DIY Short Towing Tank, power prop water flow source design

I saw some swimming pools have a propeller power water flow source. Water comes from an propeller as changable wave crests.

Would it be possible to make a short towing tank with that technology ?

Umut

 

Might be helpful: http://www.boatdesign.net/forums/hydrodynamics-aerodynamics/how-small-can-towing-tank-49914.html

 

I was wondering too. Becuase today with 3d printing and computer simulation a real small tank may be possible. I am talking about something like 2 feet in size. The trick would be to use something other than water for fluid to reduce the surface tensions etc. Hey I have the idea, if anyone wantts to build it they have to name after me.

 

mydauphin, I suppose you are joking, right?

 

http://www.panix.com/~brosen/catamarans.html

 

Scaling from a test tank to full size has limitations. It would depend on what the full size vessel length will be.

 

What you are really talking about is a water tunnel. Swimming pool technology would probably not be appropriate, because it is aimed at moving a large volume of water at slow speeds, while you need to move a small volume of water at higher speeds. I suggest you research water tunnels to see what typical facilities look like.

As with any project, the first step is to define your requirements. You need to know what kind of full scale boats you want to model, and what scaling relationships you will use to extrapolate the data from model scale to full scale. You also need to define what data you plan to collect and how it will be measured. Then you can start to form some idea of how big the tunnel's test section will be and how fast the water needs to move through it. That will give you the basic requirements for designing the rest of the water tunnel - the power requirements, propulsion type, sizing the settling chamber and return legs, etc.

 

Circulating water channel

Circulating water channels are today almost only used in Japan.
http://www.felco.ne.jp/felco/fel/english-webpage/chapter11_re.shtml
http://www.eng.kyushu-u.ac.jp/e/graduate/maritime/research/studies01.html

They are helpful in teaching naval architecture, but are not accurate enough for the prediction of the full size resistance of the ship.
The huge CWC in Berlin is now only a historic monument:
https://de.wikipedia.org/wiki/Schif...e:Berlin-tiergarten_vws_20050404_p1020295.jpg
Don't waste your time
Uli

 

just moving water in a swimming pool seems to me would not get you controlled flow you need to simulate a boat moving through the water. you would need to build a diffuser and have flow vanes to get the water all moving in the same direction through your test section.

A much easier solution is to just tow a model behind a power boat on a smooth lake surface. You would get the speed from the tow boat, and it would be easy enough to rig a scale on the tow rope to determine drag.