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Old 08-05-2017, 20:13   #901
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Re: Oceanvolt Hybrid Motor

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Originally Posted by Just Another Sa View Post
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?
Yes, you are correct... The Oceanvolt SD15 in Hydro-generation mode is not as efficient as it could be. This is because we are using the Gori propellers, which are optimised to push the boat forward. These Gori propellers are designed without any consideration for Hydro-generation.

However, the SD15 in Hydro-generation mode are able to generate significant amount of power, but not so much as to affect the speed of the boat too much. So, if you are traveling at 12 knots and generating 1.5-1.8kw the speed drops and will be barely noticeable, and not subjected to a large sail increase. Because after all the important point is propulsion. The hydro-regeneration is just an added bonus that you will not have with a diesel motor....

The new Servoprop is totally different and does not rely on a Gori propeller (or other) but is as you suggested feathering propellers.
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Old 08-05-2017, 20:50   #902
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Re: Oceanvolt Hybrid Motor

I absolutely love the idea of silent propulsion and loads of extra power for modern luxuries, but boy would I be afraid of electrical storms.
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Old 08-05-2017, 20:52   #903
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Re: Oceanvolt Hybrid Motor

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Originally Posted by BigBeakie View Post
No, it doesn't work like that. I can tell you that both Kato and the Vendee Globe boat could not detect any definite speed change when the SD15 is put into regen mode. Coeman said a couple of times at slower speeds (for him) he thought maybe there was 0.25 knot in it, but it was a maybe.

It is not putting the prop in reverse.
A frictionless perpetual motion machine. This thread is getting sillier.
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Old 08-05-2017, 21:02   #904
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Re: Oceanvolt Hybrid Motor

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I absolutely love the idea of silent propulsion and loads of extra power for modern luxuries, but boy would I be afraid of electrical storms.
Well then check out this site:

Marine Lightning Protection Inc.
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Old 08-05-2017, 21:05   #905
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Re: Oceanvolt Hybrid Motor

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Well then check out this site:

Marine Lightning Protection Inc.
I know there are systems out there, but it would still be scary in the middle of the ocean. This is why I prefer the concept of parallel hybrid systems.
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Old 08-05-2017, 21:07   #906
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Re: Oceanvolt Hybrid Motor

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Originally Posted by BigBeakie View Post
Well Ok Gentlemen. Did you ever see me say that the OV SD15 regen had no effect on boatspeed? Ever? No, you did not.So why are you taking that tack, if you'll pardon the pun.

I freely concede your (collective) point that using regen slows a boat. It slows it down by such a small amount, that it is effectively hard to determine. Therefore of no consequence. That is what has been reported to me by several OV users, and it is just not credible that they are all lying, now is it?

Now, you all are stating and/or implying that it must be a terrible drag on the boat, my goodness like "dragging a sea anchor". Otherwise why would you even be raising it?

But none of you would take a stab at quantifying it, now did you? And that would be because you (collectively) have no bloody idea.

So unless you can illuminate the discussion , or refute Colemans observation that it slowed his boat maybe a quarter of a knot, or the observers on Kato recently that it made no detectable difference, then I'm afraid we'll have to consider the possibility that you (collectively) are wrong. Ipso facto quid est demonstratum, gentlemen. Consider the evidence and first hand reports.

And Jim, I know you don't have a dog in the fight, but I'm a retired research scientist as well, so I know about data quality and experimental bias, and confirmation bias. And yes, I did physics to the B.Sc. level, so please stop saying EP transgresses the laws of the universe for cryin' out loud.
It's drag. Profile, parasitic and friction drag. It, as one responder commented, is like running an outboard in reverse that puts out the equivalent power.

It can be calculated. I would expect the claimant to post data, calculations and measurements to support their claims.

A 'little bit' is not a scientific measure. You will raise the ire of those of us who are well versed in the scientific method by making unsubstantiated claims.

We are the same people who design, engineer and certify the elevators, planes, cars and bridges you trust your life too. Excuse us if we seem difficult to deal with.
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Old 08-05-2017, 21:15   #907
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Re: Oceanvolt Hybrid Motor

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I challenge any of you to prove there is a significant reduction in speed on any boat you choose that has an Oceanvolt SD15. Any boat at all. I am challenging you to prove your assertions with empirical evidence, instead of just flapping your gums.

YOU define what is significant, if you like. Obviously it will be more than a few tenths of a knot because it has already been acknowledged and stated by those who have been on OV boats and directly observed the regen, that there is speed reduction to this magnitude.

So would you agree on 10% of boatspeed?

If it slows an 8 knot boat by 0.8 of a knot, I will concede defeat.

Because if it is any less than that WHO CARES! Oh, that's too much? Ok let's make it 5%, so that would be 0.4 of a knot. Whatever.

