Boom! Sailrocket smashes the 60 knot barrier!

Thanks to P. Dunlop for the heads up.

“this is what fast boats look like…”

We don’t have the average speed record, but its looking good for the proa contingent.

61,23 knots!!!!

That is an incredible speed when sailing. Very impressive!

Johannes.

Here is a well-written article about the Sailrocket that should interest proa enthusiasts:

    ASME - August 2013 - “Flying Boat” article

The article contains a nice sidebar detailing Bernard Smith’s aerohydrofoil concept, upon which the Sailrocket is based.

Cheers,
Paul

Here is a nicely detailed 1200-pixel-wide infographic detailing the Sailrocket design:

    Yachting World - How Sailrocket Works

The attached image is a snippet of the larger infographic.

Cheers,
Paul

Thank you Aerohydro, those are both great.

Thanks Aerohydro.

One thing I find amusing in the infographic is the bit about the main foil where it says “The design of the foil went against the views of many well-established hydrodynamicists… and proved them wrong”.  Thing is, wedge shaped foils have been in use in Hydroplane racing since the 1950’s (iirc).  For a high speed surface piercing foil, the wedge is so superior to the aerofoil that hydroplanes use nothing else.  Here are photos of the trailing edges of a rudder and skid fin (basically a bruce foil) if anyone’s interested… the leading edges are knife sharp.  Heck, they’re also used on go-fast rc boats, so they work over a wide range of reynolds numbers.  And even surface piercing propellers have wedge shaped blades.

It seems like a case of “not invented here” on the part of sailboat oriented hydrodynamicists.

Another thing I am curious about is that in the top view, the small “wing extension” is shown providing forward thrust, though I think that is impossible for a horizontal wing that is creating (upward) lift. Any thoughts on this?

Editor - 04 October 2013 06:50 PM

Another thing I am curious about is that in the top view, the small “wing extension” is shown providing forward thrust, though I think that is impossible for a horizontal wing that is creating (upward) lift. Any thoughts on this?

I think they are saying the winglet reduces the drag of the main wing which increases the lift/drag ratio; effectively moving the thrust vector forward.

Cheers,
Skip

Skip - 04 October 2013 07:01 PM

I think they are saying the winglet reduces the drag of the main wing which increases the lift/drag ratio; effectively moving the thrust vector forward.

That’s the only thing the text talks mentions.  I think the graphic is just showing that the addition of the winglet creates an increase in net thrust, without over complicating the visual by trying to depict how.

Thanks for the posts, and for the comments.  I think the text about “the design of the foil went against the views of many well-established hydrodynamicists ... and proved them wrong” is just a case of the magazine hyping the situation to make the matter sound more significant than it actually was.

Regarding the purpose of the horizontal wing extension, Skip is correct, but there are other factors at play as well.  At Sailrocket’s official website, there is an explanation as to the how this part of wingsail works:

    Sailrocket - Wing-Sail Elements (scroll down to “Wing Extension”)

As to the overall accuracy of the Yachting World infographic ... check out the front-on view of the Sailrocket, and the details of the hydrofoil. The hydrofoil’s lift vector is pointing up ... this is wrong!

Cheers,
Paul