HDTenEightyP/NetNews huggingface dataset:
From: joep@neon.dfrf.nasa.gov (Joe Pahle)
Subject: Re: Popular Flight Control Simulators?
Reply-To: joep@neon.dfrf.nasa.gov
Organization: NASA Ames-Dryden FRF, Edwards, CA
Date: Fri, 21 Aug 1992 16:31:32 GMT

In article <23932@oasys.dt.navy.mil>, vorwald@oasys.dt.navy.mil (John Vorwald) writes:
|> 
|>   I am interested in identifying the different commericial
|> simulation/analysis packages that are available for analyzing
|> control systems.  I have
|> MATRIXx and Xanalog, and I have used MatLab, however, these packages
|> have size limitations (or support limitations) that limit the
|> pratical use (at least for the PC versions).
|> 
|> I would like to know
|> what packages are used for analyzing complex flight control systems
|> of aircraft (ie: Space Shuttle, V-22, F-16, F-18, RAH-66).
|> 
|> I have two particular products that I am trying to learn more about.
|> Does Boeing Computer Services sell a simulation package (and who
|> uses it), and if they do, what is Boeing Computer Service phone number?
|> And last of all, does anyone know about a package called
|> SimuLab, and who uses it and who sells it?
|> 
|>   All responses will be tabulated and a final summary of products will
|> be provided.
|> 
|> 
|> 			    John Vorwald
John - 

We have used Matrix/x, Cntrl/C, Digikon, Matlab (old FORTRAN version),
and Pro-Matlab at NASA Dryden as well as a host of internally
developed control design/analysis programs. I have never used any of
these tools on a PC, save for Pro-matlab on a mac. I actually used
Digikon on a Cyber, which is ALOT worse than anything on a PC, but
that was awhile ago :).

I do not understand the "limitations" that you refer too for any of
the tools that you mentioned. We used Matrix/x, Pro-matlab, and Matlab
to analyze control laws for the F-8 oblique wing [never flew, but we
took it to piloted simulation], F-18 [both the existing control laws
,and the control laws for the High Alpha Research Vehicle] and some
paper studies of the HiMAT, and the AD-1. We used classical and modern
design/analysis techniques, accomplished post-flight data analysis, HQ
evaluations, and linear/non-linear simulations. In the current flight
program for the F-18 HARV, NASA teams are using both Matrix/x -system
build, and Pro-matlab -simulink for a substantial portion of
design/analysis/simulation of advanced control law designs.

Simulab (now simulink) is a product put out by the same folks as
Pro-matlab.  Similar in design to System-build (by ISI - the Matrix/x
folks), both tools are block diagram based simulation tools. I have
never used Xanalog products, but I have heard good things.

If you are unhappy with the tools in the PC environment, My personal
suggestion would be to try them on a workstation. Simulink or
System-build on a SPARC 2 with a 19" monitor is a pretty impressive
combination. 

I can understand your concern with support (and cost as well). We have
used these tools for analysis of flight critical control laws, but as
always, the verification of the answers from ANY tool is the
responsibility of the user.

Hope this helps. 
As always, my opinions are mine, not NASAs. MINE! MINE! ALLLLL MINE!

Newsgroups: sci.aeronautics
From: nironen@ntc02.tele.nokia.fi (Pasi Nironen , OH2BKX)
Subject: DC 9 for parachuting?
Organization: Nokia Telecommunications.
Date: Wed, 19 Aug 1992 12:29:26 GMT

	Hello there!

	I have recently asked to make plans how to make parachute jumps
	from DC 9 or MD 80 -series airplane.

	So far so good... Nobody has said it is totally impossible but
	there would be a long way before these jumps can be made. The
	only way out for parachuters is the rear stairs below the fuselage
	of aircraft. The stairs must be removed before this flight and 
	this is a technical modification...it's expensive,too.

	Parachuters need about 2000 m altitude and as low speed as
	possible, appr. 130 knots.

	That's all I know. I really would like to know how was the
	tests done for Boeing 737 and 727 before they were accepted
	for parachuting. Anyone know here?

