Prop efficiency curves

Does anyone have or know where to get prop efficiency curves for surface piercing props? Have any tests been done on them?
Thanks

 

There is some data in this paper:
http://www.icmrt07.unina.it/Proceedings/Papers/c/44.pdf

If you google arneson or other surface drive manufacturers you will also find some curves.

The peak efficiency I have seen in any of the data is 70%. Well below what can be achieved with a fully submerged prop or air prop but these have certain limitations.

Rick W

 

These data seem to be quite confidential and I have been searching for quite a long time.

The only documents I was able to find are a test protocol by Rolla, a paper by Marco Ferrandi, Stefano Crotti, and Michele Viviani (which contains some handy regression formulae to produce KT/KQ/η curves; I made little Excel spreadsheet of this), and finally a product leaflet by France Hélices where there are two little diagrams of unspecified surface piercing propellers. However, this seems to be no longer online.

Edit: Oops, Rick was quicker...

 

Power curve, the sub

http://zone.sousmarins.free.fr/zone sous-marins helices.htm

yes i know this is french but take a look at pictures at the end...can use translator too.
they say water is also pressure injected close inside the fairing to improve flow
i wonder what would be the efficiency of this twin pump prop with fairing around ?
0.9 region, ?

And what would give an approximate home made copy of such a propeller pump ?
Less but certainly a lot anyway, it would be worth trying

A pump jet with 2 propellers can be seen on some jet ski, should we get inspired ?

 

the jetskis are all single impeller with a stator behind it, as are most of the jetdrives currently being made.