Wingboat Design

Hi John, I understand the point that you are trying to make is that, in your opinion, 'boats' vs 'aircraft' should be classified according to your definitions. I'm sorry but I disagree with your definitions. If I accept your definitions then I would have to classify hovercrafts as 'aircraft'. My interest in this topic comes from the perspective of a radical boat designer who is interested in incorporating WIG principles into my FX-1 design, however I do plan on incorporating a water propulsion system into the design.

Regardless of that, I just enjoy a stimulating debate ... Your desription above related to the KM Ekranoplan is exactly the definition of a Type B craft... a craft which can rise onto a GE platform, but could never rise above the GE cushion. You are entitled to your opinion that the IMO is 'all wet', but I guess I look at it from a different perspective, and agree with the IMO classification that these craft are properly defined as 'boats'. Be that as it may, we are digressing from the design you are proposing. Let's forget about the 'classifications' and let's see the pics of your design concept. As you imply that you are going to incorporate GE, but power the craft through water propulsion, does it look like one of these ... ?

 

WIG Aircraft

John, here are some examples of what I would classify as a WIG aircraft... Type C craft. The first was designed by Bartini in 1959 ...the Russian 'VVA' is a classical Type C WIG design, in that it could actually fly, (although it was very inefficient as an 'aircraft'). Nevertheless, it was highly effecient when operated in 'boat' (Type B WIG) mode.

The second pic is of a WIG 'aircraft' currently under design considerations by Boeing. The 'Pelican' would be capable of operating as an aircraft, but would be most effecient operating in WIG mode (as in Type B parameters).
http://foxxaero.homestead.com/indrad_043.html

These are examples of my disagreement with your definitions between 'boat vs aircraft'. These craft are quite different in operating parameters to 'Type B' craft (True Aerofoil Boats) in that an aerofoil boat is incapable of operating as an 'aircraft'. I recognize that you will disagree with my interpretation of WIG craft definitions, but to me it is unimportant whether a boat is powered by water propulsion or air propulsion in order to qualify as a 'boat'. To me, if a boat can't fly, it's still just a boat! hehehe

Cheers

Russ

 

HeliFerry

Foxxaero,
If you mean by "radical", an innovative approach to an old problem that finally guarantees safety (because full control) in all modes of WIG "flight" I am with you; but not if you mean freaky because this boat swings a large overhead rotor.
You realize that the hard part of the HeliFerry (look at 3D views on http://users.telenet.be/heliferry ) is not the hulls (took Philips cat hulls at half their original aspect ratio) nor the wing in ground effect (is there much beyond Lippish?), but the SR/C (slowed rotor used in compound craft). The latter is being tested in real life. Look at http://www.cartercopters.com to see the ups and downs in the development. It will be pretty straightforward to take a manned operational unit from CAT and add the wing + floats to have a lifesize prototype.
Luc

 

Radical Boats

Luc, as far as the heliferry goes, I mean 'radical' as an innovative and advanced design.

Freaky or wacky boats would include such concepts as the 'Hydrocopter'. Only one of these were built (Boeing holds the patent) See pics below.

As far as WIGs go, would the 'Heliferry' be a Type B or Type C WIG ?

 

The Heliferry (HF) is meant as a type B because its focus is fuel efficiency. However, to give the HF a more all weather capability, the rotor's collective can be used to provide more lift to offset the loss of GE efficiency when cruising higher than, let's say, 1/10 of chord. This comes, of course, at a serious fuel penalty. The rotor as "lifting aid" is thus not only handy when taking off or landing. With a big enough engine it becomes a type C, but that is not the challenge.

 

Hydrocopter/Hydrokopter

A question jus semi related to this issue...
Is the name hydrocopter TradeMarked?

In Sweden Hydrokopters have been in use for a long time. Hydrokopters are used in the icey periods during autumn/winter/spring. Its a pretty flatbottomed steel or alu hull with a big propeller a the back, resembling the kind of propeller used on marsh boats in Florida.

So how big a difference would the change in spelling make k instead of c...

