has anyone tried super cavitaion

[Green Meany]

has anyone tried using super cavitation like on the full sized diesil racing boats of a few years back on hydros or for that matter on any rc boat, how it worked was that there was a tube behind the front of the top blade of the prop and exhuast gases were forced through it get the prop to unload it also meant you could use bigger props

 

[LohringMiller]

Except in extreme cases it's not really needed. Model boats have a much better power to weight ratio than full size boats. We had some issues with launching SAW boats, but they were related to fuel system problems.

Lohring Miller

 

[Brandon Atwell]

Except in extreme cases it's not really needed. Model boats have a much better power to weight ratio than full size boats. We had some issues with launching SAW boats, but they were related to fuel system problems.

Lohring Miller

Would this concept work possibly on tunnel boats? Considering the amount of wet surface the prop is forced to move and the cavitation plate itself that’s restricting the props ability to unload.

 

[Tom Foley]

That would be Ventilation actually .

 

[LohringMiller]

I've not seen any but SAW boats that had problems with launching. Some sport 40s need a good launch throw, but otherwise our engines can pull props fairly easily even when completely submerged at the start. Gas and electric powered boats can even start from a stationary floating position. Take a look at the startup video of a prop on one of our boats.


Lohring Miller

 

[john v]

I believe this piece of hose mounted directly over the prop was for getting the boat on plane, massive cavitation to increase prop rpm, once on plane the upper cavitation plate was above the water. kind of like drilling holes in your prop behind the blades in the hub to induce cavitation while getting on plane. once on plane these holes didn't do much

 

[RaceMechaniX]

When I first saw the title I thought about this crazy Russian torpedo which supercavitates from a gas generator in the nose creating an airpocket in front of the torpedo to reduce drag.

https://en.wikipedia.org/wiki/VA-111_Shkval

 

[David Ashcroft]

Detougned props or holes drilled in the leading edge of a prop can help relieve the prop when accelerating and can help maintain Rpms in the turn,,,,

Edit

 

[Samuel Hagan JR]

Detougned props or holes drilled in the leading edge of a prop can help relieve the prop when accelerating and can help maintain Rpms in the turn,,,,

Edit

any photos of the props with drilled holes. How big?

 

[David Ashcroft]

It varies on prop size,, I will get a pic as an example

 

[David Ashcroft]

It's a older practice the drilling holes,,

 

[Joey Jones]

When I first saw the title I thought about this crazy Russian torpedo which supercavitates from a gas generator in the nose creating an airpocket in front of the torpedo to reduce drag.

Yes, me too. Every nation has studied Supercavitation. I remember about 20 years ago talking to a CFD (Computational Fluid Dynamics) PHd at work about this. He was working on it. The beauty was, the bubble that formed at the tip of the projectile allowed nearly zero coefficient of friction. It doesn't take our friend Albert E. to see that would allow the torpedo to attain speeds that are only seen by aircraft. There were a few problems, however;

1) It's going so fast that it vaporizes whatever it comes into contact with...fish..whales...boats...itself
2) It's going so fast that it can't correct. If it tries to turn, it doesn't end well for the vehicle.

Again, these are all many years old observations and I was only a mere undergrad. Times have advanced and changed. If this was capable, I think we'd hear more about it. It is interesting though!

Sorry for the thread-drift...figure someone might find it interesting.

-Joey