on # 1 look at JavaFoil on the WWW enter your airfoil and if you check the
box called "Include Ground Eff" it will include it on the CL/CD graph

"BllFs6" wrote in message
...
Hi all...

I know this is somewhat off topic perhaps...but maybe somebody here has
the
tidbit of info I need....

As Im sure you all know....the Lift to drag ratio of a wing goes way up
once it
gets close to ground.....and roughly speaking the effect becomes
pronounced
when the wing has an altitude on the same order as the span of the wing or
less.....

What I was looking for was:

1..... a graph that shows the L/D ratio as the wing gets closer and closer
to
the ground......anything rough will do...I found such a rough graph once a
year
or 2 ago on the internet....but I cant find it again......

2.....question.....as you approach the ground VERY closely (lets assume
your
landing gear are up AND you somehow maintain a constant forward speed AND
you
maintain the same angle of attack) does the drag GO down or does the lift
go
up?

3.....lets assume a wingspan on the order of 6 feet and a chord of 2 to 3
feet.....flying say 6 inches to a foot about the ground at
40-60mph....(yeah,
Im gonna be building the worlds fastest flying lawnmower .....what kind
of
lifting force could I reasonably expect? .....if you dont have the values
for
the ground effect itself......I could still use the numbers for "high"
altitude
values and fudge them from there to get back of the envelope ground effect
numbers....

take care all

Blll