Just curious, utterly non-important

 

Hydro(k/c)opter

A picture is worth a short paragraph:
http://www.keksintosaatio.fi/innofin/Inventionmarket/Shipbuilding/Output/11715_e.html
Pretty nifty.

 

I've been aware of the Swedish Hydrokopter for some time. I don't know what is entailed in getting a name trademarked, or whether the Boeing concept came before or after the Swedish boat. I don't know how 'copter' or 'kopter' comes into the Swedish design? It's an 'airboat', and seems well suited to its purpose, but I wouldn't class it as a 'wingboat'.

I think the Boeing Hydrocopter and the Heliferry could be classified as 'wingboat designs' because they both utilize foils (wings) for lift. Of course, I think the Boeing 'boat' is destined for the back pages of boat design concepts, whereas the Heliferry is a highly valid concept.

Getting back to more traditional 'wingboats', a Russian company (JSE Kometal) have designed a craft to operate over ice-fields. Check out the video link on this page (originally from the French nature program called Ushuaia). The narrative is in French, but the pics are in 'universal' language.
The video takes a long time to download and I am on Cable, but it's well worth the wait to view some excellent video of the Ivolga EL-7's operational capabilities. I can see how adding a gyrocopter foil, could provide some additional advantages.

http://foxxaero.homestead.com/indwig_017.html

 

Wig

Foxxaero,

Once again you have missunderstood what I am saying. I don't wish to throw out the IMO definitions. My point is they don't define the type boat we want to build. Carefully read the type B definition.It does not permit continuous above the water operation.The appropriate definition is missing. It is missing, I suggest, because they really don't know how to classify such craft.Your reference to hovercraft is another red herring. Hovercraft are not WIG anything,and don't fit any of the definitions;why even mention them.

As to your desire to design radical craft;I always thought the goal in designing anything is functionality. If the approach is inovative,a radical design may be the byproduct. Radical is not neccessarily good.High speed and "radical" in boats is a dangerous combination.At least 10 drivers of racing boats died in one year(many more injured) due to "blow-over". It was determined by marine engineers that the cause was too much air lift coupled with pitch instabilty,and perhaps other instabilities(chine walking and transverse porpoising) Designing such craft with little technical knowledge is a high risk endeavor.

My son races hydroplanes. Worrying about blowover got me interested in such boat design.Originally my goal was 100% air lift but with emphasis on pitch stability.I now know(after designing, building and testing a prototype) that this does not result in the fastest boat only a high risk boat.

It is not my intention to discourage you; only to offer some advice based on 35 years of engineering design experience.Forget radical, think function,think about risk,think about safety.Be less parochial ,be ready to consider ideas that may not follow your own. In any event: Happy wigging.

 

Thanks John, What am I missing here?

Let's review the Type B definition ... "Type B WIG craft are those which can stabily lift onto a ground-effect cushion, but cannot sustain 'free-flight' in an efficient manner - these are classified as 'boats'. An example would be the Flightship FS-8 ... (hovercraft are also included in this classification)".

A GE cushion is a mode of operation in which the craft is IN CONTINUOUS 'above the water operation' (nothing contacting the water surface), yet you keep saying the IMO classifications do not have a classification which permits 'continuous above the water operation' ???... I'm sorry, but I fail to see your logic.

Although hovercraft are not actually wing-in-ground-effect craft, for the purposes of this discussion I included them as Type B WIG craft because while in operational mode no part of the hull is dependant upon water contact for stability, and their form of propulsion is an air propeller (as opposed to any form of water propulsion). They cannot 'fly' in the sense of conventional aircraft, and therefore they fit all the criteria for a Type B WIG boat (except they do not employ foils [wings] for lift. The above parameters seperate them from conventional boats and conventional aeroplanes, but you are correct that, (technically speaking) they are not actually Type B WIG (Aerofoil Boats)(Wingboats)... as they do not employ foils for lift.

