Newsgroup sci.engr.mech 29802

In article <5b88lp$go0@news.tamu.edu>, bnh5940@acs.tamu.edu (Blaine Hufnagle) says:
>
>In article ,
>   "Robert C. Jacobson Sr."  wrote:
>>
>>Anyone know where I can find some info on cars "drafting" behind
>>tractor trailers?  I want to know what effect it has on drag (ie
>>MPG), and how close you'd have to be.
>
>I've heard rumours to the effect that small vehicles (like a Geo Metro) can 
>get up in the draft area and either de-clutch or shut off the engine and be 
>carried by the "suction effect" of wind coming back around the end of the 
>trailer.  
>
>I have no idea if it's true.  And certainly wouldn't try it... :-)
>
>My own empirical evidence with my '79 Chevy C-10 suggests that you have to be 
>within about one  to two vehicle lengths to get any benefit, and obviously 
>the closer the better.  However, more than two vehicle lengths is into my own 
>danger range so I don't stay this close unless I absolutely have to.  I'm 
>usually not that desperate for fuel economy, and it doesn't make enough 
>difference (less than 0.5 MPG) to justify the increase in danger unless I'm 
>going into a headwind of more than 30 MPH, at which point the truck is going 
>far slower than I care to, and thus whatever benefit is lost completely.
>
>I understand from observation that the effective distance for 
>tractor-trailers is on the order of a safe distance (3-4 vehicle lengths), 
>but then the point of viability is much lower for semi's than 4-wheelers (0.1 
>- 0.2 MPG).
>
>Note for comparison that Nascar drivers who use this tactic in races usually 
>wind up being less than two feet from the car in front of them.
>
>For what it's worth, when done correctly, drafting benefits ALL vehicles 
>invoved.  That is, while the following vehicle(s) have air resistance greatly 
>reduced from the front, the leading vehicle(s) have "vacuum drag" reduced 
>greatly from the rear.  Thus BOTH vehicles get the increase in fuel economy.
>
>-blaine
>
Well, boys, I tried it, out of curiosity, with my beetle, a few
years ago, at 75mph or so. You do have to be within a carlength - 
at which point you could shut off the motor, except that the truck 
driver is likely to slam on his brakes (which my unwilling pal did) 
and give you a faceful of smoke (if you're fast enough to get around 
him, as I was.)  (Otherwise it's a faceful of steel.)
  To give the vehicle in front any advantage, you would of course
have to be adding a bit of your own power.
-markc@deltanet.com

Taftan Data is pleased to announce the release of Air and Exhaust Gas 
properties v1.0, an MS Windows application that calculates the properties of 
air/exhaust gases within a wide range of pressure and temperature. It may be 
used for analyzing a number of energy conversion components used in power 
plants and HVAC, such as gas turbines, compressors, boilers and heat 
exchangers. The accompanied help file "Thermodynamics online help" gives
a brief description of these components.
If you wish to download this application or know more about Taftan Data or 
other software developed by this company please visit our homepage:
 http://ourworld.compuserve.com/homepages/taftan/
Comments are appreciated.
Taftan Data
-- 
Taftan Data
Box 23538, 20045 Malmo, Sweden
Fax: +46 70 614 8730           Email: 100131.2557@CompuServe.Com

Marc Andelman wrote:
> Good question.  When are European patents going to be on the net.  The
> US PTO has this, and can make some money from their service by charging
> people who want complete abstracts.  Not that I like government in
> business, period, but this seems like a useful thing that did not
> cost them much to do.
> 
> Also, European patents cost a fortune and clearly favor big business
> ove small fry.
This leads on to the wider, off-topic, topic of the way that in the US,
any
non-classified work done under Government funding becomes public
domain... why
is this not possible in the UK and the EU ? That is a retorical
question, as
we all know the answer... greed.
Regards,
-- 
Peter Galbavy
Demon Internet Ltd
http://www.demon.net/ http://www.whirl-y-gig.org.uk/
http://www.wonderland.org/
  Be remembered not for your final destination in life, but for your
journey.

