Oceanvolt Hybrid Motor

[ranchero76]

Originally Posted by DotDun

Hmm, at DIY pricing of $5/AH, $25k that's for batteries. And then the 17000watts of solar required to recharge won't fit on most boats.

Up charge for going "house green":

$22k for extra battery
$13k for extra solar

Do you know how many years that $35k will support a generator and diesel???

I realize this is an extreme example, but going green, at some point, has to have an ROI associated with it.

Where and when did I say anything about "being green"?

Also, I have question. Do you have an idea how much carbon mast and boom on 60ft catamaran cost? Will be boat 2 times faster with that mast? Or even 10% faster? Or less noisy, maybe? Probably not. But people still pay these stupid money for them! Pay for nothing, just for look and couple hundred kilograms savings!!!

With OP/solar/Li-Po you're getting:
1.cool piece of modern technology,
2.silent propulsion,
3.lots of energy for pleasure use
4.not depending (almost) on fossil fuel.

For me - it's worth it.
It is not for cheap boats or moneyless sailors!!! It will never ever make sense to them! I don't know why this point continue to come up! Yes, it's not cheap and not for everyone, just like carbon mast!!!

[DotDun]

Originally Posted by ranchero76

Where and when did I say anything about "being green"?

Also, I have question. Do you have an idea how much carbon mast and boom on 60ft catamaran cost? Will be boat 2 times faster with that mast? Or even 10% faster? Or less noisy, maybe? Probably not. But people still pay these stupid money for them! Pay for nothing, just for look and couple hundred kilograms savings!!!

With OP/solar/Li-Po you're getting:
1.cool piece of modern technology,
2.silent propulsion,
3.lots of energy for pleasure use
4.not depending (almost) on fossil fuel.

For me - it's worth it.
It is not for cheap boats or moneyless sailors!!! It will never ever make sense to them! I don't know why this point continue to come up! Yes, it's not cheap and not for everyone, just like carbon mast!!!

Please report back with details when you reach all your goals.

[Just Another Sa]

Originally Posted by Just Another Sa

You are still mixing existing statements regarding props used as a turbine with imaginary statements about Oceanvolt efficiency. I'm sure you know OV produces neither props, nor turbines, only the rest of the propulsion system. The idea that the overall system could have good efficiency while regenerating with a standard marine propeller is false. It makes no difference who made it or design it, only that it has a propeller instead of a turbine that is needed to make the efficiency low.

If you consider how a fully battened mainsail function while beating to windward with all the battens inverted, you will realise why that is so. Prop as a turbine is exactly that. Guaranteed stall at the leading edge in both. And fluid flow not reattaching. How well OV makes electrical and electronic parts has no effect on this.

Claude-D, did you miss this post?
A direct link to it including your post I replied to (showing the context): http://www.cruisersforum.com/forums/...ml#post2388192

I will improve to make it even more clear for you:
If you are in port tack sailing to windward with perfect sail trim with a cat rigged boat (mainsail only) with a rotating mast. And then you tie up the mast rotator so it can't move (rotate) from the orientation it currently is with the perfect trim, and then change tack, but no batten shifts to the other side, ie they are now all inverted, you should easily understand why the performance in the new tack is dramatically reduced due to less efficiency (worse lift/drag). This is how the prop with fixed shape blades (metal or carbon laminate construction, not sail with battens) functions when it's regenerating. It has negative angle of attack while keeping the shape designed for positive angle of attack only, just like the mainsail with inverted battens and wrong mast rotation. Actually the main works a bit better, since the rotating mast still has rounded entry, unlike the prop blades having sharp entry making things even worse. Instant leading edge stall (flow separation) is unavoidable with any significant angle of attack (> 5 degs).

PS, did you also miss the answer I gave to your slow monohull question: http://www.cruisersforum.com/forums/...ml#post2388188

[Factor]

Originally Posted by cwjohm

Making up stories again Andrew - I never made a claim otherwise.

