line drag
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Luke
Dec 15, 2009, 1:22:43 AM12/15/09
to Cascade Paragliding Club
I was reading the google group message forwarded about the new Ozone
Carbon fiber! It mentioned reducing line drag and so I have to ask as
a newbie ... what exactly is line drag? Sorry if this is something I
should be expected to know!
Carbon fiber! It mentioned reducing line drag and so I have to ask as
a newbie ... what exactly is line drag? Sorry if this is something I
should be expected to know!
Ralph
Dec 15, 2009, 1:45:52 AM12/15/09
to Cascade Paragliding Club
Hi Luke
Line drag is what happens when you take the lines that go from your
risers to you wing and you push them through the air.
As you can imagine, less line equals less drag, which equals improved
performance.
Hope to see you at the Christmas party.
Ralph
Line drag is what happens when you take the lines that go from your
risers to you wing and you push them through the air.
As you can imagine, less line equals less drag, which equals improved
performance.
Hope to see you at the Christmas party.
Ralph
charlie phillips
Dec 15, 2009, 2:18:00 AM12/15/09
to rez...@qwestoffice.net, CPC
and here I thought line drag is what happens when you get dragged on launch...:-)
CP
> Date: Mon, 14 Dec 2009 22:45:52 -0800
> Subject: CPC: Re: line drag
> From: rez...@qwestoffice.net
> To: cp...@googlegroups.com
CP
> Date: Mon, 14 Dec 2009 22:45:52 -0800
> Subject: CPC: Re: line drag
> From: rez...@qwestoffice.net
> To: cp...@googlegroups.com
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Pat Chewning
Dec 15, 2009, 8:31:10 AM12/15/09
to l.dan...@comcast.net, Cascade Paragliding Club
Line Drag (v): Act of dragging a razor blade across a mirror to form a
line of coke.
line of coke.
Billb
Dec 15, 2009, 9:55:20 AM12/15/09
to Cascade Paragliding Club
Or a group of male CPCers doing the "9 Ladies Dancing" part at the
2009 Christmas party. In heels and spandex. There's a vision -
ouch! Quick - think about something else!
2009 Christmas party. In heels and spandex. There's a vision -
ouch! Quick - think about something else!
Steed family
Dec 15, 2009, 11:55:59 AM12/15/09
to l.dan...@comcast.net, cp...@googlegroups.com
OK, someone has to do the straight answer.
The lines on a paraglider are simply small-diameter cylinders held perpendicular to the wind. Cylinders are only marginally more aerodynamic than a sheet of plywood held perpendicular to the wind, which is to say, not aerodynamic -- the drag force is high and directly related to the area facing the wind, a linear relation to the line's diameter or radius. But the strength of a cylindrical line is related to its cross-sectional area, which increases with the square of the radius. So a fat line might have twice the drag, but 4 times the strength. So, one way to reduce line drag is to design a wing with fewer (but stronger) lines. Another would be to use non-cylindrical lines, but keeping them oriented into the wind and preventing oscillation would be a major challenge.
Mike
> Date: Mon, 14 Dec 2009 22:22:43 -0800
> Subject: CPC: line drag
> From: l.dan...@comcast.net
> To: cp...@googlegroups.com
The lines on a paraglider are simply small-diameter cylinders held perpendicular to the wind. Cylinders are only marginally more aerodynamic than a sheet of plywood held perpendicular to the wind, which is to say, not aerodynamic -- the drag force is high and directly related to the area facing the wind, a linear relation to the line's diameter or radius. But the strength of a cylindrical line is related to its cross-sectional area, which increases with the square of the radius. So a fat line might have twice the drag, but 4 times the strength. So, one way to reduce line drag is to design a wing with fewer (but stronger) lines. Another would be to use non-cylindrical lines, but keeping them oriented into the wind and preventing oscillation would be a major challenge.
Mike
> Date: Mon, 14 Dec 2009 22:22:43 -0800
> Subject: CPC: line drag
> From: l.dan...@comcast.net
> To: cp...@googlegroups.com
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MAX ROC PARAGLIDING
Dec 15, 2009, 12:35:29 PM12/15/09
to l.dan...@comcast.net, Cascade Paragliding Club
Sorry for the short responce here I don't have a lot of time today.
"Line Drag" is no mystery it is exactly what it says.
Lines create drag we can here it as wind whistles and sings through the lines as aglider takes off or flys by.
we can see it in our brake lines while groundhandling or in flight they are all swept back.