Beretta Fabio Alfonso wrote:
> 
> "Chang-Mun Bae"  wrote:
> 
> >I'm mechanical engineer, dealing with petrochemical equipments.
> >Sometimes, I need to calculate torque value to obtain required bolting
> >force.
> >If anybody could tell me the formula converting bolting force to torque,
> >I'd appreciate very much.
> 
> >cmbae@bbs.para.co.kr
> 
It is important to remember that the torque-force relationship is
critically dependant on thread friction, which depends on cleanliness,
lubrication, condition of threads, etc. There are several reliable ways
of determining the force in a torqued-up bolt, but applying the
calculated torque is not one of them, for purely practical reasons.
If you need to set the bolt force accurately for something critical, two
good ways of doing it are with a hydraulic nut (tensioning force applied
hydraulically, nut done up flush, hydraulic force removed) or by
calculating the bolt extension for the force you want, and tightening it
until you achieve it. This last method is commonly used for things like
connecting-rod big end bolts in competition engines, and similar
critical applications.
Cheers

Hi,
I'm looking for some feedback on internal combustion engine simulation
software from someone who has used it in research or engine development.
I am looking to purchase a package to assist in developing small engines
for competition use. To date I have identified one program which appears
to be suitable: it's called Dynomation.
Any comments or assistance appreciated.
Ben Connor

Eric Goforth wrote:
> 
> I'm trying to do some natural gas cost calculations and the
> numbers that I'm give are in $/Therm.  I have reason to believe
> that a Therm is 100 kBTU, is this correct?
A therm is 10^5 BTU.  "k" is the SI prefix for x1000, but "M" is the I-P
prefix for x1000!  Therefore, one therm is 100 MBtu.  Watch out for
software that mixes SI and I-P units and prefixes.
-- 
-----------------------------------------------------------------------
Brian A. Rock, Ph.D., P.E.        Voice:  (913) 864-3434
The University of Kansas          Fax:    (913) 864-5099
Architectural Engineering Dept.   E mailto:barock@ukans.edu
Marvin Hall                       Home page: http://www.arce.ukans.edu/
Lawrence, Kansas 66045-2222       Rock Chalk, Jayhawk, KU!
-----------------------------------------------------------------------

Archibald  wrote:
>Help! I am currently processing parts through 180C Sodium Hydroxide
>in a Teflon tank using an immersion heater covered in Teflon.
>This heater has failed 4 times with the manufacturer (Lufran) 
>replacing it each time (at no cost) with new design modifications.
Pure nickel should work - and should be a better conductor for the
heater. I'd go with a thick nickel tube protecting a conventional
resistance heater  - or if you have the money, a nickel tank with any
external heater. I'd suggest more heater surface might help your
current heaters - depending on their failure mechanism. Talk to 
INCO ( International Nickel Company - there may even be a Nickel 
development agency - there are for several other metals ), or one 
of the major industrial suppliers of caustic soda about compatible 
materials. I suspect that any cast iron may have to be of superior
quality ( less flaws/inclusions ) that standard cast iron waterpipe.
               Bruce Hamilton

In article , Doug Milliken  writes:
> I believe that the paced bicycle record was recently moved up to over 160
> mph.  The rider typically drafts behind a race car with a special "box"
> attached to the rear of the bodywork.  As with any kind of record, this one
> is not easy to set for a number of reasons -- I know one of the former
> record holders and he is a very smart & strong athlete (and also a M.D.!)
I wouldn't classify anybody who goes 160 mph a a bicycle very
smart at all. :-)
-- 
Joseph Krenson			    	| Politics I supposed to be the second-
Simulation Engineer/Vehicle Electronics | oldest profession. I have come to
(317)451-0854			    	| realize that it bears a very close
jkrenson@eng.delcoelect.com	    	| resemblance to the first. -R. Reagan

Marc Andelman wrote:
> 
> Marco Caceci wrote:
> >
> >
> > Carissimo Elio:
> > your employer would be more popular in the community if they didn't
> > treat all of us as milking cows.
> > Could you please give a reason why the full text of US patents is
> > available for free on the net, while we must pay ludicrous amounts to
> > access the EPO?
> >
> 
> Good question.  When are European patents going to be on the net.  The
> US PTO has this, and can make some money from their service by charging
> people who want complete abstracts.  Not that I like government in
> business, period, but this seems like a useful thing that did not
> cost them much to do.
> 
> Also, European patents cost a fortune and clearly favor big business
> ove small fry.
> 
> Regards,
> Marc Andelman
Marc:
the FULL TEXT and PICTURES / DRAWING (page TIFS) of all US patents since
1971/1976 is kindly provided by IBM at no cost
http://patent.womplex.ibm.com/
(they charge 2.50 USD for each document delivery of 300 dpi laser prints
up to 100 pages, I think that's fair given the time it takes to unload
on most peoples' bandwidth)
The USPO gave out free abstracts and links for a while, than decided to
ask 500 USD upfront for a password. Dorks.
I thought I'd never live to say that, but kudos to big blue
(until they decide to charge us for the service: but I am sure somebody
is downloading the whole 2.058.000+ documents right now, that'how much,
maybe 200 GB?)
-- 
Marco Caceci
EASI Technologies SA
CENT, Parc Technologic del Valles
08290 Cerdanyola Spain
e-mail 101477.13@compuserve.com
visit our homepage:
http://ourworld.compuserve.com/homepages/easi

