HDTenEightyP/NetNews huggingface dataset:
From: totran@glider.lerc.nasa.gov (le tran)
Newsgroups: sci.aeronautics
Subject: Re: Mach 1 is also density dependent
Date: 16 Dec 92 17:49:12 GMT
Organization: NASA Lewis Research Center

In article <1gnia0INNnev@rave.larc.nasa.gov> turnock@eagle.larc.nasa.gov (D. L. TURNOCK) writes:
>In article <1gn95vINNq3s@usenet.INS.CWRU.Edu>, br105@cleveland.Freenet.Edu (Jeffrey A. Del Col) writes:
>> 
>> 
>> If I am not mistaken, Mach 1 is also dependent on the density of
>> the transmitting medium. Mach 1 is faster in water than in air, and it
>> is higher at lower altitudes than at higher altitudes largely because of
>> the difference in air density. 
>> \
>> 
>> J. Del Col
>> -- 
>> Jeff Del Col      *   DECONSTRUCTION--- the critical method invented      
>> A-B College       *                      by Procrustes  
>> Philippi, WV      *                             
>>                   *         
>> 
>>
>The speed of sound in any medium is
>
>						a  = SQRT(gamma*R*T)
>
>      a = speed of sound
>      gamma = ratio of specific heats - cp/cv
>      R = gas constant for particular gas
>      T = temperature (absolute)
>
>This should work for any gas
>
>Speed of sound (Mach 1) is largely used only for compressible flow.
>
>The speed of sound in a liquid or solid is at least an order of magnitude 
>greater than in a gas and is usually termed incompressible flow in which Mach
>number has no part.
>
>Hope this helps.
>
>Dave
>
>turnock@eagle.larc.nasa.gov
>
>
>
> 

    Not true. The formula 
    a  = SQRT(gamma*R*T) 
    is applied for PERFECT GAS only.

    Le
-- 
------------------------------------------------------------------------
| Le T. Tran                | email totran@glider.lerc.nasa.gov        |        
| Sverdrup Technology Inc.  | Phone (216) 826-6701                     |
| 2001 Aerospace Parkway    |                                          |
| Brook Park, OH 44142      |                                          |
------------------------------------------------------------------------
From: norton@cco.caltech.edu (Olin Perry Norton)
Newsgroups: sci.aeronautics
Subject: Hoerner's books; new address for ordering
Date: 15 Dec 1992 23:34:01 GMT
Organization: California Institute of Technology, Pasadena
Distribution: world
NNTP-Posting-Host: alumni.caltech.edu
Summary: How to order books on lift and drag by Hoerner
Keywords: Hoerner, lift, drag, books, ordering, address

Back at the beginning of November, D. Levy posted a reference
to the books on lift and drag by Hoerner, and commented that
they were apparently no longer available. [Historical note:
the author published these books privately and sold them
by direct mail order. After he died, his widow continued
selling the books.] Mail sent to her last known address
in Brick Town, New Jersey was being returned by the post office.

Well, with some help from D. Levy and Henry V. Borst (Hoerner's
co-author on one of the books), I have managed to find the
new address for ordering these books.

It is:

Hoerner Fluid Dynamics
P. O. Box 65283
Vancouver, WA 98665

Phone: 206-576-3997

The prices are $55.00 for "Fluid-Dynamic Drag"
               $54.00 for "Fluid-Dynamic Lift"
                $4.75 handling and postage for the two books

I mailed my order on November 20 and got them yesterday (December 14).

I would like to say that I have absolutely no connection, financial
or otherwise, with the sale of these books (other than being a
satisfied customer, of course).

I am posting this information as a service to the community.
If you're not familiar with them, Hoerner's books are
fantastic compilations of information about the lift
and drag coefficients of just about anything you can think
of. I had feared that they might not be available any more,
and that I had put off buying my own copies too long.

Fortunately, that is not the case and the books are still available.

-Perry Norton


Newsgroups: sci.aeronautics
From: zwork@starfighter.den.mmc.com (Michael Corvin)
Subject: F-104 (was Re: Flying Car--Innovative Lift System?)
Organization: Martin Marietta Astronautics Group
Date: Fri, 18 Dec 1992 21:14:36 GMT

If I remember the emergency procedures right, best engine-out glide speed for
the F-104G is 245KTS with the flaps (and leading edge flaps) set to the
'takeoff' position. (The flap upper surface blowing is used only at
the full down, 'landing' setting; as the flaps, which are plain flaps,
rotate down they uncover a slot in a stainless steel duct carrying
the compressor bleed air.)

