Oh Lordy (Doug)

Not necessarily so, though most laymen would love to believe that.

Once you get your butt into court and present your stuff to a jury/judge/whatever, you enter the realm of the crap shoot in its highest form. Sure, the lot can go down the tubes if the original series of claims was not presented well, but it has a whole lot more to do with the cleverness, resourcefulness and presentation skills of one's attorney, once you take your seat in that room.

There are tons of court records in this country, alone, in which a patent was found to be bunk when, in fact, it was as clear as one could make it as to the originator of said claim.

 

Windsurfer

Jim Drake-inventor of the windsurfer-has just joined this forum; it would be great to hear his comments...

 

Yep, I shouldn't have said it "would" have remained valid, but that it "could" have remained as the next sentence said.

By the way, in no way am I a layman in the law. And I've spent days in court watching the windsurfer patent go down. Presentation skills etc count for a lot less in jurisdictions were patent cases are decided before a judge.

 

One thing you can do is to have a look at the mathematical modelling used to scale the results. If the assumptions seem reasonable, then there is a reasonable chance that the full size results will reflect the predictions, at least to some degree. If you think the assumptions are flawed, you can probably make your own predictions. If there is no mathematical modelling at all, then skeptisism is a reasonable attitude to take.

Admittedly, being able to do the maths and make the right assumptions comes with experience, but it needn't necessarily be direct experience with the product you are designing.

Mal.

 

Thanks for the info.

Just to underline it; I (and I think many other people) have got no problem with the idea that it's certainly very, very possible to get enormous benefits from models when they're used the way you say.

 

The classic NA case of scaling proving difficult is the fact that Reynolds Number and Froude Number scale at difefrent rates. It is not possible to produce a replica model that operates at the correct Fn and Rn values. The common solution is to attach studs to the bow region to artificially increase the Rn. There are many other examples of scaling problems. For model testing to be truly benefical, these need to be known, understood and accounted for. If they are, model testing can be very useful. if not, you get a surprise!

I hope Mr Drake made his fair share from the Windsurfer, but I guess its true that there are many, many more around due to the lack of patent allowing other designers to evolve the concept.

By the way, on back to the original topic. The sailrocket project (sailrocket.com) is a similar concept. It will be interesting to see how the two fare against each other, if they get built.

 

PI Design Wrote:

"By the way, on back to the original topic. The sailrocket project (sailrocket.com) is a similar concept. It will be interesting to see how the two fare against each other, if they get built."

Sailrocket is an unashamed development of the Bernard Smith concept.

Differences between Sailrocket and Monofoil:

Sailrocket has the longitudinal CG way behind the aerodynamic centre (Neutral Point) and relies on water contact for pitch stability.

Monofoil has the CG ahead of the neutral point and is aerodynamically pitch stable

Sailrocket has a rudder and a canted foil, both of which must work for directional stability/control

Monofoil has a single foil and steers by relative movement of aero and hydro force lines (hence the name). Monofoil is directionally stable about this single point of water contact

Sailrocket has a sheeted control for the wing which means that any pitch change of the vessel results in a change in the incidence of the wing, this makes the wing potentially destabilising if water contact is lost.

Monofoil has a free-feathering wing controled by a servo tab. The wing does not affect pitch stability

Sailrocket uses a conventional foil which uses the hull as a ride height control

Monofoil uses a ventilated, cranked foil unique to each tack, ride height control is a function of foil geometry and body running angle.

Both Sailrocket and Monofoil heel to weather but Monofoil lifts the body clear of the water as it does so. Body pitch angle trim changes also trim the foil (obviously) and allow foil ride height to be controlled, these trim changes do not affect the wing or the force it creates.

Sailrocket is single tack

Monofoil is equal on both tacks

Other than the canted rigs and the heeling to weather there is actually very little in common between the two craft.

Jon.

 

Thanks for that Jon. I knew they were slightly different, but didn't realise how much. Still, they do work on a vaguely similar concept...

Going back to an earlier question of mine, is there any merit in attaching WIG-style low aspect ratio wings to get the hull to fly earlier? This would allow you to use a smaller sail, so you could sail in stonger winds. Just a thought, I could be way of the mark and showing a total misunderstanding of the design.

