How to choose a NACA foil profile. 1

[TMcRally]

I'm looking for a symmetrical and an asymmetrical foil.

1. A symmetrical for a horizontal foil to fit to the rudder to reduce pitching on a sailing catamaran.

2. An asymmetrical to run in the upward waterflow rising up the stern to produce some forward lift.

The boat is a performance cruising catamaran. It weighs 7.5t and is 14.8m long, each hull is 1m wide at its widest point. It is capable of 20kn but anywhere up to 16kn is more likely.

I apologize I am well out of my depth here, if there is a simple rule of thumb or a link to "picking foils for dummies" I would greatly appreciate the help.

 

[GregLocock]

I am out of my depth, but not out of my comfort zone.

http://www.tspeer.com/Hydrofoils/h105/h105.htm

https://www.yumpu.com/en/document/read/38272735/hydrofoil-section-design

Perhaps you could contact Tom Speer directly, he was still active in 2019. This line is a classic "More important than the section shape is getting the area and the span sized right." For the symmetric one you could just remove all the camber from whichever lifting foil you select.

Here's a great thread

https://www.boatdesign.net/threads/foil-section-for-foil-board.63233/

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[TMcRally]

Thanks again Greg. I have learnt more from reading those links and Tom Speers comments than I have since I started.