Loosing the engine in the landing configuration would be very bad news
- instant wing stall.  One also has to carry close to full rpms through
touch down since chopping the throttle in the flare would drop the
plane like a rock.

In a dead-stick pattern one must have a _minimum_ 
altitude of 12,000ft AGL at the pin point (above the desired touch-down
point) to start the recommended circling approach.  There is a cute little
caution box on the diagram after the turn to final stating that one
should leave the gear up as long as possible since lowering it will increase
the rate of descent from 7,000 fpm to 13,000 fpm...

I wonder how many, if any, successful dead-stick landings of F-104s there
have been.  Possibly some out at Edwards, where there is lots of room
to come in hot, but I rather doubt that there is much chance of success under
operational conditions unless the engine failed right over an airfield with
a looong runway.

Still, an awesome machine...

-----------------------------------------------------------------------------
Michael Corvin 	      PP-ASEL, PP-G		zwork@starfighter.den.mmc.com
just another spaced rocket scientist at    Martin Marietta Astronautics Group
-----------------------------------------------------------------------------
===============    My views, not Martin Marietta's   ========================
-----------------------------------------------------------------------------
Newsgroups: sci.aeronautics,sci.environment
From: yee@atlas.arc.nasa.gov (Peter Yee)
Subject: High-flying Perseus research aircraft ready for rollout [Release 92-227] (Forwarded)
Originator: yee@atlas.arc.nasa.gov
Reply-To: yee@atlas.arc.nasa.gov (Peter Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
Date: Thu, 17 Dec 1992 01:22:30 GMT

Drucella Andersen
Headquarters, Washington, D.C.                           December 16, 1992
(Phone:  202/453-8613)

Alice Ann Toole
Aurora Flight Sciences Corp., Manassas, Va.
(Phone:  703//369-3633)


RELEASE:  92-227

HIGH-FLYING PERSEUS RESEARCH AIRCRAFT READY FOR ROLLOUT


	NASA Administrator Daniel S. Goldin will make the keynote speech
when a high-flying, unpiloted NASA atmospheric research aircraft called
Perseus is unveiled in Manassas, Va., on Dec. 18.

	When Perseus starts to fly science missions in 1994, it will gather
data to improve knowledge on the atmosphere at very high altitudes, including
the possible effect of exhaust emissions from next-generation supersonic
airliners.

	"Perseus is going to be a valuable new tool for many areas of
atmospheric research, especially understanding the processes that control
stratospheric ozone levels, so NASA and industry can produce future supersonic
transports that are both environmentally safe and economically competitive."

	Perseus, designed and built for NASA by Aurora Flight Sciences Corp.,
Manassas, Va., is the first aircraft designed specifically for atmospheric
science.  It will carry up to 110 pounds (50 kilograms) of instruments to a
maximum altitude of 82,000 feet (25 kilometers).

	Much of Perseus' technology derives from sport aviation and the record-
breaking Daedalus human-powered aircmodeled on the Daedalus design, which had
excellent aerodynamic performance.  The plane is made of lightweight composite
materials, much like sailplanes or gliders.

	Perseus' engine is based on the 4-cycle, 4-cylinder Rotax engine that
powers ultralight aircraft around the world, but is highly modified to burn a
mixture of gasoline and oxygen diluted by recirculated exhaust gas.  Aurora
developed the engine under a $500,000 NASA Small Business Innovation
Research grant.

	Perseus also is breaking new ground in other technologies like the
onboard computer which will guide many of its flights using preprogrammed
flight plans. The autopilot will keep track of the plane's location via signals
from the Global Positioning System constellation of navigation satellites.

	NASA has ordered two Perseus aircraft from Aurora Flight Sciences.
Successful research missions by the planes could lead to more general use of
advanced unpiloted aircraft for Earth science studies.

	"Perseus is not only going to do science to improve the environment,
but also is building an important new industry for the future," said Aurora
Flight Sciences President John Langford.  "It is key to a new generation of in
situ measurement platforms that will lead to discoveries in areas such as
atmospheric science, global warming and the forecasting of severe storms."
Newsgroups: sci.aeronautics
From: gale@socs.uts.edu.au (Peter Gale)
Subject: Re: TAIL ROTORS
Organization: Computing Sciences, Uni of Technology, Sydney.
Date: 17 Dec 92 04:32:46 GMT

tjgerman@53iss6.Waterloo.NCR.COM (Trevor German) writes:


>	I am an engineer and think I understand all the reasons why helos
>	have tail rotors, however, it seems to me that they may not be 
>	as nessecary as they appear. 

	Try the Sikorsky ABC aircraft, Kaman's, Russian machines,
	MDHC's MDX Explorer (1st flight this week?)...

