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Default de Laval turbine

Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


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On Mar 11, 1:22*am, "Ed Huntress" wrote:
Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


Maybe you can find a copy of:

http://www.lib.ncsu.edu/findingaids/mss00090/#IDAVNIQ

Some info he
http://www.thespacerace.com/forum/in...p?topic=2595.0

Looks like the critical bit of science is the nozzle accelerates the
steam jet to the speed of sound (and above? I assume speed of sound
for the material being run through the throat) in the constriction,
then the jet hits the divergent part of the nozzle and speeds up yet a
bit further.

Interesting stuff, and doubly cool since that principal is used in
rocket nozzle design.

So anything convergent-divergent is a de Laval nozzle.
Sounds like you could test nozzle designs just by measuring the speed
of the output jet (somehow!).

I like the brief mention he
http://www-istp.gsfc.nasa.gov/stargaze/Sgoddard.htm

" Nowadays steam turbines are the preferred power source of electric
power stations and large ships, although they usually have a different
design--to make best use of the fast steam jet, De Laval's turbine had
to run at an impractically high speed."

An impractically high speed- that makes it a cool project right there!

Dave
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Default de Laval turbine

On Mar 11, 1:22*am, "Ed Huntress" wrote:
Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


More good stuff, from astronomy sources of all places:

http://www.absoluteastronomy.com/topics/De_Laval_nozzle

http://www.mig.rssi.ru/mirrors/stern...arFAQ4.htm#q80

Dave
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Default de Laval turbine

On Mar 11, 8:08*am, wrote:
On Mar 11, 1:22*am, "Ed Huntress" wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.


Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.


I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.


Thanks to any steamers who know about these motors.


--
Ed Huntress


More good stuff, from astronomy sources of all places:

http://www.absoluteastronomy.com/topics/De_Laval_nozzle

http://www.mig.rssi.ru/mirrors/stern...arFAQ4.htm#q80

Dave



Ed,

At the following address is a very good little book on the design and
manufacture of model steam turbines:

http://ia311537.us.archive.org/2/ite...00harrrich.pdf

Also Model Engineer magazine has had articles on this subject from
time-to-time.

Wolfgang
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Default de Laval turbine

--There are a couple of articles in Model Engineer, including some
clever ways of cutting the buckets. I messed around with 'em ages ago and
wound up writing a little cnc program to make aeorfoil-shaped buckets and a
steerable inlet jet; kinda fun. The rotor was no more than 1-1/2" dia tho..

--
"Steamboat Ed" Haas : Politics is a sinkhole for
Hacking the Trailing Edge! : people without hobbies...
www.nmpproducts.com
---Decks a-wash in a sea of words---


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Default de Laval turbine

On Mar 10, 11:22*pm, "Ed Huntress" wrote:
Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


IIRC, Lindsay had some old reprints and archive.org had some stuff
buried in their old steam power books. Some of the older books are
lighter on the math and heavier on the practice, intended more for the
guys that had to maintain them. The impulse turbine is kind of dead,
the electric motor took over for running the stuff they used to use it
for, haven't seen mention of them except as historical objects in any
recent texts. When you shrink to model sizes, subtle curves in full-
size practice start resembling straight lines anyway.

Stan
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Default de Laval turbine

On Mar 11, 2:19*pm, wrote:
On Mar 10, 11:22*pm, "Ed Huntress" wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.


Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.


I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.


Thanks to any steamers who know about these motors.


--
Ed Huntress


IIRC, Lindsay had some old reprints and archive.org had some stuff
buried in their old steam power books. *Some of the older books are
lighter on the math and heavier on the practice, intended more for the
guys that had to maintain them. *The impulse turbine is kind of dead,
the electric motor took over for running the stuff they used to use it
for, haven't seen mention of them except as historical objects in any
recent texts. *When you shrink to model sizes, subtle curves in full-
size practice start resembling straight lines anyway.

Stan


Yeah, but
supersonic steam jet +
rocket nozzles +
linear equiv. speed of the rotor at about 1/2 the steam jet speed =
lotsa fun!

Where else are you going to get that much excitement with 1 moving
part?


