Hershey bar wing vs composite wing - how much drag?

Robert M. Gary wrote:

A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?

("Wayne Paul" wrote)
It is much easier to build a laminar flow airfoil and complex shaped
wing to fuselage transition using composite construction. These wing have
a better lift to drag ratio. The decrease in drag aerodynamic drag of
the wing and static drag decrease associated with the wing/fuselage
transition allow faster speeds.


Can you reword this (for some of us "Huh?" lurkers) especially the wing to
fuselage transition part?

How good/efficient are Cherokee, Ercoupe, Cessna (aluminum & rivet) wing
root fairings vs. what could be achieved with complex composite shapes?

Same question with the wing shape - to hold up the same plane, ALL else
being equal?

So ballpark - how much more efficient would the use of complex composite
construction (wings and wing root transition areas) make these planes - ALL
else being equal?

WAG - same power, weight, fuselage, etc - what improvements would these
planes see in speed, climb, stall, or fuel burn numbers?

Thanks.


Montblack

On Mar 28, 12:30 pm, Blanche wrote:
Robert M. Gary wrote:



A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?

I think part of my point is that the price of the 180 and the M20C are
pretty close. I'm not sure why people choose the 180 when its a good
30 knots slower on the same fuel burn.

-Robert

Robert M. Gary wrote:
On Mar 28, 12:30 pm, Blanche wrote:
Robert M. Gary wrote:



A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?

I think part of my point is that the price of the 180 and the M20C are
pretty close. I'm not sure why people choose the 180 when its a good
30 knots slower on the same fuel burn.

-Robert

I agree with you but I'd bet insurance and the cost of up keep added because
of the retrac gear has a lot to do with it.

On 03/28/07 14:19, Gig 601XL Builder wrote:
Robert M. Gary wrote:
On Mar 28, 12:30 pm, Blanche wrote:
Robert M. Gary wrote:



A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?

I think part of my point is that the price of the 180 and the M20C are
pretty close. I'm not sure why people choose the 180 when its a good
30 knots slower on the same fuel burn.

-Robert

I agree with you but I'd bet insurance and the cost of up keep added because
of the retrac gear has a lot to do with it.



Not to mention I could fit in a 180, but not a Mooney (although that is
changing...)

"Montblack" wrote in message
...
("Wayne Paul" wrote)
It is much easier to build a laminar flow airfoil and complex shaped
wing to fuselage transition using composite construction. These wing
have a better lift to drag ratio. The decrease in drag aerodynamic drag
of the wing and static drag decrease associated with the wing/fuselage
transition allow faster speeds.


Can you reword this (for some of us "Huh?" lurkers) especially the wing to
fuselage transition part?

How good/efficient are Cherokee, Ercoupe, Cessna (aluminum & rivet) wing
root fairings vs. what could be achieved with complex composite shapes?

Same question with the wing shape - to hold up the same plane, ALL else
being equal?

So ballpark - how much more efficient would the use of complex composite
construction (wings and wing root transition areas) make these planes -
ALL else being equal?

WAG - same power, weight, fuselage, etc - what improvements would these
planes see in speed, climb, stall, or fuel burn numbers?

Thanks.


Montblack

Let me make this as simple as possible by simply giving you an example. My
HP-14 (http://www.soaridaho.com/Schreder/N990_Borah_Mt.JPG) has a 52 foot
wingspan. The wings were built with flush rivets and have been smoothed by
adding an epoxy/balloon mixture. This is mid 1960 construction techniques
using aluminum construction. My lift to drag ratio is around 36 to 1.
However, new modern sailplanes with composite construction and modern
airfoils that only have 15 meter (just under 50 feet) wingspan have glide
ratios of around 48 to 1.

So with both of my old HP-14 and an ASW-27 (http://tinyurl.com/8lecz) loaded
to have a gross weight of 800 lbs. At best glide speed my HP-14 would have
about 22 lbs of drag while the ASW-27 would have less then 17 lbs of drag..
So the ASW-27 is 30% more efficient then my 14. If my wings did not have
flush rivets and were not smoothed the difference would be even greater.

The same is true with power aircraft. Just compare the Flight Design CT
(http://www.flightdesignusa.com/) with a Cessna 152 or a Cirrus with any
earlier conventionally constructed aircraft of similar weight and
horsepower.

To take these in steps, the wing is the most important, the fuselage shape
is also important and the junction between the wing and fuselage. I am
familiar with a smooth wing metal sailplane that was re-winged with a modern
airfoil. The new wing, has the same area and span. The original
wing/fuselage combination produced a 38 to 1 glide ratio. The updated
combination produced a 42 to 1 glide ratio. That is a 10 percent
improvement. Going from a round riveted wing to a modern airfoil should
provide a 15+% improvement.

Wayne
HP-14 "6F"

"BobR" wrote in
ups.com:

On Mar 28, 12:40 pm, Alphonse Le Creur wrote:
"BobR" wrote in
news:1175092590.355514.234030 @y80g2000hsf.googlegroups.com:







On Mar 28, 8:51 am, Nathan Young
wrote:
I have a Cherokee 180, with the short hershey bar wing. While I
love the plane, I always wish it could go a bit faster, or use a
bit less fuel to get to my destination.

