Coanda craft: why not?

Discussion in 'Boat Design' started by joceline, Feb 2, 2011.

  1. joceline
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    joceline Junior Member

    Jehardiman, again, you're not talking about the coanda effect. The coanda effect only appears when a jet travels over a curved surface and generates lift. This is not the case in the aircraft/wig-craft you show.

    Let me demonstrate you the difference. The only aircraft that is using coanda is the An-72:


    Jets are placed right above the curved surface of the wings.
  2. jehardiman
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    jehardiman Senior Member

    I beg to differ, it is exactly the case. Using the propulsion jet to lower the pressure on the top of lift wing is the idea. That Antonov you show is just one example of the use of the Coanda effect. Though the jet is strong, it is over a small area, Moving the jet exhaust forward of the wing spreads the jet over a larger area, albeit at a slightly slower speed generating less lift per area, but much more area. This is where the design tradeoffs occur, jet velocity verses area of effect.

    The transition to flight speed is not as simplistic in marine craft as it is in aircraft. In aircraft, skin friction is almost trivial compared to induced lift at transition speed, which is not the case in marine craft where more displacement means more wetted surface and therefore drag. Both the WIGs I showed before and Ekranoplans such as the A-90 use propulsion jet velocity over the lift wing, i.e. the Coanda effect, to decrease displacement (i.e. generate lift) during the transition to ground effect to reduce required power. The A-90 can even turn off the lift turbofans once full ground effect has been achieved. Like the An-72 you show, they do not use the Coanda effect for VTOL, but use it to allow take-off with less power and shorter runs. In this case, all the craft discussed use the Coanda effect synergeticly with propulsion, which is good design practice. Using a engine just to affect the Coanda effect is poor design practice unless there is an overwhelming need for VTOL.
  3. RogerHX1
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    RogerHX1 New Member

    *New Coanda WIG Watercraft*

    *HX-1* (Hover Xplorer-1) *Project Summary*

    My current project is an invention called 'HX-1' (Hover Xplorer-1). This is an outdoor Recreational Vehicle Design using a Combination of *Coanda Air Propulsion* and *Air Guided Maneuvering System* with an Aerodynamic Oval Almond Shape.

    This is not to be considered as a traditional Hovercraft, since
    the design Does Not include an Air Retainer "Skirt ".

    The HX-1 has a "Powerful Efficient Environmentally Friendly Engine" that will allow it to hover and glide at an altitude of 17' feet from ground surface at a top speed of 87 MPH over any land terrain including water or man-made surface obstacles.

    Some of the Potential uses for this Type of Vehicle include: Recreational, Competitive Racing, Search & Rescue, UAV, Cargo Transportation and Hollywood Productions .

    The Past History of the *Coanda Air Propulsion Development* has shown us Various Possibilities which allowed me has an Inventor,Designer to make the Proper Adjustments that will Revolutionize The *Recreational Transportation Industry* Around The World.

    PS. They May Have Taking Away The *AVROCAR* But They Have NOT Taking Away Our *Creative Minds*....!!!

    Additional Information Is Available Upon Request.

    Thank You For Your Attention,
    Kind Regards,
    Roger Lemire

    * Coanda Air Propulsion Prototype Development *





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  4. daiquiri
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    daiquiri Engineering and Design

  5. joceline
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    joceline Junior Member

    Daiquiri is right. (And too funny! :p)

    Inventors really need to be able to explain their thing in the simplest and clearest ways. Simple explanations of complex things means mastery and probably real innovation.

    In any case, lifting bodies are nothing new. They're older than most boatdesign forum members' grandmothers.
  6. RogerHX1
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    RogerHX1 New Member

    Some "Coanda WIG Designs" Versions Are Becoming A Copy-Cat Reality?

    The "Coanda WIG Hovercraft Design" Seems To Be Evolving Into A Copy-Cat Competition ???

    Original Design (No.1) (Ir.Marcel Schroijen - Ph.D.Student/Researcher) From (Delft University Of Technology)

    Copy-Cat Version Of (No.1) At (Boat Design Blog)

    NOTE That I May Not Have Given Much "Technical Explanation" In Regards To My "Coanda WIG Hover Xplorer 1" Design .....But I Can Guaranty You That The Coanda Air Propulsion Functionality Of My (HX-1 Design) IS NOT A COPY-CAT Version From Any One's "Coanda WIG Hovercraft Design"....!!!

    PS. If You Wish To Obtain Additional Information.....You Will Need To Sign An "NDA Agreement" :p
  7. whitepointer23

    whitepointer23 Previous Member

    when can we expect to a real life operating version, i wish you luck but will believe it when i see it. i travel in a ground effect vehicle, it has 4 rubber discs which propel it forward when in contact with the ground.
  8. whitepointer23

    whitepointer23 Previous Member

    boeing made a very similar coanda effect aircraft as well but that fell by the wayside so there must be enough problems with the principle to stop development of it.
  9. kach22i
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    kach22i Architect

  10. DCockey
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    DCockey Senior Member

    US Army Transportation Museum at Fort Eustis has an AVRO CAR and a webpage about them: museum/avrocar.htm According to the website it's not currently on display but I seem to remember seeing it when I was there a month ago. Perhaps I'm mistaken or the website is out of date. They have several "flying cars and scooters" and early hovercraft from the 1950's and 1960's on display including a "flying jeep"
  11. RogerHX1
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    RogerHX1 New Member

    Coanda Super STOL Fighter Jet Drawings

    Hi Jehardiman,

    We are presently seeking funding for the *HX-1 Prototype Design* to be built here in Canada...In regards to the "Coanda Wing Aircraft Design" you have spoke about....I found an Article on Internet that shows Drawings from a "Fighter Jet" which uses the same "Coanda Effect Principle" !...Have A Look !...





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  12. HJS
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    HJS Member


    Hovercraft + Coanda effect + Wing in ground effect + interceptor effect = HoverWig:D
    First scetch from 1965

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  13. joceline
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    joceline Junior Member

    Why is that a copy-cat design?

    Many coanda aircraft ideas have two bent wings.

    In fact, many aircraft have two wings. Are all aircraft designers copy-cats? Of course, because they all design aircraft.

    I took the coanda principle and put it on a boat. I'm sure I'm not the first one to do so. And I don't see how a boat would have a circular, disk-like shape. So I took the shape of a catamaran, and that of a single hull boat.

    All car designs are copy-cat, because they show wheels and a body on top. All flying boats are copy cat because they show wings.

    Tssssssss :rolleyes:

    The TUDelft design is not innovative. It has two wings and a coanda flow. The aircraft shown here already, like the Russian AN-72 was built in the 70s. Boeing's coanda too. Lockheed-Martin's too. So the TUDelft student is a copy-cat. But then, many aircraft have two wings.

  14. joceline
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    joceline Junior Member

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