I apologise - all i can say was after reading pages of invective and claim and counter claim and strident statements from both sides of the argument I got confused with my memory. it was in fact Seaslug (the latter day interpretation of Catty) who said:

Originally Posted by Seaslug Caravan

What on earth does Tony Longhurst, the owner, know what he wants. A punter who spent his life in the motor sports arena. He certsinly doesn't bring a lifetime of sailing experience to the table. Just vast quantities of money..

This was one of the sillier things he has said.

Apologies again

[StuM]

Originally Posted by ranchero76

Videos, videos and more videos. That's what will shut (some) opponents up.

But not videos of tractor pulls and other irrelevant comparisons such as sawmill blades.

And if you are posting videos, enough data to make valid comparisons (If you show us a GPS speed and a display showing 2250RPM, STW, Amps to motor, gear ratio/equivalent prop RPM would all be relevant).

[44'cruisingcat]

Originally Posted by StuM

But not videos of tractor pulls and other irrelevant comparisons such as sawmill blades.

And if you are posting videos, enough data to make valid comparisons (If you show us a GPS speed and a display showing 2250RPM, STW, Amps to motor, gear ratio/equivalent prop RPM would all be relevant).

And tidal flow, and wind strength and direction.

[StuM]

Originally Posted by Just Another Sa

Wrong question. The technical director of Beta Marine did not answer your wrong question, he was trying to be helpful and answered what you should have asked. And it seems you never understood that was the case.
In the real world 45HP Beta Turbo produces no thrust at all. It does produce torque if it's running. The 3 bladed fixed prop provides all the thrust regardless if it's rotated by Beta turbo, some other diesel or gasoline engine, or an electric motor.
Please try to learn the difference how engine or motors work vs how a prop work. And never to mix them up again.

You're probably wasting your time. He's already been told the same thing on numerous occasions but he still refuses to accept this basic fact.

That's why he keeps on coming up with his totally erroneous comparisons such as bollard pull numbers, tractor pulls and sawmill blades to argue his case for EP on a boat.

[cwjohm]

44C - can you please check my numbers.


I make your displacement per metre at 450Kg/m, and you are running 25HP outboards, and your motoring performance is similar to that reported for Kato 2 (7knots cruise - 10 knots max).


I make Kato 2 at approx. 500kg/m but having that advantage of longer wetted length.


Based on these numbers we would expect Kato to perform to these numbers with a similar amount of HP to yourself, or is there something wrong with my thinking here.

[44'cruisingcat]

Just under 450 kg/m, and 20 HP outboards. Top speed is about 9.5, 2 motor cruise around 7 1/2 - 8.

Before the rig was fitted we reached 10.5, into a light headwind, and speed was still slowly climbing. Didn't want to push new motors for long enough that speed would level out.

The windage of the rig makes a bit of difference.

[Claude-D]

Originally Posted by Just Another Sa

Claude-D, did you miss this post?
A direct link to it including your post I replied to (showing the context): http://www.cruisersforum.com/forums/...ml#post2388192

I will improve to make it even more clear for you:
If you are in port tack sailing to windward with perfect sail trim with a cat rigged boat (mainsail only) with a rotating mast. And then you tie up the mast rotator so it can't move (rotate) from the orientation it currently is with the perfect trim, and then change tack, but no batten shifts to the other side, ie they are now all inverted, you should easily understand why the performance in the new tack is dramatically reduced due to less efficiency (worse lift/drag). This is how the prop with fixed shape blades (metal or carbon laminate construction, not sail with battens) functions when it's regenerating. It has negative angle of attack while keeping the shape designed for positive angle of attack only, just like the mainsail with inverted battens and wrong mast rotation. Actually the main works a bit better, since the rotating mast still has rounded entry, unlike the prop blades having sharp entry making things even worse. Instant leading edge stall (flow separation) is unavoidable with any significant angle of attack (> 5 degs).

PS, did you also miss the answer I gave to your slow monohull question: http://www.cruisersforum.com/forums/...ml#post2388188

Yes, I can read it and again very nice technical explanation....