So put up or shut up, as they say. Prove your case with demonstable evidence, and I will be the absolute first to thank you. But I won't be holding my breath, because it is transparently obvious the agenda that is running here.It is always the same old gum flappers that pipe up on any EP thread. It is completely obvious. The CF members previously noted excepted, because they have demonstrated a consistent positive contribution in the spirit of offering well meaning opinions and advice. I certainly do value that, and it is the power of CF. You other guys is why people avoid contributing, which I have been told directly.

I predict there will just be a continuation of flapping gums, because your real agenda is not determining anything factual about EP, it is an agenda to discredit EP in general, and in this case OceanVolt in particular.

IMHO, You are behaving EXACTLY like the climate deniers that are co-ordinated by the Heartland Institute denial campaigns, i.e. the merchants of doubt tactics. Sadly, those tactics work, as we have seen in the tobacco "debate", the climate "debate", and as employed by the Russians to discredit and raise doubt in several political campaigns, think USA and France.

The only antidote to misinformation is...EVIDENCE. Show us your evidence, we can show you the evidence for EP, now you show us your evidence to support your assertions. In this case, the EVIDENCE that OceanVolt regeneration creates enough drag to slow a boat beyond a few tenths of a knot.
This kind of outburst is sometimes demonstrated by first year undergrad students in their first of year 1 physics.

They either learn quickly that the scientific method is how we prove any hypothesis about our physical world. Those that don't leave and preaumably buy magic beans.

How are your beans doing?
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Old 08-05-2017, 21:27   #908
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Re: Oceanvolt Hybrid Motor

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Originally Posted by BigBeakie View Post
Chris, help me out here. You said,

[I][/When these sorts of claims are made then rational debate becomes impossible.I]

For the benefit of those reading this that may have wondered why I said this,
i.e. that I thought the propulsive thrust is about equal between the OceanVolt SD15 and a Beta 45HP diesel, it might be instructive to explain this because I understand, I really do, the skepticism of those who do not understand why EP vendors and "proponents" say such things. The reason I understand the skepticism is because when I began my journey to considerEP I too started out very skeptical. It didn't make any sense to me either, back then.

I won't go into the whole discovery journey here, but I satisfied myself that indeed electric motors of a smaller HP rating than the equivalent HP diesel, do produce more torque. So what? Well, let's cut to the chase. If you want to tturn a propshaft against resistance, whatever the resistance is such as a boats displacement through saltwater, and against wind, and against waves, well then an electric motor will maintain producing torque better than a diesel engine. Basically, that's the story a nutshell. A diesel engine will stall out before an electric motor will give up, and I satisfied myself that this is true in several different industries, not just marine engines and pushing boats. For an example the local sawmill guy explained to me why they switched over many years ago to electric motors to drive a saw because with Australian hardwoods, the diesel used to stall. When they replaced the diesel with an electric about half the kW rating, the logs did not have a chance. There were several other examples I sought out, and it was consistent that that 1 electric HP does not equal 1 diesel HP IN THE WORK THAT IT CAN DO.

But to my specific statement re 15kW OV SD15 & 45HP Beta Turbo, I spoke directly to the technical director of Beta Marine in the UK and asked what is the thrust expressed in kgf of his Beta 45 Turbo. He knew that figure ( I was impressed) at is is 320 kgf at full throttle, and that is with a 3 bladed fixed prop.

When Conrad Coleman was having his boat accepted by the technical committee of the Vendee Globe, the engines all had to pass a test of bollard pull test. The OV SD15 gave a STATIC bollard pull of 290 kgf.

So, I hear you ask, what is the relationship between static bollard pull force and actual propulsive thrust that pushes your boat against wind & waves?
Good question, and I sought that answer from multiple sources such as propeller design engineers, diesel technical resources and the technical papers written that form the basis of ship propulsion system design. I did not understand the math or even tried to, I just wanted the answer. It is about 0.9 , i.e. the static bollard value is 10% less than the propulsive thrust. Therefore Coleman's SD15 static thrust of 290 kgf is 10% less than the actual propulsive thrust so 290 x 1.1=319 kgf.

319 is pretty close to 320 isn't it?

Now, if anyone can inform me how this is dramatically wrong, fair enough.

And Chris, to me your certainty that this is not worthy of "rational debate" is not, in itself, rational. But, I'm willing to listen, so please explain exactly what is wrong with my analysis, such as it is. I am just trying to figure this out.
You need to compare the power and torque curves not peak values. The peak power and torque between a diesel and an electric motor are not comparable especially if they both use the same prop.

Diesels spend much of their time at peak load. So unless you compare power and torque at a specific rpm then comparisons are meaningless.
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Old 08-05-2017, 21:30   #909
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Re: Oceanvolt Hybrid Motor

So what have I learnt from reading (mostly laughing) my way through 92 pages of posts?

