CP vs AC?
Joined: Aug 2006
Posts: 7
Likes: 1
From: Southern Coast of Ohio (~KLUK)
iirc:
c.p. – is the point along the chord where the distributed lift is centered.
a.c. – is the point along the chord where lift changes (or the sum of lift changes)take place
c,p. is rather static and a.c. will move depending on aoa, dyanmic pressure (q), and other variables.
Hope this helps as a starter, someone else I'm sure can expand and/or clarify further.
c.p. – is the point along the chord where the distributed lift is centered.
a.c. – is the point along the chord where lift changes (or the sum of lift changes)take place
c,p. is rather static and a.c. will move depending on aoa, dyanmic pressure (q), and other variables.
Hope this helps as a starter, someone else I'm sure can expand and/or clarify further.
Thread Starter
Joined: Jan 2006
Posts: 364
Likes: 0
From: EU
iirc:
c.p. – is the point along the chord where the distributed lift is centered.
a.c. – is the point along the chord where lift changes (or the sum of lift changes)take place
c,p. is rather static and a.c. will move depending on aoa, dyanmic pressure (q), and other variables.
Hope this helps as a starter, someone else I'm sure can expand and/or clarify further.
c.p. – is the point along the chord where the distributed lift is centered.
a.c. – is the point along the chord where lift changes (or the sum of lift changes)take place
c,p. is rather static and a.c. will move depending on aoa, dyanmic pressure (q), and other variables.
Hope this helps as a starter, someone else I'm sure can expand and/or clarify further.
but...
I'm a bit confused... according to my books the CP moves with AoA as well as TAS. As an example when accelerating through the transonic region, the CP shifts from about 25% chord to 45% chord...
And the CLmax vs AoA diagram, doesnt it show the CP movment compared to AoA?
Joined: Dec 2005
Posts: 41
Likes: 0
From: Canada
iirc:
c.p. – is the point along the chord where the distributed lift is centered.
a.c. – is the point along the chord where lift changes (or the sum of lift changes)take place
c,p. is rather static and a.c. will move depending on aoa, dyanmic pressure (q), and other variables.
Hope this helps as a starter, someone else I'm sure can expand and/or clarify further.
c.p. – is the point along the chord where the distributed lift is centered.
a.c. – is the point along the chord where lift changes (or the sum of lift changes)take place
c,p. is rather static and a.c. will move depending on aoa, dyanmic pressure (q), and other variables.
Hope this helps as a starter, someone else I'm sure can expand and/or clarify further.
Thread Starter
Joined: Jan 2006
Posts: 364
Likes: 0
From: EU
Other way around. Center of pressure will change with mach and aoa. It is aerodynamic center that really doesn't change, theoretically calculated at exactly 25% MAC, but typically between 23 and 27%. There was a very informative thread on this a year or 2 ago. Keith Williams explained it well.
I tried to find the thread but was unable to do so by searching for posts with his name...
Joined: Dec 2005
Posts: 41
Likes: 0
From: Canada
You're right, quite hard to find. Not much on C of P, but has AC info. Here it is, should work.
http://www.pprune.org/forums/showthr...itching+moment
http://www.pprune.org/forums/showthr...itching+moment
Thread Starter
Joined: Jan 2006
Posts: 364
Likes: 0
From: EU
You're right, quite hard to find. Not much on C of P, but has AC info. Here it is, should work.
http://www.pprune.org/forums/showthr...itching+moment
http://www.pprune.org/forums/showthr...itching+moment
Again PPRuNe proves to be the place to find answers to most questions, I'm very impressed with this forum and the people here =)
