On Feb 11, 8:58 am, "Shaun Van Poecke"
wrote:
does anyone have a good approximate way of converting flow to thrust? as an
aside, do you think you would get more meaningful motion by having, for
example 4x 1000GPH pumps, or 1x4000gph pumps?

Thanks,
Shaun

Hmmm.. Let's do a VERY Quick&Dirty approximation. 5 Amps at 12V = 60
Watts times 2 pumps =
120 Watts. 746 Watts per Horsepower. So About 120 / 746 = .16
horsepower. Assuming there are no losses (!) how fast will that move
your boat??

(Major mechanical / hydraulic issues that I can't figure out
remain).....

wrote in message
ups.com...
On Feb 11, 8:58 am, "Shaun Van Poecke"
wrote:
does anyone have a good approximate way of converting flow to thrust? as
an
aside, do you think you would get more meaningful motion by having, for
example 4x 1000GPH pumps, or 1x4000gph pumps?

Thanks,
Shaun

Hmmm.. Let's do a VERY Quick&Dirty approximation. 5 Amps at 12V = 60
Watts times 2 pumps =
120 Watts. 746 Watts per Horsepower. So About 120 / 746 = .16
horsepower. Assuming there are no losses (!) how fast will that move
your boat??

(Major mechanical / hydraulic issues that I can't figure out
remain).....


thats a good question. here's one in return; how many hp do you think i
generate with a 3 foot paddle considering that i have to move rapidly from
one side of the boat across the tramp to ther other side otherwise i go
round in circles? surprisingly, it does actually give me some progress.
but if there is a wave going against me, i go backwards.

so four pumps might give me roughly 1/4 hp? just roughly....

would there be any benefit from running the pumps in series rather than in
parallel? if might give me enough thrust to put a nozzle of some sort on
the end.... im open to suggestions!

thanks,
shaun

Per Shaun Van Poecke:
that i have to move rapidly from
one side of the boat across the tramp to ther other side otherwise i go
round in circles?

Could rudder control be an issue?

I've had Hobie 14's and 16's and as long as I kept steering (with a foot or by
sitting on the tiller bar) paddling continuously on one side worked OK.
--
PeteCresswell

On Sun, 11 Feb 2007 09:53:07 GMT, "Shaun Van Poecke"
wrote:

....
thats a good question. here's one in return; how many hp do you think i
generate with a 3 foot paddle considering that i have to move rapidly from
one side of the boat across the tramp to ther other side otherwise i go
round in circles?

shaun


I'm late to the party. A paddler is probably putting less than 60
watts into it. Less than a tenth HP.

Brian Whatcott Altus OK