Dave
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wrote in message
...
On Mar 11, 1:22 am, "Ed Huntress" wrote:
Has anyone ever built a model of a de Laval turbine? I mean one with a
real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


Maybe you can find a copy of:

http://www.lib.ncsu.edu/findingaids/mss00090/#IDAVNIQ

Some info he
http://www.thespacerace.com/forum/in...p?topic=2595.0

Looks like the critical bit of science is the nozzle accelerates the
steam jet to the speed of sound (and above? I assume speed of sound
for the material being run through the throat)...


Right. Which is much higher than the speed of sound in the atmosphere.

...in the constriction,
then the jet hits the divergent part of the nozzle and speeds up yet a
bit further.


I forget most of the dynamics, but it's pretty wild.

Interesting stuff, and doubly cool since that principal is used in
rocket nozzle design.


So anything convergent-divergent is a de Laval nozzle.
Sounds like you could test nozzle designs just by measuring the speed
of the output jet (somehow!).


Well, de Laval invented the thing (I think), so they use his name on it when
it's applied to steam turbines. There are old engineering texts I've seen
that provide formulas for all of the dimensions, based on steam temperature,
superheat, pounds of steam produced, and so on.

I like the brief mention he
http://www-istp.gsfc.nasa.gov/stargaze/Sgoddard.htm


" Nowadays steam turbines are the preferred power source of electric
power stations and large ships, although they usually have a different
design--to make best use of the fast steam jet, De Laval's turbine had
to run at an impractically high speed."


An impractically high speed- that makes it a cool project right there!


Dave


Even the little ones made for doing farm jobs, around the turn of the 20th
century, turned at speeds around 30,000 rpm. I have no idea how they held
together, given the state of metallurgy at that time.

--
Ed Huntress


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wrote in message
...
On Mar 11, 1:22 am, "Ed Huntress" wrote:
Has anyone ever built a model of a de Laval turbine? I mean one with a
real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


More good stuff, from astronomy sources of all places:


http://www.absoluteastronomy.com/topics/De_Laval_nozzle

http://www.mig.rssi.ru/mirrors/stern...arFAQ4.htm#q80

Dave


Thanks, Dave. I'm collecting a good set of references here. I have them all
saved for the next rainy weekend.

--
Ed Huntress


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wrote in message
...
On Mar 11, 8:08 am, wrote:
On Mar 11, 1:22 am, "Ed Huntress" wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a
real
de Laval nozzle, that put out some power.


Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.


I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.


Thanks to any steamers who know about these motors.


--
Ed Huntress


More good stuff, from astronomy sources of all places:

http://www.absoluteastronomy.com/topics/De_Laval_nozzle

http://www.mig.rssi.ru/mirrors/stern...arFAQ4.htm#q80

Dave



Ed,


At the following address is a very good little book on the design and
manufacture of model steam turbines:


http://ia311537.us.archive.org/2/ite...00harrrich.pdf

Also Model Engineer magazine has had articles on this subject from
time-to-time.


Wolfgang


Great. Thanks, Wolfgang.

--
Ed Huntress


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"steamer" wrote in message
...
--There are a couple of articles in Model Engineer, including some
clever ways of cutting the buckets.


That's one of the things I most want to see. I don't have time to reinvent
it all.

I messed around with 'em ages ago and
wound up writing a little cnc program to make aeorfoil-shaped buckets and
a
steerable inlet jet; kinda fun. The rotor was no more than 1-1/2" dia
tho..


I'd like to make something around 6" diameter, if I can.

Thanks, Ed.

--
Ed Huntress




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wrote in message
...
On Mar 10, 11:22 pm, "Ed Huntress" wrote:
Has anyone ever built a model of a de Laval turbine? I mean one with a
real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

--
Ed Huntress


IIRC, Lindsay had some old reprints and archive.org had some stuff
buried in their old steam power books. Some of the older books are
lighter on the math and heavier on the practice, intended more for the
guys that had to maintain them. The impulse turbine is kind of dead,
the electric motor took over for running the stuff they used to use it
for, haven't seen mention of them except as historical objects in any
recent texts. When you shrink to model sizes, subtle curves in full-
size practice start resembling straight lines anyway.


Stan


I've tried plucking out information from old steam books, but they've
generally been disappointing. There was one I saw years ago that analyzed
some of de Laval's actual production models, and that was great. But I have
no idea how to find it now.

Anyway, it's one of those pursuits that's a good challenge, and I'd like to
fool with it as I have time.

