The woodworking connection isn't exactly obvious (the frame for the
solar concentrator is wood) - but I thought the project might be of
interest to at least a few of the wreckers.

It's also not so obvious that it's an engine at all - since the only
moving parts are air and water. I /think/ it's a stirling engine; and
kind of hope that one of you folks can either confirm that or tell me
what kind of engine it really is.

It's be like winning the lottery if someone could explain to me (in
terms I could understand) why and how (with formulas!) the darn thing
works so I could do some actual design.

If you're intigued by weird motors, you might want to build one of
these (should set you back less than $5).

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/StirlingProject.html

"Morris Dovey" wrote in news:44ecc013$0$34070$815e3792
@news.qwest.net:

http://www.iedu.com/DeSoto/StirlingProject.html

Why not repost the url and the question in the sci.engr.mech newsgroup?
Not a complaint about your posting here, I'm glad you did so I could see
it, but these other guys might give you a better answer if you're wanting
it explained in numbers.

Smaug Ichorfang (in ) said:

| "Morris Dovey" wrote in
| news:44ecc013$0$34070$815e3792 @news.qwest.net:
|
|| http://www.iedu.com/DeSoto/StirlingProject.html
|
| Why not repost the url and the question in the sci.engr.mech
| newsgroup? Not a complaint about your posting here, I'm glad you
| did so I could see it, but these other guys might give you a better
| answer if you're wanting it explained in numbers.

Thanks for the suggestion! I'll give it a try - I did also get some
good info on news:altsolar.thermal but don't know my way around usenet
well enough to puzzle out which groups might be most productive - so I
decided to shar it first with friends. :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

And other Newsgroups as well:
http://groups.google.com/groups?as_q...006&s afe=off

Lots of model engine enthusiasts in rec.crafts.metalworking; a lot of them
seem to be in England.

David Merrill

Smaug Ichorfang (in ) said:
|
| Why not repost the url and the question in the sci.engr.mech
| newsgroup?

David Merrill (in F0jHg.8802$aJ.4584@attbi_s21) said:

| And other Newsgroups as well:
|
http://groups.google.com/groups?as_q...l=en&as_epq=st
irling+engine&as_oq=&as_eq=&as_ugroup=&as_usubject =&as_uauthors=&lr=&a
s_drrb=q&as_qdr=&as_mind=1&as_minm=1&as_miny=1981& as_maxd=24&as_maxm=8
&as_maxy=2006&safe=off
|
| Lots of model engine enthusiasts in rec.crafts.metalworking; a lot
| of them seem to be in England.

I've subscribed to alt.engineering, alt.sci, alt.solar.thermal, and
sci.engr.mech - and think I'm getting some good info (as I learn to
frame my questions better). Web searches have been less productive,
but not completely dry. Lotsa people talk about stirlings; but not
many have much to offer in the computational area.

I'm not a model enthusiast. My next 'model' will be about 12' (~4m)
tall and built of 4" schedule 40 PVC pipe. I'm boning up on the old
pressure/volume/temperature equations and worrying over stuff that I
haven't looked at since school more than 40 years ago.

Not surprising that the Brits are more interested - the engine was
invented by the Rev R. Stirling, a Scottish minister. Here in the
States we sometimes have a NIH (not invented here) problem...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

Morris Dovey wrote:
David Merrill (in F0jHg.8802$aJ.4584@attbi_s21) said:

| And other Newsgroups as well:
|
http://groups.google.com/groups?as_q...l=en&as_epq=st
irling+engine&as_oq=&as_eq=&as_ugroup=&as_usubject =&as_uauthors=&lr=&a
s_drrb=q&as_qdr=&as_mind=1&as_minm=1&as_miny=1981& as_maxd=24&as_maxm=8
&as_maxy=2006&safe=off
|
| Lots of model engine enthusiasts in rec.crafts.metalworking; a lot
| of them seem to be in England.

I've subscribed to alt.engineering, alt.sci, alt.solar.thermal, and
sci.engr.mech - and think I'm getting some good info (as I learn to
frame my questions better). Web searches have been less productive,
but not completely dry. Lotsa people talk about stirlings; but not
many have much to offer in the computational area.

I'm not a model enthusiast. My next 'model' will be about 12' (~4m)
tall and built of 4" schedule 40 PVC pipe. I'm boning up on the old
pressure/volume/temperature equations and worrying over stuff that I
haven't looked at since school more than 40 years ago.

Not surprising that the Brits are more interested - the engine was
invented by the Rev R. Stirling, a Scottish minister. Here in the
States we sometimes have a NIH (not invented here) problem...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto


PV/T = constant (if memory serves)
mahalo, (and apologies if memory doesn't serve)
jo4hn

As usual, you have found something very interesting, Morris.

I'm doing some in-depth research into PV's. Wind interests me too.

Ahhhh to have the time...

r

Here's an interesting site and FAQ about Stirling engines.

It is a Stirling engine and they are in use today in way's you never thought
about. From submarines to cooling infrared devices..... according to the
FAQ on this site.

http://www.stirlingengine.com/faq/on...ublic&faq_id=1

Bob S.


