Curious about Jet drives.

[Submarine Tom]

Ahhh, V8 torque and soft suspension, those were the days!

-Tom

[Fanie]

LOL Tom, probably why the old hands doesn't get sea sick so easily, them cars felt like boats on water

Still, nothing like a V8 eh. Pity about fuel being expensive and going scarce. I bet the next form of propulsion isn't going to sound like that, so better record some sounds while we have them.

[thudpucker]

Your right about the inertia. I read that in the Military section on Jet drives.
Without the stator the whole boat would tip.
There were other Hydro-dynamics the Stator took care of as well.
The output would be going out in a Scatterd mess, but the stator aligns the output to make it smooth, taking some of the resistance out of the ehausting water.

[Fanie]

*Sigh*
Yes Thuddy, if only my wife thinks I'm right a couple of times eh

[thudpucker]

There aint enough Wisdom in the world to help you with that problem.

[speedboats]

The stators need to run between the multi-stage impellors to 'straighten' the water flow so the next impellor can get a good 'bite', else the water inside the pump would end up rotating at next to the same speed as the impellor so the last one would do nothing

[thudpucker]

Yes, that's what I read. Also, though I didn't see it, I'm thinking the stator angles between Props were different than the last stator angle that wants to straighten out the flow.

On the number of Stages:
Wouldn't it be better to have a single stage rather than multiples?
There must be a reason for Multiples?

[baeckmo]

You can only achieve a certain pressure increase (=velocity increase) per stage, basically depending on impeller outlet peripheral speed. If you design the nozzle velocity (vj in my earlier text) above this limit; then you have to add another stage in series, just like we do in any other kind of rotodynamic pump.

And yes, a single stage, giving a high flow rate is generally better efficiency-wise, than a low flow - high velocity, multiple stage unit. It is all a question on finding the best balance between pump hydromechanical efficiency, the impulse efficiency and possible power density of the pump design elements.

[thudpucker]

Holy Cow, do I dont remember a lot!

Although I never got as far as Hydraulics. It's good to know we have PhD's when we need them.
Thank's y'all.

[Fanie]

It's good to know we have PhD's when we need them

Probably not many PhD's - just a desire to know and understand everything about everything...

Thanks Hoyt !

[hoytedow]

I heard the weather is wet in Safrica. How much more water do you need for a jet drive?

[Fanie]

SA is a water poor country.
I'll only admit to enough rainfall when there's more boats (with jet drives to stay on topic ) than cars here

Seems the whole world is suddenly getting more rain, there's floods in a lot of places.