original canard airfoil & VG's vs using the NASA LS(1)-0417 MOD


Doug Fortune <pentam@...>
 

A newbie question:

This rain & bug problem with the original Glasgow University
GU25-5(11)8 airfoil canard was supposed to be fixed with
the new 1981 NASA LS(1)-0417 MOD airfoil. (See Homebuilt
Aircraft Magazine March 1984 page 34).

Is this not the case? If it is the fact that the second airfoil
(or perhaps an even more recent one) fixes such a hazardous
problem (never mind the benefits of less drag), why don't
people abandon the bandaids and do "the correct thing"?

Or should I assume that anyone today building Quickies
does use the NASA canard airfoil, and the only people
discussing the VG (vortex generators) are the people who
have decided against building new canards for their older
Quickies?

Doug


Hot Wings
 

In a message dated 10/1/00 8:29:20 AM Mountain Daylight Time, pentam@...
writes:

<< Is this not the case? If it is the fact that the second airfoil
(or perhaps an even more recent one) fixes such a hazardous
problem (never mind the benefits of less drag), why don't
people abandon the bandaids and do "the correct thing"?

Or should I assume that anyone today building Quickies
does use the NASA canard airfoil, and the only people
discussing the VG (vortex generators) are the people who
have decided against building new canards for their older
Quickies? >>
====================================
I think the analogy of make-up vs plastic surgery is a better one here
than a Band-Aid. There are lots of Q's built and probably still being built
with the "old" canard and if all it takes is a little make-up (VG's) to make
it pretty then maybe this is the best way to go.
If you are going to start fresh then the "new" canard is the one to use
(and even this in my opinion is a Band-Aid, (but that is a matter for another
discussion) but the only readily available plans use the pre-made carbon
fiber spars and they are getting hard and harder to find. You could try to
make them yourself but unless you are a better than average builder you
probably won't end up with anything useable. It takes very good control of
fiber orientation and resin/fiber ratio to take full advantage of this
material and this doesn't even take into consideration that there is a lot of
"surplus" fabric floating around that is not compatible with the resin
systems most homebuilders might use. Without this level of quality control
you might as well use standard "E" glass.

"Think outside the box - but fly in the envelope"
<A HREF="http://hometown.aol.com/bd5er/Qpage.html">Q-2 page</A>
Leon McAtee


Dave King <KingDWS@...>
 

Is this not the case? If it is the fact that the second airfoil
(or perhaps an even more recent one) fixes such a hazardous
problem (never mind the benefits of less drag), why don't
people abandon the bandaids and do "the correct thing"?
The GU airfoil isn't quite the dead dog you think it is. Compared
to the alternative airfoils it actually has some advantages. A properly
built shaped and finished GU will actually produce more lift with
far less drag than the others. The problem is of course it is sensative
to dead bugs and rain. The two easy fixes I know about were
simply a matt sanded finish, and VG generators. If you look at some
other threads some people have information that a coat of wax will
cure it as well. If these are bandaid fixes they definatly are cheaper than
building a new canard and control system. You don't throw out a set of
tires because they need air...?

The following are numbers from windtunnel runs. The first is the GU, the
second
was another canard airfoil, Third is Roncz 1145RM, 4th is the LS, and
the last is the Amsoil racer airfoil. The first set of data is the airfoil
in a cruise
attitude (sort of anyway), the second set shows the results of deflecting the
elevator 15°.

Airfoil Lift Drag Moment
Gu 0.9857 0.0057 -0.1189
UA79S 0.9635 0.0071 -0.1503
1145RM 0.7417 0.0084 -0.0551
LS417M 0.8598 0.0094 -0.1078
Amsoil 0.6036 0.0098 -0.0559

25% Chord Flap deflected 15°
Airfoil Lift Drag Moment
Gu 2.119 0.0060 -0.3174
UA79S 2.105 0.0192 -0.3618
1145RM 2.075 0.0132 -0.2657**
LS417M 2.015 0.0133 -0.3040
Amsoil 1.746 0.0187 -0.2593

**33% chord


Constants:
3° alpha
1500000 Reynolds
27" Chord
Std Temp/Pressure etc etc.

As you can see the GU actually holds it own when compared to the others. I
was kinda suprised to see how well. The NLF/GAW and Roncz have thier own
quirks. They generate much higher control loads onto structure etc. The
1145 will produce
a slightly higher ultimate lift compared to the GU which means you can use
a smaller
canard to compensate but it won't be drastically faster.


