was propelling air down and under the wing.

Not sure it has any use for HPH but wouldn’t it to some degree provide a more even airflow over the whole length of a rotating wing and allow the wings to be shorter and work better at a lower rotational speed? Also multiple wings closely following each other wouldn’t be so effected by the wake of the preceding wing.

Using human power, is it better/easier to move a wing through still air or move air over a still wing?
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Old 10th January 2013, 01:48 PM   #123
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Originally Posted by ynot View Post
Intuitively (to me) they seem to have the configuration up-side-down. I would have expected it to work better if the fan was propelling air down and under the wing.

Not sure it has any use for HPH but wouldnít it to some degree provide a more even airflow over the whole length of a rotating wing and allow the wings to be shorter and work better at a lower rotational speed? Also multiple wings closely following each other wouldnít be so effected by the wake of the preceding wing.

Using human power, is it better/easier to move a wing through still air or move air over a still wing?

Well, it could provide a more uniform distribution of lift over the area of the rotor, I guess.

A wing can't tell the difference between it moving through the air and air moving by it.
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Old 10th January 2013, 02:14 PM   #124
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Originally Posted by TjW View Post
Well, it could provide a more uniform distribution of lift over the area of the rotor, I guess.
Perhaps just the inner portion could be a fanwing?

Originally Posted by TjW View Post
A wing can't tell the difference between it moving through the air and air moving by it.
Yes I understand the equivalence principle. I was asking if it would be easier for a human to move a wing through an amount of air or the same amount of air over a wing? I would have thought a wing through air would be easier because you are moving a solid object. With moving air there would always be some loss due to "slippage".
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Old 11th January 2013, 07:14 AM   #125
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Originally Posted by ynot View Post
Perhaps just the inner portion could be a fanwing?


Yes I understand the equivalence principle. I was asking if it would be easier for a human to move a wing through an amount of air or the same amount of air over a wing? I would have thought a wing through air would be easier because you are moving a solid object. With moving air there would always be some loss due to "slippage".
How would you propose to move air without first moving an airfoil through it? A displacement pump of some sort?
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Old 11th January 2013, 08:09 AM   #126
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Cool links, yknot.

I'm surprised some of the designs couldn't lift the device with the pilot not even being on it, but adjacent.
The DaVinci III, at least, got off the ground.

The fanwing is pretty cool; radical design. Would a verticle arrangement of that make a lick of sense?

My pto would likely resemble a row bike set-up, with a sliding seat.

I'm surprised that many of the attempters don't have the platform on a scale, so they could at least see how far from lift-off they were.
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Old 11th January 2013, 11:31 AM   #127
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Originally Posted by TjW View Post
How would you propose to move air without first moving an airfoil through it? A displacement pump of some sort?
Obviously you would have to use something like propellers/impellers to move the air but you wouldn’t move the main wing that provides the lift. Like two FanWings tethered together and trying to fly apart in opposite directions. Their wings wouldn’t move but they would get lift from the air moving over them.
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Old 11th January 2013, 11:43 AM   #128
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Originally Posted by quarky View Post
Cool links, yknot.
k
Originally Posted by quarky View Post
I'm surprised some of the designs couldn't lift the device with the pilot not even being on it, but adjacent.
The DaVinci III, at least, got off the ground.
Think the Da Vinci was the first to ever get off the ground and was designed by the guy that built the Upturn (I could be wrong).
Originally Posted by quarky View Post
The fanwing is pretty cool; radical design. Would a verticle arrangement of that make a lick of sense?
Think it would just go round in circles with no lift
Originally Posted by quarky View Post
My pto would likely resemble a row bike set-up, with a sliding seat.
Hope there’s going to be more description of your pto than that. How would you compensate for the constant imbalance caused by the pilot moving backwards and forwards? Two pilots moving equally and oppositely?
Originally Posted by quarky View Post
I'm surprised that many of the attempters don't have the platform on a scale, so they could at least see how far from lift-off they were.
I’m surprised they had to build some of them to know they wouldn’t fly. Some were obviously just test rigs tho.
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Old 11th January 2013, 01:15 PM   #129
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Originally Posted by ynot View Post
Obviously you would have to use something like propellers/impellers to move the air but you wouldnít move the main wing that provides the lift. Like two FanWings tethered together and trying to fly apart in opposite directions. Their wings wouldnít move but they would get lift from the air moving over them.
I don't see it. If they're unpowered, why would they do anything other than autorotate? If you're going to autorotate, why would two be an advantage?

There was an experimental light airplane designed to use a very small wing in the propeller blast -- called the SpeedBird or SpeedWing I think, but that's hazy. It flew, but the engine quit, and the pilot bailed out.
There was the Custer Channel wing, that used propeller blast over a U shaped section of wing. That was a light twin design. I would be concerned with engine-out capability. If it's no problem, then you're not getting much advantage from the configuration, and if it is, it's dangerous.
The F104 used bleed air from the compressors over the deployed flaps to increase the lift for landing. Without power (and thus, bleed air), the landing speed was above the speed rating of the tires.
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Old 11th January 2013, 01:37 PM   #130
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Originally Posted by TjW View Post
I don't see it. If they're unpowered, why would they do anything other than autorotate? If you're going to autorotate, why would two be an advantage?

There was an experimental light airplane designed to use a very small wing in the propeller blast -- called the SpeedBird or SpeedWing I think, but that's hazy. It flew, but the engine quit, and the pilot bailed out.
There was the Custer Channel wing, that used propeller blast over a U shaped section of wing. That was a light twin design. I would be concerned with engine-out capability. If it's no problem, then you're not getting much advantage from the configuration, and if it is, it's dangerous.
The F104 used bleed air from the compressors over the deployed flaps to increase the lift for landing. Without power (and thus, bleed air), the landing speed was above the speed rating of the tires.
Thanks but it was just a random thought of no consequence so letís forget it.
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Old 11th January 2013, 02:44 PM   #131
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Originally Posted by ynot View Post
k

Think the Da Vinci was the first to ever get off the ground and was designed by the guy that built the Upturn (I could be wrong).

Think it would just go round in circles with no lift

Hope thereís going to be more description of your pto than that. How would you compensate for the constant imbalance caused by the pilot moving backwards and forwards? Two pilots moving equally and oppositely?

Iím surprised they had to build some of them to know they wouldnít fly. Some were obviously just test rigs tho.
I've only begun thinking about this. It's arrogant of me that I might come up with a decent thought, but I sort-of trust me innate thinkiness.

And yes...you may have convinced me of the two-pilot approach...due to amzingly sensitive and athletic pilots...doing the dance of balance and stability.
On early hangliders, navigation was accomplished by shifting one's weight.
The caloric cost of these minute adjustments are very low. Also, no particular mechanical hoopla is required.

Still, there remains this double load (well, considering the weight of the craft, probably a third more load) which takes on the co-commitment of grander structural integrity...more weight, generally. This tech is already skirting at the edge of high tech lightness and computer assisted architecture.

I suspect a two-pilot system, which might solve stability issues, will require some other radical departure.
That fanwing plane helped me to remember to cheer-lead the radical departure stuff.

Go teams, go!

(I wish you could see my outfit just now. Talk about hot.)
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Old 11th January 2013, 03:37 PM   #132
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Originally Posted by quarky View Post
I've only begun thinking about this. It's arrogant of me that I might come up with a decent thought, but I sort-of trust me innate thinkiness.

And yes...you may have convinced me of the two-pilot approach...due to amzingly sensitive and athletic pilots...doing the dance of balance and stability.
On early hangliders, navigation was accomplished by shifting one's weight.
The caloric cost of these minute adjustments are very low. Also, no particular mechanical hoopla is required.

Still, there remains this double load (well, considering the weight of the craft, probably a third more load) which takes on the co-commitment of grander structural integrity...more weight, generally. This tech is already skirting at the edge of high tech lightness and computer assisted architecture.

I suspect a two-pilot system, which might solve stability issues, will require some other radical departure.
That fanwing plane helped me to remember to cheer-lead the radical departure stuff.

Go teams, go!