To measure the external pressure acting on a stainless steel tube (56 mm
diameter, 130 mm length, internal at atmospheric pressure), I'm
considering of gaging the inner side of the tube with strain gages.
Has anybody suggestions on the strain gage configuration (longitudinal
or conferential strain, type of gages)? 
Has anybody a formula available for the tube deformation (with fixed
ends)?
Thanks in advance,
Jan Verstricht
jverstri@sckcen.be

Ray Manning wrote:
> 
> Go buy the 1/5/97 Sunday Los Angeles Times.  Every large aerospace
> employer has full page (at least) advertisements looking for
> engineers.  Some of the jobs are in Los Angeles but a lot of them are
> not (e.g., Lockheed hiring for employment in Georgia).
> 
> Good luck!
> pauleni1@ix.netcom.com(Paul Ennin M.D.) wrote:
> 
> >Hello all I am a new suscriber to your news group.  I am a new engineer
> >and I am looking for a job.
> >Can anyone help.
> >In NY area especially!!!
You may also want to go to web site: Job Search for Chemical engineers
and search all the leading newspapers electronically from that site just
by sitting in front of your computer. The site URL is:
http://home.earthlink.net/~amrish/chemical.html.
You can also search various job search databases on the internet through
this site.
Amrish
.
.
.
.
.
.
.
.
.
.
.

Russell_Michael@hq.navsea.navy.mil (Russell) wrote:
>In article <32d8a407.129746467@netnews.worldnet.att.net>, 
>allent@mnsinc.com says...
>>
>>bnh5940@acs.tamu.edu (Blaine Hufnagle) wrote:
>>
>>>In article ,
>>>   "Robert C. Jacobson Sr."  wrote:
>>>>
>>>>Anyone know where I can find some info on cars "drafting" behind
>>>>tractor trailers?  I want to know what effect it has on drag (ie
>>>>MPG), and how close you'd have to be.
>>>
>>>I've heard rumours to the effect that small vehicles (like a Geo Metro) 
>can 
>>>get up in the draft area and either de-clutch or shut off the engine 
>and be 
>>>carried by the "suction effect" of wind coming back around the end of 
>the 
>>>trailer.  
>>>
>>>I have no idea if it's true.  And certainly wouldn't try it... :-)
>>>
>>
>>Wha? ... Man, what a whimp.  
>>
>>
>Okay, how's this....
>
>I used to ride bicycles a lot (back when I had functioning knees), and 
>once had the experience of drafting a DC city bus along a stretch of road 
>at Haine's Point in Washington at 60 mph, according to my bike speedo 
>(yeah, I know - it's waaay over the speed limit, but it was years ago and 
>the statute of limitations applies - although a speeding ticket would 
>have been worth framing).  Anyway, I was about 6 or 8 feet from the 
>bumper, and had the sensation that I was in nearly still air and wasn't 
>putting out much power at all, but it was _really_ hard to make my legs 
>move that fast.  Incidentally, there was a movie in the late 70's called 
>"Breaking Away" in which the protagonist performs the same trick behind a 
>semi. 
>
>Related to this: back in, I think, the thirties, when bike racing was 
>big, there were a few records set where a board track was laid between 
>railroad tracks and a windscreen/fairing was installed on the back of the 
>train.  The bicyclist rode on the board track just inside the fairing 
>using a track bike modified with incredibly tall gears (big chainring, 
>small sprocket).  I recall that in some cases they were towed to a fairly 
>high speed and released to avoid the difficulty of getting a tall-gear 
>single speed bike moving.  The record is something over a hundred miles 
>an hour, but I can't find a reference to be sure.  Consider the road rash 
>if you fell....
>
>There's also a weird bicycle racing sport involving bikes drafting 
>motorcycles fitted with fairings - a real spectacle, and uncomfortably 
>reminiscent of the movie "Rollerball".
>
Right on!

:Gosh.  I just try to help, and I end up doing more damage. :-(  As I
:understand it, Lahey has at least two f90 products.  The one I talked
:about (cheap/free Elf90) is intended for the educational market, and as
:such, it includes only those features required to support what is today
:considered good programming practice for new applications.  It
:specifically does not have features thought to support bad habits.
thanks for clearing that up.
Since I have no bad habbits It should work well for me :-)

Dear Group,
    I wanted to read a more detailed account of the U.S. Industrial 
revolution, specifically about the development of interchangable parts 
for machinery done by Eli Whitney as well as the development of machine 
tools for mass producing parts.
Any help would be appreciated.
Tushar J. Mithaiwala

In article <32d8a407.129746467@netnews.worldnet.att.net>, 
allent@mnsinc.com says...
>
>bnh5940@acs.tamu.edu (Blaine Hufnagle) wrote:
>
>>In article ,
>>   "Robert C. Jacobson Sr."  wrote:
>>>
>>>Anyone know where I can find some info on cars "drafting" behind
>>>tractor trailers?  I want to know what effect it has on drag (ie
>>>MPG), and how close you'd have to be.
>>
>>I've heard rumours to the effect that small vehicles (like a Geo Metro) 
can 
>>get up in the draft area and either de-clutch or shut off the engine 
and be 
>>carried by the "suction effect" of wind coming back around the end of 
the 
>>trailer.  
>>
>>I have no idea if it's true.  And certainly wouldn't try it... :-)
>>
>
>Wha? ... Man, what a whimp.  
>
>
Okay, how's this....
I used to ride bicycles a lot (back when I had functioning knees), and 
once had the experience of drafting a DC city bus along a stretch of road 
at Haine's Point in Washington at 60 mph, according to my bike speedo 
(yeah, I know - it's waaay over the speed limit, but it was years ago and 
the statute of limitations applies - although a speeding ticket would 
have been worth framing).  Anyway, I was about 6 or 8 feet from the 
bumper, and had the sensation that I was in nearly still air and wasn't 
putting out much power at all, but it was _really_ hard to make my legs 
move that fast.  Incidentally, there was a movie in the late 70's called 
"Breaking Away" in which the protagonist performs the same trick behind a 
semi. 
Related to this: back in, I think, the thirties, when bike racing was 
big, there were a few records set where a board track was laid between 
railroad tracks and a windscreen/fairing was installed on the back of the 
train.  The bicyclist rode on the board track just inside the fairing 
using a track bike modified with incredibly tall gears (big chainring, 
small sprocket).  I recall that in some cases they were towed to a fairly 
high speed and released to avoid the difficulty of getting a tall-gear 
single speed bike moving.  The record is something over a hundred miles 
an hour, but I can't find a reference to be sure.  Consider the road rash 
if you fell....
There's also a weird bicycle racing sport involving bikes drafting 
motorcycles fitted with fairings - a real spectacle, and uncomfortably 
reminiscent of the movie "Rollerball".

I'm looking for a good Delaunay mesh generator 2D (C++ with sources)
Where can I find it ?
Thanks ! 
-- 
Stéphane Paquay             LTAS, Service de dynamique des structures
mailto:paquay@pluton.ltas.ulg.ac.be

Marty Wright wrote:
> Good professional question ..... but, hardly simple!  In fact, if you
> ask ten different designers this question, you're likely to get ten
> different answers.  What you described is essentially reverse
> engineering; where we know what the parts look like and we simply wish
> to describe this geometry on an engineering drawing.
> 
A definitive answer, it's certainly not simple.
When it comes down to it, you have to choose a datum and calculate the
geometric position of each significant surface or point for the maximum
and minimum dimensions (which are not necessarily the biggest and
smallest numbers). The arithmatic is simple, but it is easy to make a
mistake in the geometry if you do not think carefully.
RegH
-- 
~~~~~~~~~~~~~~~~~~~~~~~
Advanced Power Products Pty Limited:
Engine driven Welders, Diesel & Gas driven Generators, Control Systems.
Liverpool, Australia

Hi, I'm a beginner in the study of solid mechanics. Right now, I'm studying elasticity and 
fracture mechanics. Specifically I'm interested  in the interfacial crack problems. I know
that  there are basically two kinds of methods to solve for crack tip stress distribution:
eigenfunction expansion and integral transform.  However right now I'm bothered by several
questions that I can't solve. So I decided to seek other books. Does anybody know if there
is a good book specifically in this area?   I mean, eigenfunction expansion and integral transfrom
methods in the elasticity area. Thanks in advance.
Xu
anx2@lehigh.edu

Is anyone familiar with adhesion of dry powder coatings to anodized
aluminum? I am looking for information about the feasibility of using a
dry powder painting operation to paint some anaodized aluminum instead
of using sprayers with a solvent based paint. I have been told that
there can be problems getting the coating to adhere properly because of
the anodized coating.

RAF Electronic Hardware is sending out their 3 catalogs with all
the electronic components you could ever need. We stock 90% of what we
show in our catalog and we have a liberal sample polict for your 
prototypes. Visit us at http://www.rafhdwe.com
Thank you
brian georgia

"Paul D. Rodrigue"  wrote:
>Is anyone familiar with adhesion of dry powder coatings to anodized
>aluminum? I am looking for information about the feasibility of using a
>dry powder painting operation to paint some anaodized aluminum instead
>of using sprayers with a solvent based paint. I have been told that
>there can be problems getting the coating to adhere properly because of
>the anodized coating.
>Have you considered a flame spray of plastic or metal.  Eutectic Cast-o-lin Polymer Spray has been used at Entergy-Arkansas Nuclear One
Black, Light Blue, Dark Blue, White, Safety Red, Safey Yellow, Medium 
Green, Dark Gray, or Clear

Hi all...In case anyone interested didn't know: 
You get all the (free) info you need to set up and supply review courses and 
student chapter organization fundraisers at the GLP Engineering Test Prep 
website. (Posters, syllabi and much more, free for the downloading.)
Free shipping on web orders of our FE/EIT and PE reviews. 
Big discount engineering aides like HP-48 calculators (and the best new manual for 
this great calculator--written just for engineers!) and classic reference handbooks.
There's even a question&answer; bulletin board where you can get straight answers 
to any engineering licensing questions.
-- 
JP
***********
Jeff Potter--jp@glpbooks.com
  "Out Your Backdoor" 
               Magazine of Affordable Adventure and Informal Culture
               http://www.glpbooks.com/oyb
   GLP: The Engineering Educators---FE/EIT & PE Reviews
               http://www.glpbooks.com

In article <5bgr2b$duq$1@mhafn.production.compuserve.com>,
   Eric Goforth <75052.37@CompuServe.COM> wrote:
>I'm trying to do some natural gas cost calculations and the 
>numbers that I'm give are in $/Therm.  I have reason to believe 
>that a Therm is 100 kBTU, is this correct?
A Therm is 100000 BTU, you are correct.

Jan Verstricht  wrote in article
<32DEF029.7E87@sckcen.be>...
> To measure the external pressure acting on a stainless steel tube (56 mm
> diameter, 130 mm length, internal at atmospheric pressure), I'm
> considering of gaging the inner side of the tube with strain gages.
> 
> Has anybody suggestions on the strain gage configuration (longitudinal
> or conferential strain, type of gages)? 
> 
> Has anybody a formula available for the tube deformation (with fixed
> ends)?
You need to consider thickness, of course.
What magnitude of external load are you dealing with?
Also, fixed ends in what directions? Thin shell theory
of axisymmetric cylinders gives 3: radial, longitudinal,
& circumferential.
If there is an end load, there're additional complications.
Make sure you check for buckling.
-- 
Grace + Peace   *   Peter N Roth  *   Engineering Objects International
Tools for Developers ClassBuilder 4 for Delphi, ClassBuilder++ for C++

The SeaGull Configuration Control Software package 
provides a total framework for tracking design updates,
BOM's, product trees, ECO's, ECN's, distribution lists
and acknowledgements. 
A FREE evaluation copy is available. 
More information at http://microconsultants.com/sea/seagull1.htm
David Gibson
http://microconsultants.com

In article <32DE6A15.5458@student.ulg.ac.be>, Stephane Paquay wrote:
>I'm looking for a good Delaunay mesh generator 2D (C++ with sources)
>Where can I find it ?
>
Try http://www.ann.jussieu.fr/freefem/doc/html/freefem.html
freefem-3.3 has a mesher (even an adaptive one), and it is in c++.
But check the meshing web resources as they list quite few other
sources.
Osman

I've taken on a job (pro bono) for a group in Florida
called AMSAT.  They are building a satellite to be used
by amateur radio operators.  The job is to simulate the
dynamic behavior of solar panels as they deploy,
swinging on spring-loaded hinges.  It's a simple