I would also agree with you that functionality is the goal in design which is precisely the reason why many designers are employing WIG principles in their designs. 'The Goal' is not to make a radical boat - it just so happens that employing GE is a somewhat radical approach to boat design and the configurations of such craft are somewhat unconventional (radical) in appearance, when compared to conventional boat design.

Also the goal in designing WIG is not to create a super fast boat (such as racing hydroplanes and tunnel hulls), but rather to create a relatively high speed craft (compared to conventional boats)capable of relatively high lift / 'carrying capacity' (as compared to similarly sized aeroplanes). A properly designed Aerofoil Boat has far less risk of 'blow-over' than racing hydros, and especially the Lippisch anhedral reversed delta ram foil design, because the configuration has been shown to be inherently stable.

As far as being 'parochial' have a look at my file archives (the Worlds Most Radical Boat Designs) http://foxxaero.homestead.com/newsplash.html
I consider myself to be one of the least narrow-minded thinkers in boat design. In my opinion, it is those designers who cannot see 'out of the box' of their own design experiences... who fail to look over the broad view of advances in boat design ... and who fail to see the possibilities of blending different concepts that must be considered 'parochial'.

But that's just my own .02 cents worth.

Cheers

 

Foxx, as I said only semi-related to the subject as I fully agree that an "Airboat/Hydrokopter" is no wing-boat. I just thought that since these boats have been aound for at least 25+ years (first time I saw one they might be considerably older than that) and AFAIK they have been known as Hydrokopter at least since tha time, therefore I was curious about the name Hydrocopter.

Now, lets go on with the show.

 

Thanks

Thanks Erik,

Luc - seems to be some mix-up with messages. My question was can you e-mail me some jpegs of the 'Heliferry' for use on the Worlds Most Radical Boat Designs website. contact me at foxxaero@shaw.ca

Cheers

Russ

 

What type of sea state are you going to run in? If it is a glass smooth lake then you can do just about anything. If it is rough sea conditions, then you start compromising. Your wing then has to be lifted up and be quite far back as you have shown.
Also beware of flipover. ie the Donald Campbell record boat that crashed. You need the aero centre of lift close to the LCG of the boat. If it is too far forwards then you flip over. Think of a catamaran with a deck extending right up to the nose. The racing cats have what is called picklefork hulls, ie the deck is cut back to get the centre of lift back.
regards
Frans X Liebenberg

 

SeaRam 8 project

I began to study wing-ship technology about a decade ago when I believe an article in Popular Science Magazine first presented a story about "Flare-craft" boats. I collected many promotional videos of these unique flying boats and over time concluded that they have some serious problems if they ever tried to maintain their surface-effect lift option out in open ocean seas where hills and valleys of water exist.

If flying fast off a large swell they could leave the surface effect of lift and crash into the oncoming "hillside" of another large swell.

So this conclusion lead to the idea of designing a seaplane that did not rely on the vortex compression wake of the craft against the water surface at high speeds for lift -- but rather on a kite-wing lifting platform that could foil the atmospheric wind energy over the wings into the tail area to create a stable point of low-pressure lift directly above the payload.

This design not only allows the pilot of a high-speed craft to escape the danger area of the hard water zone, but also, like any seaplane, fly as high as necessary to safely get from point A to point B over water or land.

The attached image are views of the SeaRam 8 project -- and if you are interested in going for a virtual test flight of her, you can download it for free from my one of my website pages and use either the Micro-Flight or the Virtual Sailor simulator programs as an environment for flight. These simulator programs cost about $25 each and can also be used to test many custom aircraft and boat designs created by the free 3ds file maker program called Anim8or.

http://ourworld.cs.com/duanekmccullough/vs1.htm

I have two other types of seaplane designs you can find at the above link that also use the unique kite-wing lifting platform -- check them out when you can.

 

The suggestions of FXLiebenberg are well warranted. Your design does need to ensure that the aerodyamic centre of lift is as close as possible to the LCG of the boat. It is even more complex than this, since the location of the dynamic center of Lift will change throughout the operating velocity range of the hull due. This is due to the ever-changing balance between lift/drag resulting from aerodynamic forces and hydrodynamic forces.