(I wish you could see my outfit just now. Talk about hot.)
Youíve been lucid dreaming ďVery specific stuffĒ (post #126) yet you have nothing specific to offer and you have only begun thinking about it?! Seems a bit contradictory.

Especially when also considering this post where you seemed to claim that you have offered some specific approaches that I should be adopting. In other words you claimed you already had come up with a ďdecent thoughtĒ. Merely saying that you think ďboingingĒ is the way to go doesnít explain how ďboingingĒ would work on an HPH or why it should be adopted . . .
Originally Posted by quarky View Post
You must realize by now, my cheer-leading for an alternative power take off scenario. Unless you didn't read my posts in similar threads, you must be aware of my alternate takes on this essential matter.
This is the crux of my cheer-leading.
I must ask, how do you propose to supply the human power to the system, if not through approaches I've mentioned?
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Old 11th January 2013, 04:44 PM   #133
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I respect your skepticism, as per anything I could add , by way of assistance.
All of this is beyond my smarts, as I've willingly admitted before.

Yet,

Out of the box is where I live.

Should I bail on this thread?

Perhaps.

Or, patience.

I'm not attacking anyone.
I'm thinking.

If I'm not invited to this party, that's ok.

Mostly, I think I belong here.

I will try harder.
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Old 11th January 2013, 09:20 PM   #134
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Originally Posted by quarky View Post
I respect your skepticism, as per anything I could add , by way of assistance.
All of this is beyond my smarts, as I've willingly admitted before.

Yet,

Out of the box is where I live.

Should I bail on this thread?

Perhaps.

Or, patience.

I'm not attacking anyone.
I'm thinking.

If I'm not invited to this party, that's ok.

Mostly, I think I belong here.

I will try harder.
Of course youíre welcome to post here and I hope you continue to do so. I didnít say you couldnít or wouldnít offer anything by way of assistance. I said that you seemed to be saying you had offered something that I didnít think you had; and that you seemed to be saying you had a design when apparently you didnít. I hope you still post details of whatever pto you have or come up with. I donít care how out of the box it is but expect it to receive open and honest scrutiny. Thatís what I want for any ideas I offer and I donít care how ďbrutalĒ people are in the process. I would rather pursue viability than a dream.
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Old 12th January 2013, 12:19 PM   #135
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This system has a similar action to what Iím proposing. Mine is applied directly to the wings however and I hope it works a lot better than this attempt. Even the camera man is laughing - http://www.youtube.com/watch?v=KlKSDPBSBmU

Good to see these guys having so much fun.

ETA - Given the basic human action of this attempt is so close to mine Itís interesting to analyse how well it worked (or didnít).

A lot of energy is wasted by transferring it through gears, pulleys and changes of direction.

As the pilot isnít anchored to the seat/frame the power produced is limited to the pilotís body weight. With just my legs I can lift at least twice my body weight (a person of my weight on my shoulders).

Theyíre trying to rotate small rotors quickly with an action that better suits slow and powerful. Quick is done better by pedalling a crank.
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Old 12th January 2013, 12:30 PM   #136
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Originally Posted by ynot View Post
Of course youíre welcome to post here and I hope you continue to do so. I didnít say you couldnít or wouldnít offer anything by way of assistance. I said that you seemed to be saying you had offered something that I didnít think you had; and that you seemed to be saying you had a design when apparently you didnít. I hope you still post details of whatever pto you have or come up with. I donít care how out of the box it is but expect it to receive open and honest scrutiny. Thatís what I want for any ideas I offer and I donít care how ďbrutalĒ people are in the process. I would rather pursue viability than a dream.
I confess to all the sins I've made here. Sincerely, even.
My mind gets way ahead of my typing.

I am thinking on it, and true, i have nothing of substance.
Just an affection for the quest, and an evil mind.

If I wanted to be defensive, which, clearly, I don't...
I'd mention that no one else has showed anything either.

We may be on the same ground; not sure. I've become skeptical of myself.
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Old 12th January 2013, 01:04 PM   #137
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Originally Posted by quarky View Post
I confess to all the sins I've made here. Sincerely, even.
My mind gets way ahead of my typing.

