+ Reply to Thread
Page 2 of 7 FirstFirst 1234567 LastLast
Results 16 to 30 of 105
Like Tree3Likes

Thread: Wing in ground effect boat

  1. #16
    Registered User Joe Fisher's Avatar
    Join Date
    Feb 2007
    Location
    Galesburg, KS South east Kansas
    Posts
    869

    Re: Wing in ground effect boat

    Back in the 1960's there was an article in Popular Mechanics about a hybrid boat plane. They had a small boat with the outboard engine and a long boom forward with the seaplane attached.

  2. #17
    Registered User
    Join Date
    May 2009
    Location
    High in the Andes Mountains
    Posts
    1,964

    Re: Wing in ground effect boat

    Do you mean the boat was to help accelerate the aircraft to flying speed and was then left behind? In that case the proper term is composite vehicle rather than hybrid.

    Short Mayo composite aircraft:

  3. #18
    Super Moderator orion's Avatar
    Join Date
    Mar 2003
    Location
    Western Washington
    Posts
    5,945

    Re: Wing in ground effect

    Quote Originally Posted by Starman View Post
    I got the 250% efficiency increase from the website I linked to, and I didn't believe that it's possible in a real world situation. Maybe it is possible on smooth water at very low h/c where the air under the wing completely stagnates and generates a full pressure recovery. In any case, when I figured the range I assumed no efficiency increase due to WIGE just to be on the safe side.
    If it's the case I'm thinking of, the number comes from a theoretical analysis of a wing-alone condition. The example is used to demonstrate the potential of ground effect flight however most folks seem to take a cursory glance at the example and assume that it means that somehow a WIG will be 25 times as efficient as a 747 in cruise. Nothing of course is further from the truth but in many cases the facts do not seem to deter the determined. Ground effect flight does add efficiency but the real comparison must use is one that compares transportation systems, not aircraft. Compared to high speed marine vessels, the potential of WIG operation is substantial. And herein lies the benefit of the WIG craft being classified as boats, not airplanes. In your case though I'd urge care since if you are going for free air flight you will not be a WIG - you will simply be an airplane that happens to fly really low. That then does put you in the jurisdiction of the FAA.

    Quote Originally Posted by Starman View Post
    I'm aware of the excess power situation that WIGs have, but could you state briefly what the source of the destabilization is when overpowered. High thrust line?
    It's a combination of things but simply said, the WIG craft must be able to achieve a trim and stable attitude that's a function of height. Since this condition is a function partly of speed, variances in power could cause the trimmed craft to climb, thus exceeding its trimmed attitude and thus go unstable. As you indicated in your post, the wing's resultant lift vector position changes dramatically between ground effect and free air and too much power at the wrong time is a guarantee of loud and wet noises. Yes, you also have the high thrust line issues and trim effects of the horizontal tail in the slipstream so all these things combined are a recipe for disaster, In the case of the Flarecraft, if I recall right there were two crashes, the last one fatal to the pilot.

    Quote Originally Posted by Starman View Post
    I've had my eye on WIGs for about 25 years now and it seems there are plenty of them that have acceptable functionality.
    Actually none have any real domonstratable functionality. Pretty much every Russian WIG has crashed and has within the last decade been proven unstable and poor in function. Currently all Russian WIGs are grounded and mothballed with the exception of the Amphistar, but that one will be also (if it hasn't been already) since it can be herd coming for miles and no community I know of will allow that noise anywhere near its shores.

    More modern designs have also been proven ineffective (with the exception of the Airfisch series and of course the FS-8) - the German government had a fly-off about five years ago or so and all the functional WIGs were invited to the event. If I recall right almost a dozen came. On the morning of the demonstrations there was a light wind and the lake developed a light chop. That slight surface disturbance created enough of a problem that not one of the participants was able to lift off to flight mode. Not even the more hyped ones like Dr. Fischer's Hoverwing.

