playing with"NACA" ducts on a givi screen

playing with"NACA" ducts on a givi screen

I borrow a friends bike the other day.
and On the way home I felt the strangest thing, my stomac was super cold,no mmatter how much clothes I have .......was frezzing!!!!!!.
so I study the problem and I conclude that the issue was the
execive "vaccum" generated by the wind screen,,,so I decide to go at it, with my fancy dremmel and my files..
here are pictures of the finish experiment ,but I will show you more of how I did it.

this concept will work on any other screen with similar "great " results.



frontal view


one more of the finish result

here are some photos of the prosses

I made the basic "layout" with packing tape,nothing sofisticated, but works really well.first you cut the out line,with anything hack saw anything,dremel 's are great.



more or less the same part of the job ,the most difficult that is.



cutting that angle is a "pain in the butt'' but is necesary to really eccelerate the air,,super fast

Re: here are some photos of the prosses

ricardo kuhn said:

I borrow a friends bike the other day......................so I decide to go at it, with my fancy dremmel and my files..

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Hey Rick, so let me get this right you borrow your mates GS and while you have it you hack two great holes in his Givi........ what do you do to your enemies?

My cure for a cold stomach is lots of beer and ruby.

Howard Millichap said:

My cure for a cold stomach is lots of beer and ruby.

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But not when you're riding right? I mean, you've got to keep at least one hand on the bars.

Re: Re: here are some photos of the prosses

Paul G said:

Hey Rick, so let me get this right you borrow your mates GS and while you have it you hack two great holes in his Givi........ what do you do to your enemies?

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PAUL I have "carte blanche" from many of my friends,to do what ever I think is necesary on ther bikes.
sometimes I even get pay(money , lunch, gas,accomodation) to ride there bikes ,and try to solve issues that they have, like suspension set up,handlling,noises,,,,,,etc.
I was really shure about what I was doing, and the bike perform years ahead better,so everybody win this time.

I get to PLAY, ride for FREE,and make my friends HAPPY. what else do you want from life.....?????.

Okey I can think of a few things,,but..............................

actually check

the tread that my friend (the owner of the bike) start today at ADVrider,,,,this is a serius development,,,,get use too....



http://www.advrider.com/forums/showthread.php?s=&threadid=12953

Re: playing with"NACA" ducts on a givi screen

ricardo kuhn said:

On the way home I felt the strangest thing, my stomac was super cold,no mmatter how much clothes I have .......was frezzing!!!!!!.


.....The freezing you mention was it the freezing as in San Fransisco California freezing or the freezing as in European winter freezing....?

Click to expand...

Re: Re: playing with"NACA" ducts on a givi screen

Gecko said:

ricardo kuhn said:

On the way home I felt the strangest thing, my stomac was super cold,no mmatter how much clothes I have .......was frezzing!!!!!!.


.....The freezing you mention was it the freezing as in San Fransisco California freezing or the freezing as in European winter freezing....?

Click to expand...

I when to my friends house,let my bike in there,took hisand came back home(middle of the day)

the weather condiccions were the same(if not warmer)(isolate variable) but the feeling was much colder.

MORE THAN freezing was SUCTION ,no matter how many clothes I have was "cool"in a funny way

check the ADVrider tread or the micapeak list ,,,so much activity,I thing I hit on something ,,,really HARD..

check ADV!!!!!!!!!!

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Ricardo,
Have you drawn up the template yet? I have a willing Givi screen, in fact everytime I walk past it it seems to say "NACA"!!!
Rod

Rod Souter said:

Ricardo,
Have you drawn up the template yet? I have a willing Givi screen, in fact everytime I walk past it it seems to say "NACA"!!!
Rod

Click to expand...

I'm working on it.
I trying to make a "scientific"study,to find the best possible compromise.
sorry IT takes time.

Those look f***ing cool - do you think they would work on a BMW screen for an R1100R ?

CHeers

6X

pint6x said:

Those look f***ing cool - do you think they would work on a BMW screen for an R1100R ?

CHeers

6X

Click to expand...

They will work on anything(to a variaty of degrees,specially depending on how bad is the problem)
the GIVI's for the 11 and the 1150 are really bad,but the one on the adventure I think is the wrost.

i'm working frantically to develope a "solution" but takes time to cut all the screens(22 at the moment) and even more to "isolate variable testing"all of them.

I hope soon I have some results.

Strictly speaking this isn't a NACA duct, but Ricardo probably knows this. What he's doing is very interesting nonetheless.

The NACA duct is just that; a duct opening on a surface exposed to laminar flow. The clever bit is that it minimises drag and de-lamination of air around the duct. But for it to be effective it will also have a ramp that directs the air from front to back; something missing from Ricardo's design.