	Cheerio	
		Pasi

    --------------------------------------------------------------------- 

        	"Don't panic,skydiving makes a lot of sense"
	   (Helsinki Institute of Technology PASI@FINHIT.HIT.FI)
	NOKIA TELECOMMUNICATIONS         NIRONEN@NTC02.TELE.NOKIA.FI
Newsgroups: sci.aeronautics
From: barrk@ucsu.Colorado.EDU (BARR KEITH STABLER)
Subject: Re: DC 9 for parachuting?
Organization: University of Colorado, Boulder
Date: Wed, 19 Aug 1992 14:44:11 GMT

In article <1992Aug19.142926.1@ntc02.tele.nokia.fi> nironen@ntc02.tele.nokia.fi (Pasi Nironen , OH2BKX) writes:
>	That's all I know. I really would like to know how was the
>	tests done for Boeing 737 and 727 before they were accepted
>	for parachuting. Anyone know here?

I think D.B. Cooper did the tests for the B-727.  :^)

Keith Barr
barr@ncar.ucar.edu
From: vorwald@oasys.dt.navy.mil (John Vorwald)
Newsgroups: sci.aeronautics
Subject: Reynolds number for outflow of jet blast
Date: 17 Aug 92 03:27:29 GMT
Reply-To: vorwald@oasys.dt.navy.mil (John Vorwald)
Organization: Carderock Division, NSWC, Bethesda, MD


    We are using a Navaier (?SP) Stokes Code, CFL3D, to model the
deflection of a jet blast impinging on the ground.  We have some
experimental measurements that we eventually want to correlate with.
One problem that we see is defining the 'characteristic' Reynolds
number for the problem.  This number is used for determining the
model (shape) of the boundary layer (laminar or turbulent).
    Usually, one would have a characteristic length and velocity
to use for calculating the Reynolds number, ie: chord length and
forward speed.  In this case, we are interested in the development
of the boundary layer at large distances from the place where the
jet impacts the ground.  So it is difficult for define a
characteristic length or velocity.
     The measured velocity profile does not have a boundary layer that
is characteristic of either turbulent or laminar flow.  So the
measured flow characteristics do not readily provide us with a
"representitive" Reynolds number.  It is expensive to run solutions,
so does anyone have any suggestions on how to identify a "typical"
Reynolds number for flow passing over large distances of the ground,
with varying velocity.


				 John Vorwald
				 I can neither confirm nor
				 deny _____ (fill in any word)
Newsgroups: sci.aeronautics,rec.aviation
From: louis@nrcsp1.iar.nrc.ca (Louis Bolduc)
Subject: Re: Helicopter Simulation
Keywords: heliopters, simulation
Organization: National Research Council
Date: Mon, 17 Aug 92 12:44:10 GMT

In article <34306@cbmvax.commodore.com> kcd@cbmvax.UUCP (Ken Dyke - Amiga Networking) writes:
>
>If anyone knows of any good (or even not-so-good) references on helicopter
>simulation/flight could you please send me e-mail at my address below. I am
>espescially interested in any references that have example code/algorithms
>for simulating helicopter flight.

We, at the flight research laboratory of the National Research Council of
Canada, fly a "fly by wire" helicopter. It's a Bell 205. We threw in computers
between the pilot controls and the aircraft actuators. The pilot in the left
seat still has direct control of the helicopter for safety.

We can put any mathematical model in the computers (theoretically, we can
simulate the flight characteristics of any aircraft with this airborne simu-
lator, but I would not want to try to simulate an F18).

We have mathematical models for many aircraft (including some helicopters),
but I'm not sure they can be made available free of charge (some might). They
are written in FORTRAN.