I am thinking on it, and true, i have nothing of substance.
Just an affection for the quest, and an evil mind.

If I wanted to be defensive, which, clearly, I don't...
I'd mention that no one else has showed anything either.

We may be on the same ground; not sure. I've become skeptical of myself.
Just that youíre interested is a contribution.
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Old 12th January 2013, 01:17 PM   #138
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Thanks, man.
I needed that.

My s.o. has been wondering about my fiduciary potential of late.

(I've always sucked at fiduciary potential; it's never been what's turned me on.)

sorry, honey
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Old 12th January 2013, 01:24 PM   #139
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Originally Posted by quarky View Post
Thanks, man.
I needed that.

My s.o. has been wondering about my fiduciary potential of late.

(I've always sucked at fiduciary potential; it's never been what's turned me on.)

sorry, honey
So what do you think of the Italian attempt I just linked to? Is that getting close to ďboingingĒ?
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Old 12th January 2013, 03:03 PM   #140
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Originally Posted by ynot View Post
So what do you think of the Italian attempt I just linked to? Is that getting close to ďboingingĒ?
Sorry, I must have missed it.
I looked at lots of links; must have fallen asleep.

Boinginess, as I've mentioned in weird threads of the past, came to me when examining the efficiency of the wallaby and the barracuda.

In both cases, boinginess factor is large.
As a tree-hugger bio-chem felon,
I think I may be correct, as per nature's most efficient propulsion methods.

I also may be slightly wrong...

But I don't think I've ever been 'incredibly wrong' in such matters.

Yet,
I have no idea how a flexible rod supporting the rotor blade might effect performance.

I have some idea how mama nature deals with it.

Quite possibly, my affection for evolution has biased my thinking process.
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Old 12th January 2013, 03:44 PM   #141
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Originally Posted by quarky View Post
Sorry, I must have missed it.
I looked at lots of links; must have fallen asleep.

Boinginess, as I've mentioned in weird threads of the past, came to me when examining the efficiency of the wallaby and the barracuda.

In both cases, boinginess factor is large.
As a tree-hugger bio-chem felon,
I think I may be correct, as per nature's most efficient propulsion methods.

I also may be slightly wrong...

But I don't think I've ever been 'incredibly wrong' in such matters.

Yet,
I have no idea how a flexible rod supporting the rotor blade might effect performance.

I have some idea how mama nature deals with it.

Quite possibly, my affection for evolution has biased my thinking process.
I thought your boinging method was applied to the pilot(s) not the wings. If itís the wings then it possibly makes more sense. I wouldnít call the action of a barracuda boinging however. I would more call it wriggling or whipping in a wave motion. A bit like a wave travelling along a long length of rope when you whip it on the ground. Having difficulty imagining a practical wing that could do this however.

Think Iím right in saying that the bicycle is the most efficient HPV and it doesnít use a single mechanical action directly from nature that I know of. The reason humans do so well mechanically is that we can do things that nature canít do. ďMother NatureĒ canít even fly to the stratosphere let alone the Moon or Mars.

You seem to be overlooking that humans improving on what nature does is all part of evolution.
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Old 12th January 2013, 04:46 PM   #142
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I wish.

Humans are idiotic, and about to prove it.
I wish I cared.
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Old 12th January 2013, 05:02 PM   #143
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Sorry but I really don’t understand your post.
Originally Posted by quarky View Post
I wish.
You wish what?
Originally Posted by quarky View Post
Humans are idiotic, and about to prove it.
How so?
Originally Posted by quarky View Post
I wish I cared.
About what?

Has any of your post got anything to do with HPH?
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Old 12th January 2013, 05:12 PM   #144
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Originally Posted by ynot View Post
Sorry but I really donít understand your post.

You wish what?

How so?

About what?

Has any of your post got anything to do with HPH?
Nope.

I think I posted in the wrong thread.

Much shame,

q
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Old 12th January 2013, 05:14 PM   #145
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You'll have to make allowances for quarky. He's sort of a stream-of-unconciousness poster.
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Old 12th January 2013, 05:19 PM   #146
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Originally Posted by quarky View Post
Nope.

