Will This Replace the Propeller? | Hydro Impulse Jet Pump

[@aqualectric-gi2ln]

For those who want to learn a little more about this technology, the guys from Hydro Impulse have provided some links to their comparison and test protocols: www.linkedin.com/feed/update/urn:li:activity:7074032653879971840 www.linkedin.com/feed/update/urn:li:activity:7115588448836579328

[@PepijnHazelhof]

if that's cavitation, how could it alsow occoutr in circulationpumps where there isn't any surface air?

[@matthewtatarian147]

Cavitation extracts air from the water and allows the prop to free spin.

[@matthewtatarian147]

Generally it's caused by a oversized pump so that the fluid can't flow.

[@timtortola1913]

Your explanation of cavitation is incorrect - also the standard open blade is in a closed box close to the surface vs the ducted version which is in open water. They also seem to be comparing a electric motor with a ducted fan (propeller) to a standard petrol outboard and open propeller? Apples and oranges. Normally ducted fans are safer and produce a more directional force, due to the extra surface area from the ducting they produce more drag and are less efficient at higher speeds vs standard open propeller.

[@musicalintuition]

I had the same thought about cavitation, because I know it can happen with submarines, and they're nowhere near the surface.

[@duke1467]

Thanks for pointing that out. I quit the video when they said that about cavitation then came back to check the comments.

[@MonstroLab]

kort nozzile basically with a prop shooting water through a stator like jetski's do ...this great design would help trailerable cruising sailboats with thier slow hull speeds

[@fenza1268]

So its an EDF but underwater?

[@GeorgeOu]

"20% more efficient" More efficient than what? They don't say. For them to claim regular props are only 60% efficient is also meaningless. What they likely mean is that it's 20% more efficient than a prop of similar diameter. But a regular prop isn't limited by the duct, so it can be much larger and more efficient overall.

[@corbinangelo3359]

Sidestepping? It's called Propwash. I have allot of that with my sailing yacht and have thought of constructing something like a ducting around the prop. But the thing I'm always afraid of is debris like plastic or weed getting tangled in the system. With an outboard you can just lift it out of the water and clean it of course.

[@aydrian9196]

Propwalk, no?

[@mrrustygray]

Shrouded prop. Why not just go toroidal and get more power and thrust? Seems to me it is just a captured prop. Not raining on their parade at all, but I dislike when people utilize the term 'jet" for what is essentially a captured prop and not even a turbine. Typical misinformation and hyperbole in advertising.

[@terencegillespie6675]

Say kort nozzle. Kort Nozzle. The motor has a kort nozzle. Look it up.

[@aydrian9196]

I assume you can put this prop technology on a gas engine too?

[@HFV_Junkyardin]

That would be a much better way of showing its efficiency. Put a 40hp gas on there and show what it can do. If the fuel savings, or speed are better then you’ve actually done something. But right now all the changes he’s feeling could just be the difference between gas and electric.

[@MP-qn1jw]

It's called "prop walk".

[@grantkelly7634]

Kinda pointless. You are not actually comparing it directly with a regular prop on the same boat and engine. Or anything, for that matter. All you say is it "seems" or "feels" different.

[@grancitodos7318]

Drawing air down is called aeration, cavitation, is the boiling of the water, in front of the propellor. This misnomer, has almost changed the English language, until someone wants to talk about real cavitation.

[@timlong1462]

In the boat world it's actually called ventilation if you want to get particular. You are correct about cavitation being highly misused in propeller discussion. 90% of people get it wrong.

[@XplosionNo1]

I was pissed also.

[@Dodgecramer-wj6xv]

What you said is exactly right.