>	these are complicated and expensive. Why not have a higher RPM 
>	ducted vertical fan driven through a gearbox on the main shaft 
>	pumping air down under the craft. The design of the fan should be
>	done in a way that makes it very viscous, that is, a lot of torque
>	required to move air.  

	In otherwords a power plant just to generate drag?...

>	This may have already been tried, or maybe I am missing something
	Then again maybe just hold the aircraft up with a skyhook. :-)
--
Peter Gale                        | Ph: 61 2 330-1686    | Sydney
Senior Systems Programmer         | gale@socs.uts.edu.au | Australia
School of Computing Sciences      | Fax: 61 2 330-1807   | ---------
University of Technology, Sydney  | --------------------------------
From: gt8303a@prism.gatech.EDU (The Great and Mighty Confused)
Newsgroups: sci.aeronautics
Subject: Re: Another "silent helo" theory. . .
Date: 15 Dec 92 02:05:14 GMT
Organization: Georgia Institute of Technology

Yes, some people (like myself) are working on an active noise control system
for many things, one of which is a helicopter.  Your summary of how it works
is pretty accurate.

Andy Entrekin
GTRI-CC/AERO (Aeroacoustics)
Aero Eng Student, Ga Tech
Newsgroups: sci.aeronautics
From: dennisn@ecs.comm.mot.com (Dennis Newkirk)
Subject: Re: Talking to a mach 8 airplane (communications)
Organization: secure_comm
Date: Mon, 14 Dec 1992 17:50:10 GMT

In article <1992Dec14.183245.10921@dartvax.dartmouth.edu> Robert.T.Warfield@dartmouth.edu (Robert T. Warfield) writes:
>
>  If I remember correctly, mission controll in houston can communicate
>with and recieve telemetery from the space shuttle shuttle during
>launch. Escape velocity is about Mach 25.

During reentry too.  I recall NASA Select mentioning that TDRSS
can relay the signal all the way down since there are S-band 
antennas on the orbiter's top side which is not as blocked as 
the bottom.    

Dennis Newkirk (dennisn@ecs.comm.mot.com)
Motorola, Land Mobile Products Sector
Schaumburg, IL
Newsgroups: sci.aeronautics
From: aatresa@lims02.lerc.nasa.gov (Teresa Kline)
Subject: Re: TAIL ROTORS
News-Software: VAX/VMS VNEWS 1.41    
Organization: Yeah, *right* !
Date: 15 Dec 1992 13:09 EST  

In article <10299@ncrwat.Waterloo.NCR.COM>, tjgerman@53iss6.Waterloo.NCR.COM (Trevor German) writes...
> 
>       Why not have a higher RPM 
>	ducted vertical fan driven through a gearbox on the main shaft 
>	pumping air down under the craft. The design of the fan should be
>	done in a way that makes it very viscous, that is, a lot of torque
>	required to move air.  The speed of the fan would 
>	obviosly be greater than that of the main rotor. The pitch of the 
>	fan would again be adjustable, or maybe just a damper in the airflow
>	could suffice.
> 
>	This may have already been tried, or maybe I am missing something
>	fundemental, but I am intrested in any comments or knowledge of
>	similar schemes that have been tried.
> 

It has been tried.  See any AvWeek or similar journal and look for the 
NOTAR (no tail rotor).
-- Teresa

		Life -- just for the FUN of it!!!!
Newsgroups: sci.aeronautics
From: pfloyd@titan.ucc.umass.edu (BlackWing Restorations, Ltd.)
Subject: Re: Cd of  open "box" shape...
Organization: Old Pink, care of the Funny Farm, Chalfont
Date: Tue, 15 Dec 1992 20:15:01 GMT

>>> Has anyone knoledge of the Cd value of an open box shape, with the
>>> open side toward the airflow? Is it better/worse than a flat plate,
>>>for example? 
>>Worse (ie higher drag). If you've ever seen pictures of a Pelton wheel
>>(a type of water turbine) the "paddles" are specially-shaped buckets
>>[...]
>I think the original question applied to a box without a "bottom".  i.e, a
>length of rectangular duct aligned with the stream.  In a reasonably simple
>analysis, the only difference in drag between the duct/box and an equivalent
>area of flat plate will be due to boundary layer interference in the
>interior corners.  If the box is large compared to the boundary layer
>thickness, this effect could possibly be neglected.
>It should be possible to make a reasonable approximation using standard data
>for a rectangular duct for the interior flow, and use flat plate drag on the
>outside of the box.  Try Fox & MacDonald or Schlichting for the data.