    Quote Originally Posted by Starman View Post
    I'm curious though about this website The WIG Page - information about Ekranoplan and Wing-In-Ground effect craft that I linked to earlier, which is a clearing house for the latest WIG design info. They require a fairly substantial membership payment to access the info. Have you heard of them and/or are you a member of it?
    I know it well - I was one of the founding members (although the real person behind it is Edwin van Opstal, who's one of the leading authorities in the field) and I provided the same type of technical support that I do here. After a few years though I stopped simply because there was very little new blood, the questions became repetitive and sometimes just plain dumb, and because no-one was really serious about the technology or the development of a real product. It was essentially just a bunch of amateurs playing around with toys and their pet theories, none of which really held much water. In short, it just became really disheartening so I and a few others who are into this end of things just faded from the group. I don't know its current status and I really don't want to pay so much to find out.
    "To live is to learn; to learn is to live" (author unknown)

  4. #19
    Registered User
    Join Date
    May 2009
    Location
    High in the Andes Mountains
    Posts
    1,964

    Re: Wing in ground effect boat

    Now that is disheartening

    My idea was to make a WIG and be under the jurisdiction of the Coast Guard and then after playing around with it for a couple of years adding longer wings and getting it FAA certified.

    I found some clear info on WIG design and potential titled: Australian Military Research and Studies on Wing in Ground Effect Craft. It is a pdf file that can be found on the wikipedia page on ground effect craft.

    So the story goes that by the time you add the gigantic rear wing and all the extra power that there isn't much gain in efficiency - in addition to the stability problems.

    It seems to me that the best way to get stability is to use a narrow chord wing, but then you have an aircraft, which still could utilize ground effect.

    I suppose a float plane or flying boat will need just as much power to get water plane as a WIG, but they can put the power to good use by going faster in the air.

    So, back to the drawing board.
    Last edited by Starman; May 25th, 2010 at 03:55 PM. Reason: grammar =)

  5. #20
    Registered User ekranoplan's Avatar
    Join Date
    May 2010
    Location
    Croatia
    Posts
    1

    Re: Wing in ground effect

    Quote Originally Posted by orion View Post
    Actually none have any real domonstratable functionality.
    This is not true, they all had success, only drawback was lack of funding, as I will explain later.

    Pretty much every Russian WIG has crashed and has within the last decade been proven unstable and poor in function.
    Not every one crashed, and reason was not in WIG concept, rather in human errors and continuosly smaller budget for program.
    All are landed and rotting only because then Soviet, and now Russian government, gave up from Ekranoplan program, and instead invested all money from Ekranoplan program, to nuclear submarine program. I have to add that, Hruščov's successor, Brežnjev, wasn't interested in program at all. So, as you see, Russian Ekranoplan program was placed a side only because of politics, and in early 1990's major political changes in ex USSR, now Russia.

    More modern designs have also been proven ineffective (with the exception of the Airfisch series and of course the FS-8) - the German government had a fly-off about five years ago or so and all the functional WIGs were invited to the event. If I recall right almost a dozen came. On the morning of the demonstrations there was a light wind and the lake developed a light chop. That slight surface disturbance created enough of a problem that not one of the participants was able to lift off to flight mode. Not even the more hyped ones like Dr. Fischer's Hoverwing.
    There are companies making ekranoplan's or WIG's as you want it.

    Russian ATTK ( Arctic Trade and Transport Company ) - you may call it one of successors of Russian Ekranoplan program, since many of engineers and designers ended here, and company uses some of facilities of the program:

    Products



    Asian company ( Japanes or Thai, not sure ):



    Korean company:



    Singapore company:

    http://www.wigetworks.com/index.html

    Chinese company:

    Home | Sea Eagle



    UK company:

    Flyboat,flying boat or WIG. Wing in ground effect fly boat for sale.



    I must admit, that this is very niche market, unfortunately, and any info on internet is very, very hard to find. But still, in depths of internet abyss one can find little information on them.

    Honestly, it is surprise for me also, considering what kind of things people made in their homes, it seems that WIG is really, very rare.

    So, Starman, you have my support, as I'm also considering same thing as you, but, as for me, I think first couple of years will be in learning all about WIG's I can learn.

  6. #21
    Registered User 57Marty's Avatar
    Join Date
    Mar 2007
    Location
    Southern California, near Edwards AFB
    Posts
    47

    Re: Wing in ground effect boat

    Have you seen this one? Universal Hovercraft has what I think you are talking about. Two videos


    From what I remember on the Discovery channel the craft is "flying" in Canada and does not require any kind of pilots license due to the limited height above the water. Interesting idea and definitely not an airplane.
    Marty

  7. #22
    Registered User
    Join Date
    May 2009
    Location
    High in the Andes Mountains
    Posts
    1,964

    Re: Wing in ground effect

    Quote Originally Posted by ekranoplan View Post
    This is not true, they all had success, only drawback was lack of funding, as I will explain later.

