questions on multi-wing planforms

Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small 4
wing aircraft. Not stacked, but two up front and two in the rear. I have
read frequently of problems supposedly resulting from interference of the
airflow between wings, but I can't seem to find anything very specific. I'm
fairly confident that interference between the front wings (or rear) can be
minimized by reasonable spacing and differing dihedral. I'm not sure what
the effect of the airflow coming off the front wings will have on the rear
set. I don't know whether I could remove most of the problem by having one
set considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height. The reason for
the concept is trying to get a wingspan small enough to fit into a normal
garage and conceivably take off and land from streets and highways. I
visualise something in a two place plane that would fall into something of
the appeal category of a motorcycle or small sports car. Any thoughts would
be appreciated.

Gerry

pTooner wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small 4
wing aircraft. Not stacked, but two up front and two in the rear. I have
read frequently of problems supposedly resulting from interference of the
airflow between wings, but I can't seem to find anything very specific. I'm
fairly confident that interference between the front wings (or rear) can be
minimized by reasonable spacing and differing dihedral. I'm not sure what
the effect of the airflow coming off the front wings will have on the rear
set. I don't know whether I could remove most of the problem by having one
set considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height. The reason for
the concept is trying to get a wingspan small enough to fit into a normal
garage and conceivably take off and land from streets and highways. I
visualise something in a two place plane that would fall into something of
the appeal category of a motorcycle or small sports car. Any thoughts would
be appreciated.

Gerry



Go from 4 to 1.
The Dyke Delta JD-2 will fold up to fit in a one car garage. And it is
designed to be towed behind a car on it's own wheels; though, some have
had issues with getting trailer tags to do it legally.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

pTooner wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small 4
wing aircraft. Not stacked, but two up front and two in the rear. I have
read frequently of problems supposedly resulting from interference of the
airflow between wings, but I can't seem to find anything very specific. I'm
fairly confident that interference between the front wings (or rear) can be
minimized by reasonable spacing and differing dihedral. I'm not sure what
the effect of the airflow coming off the front wings will have on the rear
set. I don't know whether I could remove most of the problem by having one
set considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height. The reason for
the concept is trying to get a wingspan small enough to fit into a normal
garage and conceivably take off and land from streets and highways. I
visualise something in a two place plane that would fall into something of
the appeal category of a motorcycle or small sports car. Any thoughts would
be appreciated.

Gerry
Look up "Monk Factor"!

"pTooner" wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small
4 wing aircraft. Not stacked, but two up front and two in the rear.
I have read frequently of problems supposedly resulting from
interference of the airflow between wings, but I can't seem to find
anything very specific.

Theory of biplanes might provide the theoretical basis. My copy of
"Theoretical Aerodynamics" by L. M. Milne-Thomson discusses wing
interference between the wings of biplanes in chapter 8. (It's a Dover
publication, so it is still in print and inexpensive.)

Also, try a Google search on this set of search words (with or without
the search word "stagger"):
aerodynamic gap biplanes

I'm fairly confident that interference
between the front wings (or rear) can be minimized by reasonable
spacing and differing dihedral.

Staggering the wings tends to help reduce interference also.

I'm not sure what the effect of the
airflow coming off the front wings will have on the rear set. I don't
know whether I could remove most of the problem by having one set
considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height.

I suspect having one set high that the other would equivalent to a large
staggering angle.

The reason
for the concept is trying to get a wingspan small enough to fit into a
normal garage and conceivably take off and land from streets and
highways. I visualise something in a two place plane that would fall
into something of the appeal category of a motorcycle or small sports
car. Any thoughts would be appreciated.

If you are not already familiar with it, you should browse this site,
which include planes that attempt to satisfy some of your requirements
(the Wernicke Aircar uses low aspect ratio wings to try to meet some of
your requirements):
http://www.roadabletimes.com/

"Ernest Christley" wrote in message
...
pTooner wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small 4
wing aircraft. Not stacked, but two up front and two in the rear. I
have read frequently of problems supposedly resulting from interference
of the airflow between wings, but I can't seem to find anything very
specific. I'm fairly confident that interference between the front wings
(or rear) can be minimized by reasonable spacing and differing dihedral.
I'm not sure what the effect of the airflow coming off the front wings
will have on the rear set. I don't know whether I could remove most of
the problem by having one set considerably higher (how much?) than the
other set or if it is reasonable to have them on more or less the same
height. The reason for the concept is trying to get a wingspan small
enough to fit into a normal garage and conceivably take off and land from
streets and highways. I visualise something in a two place plane that
would fall into something of the appeal category of a motorcycle or small
sports car. Any thoughts would be appreciated.

Gerry

Go from 4 to 1.
The Dyke Delta JD-2 will fold up to fit in a one car garage. And it is
designed to be towed behind a car on it's own wheels; though, some have
had issues with getting trailer tags to do it legally.

I'm familiar with the plane, and it is reputed to be very difficult and
lengthy to build.