The people to talk to are:

Murray Morgan    (613) 998-3180      Project engineer, airborne simulator
Barrie Leach     (613) 998-3149      Flight Research Lab, deputy director
Mac Sinclair     (613) 998-3071      Flight Research lab, director

Or if you prefer a more formal channel of communication:

        Flight Research Lab, Bldg U-61
        Institute for Aerospace Research
        National Research Council
        Ottawa  (Ont)  K1A 0R6
        Canada


| Life would be much easier to| Louis Bolduc            |     ===       __    |
| understand if mother nature | (613) 998-9780          |      \_______| _)   |
| gave us the source code.    | louis@nrcsp1.iar.nrc.ca |   __ /\      | __   |
|         - Graeme MacWilliam |      Flight Recorder    |  /  /  \    / \  \  |
|                             |      Playback Centre    | |  /_|_\/\/  | \  | |
| #include <std/disclaimer>   |                         | \    /  \/   \    / |
+----- NRC/CNRC - Institute for Aerospace Research -----+- \__/ ------- \__/ -+

Newsgroups: sci.aeronautics
From: rdd@cactus.org (Robert Dorsett)
Subject: Re: Ram jet engine in Commmercial aircraft like Boeing..
Organization: Capital Area Central Texas UNIX Society, Austin, Tx
Date: Thu, 13 Aug 1992 01:54:52 GMT

In article <1992Aug10.040933.17819@cactus.org> rdd@cactus.org (Robert Dorsett) writes:
>Off the top of my head, these airplanes have or will have RATs:
>	757
>	767
>	777
>	A300
>	A310
>	A320
>	A330
>These don't:
> [...]
>	A340
        ^^^^
> [...]
>	
>So there's no hard and fast "manufacturer culture" rule we could use
>to figure out that an airplane will have a RAT; 

Before someone else calls me a liar, I erred. :-)  The A340 does, indeed,
have a RAT, so I guess we can support the original poster's contention that
there is, indeed, a manufacturer using them as standard equipment.  I guess
Airbus is a RATty little manufacturer, after all. :-) :-)





---
Robert Dorsett
rdd@cactus.org
...cs.utexas.edu!cactus.org!rdd
From: hausslin@oasys.dt.navy.mil (Henry Haussling)
Newsgroups: sci.aeronautics
Subject: Re: CFD code required...
Date: 17 Aug 92 11:49:52 GMT
Reply-To: hausslin@oasys.dt.navy.mil (Henry Haussling)
Organization: Carderock Division, NSWC, Bethesda, MD

In sci.aeronautics, fortuna@cs.man.ac.uk (Armando Fortuna) writes:
>It would be useful to everyone interested in CFD to have more info
>about that code... Could you please post it?
>Armando

     The DTNS codes solve the Reynolds-averaged Navier-Stokes,
Navier-Stokes, or Euler equations.  They use a finite-volume approach with
artificial compressibility for steady flows.  They are written in FORTRAN
and are quite portable.  They have been run on computers ranging from
workstations to Crays.  Numerous common boundary conditions are
preprogrammed and can be invoked through simple input.  Validation is
ongoing here at DTMB and with numerous outside users.  The codes are
available to interested potential users at least within the United States..

Henry Haussling
-------
Newsgroups: sci.aeronautics
From: martinn@mksol.dseg.ti.com (niels r martin)
Subject: Re: DC 9 for parachuting?
Organization: Texas Instruments, Inc
Date: Wed, 19 Aug 1992 15:21:08 GMT

In article <1992Aug19.142926.1@ntc02.tele.nokia.fi> nironen@ntc02.tele.nokia.fi (Pasi Nironen , OH2BKX) writes:
>	Hello there!
>
>	I have recently asked to make plans how to make parachute jumps
>	from DC 9 or MD 80 -series airplane.
>
>	So far so good... Nobody has said it is totally impossible but
>	there would be a long way before these jumps can be made. The
>	only way out for parachuters is the rear stairs below the fuselage
>	of aircraft. The stairs must be removed before this flight and 
>	this is a technical modification...it's expensive,too.
>
>	Parachuters need about 2000 m altitude and as low speed as
>	possible, appr. 130 knots.
>
>	That's all I know. I really would like to know how was the
>	tests done for Boeing 737 and 727 before they were accepted
>	for parachuting. Anyone know here?
>
>	Cheerio	
>		Pasi
>
>    --------------------------------------------------------------------- 
>
Ask D.B. Cooper.  He might know!!!
-- 
________________________________________________________________________________Niels Martin				|                      
martinn@mksol.dseg.ti.com		|  AGM-88  Get out of HARM's way!!
My opinions don't represent		|  10,000+ on-time deliveries!
my employer's--but they're right!	|  Best Radar 'Detector' Around!   
Newsgroups: sci.aeronautics
From: hoyme@src.honeywell.com (Ken Hoyme)
Subject: Re: Ram jet engine in Commmercial aircraft like Boeing..
Organization: Honeywell Systems & Research Center
Date: Wed, 12 Aug 1992 21:57:46 GMT


