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15 Posts |
 Posted - 11/28/2009 : 18:30:40
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With the prize now at 250,000$ there should be a
lot more interest in HPHs. It's going to be very
interesting to see what new projects will come along.
Anyone working on one now?
Harry \../ |
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26 Posts |
Posted - 01/20/2010 : 09:28:48
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Hi harry
I think the answer to your original question is, as it is for all HPAircraft, that their potential is limited. Unfortunately helicopters will always suffer from certain fundamental characteristics that will limit them even more. Chiefly the mass of the pilot isn’t added to the kinetic energy if the flight surfaces.
A constructive point might be made with regard to drag. Clearly the power that keeps a HPA up is greater than the power produced by the pilot. So optimising this “free power” is key. What i have noted in my rather limited research is that the excepted wisdom of Airfoil mechanics is still up for debate. What really caught my eye is very low drag “acceleration foils”. They have very sharp leading edge, and work on the principle that they simply gain a resultant force from the mass displacement. I can’t point to any hard evidence. But certainly their potential is huge – if its as good as it looks.
Might be what is needed to get the HPH out of ground effect....
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26 Posts |
Posted - 01/23/2010 : 05:52:21
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Interesting point; reminds me of Colin Jackson a UK hurdler who admits to a near anorexic diet during his career, He had a very large fast twitch muscle fibre density..... its also interesting to see the different is Mr Bolts gait, compared to his peers.
I guess the real question is can you make a HPH which a 20mph person can enjoy flying?
I guess HPAircraft are also generally quite faddy, it all depends on the zeitgeist of the time...
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Posted - 01/28/2010 : 19:40:49
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"I guess the real question is can you make a HPH which a 20mph person can enjoy flying?"
Good question. Can one build a HPH that uses some sort of assistance so it would have a reasonable size rotor? Then one could fly it
in ground effect in the back field. Perhaps a meter or so off the ground. If it is light weight it would have soft crashes not hard ones ;)
Harry \../ |
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2 Posts |
Posted - 03/10/2010 : 13:05:00
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| My question would be operating at the ultra-low Reynolds numbers than HPH's operate at what point does ground effect become nonexistent? I understand for a typical helicopter it is usually between 1-1.5 rotor radii off the ground but I presume that height is significantly reduced with such slow moving rotors. If anyone knows of any research about ground effect at such low rpms please let me know. |
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26 Posts |
Posted - 03/26/2010 : 11:13:38
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I guess you could look at fixed wing HPA, and what high they stop benefiting from ground effect. Byran Allen had some issues when crossing the channel, with regard ground effect and waves, should be easy to get estimates from his accounts.
Its also likely that a HPH will have large spaces between its blades, so the down draft wont form a column like a conventional helicopter. In this regards HPH will be more similar to a fixed wing.
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Posted - 04/15/2010 : 23:13:05
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I think that all of the individuals that are trying to build an HPH should start thinking more on how to to transfer the power to the rotor(s) more efficiently rather then cocentrating whole attention on the rotor design because with choosing the right airfoil there is no win-win situation .I thought perhaps by using STOL airfoil like the once they use on the STORCH but then it struck me how much drag they will create and how much torque someone will need to move those rotors...Yes you can optimize the performance but in the end you'll have to put some serious muscle in if you want to beat Akira Naito's record,not to mention Sikorsky prize.
Right now I'm working on a device that will increase the torque put in by a human for example for one revolution on the input youwill have one revolution on the output but withmuch greater torque I know what all say that's not possible but I'm trying to proove them wrong. |
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Posted - 05/18/2010 : 11:26:54
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| I agree with the comment that airfoil optimization alone is not going to with the competition. Optimizing power input is going to be crucial. With our cockpit design we anticipate getting somewhere in the neighborhood of 800 watts for a one minute flight. With your device for increasing the torque from the pilot to the rotors does it still fall within the rules of not storing power in the system? |
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Posted - 05/26/2010 : 15:57:59
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The device that I'm working on doesn't fall under the category of power storing systems, simply because is not storing any energy unlike a spring or a tank of air or a flywheel.We need to clear what is the definition: "power storing system",and that is something that a mechanical watch will have: like the wind up spiral spring or hanging weights or a heavy flywheel that is used in old heavy mashinery in order to retain the momentum, also a pressurized airtank etc.Anny energy storing device will have the energy at anny given moment in time and willadd power to the power input of a human at the needed moment and therefore is not allowed to be implemented in a HPH.
My design of this (torque converter)doesn't use anny of the mentioned earlier no spring weights or annything like that and uses only the power put in by the human and if not opperated it will not move by itself or if left alone will stop immediatlly left alone.,I'm sorry that I can't be more specific about it, that's because I will apply for a patent after I build it.Then after I'm done with the device I will start working on the actual HPH construction. As I will progress with my work I will post more comments. |
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Posted - 07/07/2010 : 20:35:49
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What really caught my eye is very low drag “acceleration foils”. They have very sharp leading edge, and work on the principle that they simply gain a resultant force from the mass displacement. I can’t point to any hard evidence. But certainly their potential is huge – if its as good as it looks.
Might be what is needed to get the HPH out of ground effect....
(non-related ad link removed. - Moderator)
Jerick getono |
Edited by - Don S on 10/09/2011 19:35:11 |
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Talos
United Kingdom
32 Posts |
Posted - 07/09/2010 : 11:25:23
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I come into this topic a little late as my main interest is ornithopter flight. However there are some parallels in this discussion that are applicable.
The professor, is absolutely correct. You need to clear what is the definition: “power storing system”.
Every powered aircraft generates some kind of energy storage. A conventional aircraft accelerates down the runway to build up kinetic energy (storage) before it can convert it into potential energy in lifting up into the air. A helicopter does the same thing by building up the rotor’s revolutions into kinetic energy (again, storage) before it can also convert it to potential energy in lifting up into the air. The helicopter has the disadvantage that it can’t store any kinetic energy in the mass of the machine. It therefore has to generate correspondingly more kinetic energy in the rotor so that it can lift the bulk of the mass into the air.
On this last point, countrymike is saying the same thing in stating that the mass of the pilot isn’t added to the kinetic energy (store).
We can all see the build up of kinetic energy as an aircraft accelerates down a runway but some of us fail to realise that the rotor of a helicopter must do something similar. It is not a question of greater torque, so much as applying whatever torque we have until the revolutions have built up, i.e., the revs must accelerate.
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Posted - 07/17/2010 : 02:08:33
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Talos, once again we agree. -
I’ve been pondering this issue of accelerating the blades of a HPH. It occurs to me that a small weight, located within the spar, can be gradually accelerated on the blade tip with zero angle of attack. When an attempt to lift off is made the weights can be retracted to the central spindle, which will increase the speed of rotation.
Just a thought.
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Posted - 08/02/2010 : 18:48:10
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quote:
Originally posted by countrymike
Talos, once again we agree. -
I’ve been pondering this issue of accelerating the blades of a HPH. It occurs to me that a small weight, located within the spar, can be gradually accelerated on the blade tip with zero angle of attack. When an attempt to lift off is made the weights can be retracted to the central spindle, which will increase the speed of rotation.
Just a thought.
I think you are right mike. the weights can be retrackted to the central spinddle. Do you think this is a a bog factor to operate HPH?
Nate Digby
(Non-related ad link removed) - Moderator) |
Edited by - Don S on 10/09/2011 19:36:32 |
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14 Posts |
Posted - 03/13/2011 : 20:03:52
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the aerodynamics is very tricky i was working on a project soo easy to manage and the final was a disaster, imgoing to post my future results to you guys.. cheers
(non hpv related link removed) |
Edited by - Don S on 10/09/2011 19:38:47 |
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3 Posts |
Posted - 11/17/2011 : 17:23:15
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Hello all, I'm new to this forum and I'm new to helicopter design. I'm a computer technician by trade but I've always had a keen interest in airplanes and helicopters.
I learned about the Sikorsky human powered helicopter competition a few months ago and since then I have been working on a design for one. I've learned enough about helicopter aerodynamics to come to the conclusion that my design may actually work.
It all depends though on whether Sikorsky would allow a design in which the helicopter would develop a supplemental lift to the lift generated by the rotor blades. I have designed a method to generate supplemental lift and I believe it would not violate any of the competition regulations, but I'm not sure though.
So, I wanted to get other people's opinions on whether generating supplemental lift would be pemissible. This method I have in mind would not use any stored energy nor would it use lighter-than-air gases.
I don't want to spend a lot of time and money building it and then for Sikorsky to tell me "Sorry, but only the rotor blades can generate lift."
Anybody? |
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Don S
USA
88 Posts |
Posted - 11/18/2011 : 17:37:54
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The rules of the competition aren't governed by the IHPVA but they seem to have the typical catch 22 proposition. It appears that anything not prohibited in the rules is allowed as long as it doesn't violate any of the other rules.