In short the more lines and thicker lines create more drag and less and thinner lines create less drag thats why
the comp pilots use unsheathed comp lines or race lines wich have a micro coating on them.
In the old days glider had 6 (A) lines per side now there are only 3 and in some case 2 (A) lines per side.
Thanks to Hanes P. at NOVA and Rob W. while at Firebird.
A term I haven't heard for a while is Parasitic drag, wich referrers to
The largest point of drag on a paraglider wich is the pilot and harness. thats why most modern harnesses recline back
when fully engaging the speed system (aka) speed bar. in an atempt to present less drag creating more speed.
Lift to drag ratio or LD.
an upward force on the wing called lift. Dragging anything through the air, even a wing, creates air resistance which
tends to hold it back. This backwards force is called drag. Now for some aerodynamic magic - lift divided by drag tells
you exactly how well this wing will glide. It's called the lift-to-drag ratio, or LD. (Did you catch the inaccuracy in this
bit of paragliding theory? Yep, the lines and risers, not to mention your own body, also contribute to drag!)
here is a little something worth reading from our very own Stu Caruk at www.towmeup.com
and off topic but still good and recommended.
Best wishes and better flying,
Kelly Kellar
Learning, living and teaching the dream of FLIGHT.
MAX ROC PARAGLIDING
http://maxroc.com in...@maxroc.com (503)464-6140
-----Original Message-----
From: Luke [mailto:l.dan...@comcast.net]
Sent: Monday, December 14, 2009 10:22 PM
To: 'Cascade Paragliding Club'
Subject: CPC: line drag
MAX ROC PARAGLIDING
Dec 15, 2009, 12:49:27 PM12/15/09
to pch...@comcast.net, l.dan...@comcast.net, Cascade Paragliding Club
Paragliding is an addiction you can live with.
Best wishes and better flying,
Kelly Kellar
Learning, living and teaching the dream of FLIGHT.
MAX ROC PARAGLIDING
http://maxroc.com in...@maxroc.com (503)464-6140
-----Original Message-----
From: Pat Chewning [mailto:pch...@comcast.net]
Sent: Tuesday, December 15, 2009 05:31 AM
To: l.dan...@comcast.net, 'Cascade Paragliding Club'
Subject: CPC: Re: line drag
Line Drag (v): Act of dragging a razor blade across a mirror to form a line of coke. ----- Original Message ----- From: "Luke" To: "Cascade Paragliding Club" Sent: Monday, December 14, 2009 10:22 PM Subject: CPC: line drag >I was reading the google group message forwarded about the new Ozone > Carbon fiber! It mentioned reducing line drag and so I have to ask as > a newbie ... what exactly is line drag? Sorry if this is something I > should be expected to know!
MAX ROC PARAGLIDING
Dec 15, 2009, 12:51:17 PM12/15/09
to wi...@peak.org, Cascade Paragliding Club
Flying Drag Queens well it is Portland LOL.
Our you trying to tell us something Bill ?
Best wishes and better flying,
Kelly Kellar
Learning, living and teaching the dream of FLIGHT.
MAX ROC PARAGLIDING
http://maxroc.com in...@maxroc.com (503)464-6140
-----Original Message-----
From: Billb [mailto:wi...@peak.org]
Sent: Tuesday, December 15, 2009 06:55 AM
To: 'Cascade Paragliding Club'
Subject: CPC: Re: line drag
Or a group of male CPCers doing the "9 Ladies Dancing" part at the 2009 Christmas party. In heels and spandex. There's a vision - ouch! Quick - think about something else! On Dec 15, 5:31 am, "Pat Chewning" wrote: > Line Drag (v): Act of dragging a razor blade across a mirror to form a > line of coke. > > ----- Original Message ----- > From: "Luke" > To: "Cascade Paragliding Club" > Sent: Monday, December 14, 2009 10:22 PM > Subject: CPC: line drag > > >I was reading the google group message forwarded about the new Ozone > > Carbon fiber! It mentioned reducing line drag and so I have to ask as > > a newbie ... what exactly is line drag? Sorry if this is something I > > should be expected to know!
jjhalle
Dec 15, 2009, 1:20:30 PM12/15/09
to Cascade Paragliding Club
If I remember my aerodynamics, there are two kinds of drag: induced
drag and parasite drag. Induced drag is incurred in the production of
lift. Parasite drag is all drag that is not induced drag and is
incurred by the passage of the aircraft through the air.