--
Ed Huntress


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On Fri, 13 Mar 2009 16:42:57 -0400, "Ed Huntress"
wrote:


"Mark Rand" wrote in message
.. .
On Wed, 11 Mar 2009 11:19:50 -0700 (PDT), wrote:


The impulse turbine is kind of dead,
the electric motor took over for running the stuff they used to use it
for, haven't seen mention of them except as historical objects in any
recent texts.


GE turbines are/were impulse rather than reaction based for the HP and IP
cylinders as were GEC in the UK and Alcatel-Alstom in France. That's
something
like 50% of the installed base in the world. Impulse turbines are
certainly
not kind of dead, I walked past two impulse rotors this afternoon in the
erecting shop at work!


Mark Rand
RTFM


I don't know about now, but I was under the impression that large steam
turbines for years were hybrids, with one or two impulse stages followed by
a series of reaction stages.



It tends to be a graduation rather than completely one or the other. It tends
to be more impulse at the HP end and more reaction at the LP end, but there
are/were major differences in proportion. Causes problems when major companies
merge, you don't always end up with an optimum design :-|


The major difference in philosophy is that in an impulse design all the
pressure drop is across the diaphragms (fixed stages). So you can make the
rotor similar to a series of disks on a thinner shaft. This way, the
interstage glands where all the pressure drop is (diaphragm to rotor) are
shorter, due to being on a smaller diameter. The blade tip seals are far less
significant doe to the token pressure drop across the moving stage. Because
there's no pressure drop across the moving blades, there's no end-thrust
issue. The disks even have (pressure) balance holes to ensure this.

Reaction design turbines tend to be made with a barrel type rotor since the
pressure drop across fixed and moving blades is similar, so you can't benefit
from a shorter length of gland and you don't want a great big pneumatic piston
effect generating end thrust on each stage. Obviously on a double flow
cylinder, the end thrusts should balance. but on a single flow cylinder you've
got problems.

You can also play games like 100% impulse near the centre and 100% reaction
near the tips for long blades. CFD is wonderful :-)


regards
Mark Rand
RTFM
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"Mark Rand" wrote in message
...
On Fri, 13 Mar 2009 16:42:57 -0400, "Ed Huntress"

wrote:


"Mark Rand" wrote in message
. ..
On Wed, 11 Mar 2009 11:19:50 -0700 (PDT), wrote:


The impulse turbine is kind of dead,
the electric motor took over for running the stuff they used to use it
for, haven't seen mention of them except as historical objects in any
recent texts.

GE turbines are/were impulse rather than reaction based for the HP and
IP
cylinders as were GEC in the UK and Alcatel-Alstom in France. That's
something
like 50% of the installed base in the world. Impulse turbines are
certainly
not kind of dead, I walked past two impulse rotors this afternoon in the
erecting shop at work!


Mark Rand
RTFM


I don't know about now, but I was under the impression that large steam
turbines for years were hybrids, with one or two impulse stages followed
by
a series of reaction stages.



It tends to be a graduation rather than completely one or the other. It
tends
to be more impulse at the HP end and more reaction at the LP end, but
there
are/were major differences in proportion. Causes problems when major
companies
merge, you don't always end up with an optimum design :-|


The major difference in philosophy is that in an impulse design all the
pressure drop is across the diaphragms (fixed stages). So you can make the
rotor similar to a series of disks on a thinner shaft. This way, the
interstage glands where all the pressure drop is (diaphragm to rotor) are
shorter, due to being on a smaller diameter. The blade tip seals are far
less
significant doe to the token pressure drop across the moving stage.
Because
there's no pressure drop across the moving blades, there's no end-thrust
issue. The disks even have (pressure) balance holes to ensure this.

Reaction design turbines tend to be made with a barrel type rotor since
the
pressure drop across fixed and moving blades is similar, so you can't
benefit
from a shorter length of gland and you don't want a great big pneumatic
piston
effect generating end thrust on each stage. Obviously on a double flow
cylinder, the end thrusts should balance. but on a single flow cylinder
you've
got problems.

You can also play games like 100% impulse near the centre and 100%
reaction
near the tips for long blades. CFD is wonderful :-)


regards
Mark Rand
RTFM


It sounds like more formulas and calculations than I would do for fun. d8-)

'Too bad Tesla's turbine didn't pan out the way he thought it would. It sure
would make life simpler.

--
Ed Huntress


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Ed Huntress wrote:

That's one of the things I most want to see. I don't have time to reinvent
it all.

