Date: Fri, 22 Sep 1995 00:33:56 -1000 From: Bart Peeters Message-Id: <43u3ek$jn5@mo6.rc.tudelft.nl> Organization: Delft University of Technology Subject: Turbulent makers on kites Has anyone tried to add a turbulent-maker on his kite like a salling plane? It would make the aeroflow turbulent which would make the flow stick longer to the profile. Wich would given a lower drag and greater lift. I'm very interested in this idea. Bart Peeters = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Tue, 26 Sep 1995 10:40:12 -1000 From: andrew@tug.com (Andrew Beattie) Message-Id: Organization: /usr/lib/news/organisation Subject: Re: Turbulent makers on kites Bart Peeters writes: >Has anyone tried to add a turbulent-maker on his kite like a salling plane? >It would make the aeroflow turbulent which would make the flow stick longer to >the profile. Wich would given a lower drag and greater lift. If only we could get kites slick enough to need added turbulence. With Dacron leading edges, seams, spars, battons, vinyls sticking out, non-smooth fabric and wrinkles, I don't think this is likely to be a problem, but feel free to prove me wrong... Andrew -- New to rec.kites? START HERE! | To: www@kfs.org send an email message like this->| Subject: service /-\ () >< () |\/| () >< () /-\ | http://www.kfs.org/kites/welcome/index.html 80+ chrs/line looks messy on many screens. Often too messy to bother reading. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Tue, 26 Sep 1995 10:40:12 -1000 From: andrew@tug.com (Andrew Beattie) Message-Id: Organization: /usr/lib/news/organisation Subject: Re: Turbulent makers on kites Bart Peeters writes: >Has anyone tried to add a turbulent-maker on his kite like a salling plane? >It would make the aeroflow turbulent which would make the flow stick longer to >the profile. Wich would given a lower drag and greater lift. If only we could get kites slick enough to need added turbulence. With Dacron leading edges, seams, spars, battons, vinyls sticking out, non-smooth fabric and wrinkles, I don't think this is likely to be a problem, but feel free to prove me wrong... Andrew -- New to rec.kites? START HERE! | To: www@kfs.org send an email message like this->| Subject: service /-\ () >< () |\/| () >< () /-\ | http://www.kfs.org/kites/welcome/index.html 80+ chrs/line looks messy on many screens. Often too messy to bother reading. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 27 Sep 1995 01:59:10 -1000 From: bart peeters Message-Id: <44beaf$gio@mo6.rc.tudelft.nl> Organization: Delft University of Technology Subject: Re: Turbulent makers on kites andrew@tug.com (Andrew Beattie) wrote: >Bart Peeters writes: >>Has anyone tried to add a turbulent-maker on his kite like a salling plane? >>It would make the aeroflow turbulent which would make the flow stick longer to >>the profile. Wich would given a lower drag and greater lift. > >If only we could get kites slick enough to need added turbulence. With Dacron >leading edges, seams, spars, battons, vinyls sticking out, non-smooth fabric >and wrinkles, I don't think this is likely to be a problem, but feel free to >prove me wrong... > >Andrew What did you think of a sputnik or any other winglike kite? Very smooth... Bart = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 27 Sep 1995 07:44:57 -1000 From: sasaki@netopd.harvard.edu (Marty Sasaki) Message-Id: <44c2ip$cv@netope.harvard.edu> Organization: Harvard University - OIT/NSD Subject: Re: Turbulent makers on kites In article , andrew@tug.com (Andrew Beattie) writes: |>Bart Peeters writes: |>>Has anyone tried to add a turbulent-maker on his kite like a salling plane? |>>It would make the aeroflow turbulent which would make the flow stick longer to |>>the profile. Wich would given a lower drag and greater lift. |> |>If only we could get kites slick enough to need added turbulence. With Dacron |>leading edges, seams, spars, battons, vinyls sticking out, non-smooth fabric |>and wrinkles, I don't think this is likely to be a problem, but feel free to |>prove me wrong... Oh no! It's another discussion on aerodynamics! Jason, you can hit the delete key now... At higher angles of attack the airflow separates from the top surface. This dramatically decresses lift and increases drag. Turbulators have been used on aircraft of all sizes to keep the airflow attached to the top surface for a longer time. It turns out that mildly turbulent air flow, that remains attached has higher lift and reduced drag. One way to increase the turbulence would be to run a string just in front of, and over the tip surface of the wing. Another way used in airplanes (both model and full size) is to build a sharp ridge into the top surface, just behind the leading edge. While increasing the turbulence would probably help, I believe that greater gains are to be found with increasing the leading edge radius and creating positive camber in the kite sail. Another way to increase lift at high angles of attack is to use vortex generators. These are like turbulators, but they stir the air up a lot more than turbulators. The result is often much longer attachment of the airflow to the upper wing, and much higher air velocity over the part that remains attached. Lift can be increased significantly. -- Marty Sasaki Harvard University Sasaki Kite Fabrications sasaki@noc.harvard.edu Network Services Division 90 Melrose Street 617-496-4320 10 Ware Street Arlington, MA 02174 Cambridge, MA 02138-4002 phone/fax: 617-646-1925 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Fri, 29 Sep 1995 06:23:59 -1000 From: jairfoils@aol.com (JAirfoils) Message-Id: <44h6iv$1ge@newsbf02.news.aol.com> Organization: America Online, Inc. (1-800-827-6364) Subject: Re: Turbulent makers on kites We've done it. Jones Airfoils 310 Pine Hills Drive Wilmington, NC 28403 P.S. Its called a turbulator strip. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Fri, 29 Sep 1995 11:44:46 -1000 From: andrew@tug.com (Andrew Beattie) Message-Id: Organization: /usr/lib/news/organisation Subject: Re: Turbulent makers on kites jairfoils@aol.com (JAirfoils) writes: >We've done it. ...and...??? What did you gain, what did you loose? Did it perform as you expected? What *did* you expect? Are they easy to make? What did you try that *didn't* work? What kites can we see them on? Are they commercially available? Andrew -- New to rec.kites? START HERE! | To: www@kfs.org send an email message like this->| Subject: service /-\ () >< () |\/| () >< () /-\ | http://www.kfs.org/kites/welcome/index.html 80+ chrs/line looks messy on many screens. Often too messy to bother reading. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =