vance wrote:

slower, and burns less fuel at any given airspeed.  For that kind of result,
I'll trash the NACA study and never look back.

BIG SNIP

Again all this  this is highly configuration sensitive.
It is well known that a mid wing on a round fuselage has less interference
drag than a low wing on a slab sided fuselage. As I recall a high wing
on a slab sided fuselage is better than a low or mid wing.

Paul Lamar

Dale Smith wrote:

I personally believe that this will be a moot point in the future.  Blended Wing Body
designs, utilize a smooth transition from wing to fuselage ... no interference drag
whatsoever ... the "lifting body" just blends into wing ... very elegant ... very low drag.

check http://www.wingco.com for an upcoming kit. (No financial interest, but I do follow
their list).

Dale Smith

Martin built a cool looking blended wing body back about the end of WW II.
I wonder why it never caught on. It is a natural with composites.

Paul Lamar

IMHO - The blended wing will fade away - The primary advantage is that
it looks sexy - Tailless aircraft (and front tail aircraft) have the
strong disavantage in that they cannot usefully apply lift enhancing
devices - ie flaps etc without complex center of lift correction (ie the
variable sweep canard on the not very successful Starship). Therefor the
wing area is increased, increasing skin friction, and negating the
supposed drag improvement. The blended wing does not lend itself to
pressurization, and passenger windows (like sitting in the center of a
747 squared).

As Paul indicated passenger planes fly near max Cl at altitude, and
probably utilize pretty massive pitch corrections with their full flying
horizontals.
The wing root fairing question has as many varied advocates and theories
as the perpetual wing tip battle, and the answer is probably the same.
"doing nothing is usually beter than doing something wrong". Definately
avoid intersections sharper than 90 degrees - which round fuselages on
low wings do - and do correct with some success with fillets (ie
Lancairs)
 Vance

It is a long climb up the isle to the john  in a 747 during early phases
of the flight :-)

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org