EP fanatics don't know squat about physics and believe any old bollocks. Those with diesels seem to be quite well versed in the sciences and have well tuned bs detectors.
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Old 08-05-2017, 22:48   #910
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Re: Oceanvolt Hybrid Motor

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It's drag. Profile, parasitic and friction drag. It, as one responder commented, is like running an outboard in reverse that puts out the equivalent power.

It can be calculated. I would expect the claimant to post data, calculations and measurements to support their claims.

A 'little bit' is not a scientific measure. You will raise the ire of those of us who are well versed in the scientific method by making unsubstantiated claims.

We are the same people who design, engineer and certify the elevators, planes, cars and bridges you trust your life too. Excuse us if we seem difficult to deal with.
Fair point! So let's do some quantification:

Extract from our initial calculation for Kato:
3.36 Knots: resistance 391 N Power Drawn for the battery 1.76 kW
8.74 Knots: resistance 3,621 N Power Drawn from battery 30.74 kW
10.08 Knots: resistance 7,225 N Power Drawn from battery 71.45 kW
Hydro-regeneration at 10 Knots about 1 Kw....
Care to calculate the resistance and Power Drawn at 1 knots?
Probably why Tony on Kato or Conrad on his IMOCA finds it Hard to detect...and why it is barely noticeable!

Granted, Kato is more slippery than first thought. (We are getting 10 knots from 30kW) But, the math still applied.
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Old 09-05-2017, 00:34   #911
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Re: Oceanvolt Hybrid Motor

Quote:
Originally Posted by BigBeakie View Post
On the other hand the regen you would get from the OV OV SD15 Servoprop would be 1,500 watts at 7.5 knots ( 6 times as much), 3,000 watts at 10 knots
...
Quote:
Originally Posted by BigBeakie View Post
...
And here are some datapoints of boatspeed and corresponding power from the SD15 regen logged during the race:
11 knots > 2.8 kW
...

Quote:
Originally Posted by BigBeakie View Post
But fear not, dear EP deniers. The new OV regen solution soon to be released will give you about 1,800 watts at 8 knots, 2,200 watts at 9 knots, 3,000 watts at 10 knots.
Quote:
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Fair point! So let's do some quantification:
...
Hydro-regeneration at 10 Knots about 1 Kw....
...
Oh Dear.
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Old 09-05-2017, 01:07   #912
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Re: Oceanvolt Hybrid Motor

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And used to be involved with Torqueedo?
No NO, that was a different Claude, Claude Desjardins.

see.. The fastest Torqeedo? - The Torqeedo Shop
"The original Gold Rush Aggressor was trialed by Claude Desjardins of Torqeedo Australia and for a short while it was the fastest boat driven with Torqeedo motors."

By the way, How did Neils 44c Torqeedo experience pan out, or schools out.
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Old 09-05-2017, 01:42   #913
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Re: Oceanvolt Hybrid Motor

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Originally Posted by Seaslug Caravan View Post
No NO, that was a different Claude, Claude Desjardins.

see.. The fastest Torqeedo? - The Torqeedo Shop
"The original Gold Rush Aggressor was trialed by Claude Desjardins of Torqeedo Australia and for a short while it was the fastest boat driven with Torqeedo motors."

By the way, How did Neils 44c Torqeedo experience pan out, or schools out.
Both reported 6 knots with the twin 4kW motors ... So no complain about the performance of these electric motors...

4kW electric give the same speed as 9.9 Yamaha on both of these boats ....
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Old 09-05-2017, 01:57   #914
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Re: Oceanvolt Hybrid Motor

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Both reported 6 knots with the twin 4kW motors ... So no complain about the performance of these electric motors...

4kW electric give the same speed as 9.9 Yamaha on both of these boats ....
Now this is where it gets a bit murky. I know in conversations I had with Neel that any sort of wind action and he was so hopelessly under powered he was reluctant to leave the marina.

As for schools out they were so "HAPPY" with their instalation they replaced it with conventional petrol outboards.

Mr D are your pants on fire?

Just askin.
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Old 09-05-2017, 02:40   #915
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Re: Oceanvolt Hybrid Motor

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Originally Posted by Claude-D View Post
Both reported 6 knots with the twin 4kW motors ... So no complain about the performance of these electric motors...

4kW electric give the same speed as 9.9 Yamaha on both of these boats ....
Parallel universe? Alternate reality?

In our universe, the Torqueedo performs slightly worse than a Yamaha 9.9 in forward. Reverse is absolutely woeful. (If the motor actually runs in reverse..... I was there Claude)

This is because the Torqueedo prop is heavily optimised for forward, while the Yamaha props also work in reverse.
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