double-pendulum problem, treating all bodies as rigid.
This simulation is to be sure that the panels do not
have excessive overshoot, as that would damage the
satellite.
I'd like to interest someone schooled in Kane's
dynamical equations - the approach I am trained to
use - to review my work.  Two heads are better than
one, especially in spacecraft work!
No money, just the satisfaction of being able to point
to the sky and say - "I had a hand in the success of
that satellite."  Works for me.
I am "ken@sqrt-1.com" - feel free to e-mail me.
By snail mail, I am
Kenneth A. Regas, owner
Balboa Products
8280 Clairemont Mesa Blvd.  Suite 139
San Diego, CA 92111

TO: ME developers
The new issue of Mechanical Engineering magazine deals with web or
network based software development for ME applications. I would like to
start some discussion on this subject in this newsgroup. Anyone else
interested?
Ram Narayanan
Engineering Dynamics Inc.

In article <32DEF029.7E87@sckcen.be>, jverstri@sckcen.be wrote:
>To measure the external pressure acting on a stainless steel tube (56 mm
>diameter, 130 mm length, internal at atmospheric pressure), I'm
>considering of gaging the inner side of the tube with strain gages.
>
>Has anybody suggestions on the strain gage configuration (longitudinal
>or conferential strain, type of gages)? 
>
>Has anybody a formula available for the tube deformation (with fixed
>ends)?
I'm assuming you're going to use the tube as a sort of pressure gauge by
figuring the pressure from a measured strain. Your tube is too short to do
this effectively, since end effects will play a part. And depending on the
type of stainless steel you're using the stress strain curve isn't linear.
For long tubes the membrane stresses are found from elementary shell
theory. The hoop stress is Pressure x radius/wall thickness. You may or
may not have an axial stress depending on what picks up the axial force
components. Suggest you simply put a strain gauge on the inside and
measure the strain for various known values of applied pressure. You can
plot a curve of strain vs pressure to measure pressure. If you're certain
you want to measure stress and deformation, you'll probably need a strain
rosette, so you can calculate the principle stresses from the strains.
Once you get the principal strains you can figure out the deformation in
inches from shell theory. Don't forget that shell theory is based on a
perfectly round tube with a perfectly constant thickness, neither of which
may be true for your tube.
Christopher Wright P.E.    |"They couldn't hit an elephant from
chrisw@skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)
http://www.skypoint.com/subscribers/chrisw

I'm looking for a technique to measure the bores of very small (~2 mm) 
tubes. I need to measure the bore at several points along a distance of 
6 mm or so to seperate the effects of taper and bow from those of 
diameter. I need very high resolution (10^-7 m) and preferably the ability 
to measure at several angular positions at each depth to detect runout.
The surfaces are somewhat fragile, and I have scratched the polish with 
plug guages. A non-contact technique would be ideal, but I'll take what 
I can get. Guage pins also have limited resolution, and getting much of a
range of measurement requires a large collection. 
The matertial is YAG, a non-conducting oxide crystal, if that matters. I 
don't want much, do I?
Any suggestions can be sent to me at work at 
scimat@montana.avicom.net
or at home at
lazy8@imt.net
I'll post a sumary if there's any interest.
Thanks to all,
Marty

Dennis  wrote in article
<5bjpqd$4vr@opal.southwind.net>...
: ssmeyer@lamar.ColoState.EDU (Steven Meyer) wrote:
: 
: >I am in the process of designing a HVAC system with an air handler
: >that has an existing forward curve supply blower.  Ini
: >In this phase of the project I will use 15% of the blowers
: >capacity, but this low RPM range leaves me with low static
: >pressure output and near surge/unstable conditions.  I want to
: >vary (VAV) this low flow 2000 CFM to 3000 CFM but I'm concern
: >about surge problems.....Will a modulating face damper assit
: >assist my fan while VAV valves vary the flow?.....What about
: >a scroll damper/relief (and how do they work?)?....Any suggestions?
: 
: By surge do you mean power or air volume?
With centrifugal compressors and fans etc. the word surge is generally used
to describe something different or even opposite to what you're thinking of
here Dennis.
Some definitions of the word surge from my dusty dictionary:
1) Nautical, to slacken or temporarily release (a rope or cable) from a
capstan or (of a rope, etc.) to be slackened or released and slip back.
	When the fan can't create enough kinetic energy to hold the higher
pressure air on the discharge side at bay this discharge air side pressure
will be released back through the fan to the suction side and this is
"half" a surge.
2) to cause to move in or as if in a wave or waves.
	Kinetic energy = 1/2 mV^2, so you can see that any time the velocity or
mass is reduced there is a drop in the kinetic energy produced. If this
energy is below that required to hold the pressure energy on the discharge
side at bay there will be a release of pressure backward through the fan to
the suction side. But when this air gets to the suction side of the fan it
is now available to the fan as a mass with which to resume kinetic energy
production especially because usually it is still relatively compressed and
therefore fairly dense. So now normal air flow is resumed but this is only
until the supply of dense air on the suction side is again depleted. The
fan is now surging with air going back and forth through the fan impeller.
There is unwanted noise and vibration associated with this, forward curve
fans are sometimes able to surge without too much disturbance. On
centrifugal compressors operating with higher compression ratios the hot