True... but wouldn't the thickness of the sides add to the drag force,
should they be thick enough? I'm sure that the box/duct used would
have plate thickness that is <<< than the length and/or width... but
it's something to consider when figuring the Cd for that particular
piece, as there could be a non-negligible drag due to a small frontal
area... might only shift the result anywhere from .1 to 5% (maybe),
but it's something I would want to take into consideration if I was
performing a windtunnel experiment...


pf


-------------===========**********===========-------------
	       BlackWing Restorations, Ltd.
            Investigations, Personal Security
               and Restorations a specialty

     Can be reached via the following Internet address:
		pfloyd@titan.ucc.umass.edu

No case to easy, no fee too large, no ammunition expenditure
too gratuitous. no body count too high... call now for an
inexpensive consultation.

Newsgroups: sci.aeronautics,sci.space
From: sbooth@lonestar.utsa.edu (Simon E. Booth)
Subject: Re: Mach 8+ Space/Spy Plane?
Organization: University of Texas at San Antonio
Distribution: na
Date: Wed, 16 Dec 1992 09:08:29 GMT


On the subject of this mach 8 plane, a 'pulsed engine' is mentioned.

Am I to assume this operates like the pulse-jet engine on the World War
II V-1 missile?

In a recent Discovery channel documentary ('Wings of the Luftwaffe')
footage of a pulse jet being fired on the ground clearly showed flashing
exhaust flame as well as a 'smoke-ring' effect.

Just my $.02 worth.

Simon
From: maddog@kuhub.cc.ukans.edu
Newsgroups: sci.aeronautics
Subject: Another "silent helo" theory. . .
Date: 14 Dec 92 09:58:20 CST
Organization: University of Kansas Academic Computing Services

One last shot on the "silent helo" thing.  Now, this was a few years back, and
I have NO idea if anything became of it, but there was one additional theory.
There for a while, they were toying with the idea of using accoustic drivers
to offset the "hellacious" noise helos produce.  By utilizing the "wave 
addition" principles, they were hoping to eliminate noise. . .or at least
bring it to a minimum.

They were going to have sensing mics in various places beneath the blades,
sample the noise and create an "opposite" or inverted signal at the same
amplitude.  Theoretically, anyway, it would significantly reduce the noise.
(It can't eliminate it since the sources do not have the same point of
origin.  But, it's a helluva lot better than nothing!)  :-)

Sooooooo, anybody heard about this?  Or am I spewing hot air, as usual?

Catch me later!

					Maddog
				Programmed to serve. . . .

. . .did I mention that I have this great bread recipe???  :-)
From: turnock@eagle.larc.nasa.gov (D. L. TURNOCK)
Newsgroups: sci.aeronautics
Subject: Re: Mach 1 is also density dependent
Date: 16 Dec 1992 15:34:24 GMT
Organization: HELL'S NERDS
NNTP-Posting-Host: b648mac9.larc.nasa.gov

In article <1gn95vINNq3s@usenet.INS.CWRU.Edu>, br105@cleveland.Freenet.Edu (Jeffrey A. Del Col) writes:
> 
> 
> If I am not mistaken, Mach 1 is also dependent on the density of
> the transmitting medium. Mach 1 is faster in water than in air, and it
> is higher at lower altitudes than at higher altitudes largely because of
> the difference in air density. 
> \
> 
> J. Del Col
> -- 
> Jeff Del Col      *   DECONSTRUCTION--- the critical method invented      
> A-B College       *                      by Procrustes  
> Philippi, WV      *                             
>                   *         
> 
>
The speed of sound in any medium is

						a  = SQRT(gamma*R*T)

      a = speed of sound
      gamma = ratio of specific heats - cp/cv
      R = gas constant for particular gas
      T = temperature (absolute)

This should work for any gas

Speed of sound (Mach 1) is largely used only for compressible flow.

The speed of sound in a liquid or solid is at least an order of magnitude 
greater than in a gas and is usually termed incompressible flow in which Mach
number has no part.

Hope this helps.