I have followed the composite homebuilding movement for many
years, and am amazed at the sleekness of a composite wing. The
wings on
most
composites tend to be the complete opposite of a Hersey bar wing:
high aspect ratio, low thickness, no rivets, no screws for fuel
tanks,smooth curves faired into airframe, and streamlined landing
gear
structure.

So my question: How much drag does a wing on a Hersey Bar
Cherokee generate, and and hypothetically speaking, how much
faster could the plane go if it was retooled with a sleek,
composite wing?

I can't remember if it was Kitplanes or SportAviation that had a
recent article on a Piper knockoff being produced as a kitplane in
South Africa. That might be a good starting point for the
difference in performance between the different planes as well as a
discussion of the differences in design and construction. Much of
the difference has to do with better airfoil designs being used but
also weight differences.

Well, that airplane is "inspired" by the Commanche and it's really
just comparing apples and oranges since there are so many other
differences in the two airplanes, but having said that, it's better
than comparing a cherokee to a Cozy, for instance..

In any case, the Ravin Commanche is
herehttp://www.saravin.com/review.htm

ALC- Hide quoted text -

- Show quoted text -

It's about as close a comparison as can be made. I am building the
KIS Cruiser which uses a hershey bar style wing as well but the
airfoil is different. The comparison from a performance standpoint is
much faster than the Commanche for the same power (180 hp). The
difference must be attributed to several differences beyond just the
wing, weight being the most obvious.

Well, the Ravin is actually a couple hundred pounds heavier than the
original Commanche empty and has a higher gross. It also has a much
smaller fuselage cross section.
I'm certainly not saying that the Ravin is not a better airplane. It is.
I'd sure like to have one! I'm just saying that while it is probably one
of the better comparisons, no absolute conclusion may be made from it.
There's too many other things going on there. The Commanche uses what
was a then state of the art NACA 6 series laminar flow airfoil. It was
streets ahead of what was on any lightplane of the time, but it's use
was most probably not dictated by the material of which it was made. I
have no idea what the Ravin is using for an airfoil.
If Piper were to set out to make the same airplane again today using
aluminum for the wing, they could still build a more efficient wing than
they did in the fifties by simple virtue of the fact that fifty years
later there's been quite a lot of innovation in airfoils, structures and
what not. Again, I'm not saying that the Ravin isn't a better airplane,
nor am I denying that composites might be a better way to build an
airplane, just saying (at the risk of flogging the proverbial dead
horse) that the comparison , while it is as good as you're going to get,
is still flawed.


ALC

Blanche wrote in news:1175110215.538586
@irys.nyx.net:

Robert M. Gary wrote:

A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?


Well there was an article about a guy in Sport Aviation a few years ago
who had his 140 cruising at some insane airspeeds. He had a 160 engine
in it IIRC, but more importantly he had done a lot of mods to the
airframe, particularly wingtips, vortice generators and fairings for the
gear, flap hinges and so on. Each mod multiplied the good of the other
mods, of course, so he was happily whistling along at speeds that were
simply amazing. As far as I know, he does sell the STCs he got for the
airplane, but I couldn't find him wiht a quick search. I think he was in
SA about three years ago but the wife will kill me if I pull the pile
out and go through it in the living room again. I'll post it if i see
it.


ALC

Mark Hansen wrote in
:

On 03/28/07 14:19, Gig 601XL Builder wrote:
Robert M. Gary wrote:
On Mar 28, 12:30 pm, Blanche wrote:
Robert M. Gary wrote:



A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?

I think part of my point is that the price of the 180 and the M20C
are pretty close. I'm not sure why people choose the 180 when its a
good 30 knots slower on the same fuel burn.

-Robert

I agree with you but I'd bet insurance and the cost of up keep added
because of the retrac gear has a lot to do with it.



Not to mention I could fit in a 180, but not a Mooney (although that
is changing...)


What, you're on a diet?


Furry

On Mar 28, 2:27 pm, Mark Hansen wrote:
On 03/28/07 14:19, Gig 601XL Builder wrote:





Robert M. Gary wrote:
On Mar 28, 12:30 pm, Blanche wrote:
Robert M. Gary wrote:

A fast Cherokee is also known as a Mooney C model.

Hm...I always thought "fast cherokee" was an oxymoron...

And yes, I own a cherokee 180. Would I like faster? Sure! Wouldn't
everyone?

I think part of my point is that the price of the 180 and the M20C are
pretty close. I'm not sure why people choose the 180 when its a good
30 knots slower on the same fuel burn.

-Robert

I agree with you but I'd bet insurance and the cost of up keep added because
of the retrac gear has a lot to do with it.

Not to mention I could fit in a 180, but not a Mooney (although that is
changing...)- Hide quoted text -

- Show quoted text -

You do have to be a bit tall to fly a Mooney. I'm 6'4" and fit fine
but my partner is 5'10" and has a tough time reaching the rudders.

-Robert