In article <34010002@b-mrda.ca.boeing.com> berner@b-mrda.ca.boeing.com (Ann Berner) writes:

> Far
> from being along for the ride, the cables are the only way to control the
> surfaces (I guess you could call it "Fly-by-Cable"..... :))

This reminds me of a story I heard from one of our people who was
involved in discussions with the Russians on supplying avionics for
their new commercial transports.  Apparently they were claiming that
these planes would be 'fly-by-wire', but when pressed for a more
accurate translation, the 'wire' they were referring to was the
traditional cables.  I always wondered how apocryphal this story was,
but it sounded good!!


-- 
Ken Hoyme                    Honeywell Systems and Research Center
(612)782-7354                3660 Technology Dr., Minneapolis, MN 55418
Internet: hoyme@src.honeywell.com
From: thad@lever.asd.sgi.com (Thad Beier)
Newsgroups: sci.aeronautics
Subject: Flying wing stability
Date: 14 Aug 92 23:03:26 GMT
Reply-To: thad@sgi.com
Organization: Silicon Graphics

I was tinkering with the design of a tailless light plane, and was
having the most trouble with the longitudinal balance.  It is
possible to build a wing with enough reflex to have a reasonably
positive pitching moment, so that there can be a reasonable distance
between the center of gravity and the center of pressure.  But, the
problem I am having is that the distance between the elevators
(on the trailing edge of the wing) and the cg is so small that it
takes a large amount of control surface deflection to trim the
plane.  If it is to cruise at 120 knots and stall at 50 knots, then
the moment is 5.76 times as high at cruise than at stall, and
either the down trim at cruise or the up trim at stall would
be excessive.  Also, the problem with reflexed wing sections is
that the maximum lift coefficient tends to be small (~1.2 ?),
and flaps don't work because of the huge negative pitching
moment that these provide.

I was thinking of solving both of these problems by adding
slats to the leading edge.  These would be extended for low
speed flight, and retracted at cruise.  These would

1) move the center of pressure forward, relieving some of
   the low-speed trim problem
2) provide an increase in max Cl, maybe up to 1.8
3) help keep the plane from stalling, as the slats energize
   the boundary layer

What would be good references on slat designs, showing how
they change both lift and moments?  Does this sound like a
good idea?
-- 
Thad Beier..Silicon Graphics..415)390-1028..thad@sgi.com..C-172A N7770T.....FLY!
(would-be amateur airplane designer)
From: fortuna@cs.man.ac.uk (Armando Fortuna)
Newsgroups: sci.aeronautics
Subject: Re: CFD code required...
Date: 13 Aug 92 17:58:55 GMT
Reply-To: fortuna@cs.man.ac.uk (Armando Fortuna)
Organization: Department of Computer Science, University of Manchester UK

It would be useful to everyone interested in CFD to have more info
about that code... Could you please post it?
Armando


--
===========================================================================
Armando de Oliveira Fortuna                    E-mail: fortuna@cs.man.ac.uk
Dept. of Computer Science                      Tel.: +44 61 275-6132
University of Manchester                       Fax.: +44 61 275-6204
Oxford Road
Manchester M13 9PL                          "...It works better...
England                                             ...if you plug it in..."
============================================================================
All opinions expressed are MINE ONLY! If you think otherwise, THINK IT OVER!
From: Steven.Schultz@mixcom.mixcom.com (Steven.Schultz)
Newsgroups: sci.aeronautics
Subject: Su-29 info request
Date: 13 Aug 92 20:45:13 GMT
Article-I.D.: mixcom.1992Aug13.204513.16613
Organization: Milwaukee Internet Xchange BBS, Milwaukee, WI U.S.A.