I think I posted in the wrong thread.

Much shame,

q
Thanks - Now it makes sense that it doesn't make sense in this thread.
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Old 12th January 2013, 05:21 PM   #147
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Originally Posted by TjW View Post
You'll have to make allowances for quarky. He's sort of a stream-of-unconciousness poster.
I donít mind what people are as long as they donít claim to be what theyíre not.
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Old 14th January 2013, 11:31 AM   #148
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Can anyone offer any advice on the best attack angle and wing profile (cross section) for a slow moving human powered wing?
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Old 14th January 2013, 11:56 AM   #149
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Originally Posted by ynot View Post
Can anyone offer any advice on the best attack angle and wing profile (cross section) for a slow moving human powered wing?
I don't think the airfoil & alpha selection can be done independently of the rest of the system design; they'll depend somewhat on RPM, diameter, and chord width. Also, there are often trades between the best aerodynamic efficiency and structure or manufacturing concerns.

The R/C sailplane community takes their airfoils very seriously, so you might start there. A lot of good work was done by a Dr. Michael Selig at U of I: Low-speed airfoil data

You'll probably need to read up on Reynolds Numbers before you get too far into that.

I don't know if a rotor's radial flow should make a difference in airfoil selection. Rotor aerodynamics are painful, which is why I stayed well clear of the subject when possible.
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Old 14th January 2013, 12:10 PM   #150
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Originally Posted by dasmiller View Post
I don't think the airfoil & alpha selection can be done independently of the rest of the system design; they'll depend somewhat on RPM, diameter, and chord width. Also, there are often trades between the best aerodynamic efficiency and structure or manufacturing concerns.

The R/C sailplane community takes their airfoils very seriously, so you might start there. A lot of good work was done by a Dr. Michael Selig at U of I: Low-speed airfoil data

You'll probably need to read up on Reynolds Numbers before you get too far into that.

I don't know if a rotor's radial flow should make a difference in airfoil selection. Rotor aerodynamics are painful, which is why I stayed well clear of the subject when possible.
Thanks. I was meaning more general factors than specific. Like should the bottom of the wing surface be flat or should it have a slight downturn. From what Iíve read around 9 degrees seems a good attack angle to start testing. I'm thinking more wing size than rotor.
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Old 14th January 2013, 12:16 PM   #151
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Originally Posted by ynot View Post
Thanks. I was meaning more general factors than specific. Like should the bottom of the wing surface be flat or should it have a slight downturn.
That's airfoil selection. You typically don't pick the top and bottom contours of the airfoil independently; it's all one shape.

Quote:
From what Iíve read around 9 degrees seems a good attack angle to start testing.
Typically, yes, you'd want your lift coefficient to be as high as you dared, so 9 deg wouldn't be unreasonable, depending on the airfoil. And how you were measuring alpha.

Quote:
I'm thinking more wing size than rotor.
I'm not following you on that part.
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Old 14th January 2013, 01:57 PM   #152
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Originally Posted by dasmiller View Post
I'm not following you on that part.
Perhaps I'm thinking scale matters when it doesn't.
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Old 14th January 2013, 02:42 PM   #153
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Originally Posted by ynot View Post
So what do you think of the Italian attempt I just linked to? Is that getting close to ďboingingĒ?
Sorry, I just now got to looking at that link. It was good fun, though I didn't hang in there for the conclusion, I had to admire the willingness of various freaks, all over the world, to try hopeless experiments in their attics and garages.

Those guys were totally 'not' jocks.

Any reasonable attempt requires a jock, or two; not sure.

Not that athletes would have achieved lift-off therein.

As per boing-factor, which, to my mind, is just a seriously light weight fly-wheel, forget the barracuda. I don't know enough about that mechanism...look instead to the wallaby. This is where boing-factor's advantage came to light in my dim mind.

Wish I could link-up to the old Scientific American concerning this subject.
I think it was late 60's or early 70's.
That's when I got seduced by the (possibly unworthy) boing factor in uniform energy distribution.

