This week we started production of tooling for an improved rudder design for Paradox.
Design work from here on in is entirely in-house.
Design work from here on in is entirely in-house.
Considerable drag reductions should be possible through increasing the efficiency of the ‘L’ surface.
This is achieved by improving the aspect ratio of the horizontal foil.
Increasing the aspect ratio dramatically reduces induced drag. The new aspect ratio is in the realm of competition sailplane wings.
Increasing the aspect ratio dramatically reduces induced drag. The new aspect ratio is in the realm of competition sailplane wings.
Careful structural optimisation has allowed us to exploit this solution with no cost or weight penalties.
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| Mk1 rudder shown yellow, new version in red |
At the same time we have confirmed that the actual force the winglets have to generate is considerably less than initially predicted. We will test progressively smaller winglets to validate the new calculations.
When you add together the increased efficiency and the smaller force required, the size of the winglets reduces dramatically (close to 50%), giving a significant drag reduction.
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| Mk1 rudder shown yellow, new version in red |
The new rudders are conceived to be versatile in two ways:
1) The winglets have an untapered portion near the tip so they can be trimmed off at any length and still maintain an efficient planform shape.
Cutting them off 180mm from the root gives equivalent area to the “+” winglets being offered by other manufacturers (typically a pair with 100mm span each, giving 200mm total span).
However the L solution is free of the interference drag created by the intersection of three separate foils.
Any intermediate area can be chosen to suit the preferences of the user.
Any intermediate area can be chosen to suit the preferences of the user.
2) The top of the rudder is tapered such that the whole blade can be reversed. This gives the option of eliminating the winglets all together in light conditions while having them ‘on standby’ ready to deploy if the weather changes.
The compensation has also been refined (increased and redistributed vertically) to give a lighter feel on the tiller.
The new rudder will come standard with every Paradox.
The versatility of the new rudders allows us to confidently offer them for sale separately to customers who want to retrofit them to existing boats, with or without our cassette and gudgeon system.