--Tellyawhat I'll take some photos today; somewhere I've got a little
display I made that illustrates the steps required to machine a complete
rotor.

I'd like to make something around 6" diameter, if I can.

--That's massive! IIRC the one Bill Lear made for his sand racer
only had a 4" dia rotor and was rated over 100hp!


--
"Steamboat Ed" Haas : Politics is a sinkhole for
Hacking the Trailing Edge! : people without hobbies...
www.nmpproducts.com
---Decks a-wash in a sea of words---


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"steamer" wrote in message
...
Ed Huntress wrote:

That's one of the things I most want to see. I don't have time to reinvent
it all.

--Tellyawhat I'll take some photos today; somewhere I've got a little
display I made that illustrates the steps required to machine a complete
rotor.


That's great, Ed. I'll bet a lot of people here would like to see that
display.


I'd like to make something around 6" diameter, if I can.

--That's massive! IIRC the one Bill Lear made for his sand racer
only had a 4" dia rotor and was rated over 100hp!


Hmm. Maybe Lear had a reason to make it that small? I though the
single-stage de Lavals were around 6" or 8" diameter and only produced a few
horsepower.

However, that was over 100 years ago.

--
Ed Huntress



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On Mar 14, 5:34*pm, "Ed Huntress" wrote:

I'd like to make something around 6" diameter, if I can.

--That's massive! IIRC the one Bill Lear made for his sand racer
only had a 4" dia rotor and was rated over 100hp!


Hmm. Maybe Lear had a reason to make it that small? I though the
single-stage de Lavals were around 6" or 8" diameter and only produced a few
horsepower.

However, that was over 100 years ago.

--
Ed Huntress


IIRC for rocket nozzles you need to know the amount of gas first and
the atmospheric pressure where it will be used, and then you design
the nozzle.

Dan

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On Mar 14, 3:13*pm, " wrote:
On Mar 14, 5:34*pm, "Ed Huntress" wrote:

I'd like to make something around 6" diameter, if I can.
--That's massive! IIRC the one Bill Lear made for his sand racer
only had a 4" dia rotor and was rated over 100hp!


Hmm. Maybe Lear had a reason to make it that small? I though the
single-stage de Lavals were around 6" or 8" diameter and only produced a few
horsepower.


However, that was over 100 years ago.


--
Ed Huntress


IIRC for rocket nozzles you need to know the amount of gas first and
the atmospheric pressure where it will be used, and then you design
the nozzle.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Dan


The little booklet I referred to above walks you step-by-step through
the nozzle and rotor design for a model turbine.

I build 1/16 scale models of locomotive steam turbo-generators, fully
functional.

At that small size, 5/8" rotor dia. and .025" nozzle throat one can
take some liberties with the nozzle geometry. The rotor blades are
not that forgiving, even in small sizes. I use the Terry turbine
blade design which gives 180 deg flow return... very effective. The
small turbine described will light up 4 flashlight bulbs @ 2.5 volts @
1 amp @ 56,000 RPM, with 80 psig steam pressure. Increase the steam
pressure and it will burn out the bulbs in a flash. A pressure
regulator is necessary for unattended use on a steam locomotive.

Wolfgang
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On 15 Mar 2009 17:04:43 GMT, steamer wrote:

wrote:
I build 1/16 scale models of locomotive steam turbo-generators, fully
functional.

--You have *got* to post some photos! :-)


Agreed! That's been one of the big bugaboos to building a small steam
launch - I wouldn't have any way to run the nav lights and the oil
burner for the boiler. And while a double expansion auxiliary motor
spinning a Car Alternator through a step-up gear would work...

But it sounds like your turbine is aiming for 10W output, and the
small boat would need more like 1KW to 2KW output - unless you've got
a lot of excess capacity available, it might have to scale up one
notch.

-- Bruce --


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On Mar 15, 3:47*pm, Bruce L. Bergman
wrote:
On 15 Mar 2009 17:04:43 GMT, steamer wrote:

wrote:
I build 1/16 scale models of locomotive steam turbo-generators, fully
functional.

* *--You have *got* to post some photos! :-)


Agreed! *That's been one of the big bugaboos to building a small steam
launch - I wouldn't have any way to run the nav lights and the oil
burner for the boiler. *And while a double expansion auxiliary motor
spinning a Car Alternator through a step-up gear would work...

