thanks for the points.... i would suspect that everyone has a prop optimized for propulsion and therefore we'd be likely to get a lot of very similar results... the difference might come if one configured a prop with substantially too great a pitch for propulsion purposes but that it's too expensive an experiment to run just for the heck of it....
somebody here was a para-motor person and i am really wondering what would happen if one tried to use a smaller diameter carbon fiber prop.... not certain you can get one of 36" but it would be nice to be able to try that.... by just looking it appears that a great number of para-motor props are not appropriately shaped into the high aspect ratio pattern that is most efficient but are instead rather squared off and somewhat clunky looking.... the RC props do seem to be optimally shaped and sometimes built of carbon fiber to support rather large power loads but these don't have a great enough diameter... i suspect that the RC props also benefit from high RPMs for the helping to keep them straight and that while being drug through the water the pressure without such "centrifugal" force would break the props....
does anyone know of any specialty props being produced for boats that are longer and narrower like an aircraft prop?
From: Mike <biankablog@verizon.net>
To: electricboats@yahoogroups.com
Sent: Monday, October 3, 2011 7:49 AM
Subject: Re: [Electric Boats] Re: actual test data for prop regen?
Eric wrote: "Here's your first data point, my boat is 30' x 8.75', full keel, 48V system, the four blade prop is 13 x 15.5 and I get an average of about 0.3-0.4A at 6 knots. I think that Mike gets about the same results with Bianka, I don't know his technical particulars. But his boat is 2.5' wider, has a fin keel, a spade rudder and an exposed prop. And he's getting the similar results at the same speed, so this may point to the fact that if the drive is geared correctly for the prop, the regen results are similar for a wide range of prop and boat configurations." Eric & Mike: FYI. My prop is a 16 inch with a 13 pitch and is a right handed prop. Again it was the same prop that was used with my Westerbeke 27 diesel. Not sure how much improvement I could get in propulsion or regen if I changed it. I can't go up in diameter unless I extend the shaft. Really don't want to spend hundreds of dollars on a new prop to try and find out right now either. I'm a "if it ain't broke don't fix it kind of guy". But, if there would be a dramatic improvement in what I have now I might consider it at some point. Capt. Mike http://biankablog.blogspot.com -- On Sun, 10/2/11, Eric <ewdysar@yahoo.com> wrote:
|
__._,_.___
MARKETPLACE
.
__,_._,___
No comments:
Post a Comment