Kite Development

Total Posts: 17

Joined 2010-11-15

PM

 

G’day Guys

i was doing a bit of researching the other day and came across a couple of 3 and 5 strut Razor prototypes for sale.
OR are obviously experimenting with other very different configurations to further develop their current products and this got me wondering what other things they have tried in the last couple of years and how it performed?

i am very interested in the design and development of the kites i use (probly due to studying Aerospace engineering for a couple of years) as i am sure many other OR riders are.
so if any of the development crew have some spare time to give an insight into OR’s recent experiments im sure many would enjoy reading it.

on a side note; have you guys tried out using more but smaller Venturi vents (see attachment to see what i mean).
i have found with my 10m 2012 razor in its bottom end that it can feel chocked or over trimmed at the point where it provides sufficient lift to be able to ride (after playing around with the trim i find it likes to have a little depower on even in light winds).
i would put this down largly to the High angle of attack (AoA) producing a higher drag.
i believe that smaller venturi vents would provide slightly better lift at lower AoA (ie AoA the a kite without Venturi would fly at) while still preventing stall at higher AoA.
i hope that makes scense…

cheers

Image Attachments

venturi.jpg

Total Posts: 8

Joined 2011-05-12

PM

 

Hello Aussie Dan,

Very kool idea. Do you think the flow might start to become more turbulent as more vents are added? Do you have assess to any CFD programs? I would love to see how the flow changes as you add more vents and maybe play around with the length of section.

Have you already graduated or are you still studying? Either way which uni did/ do you attend?

Great post!


Total Posts: 17

Joined 2010-11-15

PM

 

Hi John
i studied at RMIT in Melbourne, i only did 2 years of study and that was 5 years ago… so i could be totaly wrong :-p

so my thoery behind the idea is:
the venturi works in a similar mannor to a wing with a slotted flap (without the flap changing angle), it helps to maintain laminer (non turbulant) airflow over the upper surface of the canopy at High Angle of Attack (AoA); this provides more lift at slower airspeed and prevents stalling.
if you compare a kite with and without the venturi, the kite without will have slightly better lift up to the angle it looses laminer flow and stalls (the venturi does not provide extra lift up to this point and is efectivly just a hole in the canopy letting air pressure through)
at the point where a normal kite will stall is where the venturi becomes effective and allowes the AoA to increase a few more degrees and hence increasing the wind range of the kite.
i believe that by reducing the size of the “holes” in the canopy the kite will have greater power at lower AoA when the venturi is not coming into play.
this should not afect how the venturi works at high AoA.

like i said; it is just a theory and things like added turbulant airflow or dificulty in manufacture may make it not worth while…
OR may have already explored it and proven that it does not work…

i am very interested to know how the 3 and 5 stut kites differed from the 4 strut versions if anyone can tell me???


Avatar

Total Posts: 517

Joined 2008-04-13

PM

 

Hi Dan,
Thank you for opening up this topic.
Being involved in Ocean Rodeo R&D I can confirm that the layout of the venturi slots is a discussion since long. We are aware that the bulged flaps are not the best aerodynamic shape - like many other parts of kites in general - but we need something the factory can build within tolerances and cost limits, and still works. It’d be interesting for you to stick a bunch of tell tales on the top canopy to see how it really works, this is how Ross tuned the venturis. Of course,  we’d be happy to look into any points of improvement you may find!

Ocean Rodeo is one of the most innovative kite brands around, and there’s always a lot going on. Regarding discussing R&D on a public forum, OR is a bit restraint. Not only do we want to keep competitors from running off with our ideas, most ideas need lots of testing and developing and you’d be surprised how low the success rate is, my guess is that one out of five or maybe even ten really promising ideas don’t even pass prototyping. It would take a days job to organize any public discussion around that, and honestly, it would stir a lot of turbulence amongst dealers and in the end the users too. We’re just not so much about hyping the “next big thing you don’t have”, like some cell phone brands do.

Personally, if kite development had stopped in 2008 I could be riding that 08 Rise for the rest of my life! Not sure about the Bronco.

Having said that, 2014 will be nice. Very nice. wink


Total Posts: 17

Joined 2010-11-15

PM

 

Thanks for the Reply El Rudu.

i had suspected that manufacuting cost vs performance gains may be a flaw in my theory as i am sure it is to many of the ideas you guys have had over the years.
it does not suprise me at all how many ideas are actualy put into productin, i can imagine R&D of new kites would be based alot more on trial and error than many other products.
i understand OR dont want to reveal any secrets, i was more refering to the things you have tried that did not work out… (such as the 3 and 5 strut kites i found for sale)

OR definatly dont hype up thier un-release products like other brands do but a few more teasers would be nice every now n then tongue wink
looking forward to the next additions to the OR line up.