The "Hull Vane" Concept

It can be shrinked down to a single common point - the electronics. Had every other aspect of human society develop at the same pace the electronics did in the last 40 years, by now we would be flying around the planets in the Solar system in anti-gravity vehicles.

 

PAR,
two points come to mind from your post. First, the cost/performance of electronic control and (to a lesser extent) actuation have dropped dramatically in the past decade. Automotive grade microprocessors are robust and dirt cheap. For small actuations piezoelectric is similarly low cost and robust. The point is that if your inventions value was undermined by the cost of control it is looking a lot better today.

I suspect your patent is sitting doing nothing and that you will still judge the cost, risk and return of updating and pursuing it undesirable. There are organizations that make a business buying the rights of patents and enforcing them. 'Trolling' is a growth industry.

 

My patent is employed on a few of my designs and works, for it's intended use. I expected further development and have personally "played" with it and have seen good results, but that's as far as I've taken it and probably want to take it. It does add measurably to efficiency, but as with all things there's some trade offs, such as engine or leg up draft increase, strike vulnerability, efficiency drops when out of the effective operation range, etc., etc., etc.

Agreed, most of the advances could be nailed down to computation speed and data storage/retrieval, though there's some social, marketing and mechanical advances too. Simply, I think we've come a long way since I was a kid, much of which is taken for granted.

 

I think there are at least two different ideas being rolled up into one here. If the foil is tucked up under the boat as shown in the original image, about all it is good for is to try to use it to control the hull's transverse pressure gradient ahead of the transom. This can have a big effect on the turbulent drag that a transom creates. This drag component can be quite large, and you wouldn't need a movable foil to do do this. The second idea is the more obvious one. Stick a foil aft of the transom where it doesn't much influence the hull and get some thrust out of it. That would be tricky considering the large momentum defect near the surface, the vorticity near the surface, and the fact that there just isn't any angle to work with away from the surface. On the I14, that's a really big foil compared to the vessel's all up weight. It would have a massive pitch damping component. It think it earns its keep by keeping the power on the sails. It couldn't generate thrust because at that depth/hull length ratio, I don't think there is going to be any appreciable angle to work with.

 

My foil does precisely what you've first described and controls the pressure wave ahead of the transom. I've also played with an articulated version, but again the control and sensory requirements . . . With relatively fixed speed, displacement/semi displacement craft, real improvements can be seen, of course at the specifically targeted speeds.

 

Which, again, is cool.

For articulation: have you considered a less managed approach where there are but a few settings for zones of relative velocity, or maybe just throttle settings if under power. The former could be provided blindly by GPS (blind with respect to currents, that is) or by one of the varied devises to measure speed relative to the water. You might even take a page from those line-up-the-needle light meters in old cameras and have the crew provide the physical effort to put the thing where a dial indicates.

 

Yeah, that was the first thing I tried, letting a flap control incidence, as it moved around in the pressure gradient, but it was twitchy, so I dampened it a few times, which made response time sluggish. It worked, but wouldn't maintain level trim, preferring to "hunt around". Next up was a few wands and typical controls, but these had their own issues, so it was canned in favor of the fixed incidence foil. I also tried multiple foils, with a forward foil having more incidence, thinking it would stall and lose lift, before the aft foil, hopefully keeping the aft foil hooked up. This worked, but a significant drag hit and a narrow effective speed range. This testing crap sucks . . .

 

Hi all,

*** Disclaimer: I work for Hull Vane BV ***

we've posted a video on Youtube explaining the working principles:
http://www.youtube.com/watch?v=4Npm5FXnOLE

To answer a few of the other questions:
1. Yes, the concept to place a foil underwater in this location to produce forward thrust is novel and the Hull Vane is patented. It's taken over 12 years of development, numerous CFD studies, model testing in towing tanks, and finally full scale seatrials to prove the concept. That's a very significant investment in time and money, which the inventor hopes to recover. Without patent protection, there would be no stimulus for innovation.

2. The Hull Vane is fixed and has no moving parts. The speed range is indeed limited. Below Froude numbers around 0.2 the performance can be negative (creating drag instead of thrust). That makes the Hull Vane unsuitable for bulk carriers and large tankers. That said, there are many vessels which consistently sail at speeds above Fn = 0.2, such as ferries, container vessels (not all), cruise ships, roro-vessels, reefers, car carriers, patrol vessels, (some) offshore supply vessels, motoryachts, etc.
The Hull Vane is not suitable for planing vessels. There you enter into hydrofoils which have a different goal (reduce wetted surface and displacement), different location and different geometry.

More info can be found also on www.hullvane.com. We will have a stand at the SMM in Hamburg the coming week, so if you're there, come by and say hello.

3. As Daiquiri pointed out, similarities to the Hull Vane can be found in car spoilers - this helps a lot to explain as people are more familiar with this. However the medium, the area of use and the position are different enough to speak of a novelty. Let's just say poorly sticking glue also existed before they decided to create the Post-It note.

Thanks for your interest,

Bruno

 

Thanks for the post.

Where is it patented? Is a copy of the patent available, or what is the patent number?

 

Good for you ..I hope it proves to be a commercial success!

I'm struck, however, by the fact that our hydrodynamics guys have noted, for decades now, that the placement and AOA of the rear foils on many of our hydrofoil and foil-assisted designs (never a trivial design exercise, that) produced over that period resulted in a "negative" drag on that foil for certain overall geometries and under some operating conditions. Just never thought of turning that "effect" in to a stand-alone product.

 

Well, looks like you should have thought of it, because you'll be breaching Innomare's patent the next time you do that thing.

 

That depends on what the patent actually covers.

 

This has been done and used for about the past 20 years although the 'foil' was placed on the stern shoe under the rudder and gives a bit of a 'boost' on slower boats. It also dampens pitching to a small degree.
The Kort nozzle works on a similar principle.

 

Well, unless you are Par.

Also, IIRC, a patent cannot cover something considered a common practice, so hydrofoil designers are safe.

 

LOL. I'm quite certain that the art of placement and AOA of a set of lifting foils under any craft can be found in decades of prior art. Foil-to-foil interference, down wash effects (from hull and forward foils), etc have been known and understood for a long time.

That's not the same thing, really, as taking just one piece of that flow situation...a rear-mounted foil..and only focusing on one component of the 3D hydrodynamics as your optimization goal. Put another way, we discovered that the aft foils in some of our hydrofoil vessel designs could have effectively zero or even negative drag; but that more often than not was a "byproduct" of locating that foil in the most L/D efficient position and AOA. We never came up with the idea of putting a foil off the stern of a vessel solely to "capture" that particular hydrodynamic benefit, although I've seen many inventions over the years that claim to be able to recover wake energy for the benefit of the craft making the wake. In this particular case, I can see how it would indeed work under some circumstances.