Those wallabies paid no relative price for going at top speed.
Yes, it required more energy, but not at the normal cost, respective to other mammals.

This is the crux of my boing affection.
I extrapolated this onto the barracuda's tail, and I may well have done that wrongly.

I think not. Cartilage has bungy aspects.
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Old 14th January 2013, 02:54 PM   #154
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Originally Posted by ynot View Post
Thanks. I was meaning more general factors than specific. Like should the bottom of the wing surface be flat or should it have a slight downturn. From what Iíve read around 9 degrees seems a good attack angle to start testing. I'm thinking more wing size than rotor.
Rotor = wing = propeller
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Old 14th January 2013, 04:16 PM   #155
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Originally Posted by CNY_Dave View Post
Rotor = wing = propeller
Yes and no. They are all aerofoils but they have different shapes and sizes and are used for different applications at different speeds. I was just trying to point out that my design has more of a slow moving wing than a smaller and faster rotor. Choppers normally have rotors not wings.
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Old 14th January 2013, 07:39 PM   #156
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Originally Posted by ynot View Post
Yes and no. They are all aerofoils but they have different shapes and sizes and are used for different applications at different speeds. I was just trying to point out that my design has more of a slow moving wing than a smaller and faster rotor. Choppers normally have rotors not wings.
Yes, they have a specialized terminology, but the air finds it difficult to tell the difference.

XFLR5 is free, and will let you evaluate airfoils without having to actually build anything.
You can find a good selection of airfoil coordinates here.
Many of them have a graphic file associated with them so you can an idea of what they look like. Some of the high lift designs can be weird.
XFLR5 can import the coordinate files and/or generate arbitrary NACA 4 digit airfoils.
It will also let you build up an arbitrary shape by pulling the control points on splines this way and that.

After you have your shape, it will analyze the airfoil, and calculate how much lift and drag it will have at a particular alpha and Reynolds number.
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Old 14th January 2013, 08:01 PM   #157
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well...

TjW is the awesomeness of these forums.
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Old 14th January 2013, 09:52 PM   #158
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Originally Posted by TjW View Post
Yes, they have a specialized terminology, but the air finds it difficult to tell the difference.

XFLR5 is free, and will let you evaluate airfoils without having to actually build anything.
You can find a good selection of airfoil coordinates here.
Many of them have a graphic file associated with them so you can an idea of what they look like. Some of the high lift designs can be weird.
XFLR5 can import the coordinate files and/or generate arbitrary NACA 4 digit airfoils.
It will also let you build up an arbitrary shape by pulling the control points on splines this way and that.

After you have your shape, it will analyze the airfoil, and calculate how much lift and drag it will have at a particular alpha and Reynolds number.
Very helpful - Thanks
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Old 15th January 2013, 09:11 AM   #159
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Originally Posted by ynot View Post
Yes and no. They are all aerofoils but they have different shapes and sizes and are used for different applications at different speeds. I was just trying to point out that my design has more of a slow moving wing than a smaller and faster rotor. Choppers normally have rotors not wings.
Only difference between a rotor or a prop or a wing is that the wing expects to see pretty much the same conditions from root to tip.

Lift is lift no matter which way the resultant is pointed.
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Old 15th January 2013, 09:42 AM   #160
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Originally Posted by CNY_Dave View Post
Only difference between a rotor or a prop or a wing is that the wing expects to see pretty much the same conditions from root to tip.
Hence my concerns about the effects of radial (spanwise) flow on the rotor. Of course it's been studied to death; I'm just not familiar with it. And, also of course, there's some spanwise flow on a fixed wing, too; otherwise we wouldn't have induced drag and gliders would have ugly wings.

In addition to the varying-conditions-along-the-span, props typically have to deal with a large free-stream axial velocity component (yes, I'm being a little sloppy with my axis names), hence the twist of the prop blades, the painful selection of a design point, etc. For heli rotors, there's often a large velocity component in the plane of the rotor, which is also painful to deal with. The HPV heli should have near-zero axial and in-plane components to deal with, making the design problem much simpler.
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