Lift to drag ratio is a calculation used to understand the performance
characteristics of an airfoil (i.e. a lift producing body.) It
compares lift to induced drag at various angles of attack. For any
airfoil that is actually used on an aircraft, L/D increases with angle
of attack to a point generally a few knots above stall, after which it
decreases to stall. L/D(max) is the top of the L/D curve and the
point at which any change in angle of attack decreases L/D. For an
airplane pilot, it is the point at which any stick motion, forward or
back, decreases L/D and therefore increases sink rate. It is also the
point at which max lift is created using minimum thrust. I assume all
this is relevant to paragliders somehow but I am not good enough to
figure out how.
I don't think L/D is calculated by including parasite drag.
drag and parasite drag. Induced drag is incurred in the production of
lift. Parasite drag is all drag that is not induced drag and is
incurred by the passage of the aircraft through the air.
Lift to drag ratio is a calculation used to understand the performance
characteristics of an airfoil (i.e. a lift producing body.) It
compares lift to induced drag at various angles of attack. For any
airfoil that is actually used on an aircraft, L/D increases with angle
of attack to a point generally a few knots above stall, after which it
decreases to stall. L/D(max) is the top of the L/D curve and the
point at which any change in angle of attack decreases L/D. For an
airplane pilot, it is the point at which any stick motion, forward or
back, decreases L/D and therefore increases sink rate. It is also the
point at which max lift is created using minimum thrust. I assume all
this is relevant to paragliders somehow but I am not good enough to
figure out how.
I don't think L/D is calculated by including parasite drag.
Luke
Dec 15, 2009, 1:32:41 PM12/15/09
to Cascade Paragliding Club
Nice info! thanks for all the replies. I feel like I got a free
physics lesson from all the replies. The towmeup link that Kelly sent
was a good read as well though it was not related to line drag.
Luke
On Dec 15, 8:55 am, Steed family <steedfam...@hotmail.com> wrote:
> OK, someone has to do the straight answer.
>
> The lines on a paraglider are simply small-diameter cylinders held perpendicular to the wind. Cylinders are only marginally more aerodynamic than a sheet of plywood held perpendicular to the wind, which is to say, not aerodynamic -- the drag force is high and directly related to the area facing the wind, a linear relation to the line's diameter or radius. But the strength of a cylindrical line is related to its cross-sectional area, which increases with the square of the radius. So a fat line might have twice the drag, but 4 times the strength. So, one way to reduce line drag is to design a wing with fewer (but stronger) lines. Another would be to use non-cylindrical lines, but keeping them oriented into the wind and preventing oscillation would be a major challenge.
>
> Mike
>
> > Date: Mon, 14 Dec 2009 22:22:43 -0800
> > Subject: CPC: line drag
> > From: l.daniel...@comcast.net
> Hotmail: Trusted email with powerful SPAM protection.http://clk.atdmt.com/GBL/go/177141665/direct/01/
physics lesson from all the replies. The towmeup link that Kelly sent
was a good read as well though it was not related to line drag.
Luke
On Dec 15, 8:55 am, Steed family <steedfam...@hotmail.com> wrote:
> OK, someone has to do the straight answer.
>
> The lines on a paraglider are simply small-diameter cylinders held perpendicular to the wind. Cylinders are only marginally more aerodynamic than a sheet of plywood held perpendicular to the wind, which is to say, not aerodynamic -- the drag force is high and directly related to the area facing the wind, a linear relation to the line's diameter or radius. But the strength of a cylindrical line is related to its cross-sectional area, which increases with the square of the radius. So a fat line might have twice the drag, but 4 times the strength. So, one way to reduce line drag is to design a wing with fewer (but stronger) lines. Another would be to use non-cylindrical lines, but keeping them oriented into the wind and preventing oscillation would be a major challenge.
>
> Mike
>
> > Date: Mon, 14 Dec 2009 22:22:43 -0800
> > Subject: CPC: line drag
> > To: cp...@googlegroups.com
>
> > I was reading the google group message forwarded about the new Ozone
> > Carbon fiber! It mentioned reducing line drag and so I have to ask as
> > a newbie ... what exactly is line drag? Sorry if this is something I
> > should be expected to know!
>
> _________________________________________________________________
>
> > I was reading the google group message forwarded about the new Ozone
> > Carbon fiber! It mentioned reducing line drag and so I have to ask as
> > a newbie ... what exactly is line drag? Sorry if this is something I
> > should be expected to know!
>
> Hotmail: Trusted email with powerful SPAM protection.http://clk.atdmt.com/GBL/go/177141665/direct/01/
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