gas (greater heat of compression) surging back to the suction side is
further heated when thrown back to the discharge side, I've heard of freon
fires starting like this. Of course your amps are going to surge too as in
they will be wave like because air surging back through the fan offers no
load but the amps return for the period that this air is again thrown into
the discharge side.
However, studying a PD/CFM graph of forward curved fans shows that since
the power lines cross the performance lines, any small drop in static
pressure will cause a relatively large increase in power consumption with
the increased CFM raising amps and possibly overloading the compressor. So
in a way you could call this a surge but I don't think the word was used
here to mean this.
....keep talking. (Stephen Hawking)
-- 
Marc O'Brien
Industrial refrigeration mechanic

NGQL48A@prodigy.com (T Mi) wrote:
>Dear Group,
>    I wanted to read a more detailed account of the U.S. Industrial 
>revolution, specifically about the development of interchangable parts 
>for machinery done by Eli Whitney as well as the development of machine 
>tools for mass producing parts.
>Any help would be appreciated.
>Tushar J. Mithaiwala
The Science Musuem in London publish a book called the History of Machine tools by
L.C. Rolt.
Although this book covers mainly the English ind.rev. it has some chapters on
American Ind.Rev. and if my memory serves me questions the part Eli Whitney played in
it. These are Rolts views and I don't want to get into a dick slapping contest with
anyone but two sides of a view are better than one.

Our new manual shows how to set up an analysis program using vibration,
infrared thermography and ultrasonic analysis as well as spectrographic
oil analysis on Chillers and Heat Pumps while they are operating. Several
actual examples are presented with accompaning data/reports. This is a
real "How to" book written in standard, simple terms and should be a must
for those operating or maintanining Chillers and Heat Pumps.              
^^^^
How to Analyze Chillers/Heat Pumps Manual
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  
Table of Contents-
   NEED FOR ANALYSIS
      Equipment -Types/Systems
      Service
      Cost of outages/collateral damages
      Cost of replacement
   NON DESTRUCTIVE TESTING(NDT)
      Vibration
         Axes of measurements
      Ultrasonics
         Leaks-air/refrigerant
      Infrared Thermography
         Heat losses
         Electrical systems
   COMPUTER ANALYSIS
      Mass/Energy Balance/Performance
      Spread Sheets
      Data Collection/entry
   MAINTENENACE SCHEDULES/COSTS
   TROUBLESHOOTING SYSTEMS
   APPENDIX-Actual cases/results
   REFERENCES
Comes in a 3 ring notebook,61 pages-Drawings, Photographs, Charts, Tables
 Cost is $65 + $3.80 S/H USA
Information at E mail: heatscan@kalama.com
Tele: 360 423-7167

*********************************************
*****   Two Day Short Course for Industry   *****
    "A Practical Approach to Process Control"
              March 17 & 18, 1997
              June 23 & 24, 1997
     The University of Connecticut at Storrs
              by Prof. Doug Cooper
********************************************
This course has been offered many times over the last five
years. Written comments by past participants include:
  - "I learned concepts which will help me greatly in my job"
  - "[Doug Cooper] is very knowledgeable...[His] teaching 
     style stimulated my interest"
  - "The software was easy - and even fun - to use"
  - "I will make sure my co-workers attend the next course"
Course Description ********************
   This two day course gives you intensive hands-on 
   training in modern methods and practices of automatic 
   process control. Rather than lectures filled with 
   complicated mathematics and puzzling plots, this course 
   puts you in front of a computer where you face real-world 
   control challenges.
   At the computer, you enter a simulated environment of
   a control room in a production facility. There, you run 
   experiments on several processes, animated in color-
   graphic display, to obtain measurement data. You will 
   learn proven methods for modeling this data for controller 
   design and tuning. And you will follow through and
   implement and test your controller designs to gain hands-
   on experience in set point tracking and disturbance 
   rejection. In fact, you will "test drive" each of the 
   concepts discussed in the short course using the software.   
Who Will Benefit ********************
   Operators and Technicians who use automatic control 
     systems in their jobs. You will learn the basics of 
     process control and gain exposure to advanced topics.
   Engineers who have production, design or research 
     responsibility. You will learn modern methods for 
     assessing control loop capability and for designing and 
     tuning control loops from basic applications up through
     advanced strategies.  
   Managers and Supervisors who supervise engineer, operator, 
     and technician practitioners. You will strengthen your 
     background in this important subject, thus improving 
     your companies competitiveness and profitability. 
2-Day Outline ********************
   Day 1:
     - Fundamentals of Process Dynamics and Control  
     - Fitting Process Models to Plant Data
     - Using Process Models for Controller Tuning 
     - Tuning of P-Only, PI, PD, and PID Controllers
   Day 2:
     - Tuning PID Controllers in Industrial Applications 
     - Cascade Control Design and Implementation
     - Feed Forward and Decoupling Control
     - Parameter Scheduling and Adaptive Control
Short Course Software ********************
   The computer software used in this short course is the 
   Process Identification and Control Loop Explorer System.
   This software is well-proven and time tested. In fact, it 