Dave


Sam Hoskins <shoskins@...>
 

Doug,

It boils down to this:

Old GU canard; install vortex generators.

New LS canard, vortex generators are not required.

Some people are still installing the GU canards for various reasons, but
it's best to get the LS. If you have to spend a grand or so for a set of
carbon spars, get 'em.


Sam Hoskins,
Lots of years and hours in my LS Q-200



Doug Fortune wrote:

A newbie question:

This rain & bug problem with the original Glasgow University
GU25-5(11)8 airfoil canard was supposed to be fixed with
the new 1981 NASA LS(1)-0417 MOD airfoil. (See Homebuilt
Aircraft Magazine March 1984 page 34).

Is this not the case? If it is the fact that the second airfoil
(or perhaps an even more recent one) fixes such a hazardous
problem (never mind the benefits of less drag), why don't
people abandon the bandaids and do "the correct thing"?

Or should I assume that anyone today building Quickies
does use the NASA canard airfoil, and the only people
discussing the VG (vortex generators) are the people who
have decided against building new canards for their older
Quickies?

Doug


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Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://web2.airmail.net/qba321tm/q-page1.html


L Koutz <koutzl@...>
 

Doug
There is nothing wrong with the Gu25 WITH VG's.
It is a cheap and easy fix to loss of laminar flow that occcurs with any
debris on the canard.
From my viewpoint you either have the VG's or you are going to scare
yourself -REALLY BAD sometime or other flying with that wing. There is
nothing sacred with placement. I have seen the VG's several places,
different spacing, size etc. Some people are discussing that subject. And
there is a "recommended" place for them. But these planes ARE called
Experimental so adventuresome individuals try different placements. Nuff
said, but just my opinion ( and 15 years of listening) as I don't own one
and have never flown one.

The LS-1 is different.
It does not need VG's to fly OK.
But I am trying to fix a problem that most drivers don't even know they
have. In my plane there is a loss of lift from the top of the elevator when
the elevator goes down even the least little bit. I figure if I can get the
lift back I can land slower, and GOD knows we could use a plane that lands
slower. Plane flys OK but I want more. It's not a problem.
It's just that a few of us want to know how the airflow is traveling over
the canard and don't really know how to figure it out and really all the
canards are similar but not EXACTLY the same so everyone's flows are
slightly different. Anyway, it is not a PROBLEM. We are just trying to
figure airflow out for optimum speed. We are Experimenting! Just my
thoughts.
Larry

----- Original Message -----
From: "Doug Fortune" <pentam@...>
To: <Q-LIST@...>
Sent: Saturday, September 30, 2000 10:20 PM
Subject: [Q-LIST] original canard airfoil & VG's vs using the NASA
LS(1)-0417 MOD


A newbie question:

This rain & bug problem with the original Glasgow University
GU25-5(11)8 airfoil canard was supposed to be fixed with
the new 1981 NASA LS(1)-0417 MOD airfoil. (See Homebuilt
Aircraft Magazine March 1984 page 34).

Is this not the case? If it is the fact that the second airfoil
(or perhaps an even more recent one) fixes such a hazardous
problem (never mind the benefits of less drag), why don't
people abandon the bandaids and do "the correct thing"?

Or should I assume that anyone today building Quickies
does use the NASA canard airfoil, and the only people
discussing the VG (vortex generators) are the people who
have decided against building new canards for their older
Quickies?

Doug





To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://web2.airmail.net/qba321tm/q-page1.html




Ed MacLeod <ed@...>
 

Thanks Dave for the GU lesson. Good stuff.

Ed m


Michael D. Callahan <micallahan@...>
 

Yeah, those original spars were filament wound on a lathe... not exactly
home shop machinery! Mike C.

----- Original Message -----
From: <BD5ER@...>
To: <Q-LIST@...>
Sent: Sunday, October 01, 2000 10:37 AM
Subject: Re: [Q-LIST] original canard airfoil & VG's vs using the NASA
LS(1)-0417 MOD


In a message dated 10/1/00 8:29:20 AM Mountain Daylight Time,
pentam@...
writes:

<< Is this not the case? If it is the fact that the second airfoil
(or perhaps an even more recent one) fixes such a hazardous
problem (never mind the benefits of less drag), why don't
people abandon the bandaids and do "the correct thing"?

Or should I assume that anyone today building Quickies
does use the NASA canard airfoil, and the only people
discussing the VG (vortex generators) are the people who
have decided against building new canards for their older
Quickies? >>
====================================
I think the analogy of make-up vs plastic surgery is a better one here
than a Band-Aid. There are lots of Q's built and probably still being
built
with the "old" canard and if all it takes is a little make-up (VG's) to
make
it pretty then maybe this is the best way to go.
If you are going to start fresh then the "new" canard is the one to
use
(and even this in my opinion is a Band-Aid, (but that is a matter for
another
discussion) but the only readily available plans use the pre-made carbon
fiber spars and they are getting hard and harder to find. You could try
to
make them yourself but unless you are a better than average builder you
probably won't end up with anything useable. It takes very good control
of
fiber orientation and resin/fiber ratio to take full advantage of this
material and this doesn't even take into consideration that there is a lot
of
"surplus" fabric floating around that is not compatible with the resin
systems most homebuilders might use. Without this level of quality control
you might as well use standard "E" glass.

"Think outside the box - but fly in the envelope"
<A HREF="http://hometown.aol.com/bd5er/Qpage.html">Q-2 page</A>
Leon McAtee


To unsubscribe from this group, send an email to:
Q-LIST-unsubscribe@...

Quickie Builders Association WEB site
http://web2.airmail.net/qba321tm/q-page1.html



Jeremy Prizevoits <JerryPrize@...>
 

Hey guy's,

I have been silently listening to the debate that is going on regarding the
GU canard and the truth is that many of your certified aircraft are covered
with " aero- dynamic fixes". For instance the Citation Excel ( which I was
the prototypes crew chief when I worked in Experimental flight test)
exhibited less than desirable stall characteristics. Also there was not
enough elevator throw to trim the aircraft and flare for landings. Back to
the wind tunnel you think right? No way, we installed a wing fence, VG's,
BLE's, strakes and my favorite after thought the two position tail that
requires a hydraulic screw that moved the tail two degrees when the flaps
were deployed for landing. The increased angle of attack gave the pilot back
the elevator throw the pilot needed. Now if you want to see a really ugly
example of what I am talking about go look at how a Lear 35 airfoil looks.
Darn airplane looks like a porcupine with all of it's fixes.
Now Larry,
For your endeavor your right on tract for the tuft's. You might want to
mount a remote camera somewhere focused on the tufted area because it is
doubtful that you will be able to watch and fly at the same time. When I
worked in flight test we time stamped the tape and the copilot and pilot
marked the maneuvers and the approximate time or so they said. The end
result though is a great visual of what the air is doing around the airfoil.
Plus making tufts out of yarn and taping them in 3" intervals is fun for the
whole family! I can't believe I use to get paid an A&P's wage to do it. If
guys are really nice I'll tell you of the joy's of breaking big pieces of
chalk into little pieces of chalk for thrust reverser testing.

See you at the Flyin

Jerrry

-----Original Message-----
From: L Koutz [mailto:koutzl@...]
Sent: Sunday, October 01, 2000 10:14 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] original canard airfoil & VG's vs using the NASA
LS(1)-0417 MOD

Doug
There is nothing wrong with the Gu25 WITH VG's.
It is a cheap and easy fix to loss of laminar flow that occcurs with any
debris on the canard.
From my viewpoint you either have the VG's or you are going to scare
yourself -REALLY BAD sometime or other flying with that wing. There is
nothing sacred with placement. I have seen the VG's several places,
different spacing, size etc. Some people are discussing that subject. And
there is a "recommended" place for them. But these planes ARE called
Experimental so adventuresome individuals try different placements. Nuff
said, but just my opinion ( and 15 years of listening) as I don't own one
and have never flown one.

The LS-1 is different.
It does not need VG's to fly OK.
But I am trying to fix a problem that most drivers don't even know they
have. In my plane there is a loss of lift from the top of the elevator when
the elevator goes down even the least little bit. I figure if I can get the
lift back I can land slower, and GOD knows we could use a plane that lands
slower. Plane flys OK but I want more. It's not a problem.
It's just that a few of us want to know how the airflow is traveling over
the canard and don't really know how to figure it out and really all the
canards are similar but not EXACTLY the same so everyone's flows are
slightly different. Anyway, it is not a PROBLEM. We are just trying to
figure airflow out for optimum speed. We are Experimenting! Just my
thoughts.
Larry