Once the boat is moving, the relative velocities of the water past the oar are much lower, so many of the variables that you are looking at become...
It is very interesting to read all the different viewpoints on this. It is what makes propeller design such an interesting topic in my opinion....
That is an interesting way of looking at the problem, unfortunately it is an oversimplification and not actually correct. If the boat were not...
Thanks for the update, very interesting. I did read the article. I agree with your statement that the only way to really make an improvement in...
The prop will produce out of plane forces if it is operating at an angle of attack. Angle of attack can come from tilting the drive, tilting the...
It is fun to build, but I think that Gonzo has it right. Adding blade area only helps if the prop is really overloaded, this one is not. Adding...
The short answer is no, the props are not too big. Even at only 8-10 kts they are probably only using about 120 HP/shaft. The problem is likely...
here it is
Yeah, OK. I was not trying to say that you shouldn't ever ease the sheet, but the more you can sail without doing so, the better your chance of...
The extreme flexibility helps the iceboat in a few ways which are not really needed for most sailboats. It allows the sails to be flattened...
Propellers are very sensitive to the inflow velocity, which means vessel speed. So when moving at a slower speed more power will be required to...
Sounds interesting, but why do you think that optimizing Cl/Cd of a blade section will produce a better propeller? It seems to me that more...
The rule of thumb about right, so you need approx 2500 HP/shaft to get to 50 MT; maybe a bit less with a Tractor tug. How did you arrive at 273...
that came from sine(beta) and cos(beta). People usually use beta for pitch angle, but for various reasons used phi here Old guys used to try...
One thing I just noticed is that "skew" is projected skew in radians, not expanded skew as it says in the comments. "dtor" is simply the...
Here is some VB code to turn radial data (pitch, chord, rake, skew) and section offsets into X,Y,Z coords For i = 1 To nr...
Hmm, seems like that would be 1.25 EAR
282? seems like EAR should be more like 195. I don't use the empirical formulas, so I can't comment on the validity of the results.
I'm not sure what you are anticipating for max speed, but I think that the 5 PSI estimate is too low. I calculate about 12 PSI which may be OK,...
I don't think that you will be too happy with the performance of a 17X10 prop on this boat. I didn't read everything posted here, but I suspect...