If your new method provides additional lift without violating any of the competition rules than most likely the spirit of the competition will prevail for determining if you have created a human powered helicopter or something else but staying with in the 10 meter square area during the flight would seem to clarify the definition.
On the positive note, if your method results in a patentable invention that will allow the average athlete to achieve and maintain recreational flight than the money spent in development will likely pay off and you probably don't need to worry about the $250,000 prize.
"it's important to understand what makes them fast. It's more important to understand what keeps them from going faster." DS |
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3 Posts |
Posted - 11/21/2011 : 10:16:28
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quote:
Originally posted by Don S
The rules of the competition aren't governed by the IHPVA but they seem to have the typical catch 22 proposition. It appears that anything not prohibited in the rules is allowed as long as it doesn't violate any of the other rules.
If your new method provides additional lift without violating any of the competition rules than most likely the spirit of the competition will prevail for determining if you have created a human powered helicopter or something else but staying with in the 10 meter square area during the flight would seem to clarify the definition.
On the positive note, if your method results in a patentable invention that will allow the average athlete to achieve and maintain recreational flight than the money spent in development will likely pay off and you probably don't need to worry about the $250,000 prize.
"it's important to understand what makes them fast. It's more important to understand what keeps them from going faster." DS
Thanks. You've brought some things I haven't thought about before such as patenting this method I have in mind.
I've contacted Sikorsky and asked them if additional lift is permissible, but they won't comment on it...they just keep telling me to adhere to the rules. I'm guessing that the idea of using additional/supplement lift is something that nobody has brought up before and they don't have a definite answer for it. |
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Don S
USA
88 Posts |
Posted - 11/21/2011 : 18:30:38
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quote:
I've contacted Sikorsky and asked them if additional lift is permissible, but they won't comment on it...they just keep telling me to adhere to the rules. I'm guessing that the idea of using additional/supplement lift is something that nobody has brought up before and they don't have a definite answer for it.
They are likely needing more information on how this additional lift will be provided before they can determine if it complies with the competition rules so their response seems logical. From a laypersons perspective it would seem that you could be more specific to a rules committee and include a disclaimer that the information is for rules determination only and is not to be disclosed to the public or used to circumvent a pending patent related to the technology. The patent pending notice might give limited protection covering your idea. Another option might be a patent disclosure form that you could ask if members of the rules committee were willing to sign.
The catch seems to be that you can show up at a competition with your invention and see if it is allowed so you can compete for the prize or you can disclose more information to the committee and try to reserve patent rights which might be more valuable than the prize.
"it's important to understand what makes them fast. It's more important to understand what keeps them from going faster." DS |
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3 Posts |
Posted - 11/22/2011 : 11:23:56
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quote:
Originally posted by Don S
[quote]
They are likely needing more information on how this additional lift will be provided before they can determine if it complies with the competition rules so their response seems logical.
I sent them another e-mail this morning giving them a more detailed description of my design and of the method I would use to create additional lift. Hopefully, with this new description they can offer me an opinion on whether my design would qualify for the Sikorsky Prize competition or if I need to go back to the drawing board.
Thanks again for the tips you've given me. I will keep them in mind. |
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jnyyz
Canada
4 Posts |
Posted - 05/18/2012 : 03:38:50
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From: "Cameron D. Robertson" <cameron.d.robertson@gmail.com>
Date: May 17, 2012 9:30:32 PM EDT
To: undisclosed-recipients:;
Subject: Working on a Historic Aviation Project: The Atlas Human-Powered Helicopter
Dear friends and family,
This summer I am working on a team that is building a human-powered helicopter, to attempt to win the Sikorsky Prize and achieve a historical aviation first. The project is primarily funded through corporate sponsorship and generous individual donors, and any way you can help us spread the word brings us one step closer to our goal.
Here's some easy, but tangible ways that you can help us out:
- Check out our Kickstarter page (www.kickstarter.com/projects/1156290643/atlas-a-human-powered-helicopter-for-a-historical) where you can:
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- Share this email with all of your friends
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--
Cameron D. Robertson
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jnyyz
Canada
4 Posts |
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Leonard33
4 Posts |
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jnyyz
Canada
4 Posts |
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baldwinweb24
1 Posts |
Posted - 07/04/2013 : 01:29:20
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| Yes, I read their blog and they deserve the price. |
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