   is currently being used in more than 100 college-level 
   process control courses around the world.  
   The software offers a virtual world of processes and 
   controllers for hands-on experimentation and study. 
   Processes available to demonstrate short course concepts 
   include: level control of a tank, temperature control of 
   a heat exchanger, concentration control of a reactor and 
   purity control of a distillation column.
About the Instructor ********************
   Prof. Doug Cooper of the Chemical Engineering Department 
   at the University of Connecticut, has been teaching and 
   directing research in control for fifteen years. The goal 
   of his research is the development of advanced control 
   systems which are easy for practitioners to use. Recent 
   efforts have focused on how neural networks can 
   contribute to this goal. 
   Industrial and laboratory applications he has studied 
   include fluidized bed incineration, injection molding, 
   distillation, heat exchange and surge tank control. Doug's 
   past experience as an industrial practitioner sparked his 
   interest in teaching process control from a real world 
   perspective. This interest ultimately led him to author 
   the popular Picles and Digest process control software.
Price ********************
   The registration fee for the short course is $795 and 
   includes a workbook with over 150 pages of course material.
For More Information, Contact ********************
   Prof. Doug Cooper 
   Chemical Engineering Dept., U-222
   University of Connecticut
   Storrs  CT  06269-3222 
   Phone: (860) 486-4092
   Fax:   (860) 486-2959
   E-mail: cooper@eng2.uconn.edu
*****************************************************
          News Group Registration Form
  "A Practical Approach to Process Control"
          Held at the Beautiful
  University of Connecticut Storrs Campus
            8:00 a.m.- 4:00 p.m.
Check One: 
____March 17 & 18, 1997
____June 23 & 24, 1997
Name:___________________________________________
Title:_____________________________________________
Organization Name:__________________________________________
Address:____________________________________________________
City:_________________State:_____________Zip:_______________
Business Phone:______________________________________
Business Fax:________________________________________
E-Mail:______________________________________________
Mail completed form and check or purchase order for $795, 
payable to The UNIVERSITY OF CONNECTICUT, to:
       Prof. Doug Cooper 
       Chemical Engineering Dept.
       University of Connecticut, U-222 
       Storrs  CT  06269-3222
       Phone: (860) 486-4092
       Fax:   (860) 486-2959
       E-mail: cooper@eng2.uconn.edu

hi all,
I'm working on a project of CAE system for deep drawing die design in aeronautic industry. 
I think the CAETROK is a similar project for automotive industry. I'd like to get more general information about CAETROK and the adress or e-mail of persons who are working on it.
Thanks in advance. If you know any project on this topic, please inform me.
Droping me a copy will be very appreciated.
Best Regards.
duprieu@enstimac.fr

	I'm developing a technical office, and I'm looking for
software or information about comercial software about the next:
	. Industrial factories
	. Steam machines
	. Compressed air
	. low voltage electrical system
	. high voltage electrical system
	. ground references
	If you know something about, could you send me an e-mail giving me
the references to find that I'm looking for?.
	Thank you.
	e-mail: efr@bebe.uv.es
	Eduardo Figueres Romero
	C/Belgica,4 - 22
	46021 Valencia (SPAIN)

In article ,
   kcb@phoenix.net (K. C. Bennett) wrote:
>Status report:
>
>There are currently three separate investigations going on:  OSHA, the
>Wyman-Gordon company, and an independent investigation by lawyers for the
>family of one of the men killed in the accident.  According to the Houston
>Chronicle, they expect some results within a week or two.
>
>There was a joint memorial service here in northwest Houston this past
>Sunday, attended by over 2000 people.
>
>K. C. Bennett
Having been through a refining incident where a fatality occurred, I have to 
say at this point: 1) The private investigation (by the lawyers) will not be 
release at this point (parts yes, at trial maybe, if settled probably not), 
2) OSHA may be leaving the site but you will not see their final report for 
at least 3 months (probably longer, and maybe never), and 3) Any report by 
the company will be considered (rightly or wrongly) suspect and biased.
It is a shame that these events occur. If the company was truly at fault, 
the fines should be heavy. Personally (based on almost no knowlege of the 
event) my _GUESS_ is human error or not following an established procedure 
was the root cause.
My condolences to friends and families of the victims,
DAC
-------------------------------------------------------------------------
David Carrell                         All comments above are mine, and
Process Control Engineer              do not necessarily reflect the
Conoco, Inc.                          opinions of Dupont and/or Conoco,
*carrelda*@pore.dnet.dupont.com*      [and why should they]
(return address altered to reduce
adds, remove *'s for real address)

osman buyukisik  wrote in article
...
> In article <32DE6A15.5458@student.ulg.ac.be>, Stephane Paquay wrote:
> >I'm looking for a good Delaunay mesh generator 2D (C++ with sources)
> >Where can I find it ?
> >
> Try http://www.ann.jussieu.fr/freefem/doc/html/freefem.html
> freefem-3.3 has a mesher (even an adaptive one), and it is in c++.
> But check the meshing web resources as they list quite few other
> sources.
> 
> Osman
-- 
"Some people think football is a matter of life and death.
I don't like that attitude. 
I can assure them it is much more serious than that.":-Bill shankly 
LINK DOES NOT WORK