Gerry

"ELIPPSE" wrote in message
oups.com...

pTooner wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small 4
wing aircraft. Not stacked, but two up front and two in the rear. I
have
read frequently of problems supposedly resulting from interference of the
airflow between wings, but I can't seem to find anything very specific.
I'm
fairly confident that interference between the front wings (or rear) can
be
minimized by reasonable spacing and differing dihedral. I'm not sure
what
the effect of the airflow coming off the front wings will have on the
rear
set. I don't know whether I could remove most of the problem by having
one
set considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height. The reason for
the concept is trying to get a wingspan small enough to fit into a normal
garage and conceivably take off and land from streets and highways. I
visualise something in a two place plane that would fall into something
of
the appeal category of a motorcycle or small sports car. Any thoughts
would
be appreciated.

Gerry
Look up "Monk Factor"!

In quotes that term doesn't bring any reponse in google. Without quotes it
brings an unmanageable amount but doesn't appear to have anything to do with
aerodynamics. Can you elaborate a bit?
Gerry

All very helpful and interesting stuff. Thanks a lot.
Gerry
"Jim Logajan" wrote in message
.. .
"pTooner" wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small
4 wing aircraft. Not stacked, but two up front and two in the rear.
I have read frequently of problems supposedly resulting from
interference of the airflow between wings, but I can't seem to find
anything very specific.

Theory of biplanes might provide the theoretical basis. My copy of
"Theoretical Aerodynamics" by L. M. Milne-Thomson discusses wing
interference between the wings of biplanes in chapter 8. (It's a Dover
publication, so it is still in print and inexpensive.)

Also, try a Google search on this set of search words (with or without
the search word "stagger"):
aerodynamic gap biplanes

I'm fairly confident that interference
between the front wings (or rear) can be minimized by reasonable
spacing and differing dihedral.

Staggering the wings tends to help reduce interference also.

I'm not sure what the effect of the
airflow coming off the front wings will have on the rear set. I don't
know whether I could remove most of the problem by having one set
considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height.

I suspect having one set high that the other would equivalent to a large
staggering angle.

The reason
for the concept is trying to get a wingspan small enough to fit into a
normal garage and conceivably take off and land from streets and
highways. I visualise something in a two place plane that would fall
into something of the appeal category of a motorcycle or small sports
car. Any thoughts would be appreciated.

If you are not already familiar with it, you should browse this site,
which include planes that attempt to satisfy some of your requirements
(the Wernicke Aircar uses low aspect ratio wings to try to meet some of
your requirements):
http://www.roadabletimes.com/

"Jim Logajan" wrote in message
.. .
"pTooner" wrote:
Firstly, I am new here although I've been reading for a few days. For
anyone with more knowledge than I, I keep considering building a small
4 wing aircraft. Not stacked, but two up front and two in the rear.
I have read frequently of problems supposedly resulting from
interference of the airflow between wings, but I can't seem to find
anything very specific.

Theory of biplanes might provide the theoretical basis. My copy of
"Theoretical Aerodynamics" by L. M. Milne-Thomson discusses wing
interference between the wings of biplanes in chapter 8. (It's a Dover
publication, so it is still in print and inexpensive.)

Also, try a Google search on this set of search words (with or without
the search word "stagger"):
aerodynamic gap biplanes

I'm fairly confident that interference
between the front wings (or rear) can be minimized by reasonable
spacing and differing dihedral.

Staggering the wings tends to help reduce interference also.

I'm not sure what the effect of the
airflow coming off the front wings will have on the rear set. I don't
know whether I could remove most of the problem by having one set
considerably higher (how much?) than the other set or if it is
reasonable to have them on more or less the same height.

I suspect having one set high that the other would equivalent to a large
staggering angle.

The reason
for the concept is trying to get a wingspan small enough to fit into a
normal garage and conceivably take off and land from streets and
highways. I visualise something in a two place plane that would fall
into something of the appeal category of a motorcycle or small sports
car. Any thoughts would be appreciated.

If you are not already familiar with it, you should browse this site,
which include planes that attempt to satisfy some of your requirements
(the Wernicke Aircar uses low aspect ratio wings to try to meet some of
your requirements):
http://www.roadabletimes.com/

I am getting lots of good info from the sources you recommend and I'll try
the book store tomorrow for that book. If they don't have it I'll go to
Amazon. My basic concept/question is like this. Assuming optimum airfoil
in each case which may well be different; I could build a 20ft span 4 ft
chord wing for 80sqft or two 20span 2 ft chord or 4 10ft span 2 foot chord
and they all equal the same area. What would be their relative lift and
drag numbers? (probably pretty close) BUT would they have strange
characteristics at odd angles of attack? (That is a semi-rhetorical
question)

Gerry

"pTooner" wrote in message
.. .

"Ernest Christley" wrote in message
...

snip


I'm familiar with the plane, and it is reputed to be very difficult and
lengthy to build.

Gerry

Not compared to designing, building, and testing a unique design with an odd
planform...

KB

"Kyle Boatright" wrote in message
news

"pTooner" wrote in message
.. .

"Ernest Christley" wrote in message
...

snip


I'm familiar with the plane, and it is reputed to be very difficult and
lengthy to build.

Gerry

Not compared to designing, building, and testing a unique design with an
odd planform...

KB

Welllll, I guess I can't argue with that. G
Gerry