* But it sounds like your turbine is aiming for 10W output, and the
small boat would need more like 1KW to 2KW output - unless you've got
a lot of excess capacity available, it might have to scale up one
notch.

* -- Bruce --




I shall make an effort to post some pics over the next little while.

For electric power on a steam yacht I'd convert a 2 cylinder cast iron
automotive air conditioning compressor into a steam engine -I did this
for a friend- and run a good quality automotive alternator via a
toothed belt, speeding up the drive by say 3:1. This would keep
things quiet. Plans for this conversion were available in the popular
do-it-yourself press in the late '70's or so.

As to powering a model racing boat... It has been done. There is -
another- little book available, but not on-line as far as I know,
entitled Experimental Flash Steam. It covers the topic of steam
powered racing boats using flash or monotube boilers with piston steam
engines mostly; one experimenter did build a turbine powered boat.

It is a fascinating book if you can find a copy, covering details such
as feed, fuel, and oil pumps, and controls.

I think that a 1 to 2 KW small steam turbine is doable especially if
you don't need electric output or if it doesn't have to look "scale".
My little turbine's output is primarily limited by the scale
alternator... you can only squeeze so many turns of a certain sized
wire into the available space; whereas the power can always be
increased by increasing the number of steam nozzles until you have
reached full admission ie. a full 360 deg. nozzle ring. Nothing to
stop one from fitting, at the design stage, 30, 40, or 60 steam
nozzles.

The way I would approach it would be to design the steam nozzles as a
full-admission nozzle ring and 3 or 4 pass terry turbine wheels as
these are quite easy to make. With a small CNC mill even Laval (or
was it Parson?) turbine wheels are not difficult to make.

Turbines are a fascinating subset of the live steam hobby and I would
encourage those interested to have a go. But read up on it first as
there is no sense in re-inventing the wheel.

Wolfgang
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On Wed, 11 Mar 2009 01:22:23 -0400, "Ed Huntress"
wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.


Ed, I'm not a steamer but have made quite a few de Laval nozzles in
graphite, for small rocket motors. For motors under 1.5" diameter,
the nozzles were (usually) formed using an ordinary 82 degree
countersink for the entrance cone and a 29 degree cone-shaped carbide
burr for the exit cone. They worked a treat.

Rules of thumb for rocket motors operating at about 600-1000 psi (may
have nothing whatever to do with steam): diameter of exit is about 2x
diameter of nozzle throat; throat length is as short as is practical
but should not exceed 1/2 the throat diameter; rounding off the sharp
edges of the throat will improve performance.

Hope this helps -- Terry
"As a matter of fact, I *am* a rocket scientist... :-)
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"Terry" wrote in message
news
On Wed, 11 Mar 2009 01:22:23 -0400, "Ed Huntress"
wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a
real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.


Ed, I'm not a steamer but have made quite a few de Laval nozzles in
graphite, for small rocket motors. For motors under 1.5" diameter,
the nozzles were (usually) formed using an ordinary 82 degree
countersink for the entrance cone and a 29 degree cone-shaped carbide
burr for the exit cone. They worked a treat.

Rules of thumb for rocket motors operating at about 600-1000 psi (may
have nothing whatever to do with steam): diameter of exit is about 2x
diameter of nozzle throat; throat length is as short as is practical
but should not exceed 1/2 the throat diameter; rounding off the sharp
edges of the throat will improve performance.

Hope this helps -- Terry
"As a matter of fact, I *am* a rocket scientist... :-)


It's a great help, Terry. The hard part of this, for me at least, has always
been to get *practical* information, and every bit helps.

Finally I'm accumulating some here. Now, all I need is time to put it to
use.

--
Ed Huntress


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Default de Laval turbine

On Wed, 11 Mar 2009 01:22:23 -0400, Ed Huntress wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a
real de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.



Ed, I've uploaded a bunch of pages relative to turbines, 3 of which pages
contain references to Model Engineer articles on building model turbines;
they're at:
http://www.box.net/shared/7fe502646h

In ME No. 4320, 29 Feb.13 Mar 2008, is the second part of an article on a
gauge 1 turbine loco pp.274-277. with some information on cutting the
turbine blades.

