Duct and Props Design

Hi guys,

I’m a French mechanical engineering student and I am working on a project about an e-foil build. I already design the main part of the project but now I have to deals with the main parts : prop and duct. I should like to design someting with good performance, that’s why I am extremely thorough about the prop and duct design.
I would like to know if you guys can give me some advises about the duct. In addition to being a safety components, it’s also a parts which can higly improve the performance of my Efoil.

I would like to know more about the space between duct and prop : To avoid vortex and be the more efficient, how short should be this space ?

And about the profil of these duct, I saw the rice Nozzle seems to be the best profil for our e-foil. What do you think about it ?

Thanks for taking the time to read my post.

Lucas G.

Yes, Rice-nozzle is faster. It’s easy to understand from this picture: https://gcaptain.com/wp-content/uploads/2012/03/Screen-shot-2012-03-02-at-12.55.58-PM.png

There are a few links on this forum like:

Also, a parametric SW would be useful in your case like CAESES. Worth asking them a student licence:
Case studies range from 2015 › CAESES to 2019 › CAESES
including 2016, 2017 and 2018

Two guys/companies present on this forum have had good results using this SW. Maybe can they orientate you on interesting trails:
@Flying_Rodeo efoil Flying Rodeo › CAESES
@Vefoil : Jet Impeller Optimization for an Electric Hydrofoil Surfboard (efoil) › CAESES