Horton Wings a poor wing, try the Marske concept.
Matthew Redsell
high drag, have a poor spar shape, have poor airflow over the airfoil.
All these factors contribute to spins and stalls. A much easier solution
is a straight wing (or slightly forward), no washout and a good stable
airfoil. Jim Marske has done it for over 30 years... and going strong!
One flight on a monarch is all you need to be convinced... ask Dave
Wells.
The Markse flying wing will not stall because the airflow separates at
the trailing edge making the elevator less effective at high angles of
attack. The wing then decreases the pitch picks up speed and then pulls
the nose back up. And there is no drag associated with this elevator on
the trailing edge of the wing . It also increases the reynolds numbers!
And you say that one cannot get the Cl..... well we have up to date
airfoils and this is now possible. One of the appealing things about
these wings is the low drag.
There are no bad habits in a Marske Wing. -mat
--
Matthew J. Redsell <cont...@continuo.com>
CONTINUO 1-800-231-2489
Marske Flying wings <http://www.continuo.com/marske>
Windrose Website: <http://www.continuo.com/windrose/windrose.htm>
Phone outside North America 607-569-2489
Fax: 607-569-2776
Emilis Prelgauskas
Wings
in which all model and sailplane types to date are reviewed.
The book traces some of the work done on the SB-13, and why its planform
etc. evolved.
Emilis
Angelomant
>Flying wing technology is revisited in a german book simply called >Flying
Wings in which all model and sailplane types to date are >reviewed.
Where can I get it? Who's the author? Thanks for the info.
Angelo Mantas
Angel...@aol.com
Angelo Mantas
Al Bowers
angel...@aol.com (Angelomant) writes:
> Emilis wrote;
>
> >Flying wing technology is revisited in a german book simply called Flying
> >Wings in which all model and sailplane types to date are reviewed.
> Where can I get it? Who's the author? Thanks for the info.
In the USA the book is published by the AIAA. The three most useful
books are probably:
"Tailless Aircraft in Theory and Practice"
by Karl Nickel and Michael Wohlfhart (Translated by Eric Brown).
"Nurflugel: Die Geschichte der Horten-Flugzeuge 1933-1960
by Reimar Horten and Peter F Selinger (Translated by Jan Scott).
"The Horten Brothers and Their All Wing Aircraft"
by David Myhra.
It should be noted that something of a "blood feud" existed betwen Dr
Nickel and Dr Horten for the last 40 years of Horten's life. And I
believe this division is due to Dr Nickel's view that superior
performance was available through the use of vertical surfaces
(specifically winglets). Similar divisions occur amongst others of
the Horten's followers. Dr Nickel was one of the mathmaticians
working for the Hortens during WWII (Dr Nickel is married to Gunhilde
Horten, Reimar's, Walter's and Wolfram's sister). Dr Nickel
critisizes the Hortens for never solving the adverse yaw problem, and
I believe Dr Edward Udens has found the solution which the Hortens
lacked. Dr Udens' solution is in the design of the elevon control
system. The elevons need to locate as much area outboard near the tip
as is possible. Because the Hortens used inboard elevons, their
designs would always exhibit adverse yaw. By extending the work of
Horten and Udens, I found that the adverse yaw will always arise given
a sufficiently low lift coefficient (high enough speed).
unfortunately, this is where directional stability also decreases,
making any adverse yaw more apparent and difficult to accept (these
results were based on Udens' U20 design, and my work on the Horten
Piernifero III H Xc design).
As for claims that high taper ratios cause stall'spin problems, it
should be noted that none of the Horten's aircraft (with a single
exception) had any tendency to stall/spin (the exception was the H IVb
which used an airfoil which resulted in stall at the tips). The
aircraft simply "mush" forward in controlled flight post-stall.
None of this should be taken to to assume that the flying qualities of
Horten sailplanes were exemplary. In fact the aeroelastic problems
caused large couplings between the pilot and the aircraft (very PIO
prone). Modern materials would solve this problem.
Jim Marske's designs deserve a comment. Jim's designs appears to have
solved a number of flying wing problems. Someone should take it upon
themselves to fully analyze a Marske design and evaluate it
independently. Because just as the Horten designs have solved the
problem of stall/spin with high taper ratios and sweep, so likewise
has Marske solved the problem of non-minimum phase control in planks
with his flying wings (always the most critical problem in Fauvel
flying wings). IMHO.
Al Bowers