I'd like any info on the Su-29, a Sukhoi OKB aerbatic aircraft based
on t Su-26M.

-- 
Steve Schultz     Steven.Schultz@mixcom.com
Newsgroups: sci.aeronautics
From: paulg@griffin.demon.co.uk ("Paul J. Gravestock")
Subject: ALA-40 Thermoplane 
Distribution: world
Organization: Where's the beach ?
Date: Wed, 12 Aug 1992 14:25:22 +0000


In article <1992Aug10.194050.8723@phri.nyu.edu> roy@alanine.phri.nyu.edu writes:

>
>What's a thermoplane?
>-- 

The picture I saw showed a 40m diameter 'Enterprise' lile disk with the
fuselage of a Mil Mi-2 helicopter (less rotors ad tail) strung underneath it.
Quite how it all works is beyond me.

Paul

------------------------------------------------------------------------------
Paul J. Gravestock                  | email: paulg@griffin.demon.co.uk
Hertfordshire                       |        pgravestock@cix.compulink.co.uk
England                             |
------------------------------------------------------------------------------
From: vorwald@oasys.dt.navy.mil (John Vorwald)
Newsgroups: sci.aeronautics
Subject: Interpolation routine for algebric grid
Date: 12 Aug 92 17:30:44 GMT
Reply-To: vorwald@oasys.dt.navy.mil (John Vorwald)
Distribution: usa
Organization: Carderock Division, NSWC, Bethesda, MD

Hi

  I need to interpolate the output from a CFD code at locations that
will be measured experimently.  The CFD grid is rather deformed, since
it is shaped to the body.  The experimental values will be measured
along stright lines perpendicular to the body.

  I can think of two ways to do this problem.  Search through the
CFD geometry data to find the closest point.  Starting from the closest
point, construct a "box" that encloses the point.  Then do linear
interpolation to colaspe the "box" to a plane containing the point,
followed by linear interpolation to colaspe the plane to a line
containing the point, followed by linear interpolation to the point.

  The second method is to just find the N closest points (N ~ 8) and
do a weighted averaged based on the distance to the point.

  The CFD code is CFL3D from NASA.

  Does anyone have any suggestions on this problem (or solutions).

			      Thanks
			      John Vorwald
Newsgroups: sci.aeronautics
From: rfedkiw@crenshaw.math.ucla.edu (Ronald Fedkiw)
Subject: Axisymmetric Navier Stokes Equations
Organization: UCLA Mathematics Department
Distribution: usa
Date: Sun, 16 Aug 92 21:29:19 GMT

I'm trying to do a calculation of the full compressible Navier Stokes
equations for flow past an axisymmetric blunt body.
So, I put the equations into axisymmetric form and multiply
through by 1/Jacobian = r = distance from centerline (of axisymmetry).
I need to do this to put the equations back into conservative form for 
my method.
The obvious problem is that the equations are no longer valid along
the axis of symmetry (where r = 0). The Jacobian here is infinite.
I'm not quite sure what the implications of an infinite Jacobian are,
but from looking at my equations it becomes obvious that they cannot 
be used to solve the flowfield at r=0.

I was wondering what sorts of methods ae in common practice to solve
for the flowfield near r=0.
The solution is important here since this is where the flow passes
through the strongest portion of the shockwave. (It's a normal shock
at r=0 and the heating is high, also this is the where the stagnation
streamline lies.)
So, I need a good method, this might be the most important part of the flow!

Any help is greatly appreciated.

(I've thought about bounding the domain of the grid away from r=0,
 by 1/2 of a grid cell, but what boundry condition would I use?)