    Not every one crashed, and reason was not in WIG concept, rather in human errors and continuosly smaller budget for program.
    All are landed and rotting only because then Soviet, and now Russian government, gave up from Ekranoplan program, and instead invested all money from Ekranoplan program, to nuclear submarine program. I have to add that, Hruščov's successor, Brežnjev, wasn't interested in program at all. So, as you see, Russian Ekranoplan program was placed a side only because of politics, and in early 1990's major political changes in ex USSR, now Russia.

    There are companies making ekranoplan's or WIG's as you want it.

    Russian ATTK ( Arctic Trade and Transport Company ) - you may call it one of successors of Russian Ekranoplan program, since many of engineers and designers ended here, and company uses some of facilities of the program:
    ...

    I must admit, that this is very niche market, unfortunately, and any info on internet is very, very hard to find. But still, in depths of internet abyss one can find little information on them.

    Honestly, it is surprise for me also, considering what kind of things people made in their homes, it seems that WIG is really, very rare.

    So, Starman, you have my support, as I'm also considering same thing as you, but, as for me, I think first couple of years will be in learning all about WIG's I can learn.

    Thank you Ekranoplan, I have seen most of those videos, but not of the one from Korea. I really like the style of that one and also the overall layout, type of wing, etc.

    It is easy to see that there are many of these WIGs that have been made and that they have flown and flown well. The idea that many of them have crashed was disappointing, but then I suppose that most airplane designs have crashed as well.

    It seems to me that if the horizontal tail is large enough and the wing is a reverse delta that the stability problem shouldn't be too much of a problem. Possibly it can be more of a problem at higher speeds well above takeoff speed.

    One thing I've thought of is to have a surface follower that will automatically control the elevator to maintain the craft a certain height above the surface. This could be a mechanical follower or it could be electronic, using a radar or sonar mechanism. I prefer mechanical ones.

    One thing that was disappointing was that during the German contest that none of the WIGs was able to take off due to the water being slightly rough. If I make one of these I want it to be able to take off from the middle of the ocean, not when it is rough and stormy, of course, but when it is calm to moderate. Taking off in moderate swells would be kind of like taking off in a regular plane from a undulating runway built on gently rolling hilly terrain because ocean swells are actually pretty far apart. If all it takes is a lot of power then I'll give it a lot of power. I'm not afraid of using a lot of power, but then that evidently can be destabilizing.

    Most of the videos I've seen show the craft operating only on smooth water but some of the advertisements claim that they can operate in waves of various heights. This video Aron-7 Wing-in-Ground-Effect (WIG) Seaplane Video shows the Korean Aron 7 taking off from relatively rough water at one point (40 seconds). It also looks like it is underpowered and requires a long time to take off. The Aron & however, has a relatively long wingspan and therefore would probably not be able to qualify as a boat. The good thing about the long wingspan is that the wing chord is smaller and therefore the stability problem is lessened. It has a relatively small horizontal tail but it is pretty far back. In the videos you can see that it appears to be constantly changing it's pitch attitude.

    It is good to see that the Airfisch * has been taken over by a Singapore company.

  8. #23
    Registered User
    Join Date
    May 2009
    Location
    High in the Andes Mountains
    Posts
    1,964

    Re: Wing in ground effect boat

    Quote Originally Posted by 57Marty View Post
    Have you seen this one? Universal Hovercraft has what I think you are talking about. Two videos

    From what I remember on the Discovery channel the craft is "flying" in Canada and does not require any kind of pilots license due to the limited height above the water. Interesting idea and definitely not an airplane.
    I've seen these and what is remarkable is that it has such a poor wing which the designer evidently just guessed at, the horizontal tail is small and close to the wing, which has a large chord, and yet it seems to be quite stable.

    If it can fly to 50 ft as it says in the video then it must be registered as an aircraft whether or not the driver chooses to fly it that high, unless it's light enough to qualify as an ultralight.