Dave

turnock@eagle.larc.nasa.gov



 
Newsgroups: sci.aeronautics
From: Michael F. Kamprath <kamprath@space-grant.sprl.umich.edu>
Subject: Spanish translations of aeronautic terms
Date: Thu, 17 Dec 92 17:56:17 EST
Organization: University of Michigan, Aerospace Engineering
X-Useragent: Nuntius v1.1.1d12
X-Xxmessage-Id: <A756703C7801C4FC@sprl-mac2016.sprl.umich.edu>
X-Xxdate: Thu, 17 Dec 92 23:58:20 GMT

Could someone help me translate the following English aeronautical engineering
terms into the proper Spanish words (that is, the words used when refering to
the same thing).  Here they are:

	glider
	computer aided design

	Tip chord
	Root chord
	span
	(tip) sweep
	
	Main wing
	Stabilizer
	Vertical tail
	Fuselage
	
	Angle of attack
	Stabilizer incidence angle
	
	center of gravity
	neutral point
	pitching moment
	
	lift 
	drag
	forces
	velocity
	
This is all for an educational program I wrote (on the Mac) that I now want
to translate to Spanish.  I know it can't be done easily with the 7-bit ASCI
character set on USENET, but if you could also indicate the proper accent marks
(since we don't really have them in English, I don't know the proper names of
the characters).

Thanks for any help!

======================================================================
|Michael F. Kamprath                   | The University of Michigan  |
|  kamprath@space-grant.sprl.umich.edu |      Aerospace Engineering  |
|  kamprath@engin.umich.edu            |      Graduate Student       |
======================================================================
From: br105@cleveland.Freenet.Edu (Jeffrey A. Del Col)
Newsgroups: sci.aeronautics
Subject: Mach 1 is also density dependent
Date: 16 Dec 1992 12:58:39 GMT
Organization: Case Western Reserve University, Cleveland, OH (USA)
Reply-To: br105@cleveland.Freenet.Edu (Jeffrey A. Del Col)
NNTP-Posting-Host: hela.ins.cwru.edu


If I am not mistaken, Mach 1 is also dependent on the density of
the transmitting medium. Mach 1 is faster in water than in air, and it
is higher at lower altitudes than at higher altitudes largely because of
the difference in air density. 
\

J. Del Col
-- 
Jeff Del Col      *   DECONSTRUCTION--- the critical method invented      
A-B College       *                      by Procrustes  
Philippi, WV      *                             
                  *         
Newsgroups: sci.aeronautics
From: mperlman@nyx.cs.du.edu (Marshal "Airborne" Perlman)
Subject: Re: Mach 8 airplane
Organization: University of Denver, Dept. of Math & Comp. Sci.
Date: Fri, 11 Dec 92 18:32:34 GMT

aerbgam@vmsa.technion.ac.il writes:

>I heard that the USAF has a Mach 8 airplane.
>Any information will be weell apriciated.


I would not doubt it one bit. AFTER hiding the F-117a from us for 

a great deal of years... who knows...




--
|o| Marshal Perlman                             Internet: perlman@cs.fit.edu |o|
|o| Florida Institute of Technology                              IRC: Squawk |o|
|o| Melbourne, Florida                                   Private Pilot, ASEL |o|
|o| 407/768-8000 x8435                            Goodyear Blimp Club Member |o|
From: ghee@vision.larc.nasa.gov (Terry A. Ghee)
Newsgroups: sci.aeronautics
Subject: Re: Paul Moller/One in every garage
Date: 16 Dec 1992 12:22:21 GMT
Organization: NASA Langley Research Center, Hampton, VA  USA
Distribution: usa
NNTP-Posting-Host: vision.larc.nasa.gov

>Something I've been churning in my mind--what about blowing air OVER the
>tops of large, stationary wings?  Some sort of huge blower on the inside--its
>output ducted over wings sticking out of the sides.  Wouldn't a good deal of
>lift be produced if the air below the wing was still, while the air over top
>would be be flowing quickly?


It's already invented, called circulation control (if I read your description
of your idea correctly).  The problem is you need moving air (the wing must be moving
through the air) for this concept to work well.  Just the jet alone probably
would not gain appreciable lift.
T.A. Ghee
Newsgroups: sci.aeronautics
From: ahng@ee.ualberta.ca (Allan Hong-Kay Ng)
Subject: Re: zero angle of incidence...
Organization: University Of Alberta, Edmonton Canada
Date: Sat, 12 Dec 1992 04:46:43 GMT

ecf_stbo@jhuvms.hcf.jhu.edu (The intricate progressive rock of Hatfield and the North) writes:

>I am basically naive of aerodynamics and this question may not even make
>sense but here goes: Are there any foil shapes that can generate a 
>net lift at 0 angle of incidence? 

Hi
  Maybe this will help.  So I dig out my text book and it says "The
  Angle of Incidence is the angle which the wing is permanently inclined
  to the longitudinal axis of the airplane.  Choosing the right angle of
  incidence can improve flight visiblity, enhance TO and landing characteristics
  and reduce drag in level flight."  
  Whew.
  So I think that this imples the answer to your question is yes.  The angle
  of incidence is it seems a design refinement.
						
						A. Ng
						PPL

Newsgroups: sci.aeronautics