HTH,
Mike in BC
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"Michael Gray" wrote in message
news:AsQwl.17741$Db2.1307@edtnps83...
On Wed, 11 Mar 2009 01:22:23 -0400, Ed Huntress wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a
real de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.



Ed, I've uploaded a bunch of pages relative to turbines, 3 of which pages
contain references to Model Engineer articles on building model turbines;
they're at:
http://www.box.net/shared/7fe502646h

In ME No. 4320, 29 Feb.13 Mar 2008, is the second part of an article on a
gauge 1 turbine loco pp.274-277. with some information on cutting the
turbine blades.

HTH,
Mike in BC


Hey, thanks, Mike. They look great.

Far be it from me to look a gift horse in the mouth, but for future
reference, you might consider using the compressed TIFF format, rather than
JPEG, when you want to reproduce a printed page. Because of the way the JPEG
compression works, it makes the edges of letters (and any sharp edges)
fuzzy, the fuzziness depending on how much you're compressing. TIFF doesn't
do that, and you can save the space involved in reproducing color, if those
settings are available to you. For an all-type page, or one with type and
line drawings, you can use 2-bit compressed TIFF and usually you'll get a
file that's both smaller than the equivalent JPEG, and much easier to read.
It also prints much better.

However, in this case, I can read those pages perfectly well. I'm going to
take a close look this weekend.

Thanks again.

--
Ed Huntress




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Default de Laval turbine

On Fri, 20 Mar 2009 13:51:15 -0400, Ed Huntress wrote:

"Michael Gray" wrote in message
news:AsQwl.17741$Db2.1307@edtnps83...
On Wed, 11 Mar 2009 01:22:23 -0400, Ed Huntress wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a
real de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple
or they're too abstract on the engineering theory side.



Ed, I've uploaded a bunch of pages relative to turbines, 3 of which
pages contain references to Model Engineer articles on building model
turbines; they're at:
http://www.box.net/shared/7fe502646h

In ME No. 4320, 29 Feb.13 Mar 2008, is the second part of an article on
a gauge 1 turbine loco pp.274-277. with some information on cutting the
turbine blades.

HTH,
Mike in BC


Hey, thanks, Mike. They look great.

Far be it from me to look a gift horse in the mouth, but for future
reference, you might consider using the compressed TIFF format, rather
than JPEG, when you want to reproduce a printed page. Because of the way
the JPEG compression works, it makes the edges of letters (and any sharp
edges) fuzzy, the fuzziness depending on how much you're compressing.
TIFF doesn't do that, and you can save the space involved in reproducing
color, if those settings are available to you. For an all-type page, or
one with type and line drawings, you can use 2-bit compressed TIFF and
usually you'll get a file that's both smaller than the equivalent JPEG,
and much easier to read. It also prints much better.

However, in this case, I can read those pages perfectly well. I'm going
to take a close look this weekend.

Thanks again.


Thank you for the advice, don't worry I shan't get in a tiff about
it. :-)

Mike in BC
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"Michael Gray" wrote in message
news:%qUwl.18901$PH1.10418@edtnps82...
On Fri, 20 Mar 2009 13:51:15 -0400, Ed Huntress wrote:

"Michael Gray" wrote in message
news:AsQwl.17741$Db2.1307@edtnps83...
On Wed, 11 Mar 2009 01:22:23 -0400, Ed Huntress wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a
real de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple
or they're too abstract on the engineering theory side.


Ed, I've uploaded a bunch of pages relative to turbines, 3 of which
pages contain references to Model Engineer articles on building model
turbines; they're at:
http://www.box.net/shared/7fe502646h

In ME No. 4320, 29 Feb.13 Mar 2008, is the second part of an article on
a gauge 1 turbine loco pp.274-277. with some information on cutting the
turbine blades.

HTH,
Mike in BC


Hey, thanks, Mike. They look great.

Far be it from me to look a gift horse in the mouth, but for future
reference, you might consider using the compressed TIFF format, rather
than JPEG, when you want to reproduce a printed page. Because of the way
the JPEG compression works, it makes the edges of letters (and any sharp
edges) fuzzy, the fuzziness depending on how much you're compressing.
TIFF doesn't do that, and you can save the space involved in reproducing
color, if those settings are available to you. For an all-type page, or
one with type and line drawings, you can use 2-bit compressed TIFF and
usually you'll get a file that's both smaller than the equivalent JPEG,
and much easier to read. It also prints much better.