  9. #24
    Registered User
    Join Date
    May 2009
    Location
    High in the Andes Mountains
    Posts
    1,964

    Re: Wing in ground effect boat

    Hi, I solved the stability problems for WIG craft

  10. #25
    Formerly Unknown Target Inverted Vantage's Avatar
    Join Date
    Jun 2008
    Posts
    1,053

    Re: Wing in ground effect boat

    orion, apologies if you've heard this question before (I'm sure you have), and I'm not very educated on boat design...what research has there been on using hydrofoils as boosters to push the hull up out of the water, reducing drag and thus reducing the required thrust to pull the vehicle completely out of the water?

  11. #26
    Super Moderator orion's Avatar
    Join Date
    Mar 2003
    Location
    Western Washington
    Posts
    5,945

    Re: Wing in ground effect boat

    It has been explored and is considered a promising (our concept uses the idea for instance) however it is not popular because a similar idea was incorporated into a test version of the X-114, which crashed because the pilot forgot to retract the foils and they dug in during a turn, destroying the craft.

    The other problem is that in order for them to be fully functional they have to be submerged, even as the craft leaves the water. This however means that they're likely to be submerged or in water contact as the craft approaches the takeoff/cruise speed so the system does require some form of retraction so as to allow a low drag transition to flying speed. Our system is looking toward an automated retraction - without that the scenario of them inadvertently contacting the surface is very real.
    "To live is to learn; to learn is to live" (author unknown)

  12. #27
    Formerly Unknown Target Inverted Vantage's Avatar
    Join Date
    Jun 2008
    Posts
    1,053

    Re: Wing in ground effect boat

    What about a forward swinging spring mechanism? While the craft is water bound, the hydro pressure of the water, coupled with a mechanical lock, keeps the hydrofoils locked backwards. When the pilot pulls a lever, it decouples the lock, allowing the legs to swing forward automatically via the spring. The biggest issue you'd have is making the spring strong enough to pull the foil forward, while at the same time weak enough so as to let them stay stuck down.

  13. #28
    Super Moderator orion's Avatar
    Join Date
    Mar 2003
    Location
    Western Washington
    Posts
    5,945

    Re: Wing in ground effect boat

    While certainly a viable possibility, the problem is that it still requires pilot action. The retraction itself is not so much an issue - it's more so finding a way to guarantee that said retraction will take place every time.
    "To live is to learn; to learn is to live" (author unknown)

  14. #29
    Formerly Unknown Target Inverted Vantage's Avatar
    Join Date
    Jun 2008
    Posts
    1,053

    Re: Wing in ground effect boat

    If it absolutely must be automated, you could have a pressure sensor on the struts. When the craft lifts up out of the water, the hydro pressure stops and an electrical signal is sent to the latch to disengage and pull up the foils.

  15. #30
    Moderator autoreply's Avatar
    Join Date
    Jul 2009
    Location
    Leiden, Netherlands
    Posts
    8,407

    Re: Wing in ground effect boat

    Quote Originally Posted by Unknown Target View Post
    If it absolutely must be automated, you could have a pressure sensor on the struts. When the craft lifts up out of the water, the hydro pressure stops and an electrical signal is sent to the latch to disengage and pull up the foils.
    And when any of those systems (pilot included) will fail you're in a serious crash.

+ Reply to Thread
Page 2 of 7 FirstFirst 1234567 LastLast

Similar Threads

  1. Wing geometry "finalized"
    By addaon in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 0
    Last Post: February 15th, 2009, 05:46 PM
  2. Ground Effect - Flying Planks and Control Deflection
    By Topaz in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 2
    Last Post: January 15th, 2008, 10:57 PM
  3. Careful, it might FLY!
    By Tinbuzzard in forum Rules and Regulations / Flight Safety / Better Pilots
    Replies: 16
    Last Post: January 7th, 2008, 03:08 PM
  4. Wings in Ground Effect - Orion?
    By Topaz in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 6
    Last Post: August 26th, 2005, 09:28 PM
  5. Designing to fly in Ground Effect
    By parkpointer in forum Aircraft Design / Aerodynamics / New Technology
    Replies: 6
    Last Post: November 25th, 2003, 07:28 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts