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Thread: ROLLS-ROYCE CRECY

  1. #51
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    Default Re: ROLLS-ROYCE CRECY

    I understand the venturi principle clearly, and I see what the drawings are representing.

    What I don't see is some form of evidence that this would be more efficient than a standard 2 or 3 blade windmill.


    Resistance of the wind to flow into and through the venturi rather than around it, and the drag of the walls within the long tapered tube will make it less efficient. Further resistance/drag will result from the air being drawn through that long"tube" from the generator turbine to the venturi device.


    Also, the smaller diameter generator turbine fan won't be nearly as efficient as a modern windmill propeller, whose blades aren't all that dis-similar to that in form (long span, short chord) and materials) carbon fiber) of a very efficient thermal competition glider. I'm sure technology learned by the wings of the latter has gone into the former.


    What makes the venturi "windmill" superior? I can see that it would be safer for predatory birds, many of which are dying from being struck while hunting around windmill farms, but I don't think it would be more efficient than a modern 'mill.


    Just my thoughts. I'm not trying to offend anyone. Have anyone tried placing a large venturi out in the open breezes and measured the results yet under real world conditions?


    .



    I don't know about the RAMJET-IN-A-VENTURI idea either. Sure, the airflow at the narrowest point is increased in velocity, but there's also that significant drop in pressure, negating any benefits of the former for the internally mounted engine. The airflow reaching the front of the ramjet would be moving faster, but at a lower pressure and so will not result in more air being compressed into the engine. It might even lose power.

    Ramjets rely on the air being forced and compressed under pressure into it's inlet for proper operation. Lower air pressure, such as that encountered at higher altitudes (or at the venturi's throat) result in less jet engine power output. Said aircraft jet engines have to fly faster in thinner air to achieve the same power. There is no power gain.


    .
    Last edited by AirDOGGe; 06-05-2011 at 12:06 AM.

  2. #52

    Default Re: ROLLS-ROYCE CRECY

    Your doubt in both cases, virtually the same properties are for a venturi tube.Maybe start from the second issue of ramjet.
    Indeed you are right, the pressure decreases. But it is by how much. Venturi type into the calculator, which gives a link, such values ​​.1000 mm and 500 mm in diameter. You'll see that the pressure falls by only 3 mmHg, as much as a small change in the weather. So very little. But the speed in the narrowest place is as much as 6 times greater... and it is known that the jet must have a framework for high speed input, because only then is a good efficient....

    http://www.flowmeterdirectory.com/fl...turi_calc.html

    As regards the first issue, that of efficiency in relation to the traditional windmill is to present two part.
    The most important thing is a wind speed that is achieved at the narrowest point.
    In the formula for the power of the windmill, there are two variables. Wind speed and diameter of the fan. the fact that the speed, power depends on the third power, and the diameter only in the second... So there will generally follows the model that is appropriate to increase the velocity of wind, and reducing the diameter of the fan. Thanks to this we get greater power.














    Conclusion. The venturi tube, the energy involved produkcjii WHOLE air mass at a given time as there is a venturi tube inside. This follows from the Bernoulli's principle that there must be continuity in the flow. A pipe can have a length and 500 meters...
    A traditional windmill, at most, the air mass, multiplied by max disk windmill , say 1 - 3 m.
    From here you receive such a big difference of power, with the same input speed of the wind. Just a whole mass of work has been hectic

    Ideal can see the difference in energy received in a gauge air -powered vacuum with a venturi tube. which is diameter 3 / 4 inch, hard disk drives and up to 8000 RPM gyroscope, which has a diameter of 2 inches.
    Imagine now that such energies would produce a windmill with a diameter of 3 / 4 inches..
    And no, even the most modern building of a traditional windmill, he can not s Compare and contrast this...

    regards Andrew
    Last edited by Feliks; 06-05-2011 at 07:02 AM.

  3. #53
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    Default Re: ROLLS-ROYCE CRECY

    None of this addresses my question of drag and resistance reducing efficiency. The wind will want to go around rather than through such a device.


    Because of this and other factors, it sounds like such a device would have to be several times larger then a equivalent-output standard windmill, and occupy a MUCH larger footprint on the ground (500 meters you say?).


    What DOES make sense is to combine the two systems. Place a very efficient propeller-type turbine within the narrowest point of a venturi.

    You'd achieve a faster airflow with the venturi, AND capture more energy, the best of both worlds.

    (searching the net...)


    Looks like someone has already taken that path:

    http://www.energysense.ie/Windmill.html


    .
    Last edited by AirDOGGe; 06-05-2011 at 10:42 AM.

  4. #54

    Default Re: ROLLS-ROYCE CRECY

    Quote Originally Posted by AirDOGGe View Post
    None of this addresses my question of drag and resistance reducing efficiency. The wind will want to go around rather than through such a device.


    Because of this and other factors, it sounds like such a device would have to be several times larger then a equivalent-output standard windmill, and occupy a MUCH larger footprint on the ground (500 meters you say?).


    What DOES make sense is to combine the two systems. Place a very efficient propeller-type turbine within the narrowest point of a venturi.

    You'd achieve a faster airflow with the venturi, AND capture more energy, the best of both worlds.

    .
    None of this addresses my question of drag and resistance reducing efficiency. The wind will want to go around rather than through such a device.
    No, I will want to go around. It just so it looks at first glance.
    Why not? Sent because the in narovest place occurs during movement of vacuum that will suck the wind to the venturi tube. Of course condition is laminar flow through the cones, tubes, or do not occur turbolent. It's a little like an airplane wing. If there is no laminar flow, the lift force disappears and the plane falls. Here, too, will disappear if the laminar flow venturi tube, not give us a profit on what we expect. To maintain the flow laminar, cones are not allowed to have larger angles than those resulting from the calculation. Therefore, they must have adequate length, the relatively large for its diameter. The plane did not fall then = ( expected to give a venturi tube laminar undisturbed flow ) and gain velocity and pressure drop.

    This link, which I received from you, thank you for that, it is only a substitute and the name of a venturi tube.

    So the truth, this is just only enclosed propeller...

    That is made ​​that not only you have doubt. I had already dissipated before it, and historical perspective on the forum are Autosport.
    http://forums.autosport.com/index.php?showtopic=74960&st=440 start post 461

    Regards Andrew

  5. #55
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    Default Re: ROLLS-ROYCE CRECY

    Well, it's more than just a ducted windmill. The "duct" is venturi shaped and does what a venturi suppose to, increase airflow velocity at it's narrowest point. They don't make use of any drop in pressure at the throat, but this particular design isn't intended to use any.

    Quote from the website:

    "The venturi duct unique design accelerates light winds by up to 50%....Thanks to the venturi's high efficiency when other windmills are producing negligeable current the "donQi" offers useable power. "


    Your design uses air flow produced by reduced pressure at the throat to rotate a turbine, and theirs places an efficiently designed windmill within the throat to make use of the increased air velocity there. Formulas and lab tests tell us a lot, but they don'[t always prove correct when taken outdoors and placed in a real environment.

    In truth, I think your design would do better using something like their windmill instead of a multi-bladed turbine wheel. The latter usually need very high air flow velocities to prove efficient, while the former work better with slower moving air.


    Only time and real-world experiments will tell which is the better path. Are you going to build a scale model for tests?
    Last edited by AirDOGGe; 06-08-2011 at 09:09 PM.

  6. #56

    Default Re: ROLLS-ROYCE CRECY

    Maybe ...

    Another animation:

    http://www.youtube.com/watch?v=Tz2rQvCxp44

    Regards Andrew: D

  7. #57
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    Default Re: ROLLS-ROYCE CRECY

    Looking at the 2 concepts has given me an idea to improve performance.

    Why not use the capabilities of BOTH designs in one unit. Use the wind to force more air through the turbine intake, supplementing what airflow the venturi is producing via lower pressure downstream:




    Really, the best layout of this concept would be to relocate the turbine vertically so that the intake is short in length for less drag losses, similar to those fan-venturi's I posted earlier. I didn't have time to draw all that right now (it's late and I'm heading to bed).


    Look do-able?


    .
    Last edited by AirDOGGe; 06-22-2011 at 02:55 AM.

  8. #58
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    Default Re: ROLLS-ROYCE CRECY

    This thread is NINE years old, and has nothing to do with the original content. Maybe it's time to let it go....or...heck, start a new one.


  9. #59

    Default Re: ROLLS-ROYCE CRECY

    Quote Originally Posted by AirDOGGe View Post
    Looking at the 2 concepts has given me an idea to improve performance.

    Why not use the capabilities of BOTH designs in one unit. Use the wind to force more air through the turbine intake, supplementing what airflow the venturi is producing via lower pressure downstream:




    Really, the best layout of this concept would be to relocate the turbine vertically so that the intake is short in length for less drag losses, similar to those fan-venturi's I posted earlier. I didn't have time to draw all that right now (it's late and I'm heading to bed).


    Look do-able?


    .
    Very well that you understood the idea, and now you can develop it further. Thanks to such people, shure will serve others.

    But, ideas and further improvements must be thought out.

    For example, this " Bost ", the first would always be directed to the wind, which would very coplicate structures. Besides, can you imagine, " Bost ", " Katrina or the tornadoes? Because I did not really..
    Therefore, it would not be a significant expansion of efficiency but only complication.

    And the variance is the one who just shows the possibilities. Other variants had already been published. Accept that in practice, time will show


    Quote Originally Posted by Feliks View Post
    The first windmills pumped water in America. To sustain this good tradition, I developed a little more modern sytem for the production of electric current in a similar way of pumping water.Whether American landscape views, are water sphere.I decided to add this view to the next shot where the water will be collected water so that it could give electrical energy when draining it back into the lower reservoir.




    This water will be pumped sphery as in the first versions of windmills, wind.
    The wind turbine will move a small diameter, but it is a multi-blade, placed together with the hydraulic pump in the middle of a specially constructed balloon. Balloon will be tethered, as previously barrage balloons.
    Only that will go along the line, hydraulic pipes, the hydraulic motor, which will be driven water pump located in the lower reservoir.The water pump will continuously pump water to sphery. Now the water falling from the lower reservoir back to the shery, will do an electric current through hydrogenerator.






    Every so water sphere about the capacity of 2000 m 3, and the height 100 m can give power 10 MW for 3 minutes. If filling pumps water with the one I believe loss is managing to fill waters up, we will have it 10 MW driven with wind turbine in balloons.
    Of course, the balloons could be filled up by hydrogen, because today we have very good material on the shell.
    This system could be installed in any place where electricity is needed, and thus would have limited losses on the transfer.
    Also low noise, and the invisibility of the rotating blades, not to interfere in coexistence with the environment.Balloons can be affixed to a height of 150 to 200 meters, where the wind is always blowing on the ground even when there is absolute silence.
    some links:
    http://media.primezone.com/cache/189/int/8385.jpg

    http://www.youtube.com/watch?v=mu2gl...yer_embedded#!

    http://www.engadget.com/2010/06/21/n...ong-endurance/

    http://www.youtube.com/watch?v=W3n5c...layer_embedded


    Of course, two rotate in one direction and two in the opposite direction.
    You must use a very light hydraulic oil. If it were not frozen in winter.
    Hydraulic pump in the balloon has the best power to weight ratio. All the airlines are working on the hydraulic actuators.
    Of course, all of the balloon must be tested in the wind tunnel aerodynamic, in order to fully match the efficiency of the 21st century
    Some pictures of how to create a balloon from the inside






    and NASCAR wind tunnel



    There is a way to shorten a bit of flexible hydraulic tube...



    Well, if it accidentally escaped gas from the balloon and so it can be



    Name : Jazz Big Band


    Rotating Dixieland Yoda.





    Next Dixieland :




    To those dixielnds can efficiently drive Hydraulic, it may have, no peaks of specialized software, use the links below.

    http://www.hippocampus.org/homework-...imulation.html




    A new way of sailing through a balloon which has the wind, and transmits energy to the propeller using hydraulics




    And sailing version of the Venturi jets



    Regards Andrew

    Andrew
    Last edited by Feliks; 06-29-2011 at 06:53 AM.

  10. #60

    Default Re: ROLLS-ROYCE CRECY

    Originally posted by monkeysandbearspants
    Having digested the content of the thread i conclude that the answer could be one of these !!

    However weight may be an issue and mostly certainly there would need to to be some boot modifications!




    http://www.full-ahead.net/Silownia/s..._index_ang.htm

    http://www.full-ahead.net/Silownia/s..._urw_zawor.htm

    http://www.full-ahead.net/Silownia/s..._index_ang.htm

    double bottom fo foam
    http://www.youtube.com/user/pawielus?gl=PL&hl=pl#p/u/53/Cfp0BWKwdgY dno


    large swimmer:
    http://www.youtube.com/user/pawielus...92/mnxWu3oWghs

    Regards Andrew

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