 

The way to fly in lighter winds is to fit a bigger wing. We have found that the transition from planing to flight is very smooth and progessive however and partially wing-borne operation is a perfectly viable way to sail.

Wing in ground effect craft are one of those apparently attractive concepts that is easily mis-used. The reason that they get such a benefit from ground effect is that they are low aspect ratio, short span aircraft in the first place and induced drag is much more evident than it will be for (say) a sailplane. This makes the ground effect cushion much more noticeable although a normal aircraft may actually carry the same payload for a lower specific fuel consumption. They are very attractive as military vehicles however as the stable, very low altitude flight at decent cruising speeds is potentially very stealthy. A case of horses for courses.

Jon.

PS: I just noticed that I misunderstood your question! Early flight was helped on the first models with a small hydrofoil under the nose (which also avoided pitchpoling during acceleration from rest). As the hull forms have improved the partial planing/flying mode is easily reached so there is little need to help an early take-off.

 

The Layman Thing

Haven't passed the bar exam? No J.D. degree? That equals layman, no matter how much time you've been in a court room. The Court Clerk is a layman, the Bailiff is a layman. They're all laymen except the practicing attorneys and the judge. But that's a minor point, really.

Truth is, any time one human being puts their argument before another human being, all the subtle and nuanced functions of style, prep, clothing, grooming, intonation, etc., etc., enter the picture. The practice goes well into how big should the display charts be in a given setting, what colors should be used for salient points and on and on. If these things didn't matter, there'd be no need for salesmen for anything. The products would simply sell themselves based on pure data as presented. Patent haggles do not escape the process.

There isn't a judge or jury alive who is not affected by that process. It's this simple observation that gives functional purpose to the craft and science of jury selection consultants, practice trial scenarios, sample jury test runs, etc.

When there's big money on the line (and what other scenario would logically qualify in the pursuit of a patent hassle? Pride? Arrogance?) the side that ignores the above mentioned realities will be muttering to themselves as they leave the courtroom. Call it tools of the trade, or anything you like, but lack of thorough preparation will send you to the back of the pack virtually every time out.

 

They're also really easy to shoot down with small arms fire.

It's not good when a $40+ million aircraft is lost to a 4 cent bullet. It's one of the key reasons why Apache attack helicopters are flying severely restricted mission support in Iraq right now. (among other reasons)

 

Surely America is the only country daft enough to allow the jury to be hand selected...

 

"They're also really easy to shoot down with small arms fire.

It's not good when a $40+ million aircraft is lost to a 4 cent bullet. It's one of the key reasons why Apache attack helicopters are flying severely restricted mission support in Iraq right now. (among other reasons)"

Sounds like you like them about as much as I do! I'd rather have a decent aircraft.

Jon.

 

You might say that, Jon. I was in two helicopter crashes while in the military. While I have an aversion to them personally at this point in my life, I do see their value for certain, mission specific, assignments. One simply has to be willing to assume the risks (and costs) associated for the expectational gains.

It's the vast accumulation of maintenance intensive, fiddly bits that gives me pause. I think it's the obligation of every designer to remove as much of the "extranea" as they can while they advance the art. Unfortunately, most of the existing design paradigms do not fully address that philosophy. The result is, we are further removed from our interpersonal contact with said wonderful new object in our lives.

At one point, this race to embrace technology will so far exceed the human capacity to participate that it will only serve itself. Won't that be an interesting dilemma? Didn't Ahhnold do a couple of movies about that potential?

 

Chris,

I was actually referring to Wing In Ground effect craft but your point about helicopters is well made (Helicopters don't actually fly, they're so ugly that the earth stays away).

While I worked for the CAA here in the UK I was involved in various airworthiness rulemaking activities and it was clear that the rotorcraft fraternity had a very different take on aircraft safety than the fixed wing crowd. One memorable exchange went along the lines of:-

Rotorcraft engineer: "We don't want to be tarred with the fixed wing brush"

Airworthiness specialist: "What, you mean with their ten-times better safety record?"

I tend to think of helicopters as being hugely attractive aircraft when viewed from a liferaft looking up however, although for fun I would rather not fly an aircraft with blurred wings...

Jon.