The shape of the hole in the screen without the ramp may turn out to be less important than the shaping of the leading and trailing edges in order to minimise drag and delamination of the airflow that will now be occurring on the inside of the screen.

Of course there are a few bikes that have holes in the screen, this one springs to mind...



It would be interesting to complete the duct with a ramp and see what happens to the airflow.

I almost bought a Dremel myself today on the strength of Ricardo's idea. Brilliant stuff!

City Slicker said:

It wouinteresting to complete the duct with a ramp and see what happens to the airflow.
ld be
I almost bought a Dremel myself today on the strength of Ricardo's idea. Brilliant stuff! [/B]

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first thanks for the complements,I love to inspire people,,for sure go and buy the Dremmel, they are very usefull, for so many things.

about this comment
I"t would be interesting to complete the duct with a ramp and see what happens to the airflow."

Remenber that the "silver" screen kind of server that function.
the photos on this tread are just one attempt,totally "gestimation"just empirical wisdom,I do know they are not NACA ducts and for sure they do not serv as naca ducts,being on a vertical posstion,but you still have a few desirable features,NO wind noise(whissel effect)
no water coming from the holes,water kind of evaporates(atomizes) .

The NACA(in a losse term) project.
I decide that a sufficient amount of people suffer from poor riding conford do to the execive noise and turbulence on the GS's,so I decide to dedicate some time,(no monetary benefit) and try to come up with a "FIX" improvent,,etc at least do a rigurous study and see that I can do.

project parameters,needs to be simple ,repitable,with OUT a execive amount of skill require,not super crazy tools.
the idea by the time I'm done,is you will have a "downloadable" file(plus a copy of the document photos and everything),that you can just print and then,glue ,trace,mark ,,whatever on you screen,so you can generate the same results your self.

well so far I have 22 screen,aftermarket and stock ,crash and new for the R11 GS and the R1150 GS,and I'm going to try different concepts from just drilling round holes(very easy) to thermoforming REAL NACA's on screen to change the shape(almost unrepitable) with out the proper equipment.

so soon,after I'm done,hopefully I will have sufficient data,to chose what is the best compromise possible ,maybe I will come with a "decent Improvement" version that anybody can do,and a "super high performance" that will need some serius commitment.

you need to remenber that the GS is one of the most poorly design bikes in terms of aerodinamics, so no matter how good the solution, will not be "perfect"I way more complete Up -grade will be nedded,but at least the noise and the buffeting will diminish,,hey that is a start in my book

Ricardo

With all the research and development you're putting into this, I hope you are able to come up with a template which you can actually SELL and make a bit of cash with !

Good luck - I await your findings with interest.

Cheers

6X

pint6x said:

Ricardo

With all the research and development you're putting into this, I hope you are able to come up with a template which you can actually SELL and make a bit of cash with !

Good luck - I await your findings with interest.

Cheers

6X

Click to expand...

for me sometimes PASSION is more important than money.
I'm just no driven by the monetarie sourses,beside feels better to do for the "HELL of IT"than a small retribution.

this one is "on the house"

So what variations on the first screen design are you considering Ricardo?

City Slicker said:

So what variations on the first screen design are you considering Ricardo?

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from the easiest to manufacture ,,to the F#@%& Impossible

A)round holes(2 or 3 of them)done with a hole saw and then sand and polish,or done at and acrilic shop(this is for reference)

B)increase the space undernet the windscreen,with a sharp edge,trying to increase the flow or air.(will only work on the 1150GS)

C)ROUND HOLES on a 45 degree angle done on a milling machine on one operation,I think this ones have a lot of potencial,you need the machine shop to do it but is almost no skill involve.

D)different profile shapes of the NACA ducts with different proportions, sizes and quantitys.LOTS of hand skill and a high risk to F$#@ UP....to many angles and very difficult to make,specially to polish.

E)naca ducts with a hand made backing(second mini screen) if this work maybe I can make some for sell and retrofit,but will take some skills to cut and glue,bolt,,etc).

F) thermoform the NACA shape into the screen(needs a mold) and is very difficult to do,specially to keep translucent,at least optically clean..

so far those are the candidates,and in them are many choices,this is just for testing,after i figure out the effects of each of this,I will go into a deeper evolucionary label to finish the project.

NOTE: I do know ......some of this sistem will not work already,but to generate a "study" you need to have all the choices,to compare all of them,I will use the stock's for reference sake too.

What was it about the first design attempt that you weren't happy with? It seemed to work very well with a brilliant testimony from the riders.