Vance/Frank
I will tag with you guys on this when I get farther along. The paper references a book "The Wagenigen propeller series, MARIN Publication 92-001, May 1992. I sent and email to the MARIN company to see if they would end me a PDF. They sent a note back that the report is really a book and it comes with software they use for sizing ducted props. I have ordered the book and software. After I have had a chance to digest, we can discuss a game plan. My guess is we would size the ducted prop for the max power the Minn Kotta can put up. Per the paper, we will need to decide if we want a ducted prop optimized for forward thrust or optimized for equal thrust for forward and reverse. I would vote for optimize for forward thrust. I am going to need to
do a tear down of a Minn Kota so that I can measure parts so that I can create a 3-D model of the 101 in Inventor. Then we will need to run the software to select the prop. We would then need to decide on how the fabricate the nozzle and mounting of the motor and nozzle. Frank has some thoughts on how to fabricate nozzle using FRP layup on a SS ring. We have a lot of options in this. Another approach would be to use a CNC machine and fabricate off the Inventor 3-D file with T6-6061 aluminum and anodize. This might be a bit pricey but we would have high tolerance of the shape of the nozzle which would improve our bench testing of thrust. I would also like to come up with a common off the shelf wet connector and whip that we could use. We also need to see what kind of oil has worked best for minimizing friction in the housing. I think Peter and Carsten have some expericne with this.
Latter
Cliff
Great works are performed not by strength but by perseverance.
Samuel Johnson
From: "vbra676539@aol.com" <vbra676539@aol.com>
To: personal_submersibles@psubs.org
Sent: Fri, October 30, 2009 5:02:44 PM
Subject: Re: [PSUBS-MAILIST] Thruster Design
Sign me up as a test bed, Cliff. I've got the thrusters, and it would be helpful to reduce overall diameter somewhat while increasing output. The 101s are good out of the box for the money, but any improvement
would be welcome.
Vance
-----Original Message-----
From: Cliff Redus <cliffordredus@sbcglobal.net>
To: personal_submersibles@psubs.org
Sent: Fri, Oct 30, 2009 10:47 am
Subject: Re: [PSUBS-MAILIST] Thruster Design
FYI http://nopr.niscair.res.in/bitstream/123456789/6211/1/IJMS%2038%283%29%20338-345.pdf is a link to a paper on design of a thruster using a Kort nozzle. The thruster is small relative to what we
normally us at 0.5 hp but the paper is interesting in that it goes through the design process using both bench testing and CFD. It gives some good references on software for thruster design and standard profiles for thrusters props. My interest in this on the boat I am doing the conceptual engineering on, I would like to use a Kort nozzle both from an efficiently point of view and the safety of a shrouded prop. I am thinking it would be straight forward to use the process outlined in the paper to marry a Minn
Kotta 101 motor with
Wagenigen ducted propeller
KA series 19A. This would give a good low cost ducted thruster a
psubber could fabricate.
Cliff