reynolds number

"Brian Whatcott" wrote

I could even go a little further: if you get yourself in a situation when
you have to deploy your considerable engineering skills in evaluating Re,
it is because you forgot to use your even more considerable judgment is
selecting well-liked, useful, relevent airfoils.

:-)
Amen!

Ya define the mission, and how fast you think you will go and look at the
list of airfoils used on airplanes of similar speed and mission. That makes
airfoil choice a real choice.
--
Jim in NC

Morgans schreef:


"Brian Whatcott" wrote

I could even go a little further: if you get yourself in a situation
when you have to deploy your considerable engineering skills in
evaluating Re, it is because you forgot to use your even more
considerable judgment is selecting well-liked, useful, relevent airfoils.

:-)
Amen!

Ya define the mission, and how fast you think you will go and look at
the list of airfoils used on airplanes of similar speed and mission.

And that's the lines along which I was thinking, until this Reynolds
thing crossed my way. My gratitude to all who responded, I have received
a powerful lot to put under my thinking cap for the next couple of
weeks/months/years

KA

On Sat, 27 Jun 2009 17:43:27 -0400, "Morgans"
wrote:



"Brian Whatcott" wrote

I could even go a little further: if you get yourself in a situation when
you have to deploy your considerable engineering skills in evaluating Re,
it is because you forgot to use your even more considerable judgment is
selecting well-liked, useful, relevent airfoils.

:-)
Amen!

Ya define the mission, and how fast you think you will go and look at the
list of airfoils used on airplanes of similar speed and mission. That makes
airfoil choice a real choice.

....and then you look at mark langford's web site and pick the aerofoil
according to thickness. ...from the list of excellent aerofoils
developed for the KR2S on his web site. :-)

you dont have to be correct or competent to design an aeroplane.
you stand the chance of designing a damn site better one though if you
are. having experience and attitude sometimes gets you there.
competence can mire you in decisions and see you achieve nothing.

Why is the Wittman W8 tailwind still a standout in the efficiency
figures?

Stealth Pilot

"Stealth Pilot" wrote

Why is the Wittman W8 tailwind still a standout in the efficiency
figures?

Seems to me that it has a few things that keep it on top.

See if you think I am on the right track.

The shapes used in the fuselage and anything that is sticking out in the wind
are all good aerodynamic tradeoffs of slippery and light.

The basic shape of the fuselage is good for contributing to the lift of the
aircraft, more than most other designs. Probably the most important feature of
the design, in my eyes.

Attention is always on making structures easy to build light and no extra weight
is there that does not contribute to lightness.

The airfoil and fuselage are light enough and slippery enough to be powered by a
small engine, so extra engine weight and fuel weight does not have to be carried
around, which allows the structures to be built more lightly. It is sort of a
good circle that keeps weight down, versus the other circle that keeps growing
the weight of the aircraft.

How did I do? g
--
Jim in NC

On Tue, 21 Jul 2009 00:40:21 -0400, "Morgans"
wrote:


"Stealth Pilot" wrote

Why is the Wittman W8 tailwind still a standout in the efficiency
figures?

Seems to me that it has a few things that keep it on top.

See if you think I am on the right track.

The shapes used in the fuselage and anything that is sticking out in the wind
are all good aerodynamic tradeoffs of slippery and light.

The basic shape of the fuselage is good for contributing to the lift of the
aircraft, more than most other designs. Probably the most important feature of
the design, in my eyes.

Attention is always on making structures easy to build light and no extra weight
is there that does not contribute to lightness.

The airfoil and fuselage are light enough and slippery enough to be powered by a
small engine, so extra engine weight and fuel weight does not have to be carried
around, which allows the structures to be built more lightly. It is sort of a
good circle that keeps weight down, versus the other circle that keeps growing
the weight of the aircraft.

How did I do? g

pretty damn good.