Ron Fedkiw

--
Ron Fedkiw (rfedkiw@redwood.math.ucla.edu)

A plan is made by someone who is sitting and thinking ...
while others are doing.
From: berner@b-mrda.ca.boeing.com (Ann Berner)
Newsgroups: sci.aeronautics
Subject: Re: Ram jet engine in Commmercial aircraft like Boeing..
Date: 11 Aug 92 15:02:30 GMT
Organization: Boeing Commercial Airplanes MR&D

/ b-mrda:sci.aeronautics / rdd@cactus.org (Robert Dorsett) / 11:21 pm  Aug  8, 1992 /
In article <furtaw-070892160744@145.1.92.170> furtaw@comm.mot.com (Bob Furtaw) writes:
>>[ on the 767 and its hydraulics] 
>>Also,  there is a back up cable system that drives the control surfaces
>>just as in a conventional aircraft.  As you might expect, most of the time 
>>it just goes along for the ride. :-)

>Could you re-check your notes and confirm that statement?  All of my 
>sources very explicitly state "No manual reversion" for the 757/767.
>The last Boeing airplane with cables to the surfaces was the 727.  Sticking
>them in the 757/767 would have been a major reversal of design 
>philosophy...

At least for the 757, Robert is right.  The documents state specifically
"no manual reversion".  It should be noted, however, that cables ARE 
part of the flight control system.  For pitch control, for
example, the cables travel all the way back to the elevators, where PCAs,
(power control actuators), use hydraulics to actually drive the surfaces.  Far
from being along for the ride, the cables are the only way to control the
surfaces (I guess you could call it "Fly-by-Cable"..... :))

_____________________________________________________________________________
Ann Berner						Opinions expressed are
Boeing Commercial Airplanes				mine alone; I do not
berner@b-mrda.boeing.com				speak for Boeing.
From: kenw@anasaz.uucp (Ken Wilkerson)
Newsgroups: sci.aeronautics
Subject: Ceramics in gas turbine engines
Keywords: ceramics, engines
Date: 18 Aug 92 23:40:01 GMT
Organization: Anasazi, Inc.  Phoenix, Az


I was wondering what research and development was going on about aircraft
gas turbine engines using ceramic turbine blades.

Ken
kenw@anasazi.com
From: j.jahn@abbs.hanse.de (Jost Jahn)
Newsgroups: sci.astro
Subject: Sunspots at 15.08.1992.
Date: 17 Aug 92 11:48:52 GMT
Reply-To: j.jahn@abbs.hanse.de
Distribution: sci
Organization: ABBS AstroMail, D-W 2121 Dahlenburg / Germany
X-Version: ZerUU V6.45c

Sunspots at 15.08.1992., 0 h UT.

No.    Pos.  Cl.  Ar.  Mag. SF  F  M  X
---------------------------------------
7248 12S 86W Dko  120   b    1
7256 15S 15W Cso   40   b
7260 17N 41E Eki  830   b    6
7261 22S 11W Dao   60   b    6
7262 17N 16W Bxo   10   b
7263 16N 05W Bxo   10   b


No optical or x-ray flares yesterday observed.


 
--
------------------------------------------------------------------------------
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------------------------- for amateur astronomers ----------------------------
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From: jarleb@athena.uio.no (Jarle Brinchmann)
Newsgroups: sci.astro
Subject: Meta-model, pubished ?
Date: 18 Aug 92 10:29:14 GMT
Reply-To: jarleb@athena.uio.no (Jarle Brinchmann)
Organization: University of Oslo, Norway

I'm sorry if I am a bit late, but I have been off the net the whole
summer, so I
just wondered if The MetaModel, or parts of the ideas have been
published, and
if so, can anyone provide me with some pointers to the literature...

As an aside :
I hope that the discussion concerning these issues can be a bit more
scientific 
and not som personal that it has been some times before. I can't really
see the 
reason for emphatic attacks on theories that goes against the main
stream. So good
luck to the participants on either side, hope none of you wins too fast,
the
discussion introduces, at least me as an beginning graduate, to lots of
issues concerning the Standard Model.


						Jarle.