Figure 8
  1. For more information email us at:
info@windray-sailboards.com
 
Technology

Three of the technologies that have been developed (one patented and two patents pending) are:

Planing watercraft (yachts to kite boards and sailboards) with High Lift Surfaces, that reduces the speed needed to plane by about 30%. This is due to an increase of lift to drag of about 100% at transition speeds through slow to medium planing speeds of hulls with these high lift surfaces. Roughly 50% is due to increased lift from the cambered surfaces and 25% is due to the rocker surface in front of the camber, which makes the  lift vector more vertical, thus reducing the dynamic drag.  This is only possible due to the details of the size and position of these surfaces.



 Figure 7 shows drag data for  1/2 scale models of  sailboards with and without the High Lift Surfaces. Series 2 shows the data for a model with a high lift surface. Series 1, 3 and 4 are for previous 1/2 scale models which do not have the high lift surface.

Fig_7A






Thus the lift/drag is increased by 100% or more at least from 6 to 23 mph.
For series 1, 2 and 4 the Center of Gravity, CG, was shifted for different
 speeds over the range that a normal sailboarder would shift their CG.
In series 3 the CG was not shifted.







fig_8B








Where series 1 and 3 are for the yacht model on waves and flat water,
series 2 is published yacht data adjusted to the same length of 160 cm as it is on the model.
For a yacht and this data, the position of the CG was fixed
.



2)  Sailboards with winglets and winglets with slots. These allow the boards to plan at low board speed and less wind for a given sail size. They do this by a) allowing water to produce lift both on top and under the winglet and b) reducing the wave drag when the said water on top and under the winglet come smoothly together behind the board thus greatly reducing the wave drag. One of the “Windray sailboard” loses its wave drag at 6 mph (10 km/h).  Another board, with only 105 L, loses it at 7 mph. This later board is shown after “2)”


CatRay_winglet


Top/back view of Cat Ray which loses its wave drag at 6mph.






0002
In displacement mode the side winglets are mostly under water thus its wave drag is like that of a narrower board.





At 6 mph the water on top of the winglet and that
under the winglet come smoothly together.  The board is very quiet at this speed. At 6mph it still has some displacement lift but has mostly planing lift.
  So Cat Ray essentially planes at 6mph.




NRay_slotted_winglet
This board has a winglet with a forward slot, using the Coanda effect. The slot is in the water when the board is starting to plane giving lift from both sides of the winglet. It is mostly out of the water when planing fast.



2)  Camber/slope step, which allows a) the board to plane as if the step were not there, b) unlike other vented or unvented steps has almost no turbulent /wave drag and c) dewets behind the step at about 14 mph to reduce both the wetted surface area and the lift at the back of the board thus further reducing the wetted surface. These steps therefore increase the board speed without affecting the planing characteristics of the board.

Ray1



105 L Ray Board. Its Camber/slope step makes it very fast.



Bottom view of Cat Ray. These steps are unlike other sailboard steps. They were designed from both theory and experiments.


 
Catray2C
Bottom of board showing camber on the right (47-57 cm) step depth of  ~ 3 mm, 47 cm from end of board and an upward slope from 37 cm to 47 cm. There is also a cusp (two curves coming to a point) behind the measuring tap that runs from 0-47 cm, which prevents  water from wetting the area behind the step when planing at above about 15 mph (25 km/h). The step is not sharp but rather rounded.
If you would like to participate in any of these technologies contact us as info@windray-sailboards.com

3)  We have amazing new results which can further increase both the lift/drag and responsiveness of the sailboard.


If you would like to share this information and further developments please request a confidential disclosure agreement at info@windray-sailboards.com




 
 
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