However, in this case, I can read those pages perfectly well. I'm going
to take a close look this weekend.

Thanks again.


Thank you for the advice, don't worry I shan't get in a tiff about
it. :-)

Mike in BC


Ugh... Well, it's strictly in the interest of better computing for all. d8-)

--
Ed Huntress


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Thank you for the advice, don't worry I shan't get in a tiff about it.
:-)

Mike in BC


Ugh... Well, it's strictly in the interest of better computing for all.
d8-)


Perhaps I should have put ("English humour") rather than a smiley face -
I really do appreciate your telling me about the TIFF file compression.
Or was your "Ugh" at the low level of my pun? Apologies offered.
Mike
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"Michael Gray" wrote in message
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Thank you for the advice, don't worry I shan't get in a tiff about it.
:-)

Mike in BC


Ugh... Well, it's strictly in the interest of better computing for all.
d8-)


Perhaps I should have put ("English humour") rather than a smiley face -
I really do appreciate your telling me about the TIFF file compression.
Or was your "Ugh" at the low level of my pun?


Yes. g

Apologies offered.
Mike


I'll get over it.

Anyway, I'm looking forward to reading what you provided and learning more
about these things. I saw a de Laval cream separator on my family's farm in
New Hampshire over 50 years ago, and maybe I got fascinated by the name. But
I'm impressed with the sophistication of de Laval's (and others')
engineering on steam turbines in the late 19th century. They were really
pushing the envelope.

--
Ed Huntress


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Anyway, I'm looking forward to reading what you provided and learning
more about these things. I saw a de Laval cream separator on my family's
farm in New Hampshire over 50 years ago, and maybe I got fascinated by
the name. But I'm impressed with the sophistication of de Laval's (and
others') engineering on steam turbines in the late 19th century. They
were really pushing the envelope.


Ed, further to our correspondence, I've uploaded a spreadsheet listing of
Model Engineer references to model steam turbines to:
http://www.box.net/shared/mx1qds1uhc

Now THAT should keep you busy for the weekend. Hope you have access to a
library with old MEs.

Mike in BC
P.S. Why don't the present publishers, who seem to have a predilection
for digital whatevers, put out a complete issue on CD as National
Geographic have done? Any one who'd go for this at say about $100 or so
for the first hundred years email:



Sirs, it would be of great help to those of us who constantly have to
reference back copies of Model Engineer, but who don't have ready access
to those back copies, if you would consider issuing a set of CDs similar
in nature to those issued by the National Geographic magazine i.e. 100
years of back issues for a little over $100.
I am quite sure that I am not the only person who would welcome such an
offer.
There would still be a demand for "hardcopy" back issues for those who
prefer them, but a fully searchable CD would be of inestimable value to
the rest of us.
yours sincerely,

Michael Gray



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"Michael Gray" wrote in message
news:1W9xl.18988$PH1.17553@edtnps82...

Anyway, I'm looking forward to reading what you provided and learning
more about these things. I saw a de Laval cream separator on my family's
farm in New Hampshire over 50 years ago, and maybe I got fascinated by
the name. But I'm impressed with the sophistication of de Laval's (and
others') engineering on steam turbines in the late 19th century. They
were really pushing the envelope.


Ed, further to our correspondence, I've uploaded a spreadsheet listing of
Model Engineer references to model steam turbines to:
http://www.box.net/shared/mx1qds1uhc

Now THAT should keep you busy for the weekend. Hope you have access to a
library with old MEs.


Mike, I don't think I responded to this old message, but thanks. There's
half of my remaining lifetime of spare-time hobby study. g

I'll work on that one for a while.

--
Ed Huntress



Mike in BC
P.S. Why don't the present publishers, who seem to have a predilection
for digital whatevers, put out a complete issue on CD as National
Geographic have done? Any one who'd go for this at say about $100 or so
for the first hundred years email:



Sirs, it would be of great help to those of us who constantly have to
reference back copies of Model Engineer, but who don't have ready access
to those back copies, if you would consider issuing a set of CDs similar
in nature to those issued by the National Geographic magazine i.e. 100
years of back issues for a little over $100.
I am quite sure that I am not the only person who would welcome such an
offer.
There would still be a demand for "hardcopy" back issues for those who
prefer them, but a fully searchable CD would be of inestimable value to
the rest of us.
yours sincerely,

Michael Gray



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