However, what is your point? Are you saying that the hydro-generation on Oceanvolt motors can be improved? Yes, I am sure it can (and have with the new Servoprop) Or are you saying it it is nothing special? No, it is not, but it is there and working and have been tested on boats around the world. Or are you saying that the regen function on Oceanvolt motors does not exist?

[cwjohm]

Just under 450 kg/m, and 20 HP outboards. Top speed is about 9.5, 2 motor cruise around 7 1/2 - 8.

Before the rig was fitted we reached 10.5, into a light headwind, and speed was still slowly climbing. Didn't want to push new motors for long enough that speed would level out.

The windage of the rig makes a bit of difference.

Yes, windage and loading with fuel and water.

However, if the OV claims are true you could equip 15KW EP and you would double the propulsive power. You would have the advantage of being able to tow two water skiers.

I think there is a strong case to argue that OV 15KW is roughly equal to 25Hp diesels, and the laws of physics remain unbroken.

[Claude-D]

Originally Posted by 44'cruisingcat

Just under 450 kg/m, and 20 HP outboards. Top speed is about 9.5, 2 motor cruise around 7 1/2 - 8.

Before the rig was fitted we reached 10.5, into a light headwind, and speed was still slowly climbing. Didn't want to push new motors for long enough that speed would level out.

The windage of the rig makes a bit of difference.

Ok, now we have some data... Is your boat an Oram 44C ?

Perfect for an electric to petrol comparison, as we have data on both!

[Claude-D]

Originally Posted by cwjohm

Yes, windage and loading with fuel and water.

However, if the OV claims are true you could equip 15KW EP and you would double the propulsive power. You would have the advantage of being able to tow two water skiers.

I think there is a strong case to argue that OV 15KW is roughly equal to 25Hp diesels, and the laws of physics remain unbroken.

To get the same performance on the 44C you will need about 8kW per side, maybe less but I will run the numbers....

[Claude-D]

Originally Posted by cwjohm

44C - can you please check my numbers.


I make your displacement per metre at 450Kg/m, and you are running 25HP outboards, and your motoring performance is similar to that reported for Kato 2 (7knots cruise - 10 knots max).


I make Kato 2 at approx. 500kg/m but having that advantage of longer wetted length.


Based on these numbers we would expect Kato to perform to these numbers with a similar amount of HP to yourself, or is there something wrong with my thinking here.

Yes, Kato is a very slippery boat. However, the only meaningful what that you can predict performance and power usage is to actually calculate this. (Yes also including rigging and superstructure drag). This is done by using a combination of mathematical model well know by all naval architect.

Or it is done by comparing know boats. For example we know the speed of an Oram C44 can do with petrol outboard. And we also know much speed they get with an electric motor. So, if all of this fit with our mathematical model, all is good...

[Just Another Sa]

Originally Posted by Claude-D

Yes, I can read it and again very nice technical explanation....

However, what is your point? Are you saying that the hydro-generation on Oceanvolt motors can be improved? Yes, I am sure it can (and have with the new Servoprop) Or are you saying it it is nothing special? No, it is not, but it is there and working and have been tested on boats around the world. Or are you saying that the regen function on Oceanvolt motors does not exist?

Point is that the whole system can not be very efficient in generation mode as long as a normal prop is used. If you accept that as a fact would you mind informing BigBeakie about that, he seems to listen to you, and might stop repeating that false claim over and over again.
Now having said that, it seems some boats (like Kato) can perform quite well while regenerating, but that simply has nothing to do with high efficiency of the system, no matter how efficient OV provided parts might be. It's all about enough sails up compared to the amount of regeneration power produced for any given speed.

That is the point number one, as repeated false claims kill any reasonable discussion about the subject, and might even turn potential customers away, as nobody likes false claims. Efficiency is well defined word and should not be used to express just about anything one wants to.

Point too, can you tell us more about the servoprop?
Just another feathering prop with actively controlled pitch, or what exactly?
What about the shape of the blades, of symmetrical section, or?