High Bypass Turbine/Venturi to supply pressurized water

[stevenrs11]

So, I get tired of seeing manufactures of various water nozzles claim that their nozzle magically increases pressure. Garden hose nozzles (this chunk of brass makes your 30 PSI into a pressure washer!¡!) and showerheads (Simpsons, anyone?) are particularly bad offenders.

My question is would it ever be worthwhile to *actually* increase the pressure of some of the water, at the sacrifice of the rest? Imagine your 30 PSI showerhead that 'split' the water into a low pressure rain type spray to make you feel wet, and another much higher pressure stream to give the illusion that there is more water than there actually is.

Or imagine a sprinkler for a large lawn. I personally am fond of the impact type sprinklers because they make that great chak-chak-chak-t-t-t-t noise, so I'll talk about them. The reason that they work so well is because they utilize the maximum amount of water pressure to first generate a high velocity water stream for maximum distance and then slow only part of it down to generate an even spray pattern.

Still, it's wasting energy. Imagine if you recycled the energy lossed from slowing down some water to further accelerate the rest?

I can think of two ways to do this. One, build a sort of miniature turbofan but in reverse, and drive most of the water through what would have been the bypass, which I *think* would then pressurize the rest of the water which would be flowing through the compressor portion.

I feel like it should be possible using a Venturi nozzle of some sort, but I can't think exactly how that would work.

Are there any other practical ways you can think of to do this? Maybe a centrifugal pump but with multiple 'taps'. I know that would work with an actual pump, but not sure if it would if the water is what's driving it.

Now, I know I could attach two separate pumps together through a gearing mechanism, but that's not a particulaly elegant solution.

 

[Nidum]

There are several devices for increasing pressure of a fraction of the total water flow .

One of the most common devices was the 'pulsometer' . This used a controlled water hammer effect and was used to take water from running streams and give some of it enough pressure to rise numerous metres up to where it was needed .

You can always devise a 'water engine' to drive a pump but it can never be a very efficient use of water .

You need an additional power input to get higher pressures and still maintain the full water flow .

Probably easiest just to use an i/c or electrically driven pump .