"Morris Dovey" wrote in message
...
The woodworking connection isn't exactly obvious (the frame for the
solar concentrator is wood) - but I thought the project might be of
interest to at least a few of the wreckers.

It's also not so obvious that it's an engine at all - since the only
moving parts are air and water. I /think/ it's a stirling engine; and
kind of hope that one of you folks can either confirm that or tell me
what kind of engine it really is.

It's be like winning the lottery if someone could explain to me (in
terms I could understand) why and how (with formulas!) the darn thing
works so I could do some actual design.

If you're intigued by weird motors, you might want to build one of
these (should set you back less than $5).

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/StirlingProject.html

BobS (in ) said:

| Here's an interesting site and FAQ about Stirling engines.
|
| It is a Stirling engine and they are in use today in way's you
| never thought about. From submarines to cooling infrared
| devices..... according to the FAQ on this site.
|
| http://www.stirlingengine.com/faq/on...ublic&faq_id=1

Thanks for the confirmation!

Interesting FAQ. I had wondered about the reversability of the
stirling cycle (whether the engine would produce both hot and cold if
mechanical energy was supplied).

I still haven't found anything I could recognize as computationally
useful...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

BobS wrote:
Here's an interesting site and FAQ about Stirling engines.

It is a Stirling engine and they are in use today in way's you never thought
about. From submarines to cooling infrared devices..... according to the
FAQ on this site.

http://www.stirlingengine.com/faq/on...ublic&faq_id=1


I'm not so sure that its a true Stirling engine. Notice that the
heating
part of the cycle corresponds to when the water is being heated, and
the cooling part of the cycle occurs when the water level in the
heater drops below the heater so I think that evaporation and
condensation of the water plays a role. There is no phase change in
a true Stirling engine, right?

It looks to be a more sophisticated version of the 'putt-putt' toy
boat engines made in India and sold as toys. Basicly a vaccuum
engine (low-pressure steam engine) with the water doing double
duty as both the working fluid and the counterweight.

This one would operate without actually boiling, depending
on the vapor pressure of water as a function of temperature.

But if most of the volume change in the air loop is due to expansion
rather than evaporation then the phase is just a means of transfering
heat to the air and it would be predominately a Stirling engine.

--

FF

See? Posting here was a good idea:

http://www.garrettwade.com/jump.jsp?...oductID=107207

-Zz

Zz Yzx (in ) said:

| See? Posting here was a good idea:
|
|
http://www.garrettwade.com/jump.jsp?...07207&itemType
=PRODUCT&iProductID=107207

Cute little things, aren't they? I admit that I wouldn't have guessed
Garrett Wade would be selling them - but I like the smaller number of
moving parts (and the cost) of mine better.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

On Wed, 23 Aug 2006 15:48:37 -0500, "Morris Dovey" wrote:

The woodworking connection isn't exactly obvious (the frame for the
solar concentrator is wood) - but I thought the project might be of
interest to at least a few of the wreckers.

It's also not so obvious that it's an engine at all - since the only
moving parts are air and water. I /think/ it's a stirling engine; and
kind of hope that one of you folks can either confirm that or tell me
what kind of engine it really is.

It's be like winning the lottery if someone could explain to me (in
terms I could understand) why and how (with formulas!) the darn thing
works so I could do some actual design.

If you're intigued by weird motors, you might want to build one of
these (should set you back less than $5).

Morris,

Check out this site. I knew one of these guys about a lifetime ago. He had an old three tailed
Mooney he used for aerobatics. Anyway, they've been working on this, originally for third world
applications, since the early 70's.

http://www.sunpower.com/

Athens is a great town. Small town feeling, but high tech due to the university.

Regards,
Roy

Roy (in ) said:

| Check out this site. I knew one of these guys about a lifetime
| ago. He had an old three tailed Mooney he used for aerobatics.
| Anyway, they've been working on this, originally for third world
| applications, since the early 70's.
|
| http://www.sunpower.com/
|
| Athens is a great town. Small town feeling, but high tech due to
| the university.

Thanks! I'd already visited their web site and decided that those
folks and I have very different views about what's affordable for
those developing areas most in need of this kind of technology. I've
saved their home page URL for revisiting from time to time.

Your comments about Athens echo what I've heard from students and
alums. I've never visited there - but think it'd be enjoyable.

I'm very much a newcomer to stirling design - but I've been working
(off and on) on the collection of solar radiation since early 70's and
that first OPEC crunch.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/StirlingProject.html

Wed, Aug 23, 2006, 3:48pm (EDT-1) (Morris*Dovey) said
something about:
The woodworking connection isn't exactly obvious (the frame for the
solar concentrator is wood) - but I thought the project might be of
interest to at least a few of the wreckers. snip

Put it ta work.
http://www.geocities.com/wastewatts/boatpage.html



JOAT
Justice was invented by the innocent.
Mercy and lawyers were invented by the guilty.

J T (in ) said:

| Wed, Aug 23, 2006, 3:48pm (EDT-1) (Morris Dovey)
| said something about:
| The woodworking connection isn't exactly obvious (the frame for the
| solar concentrator is wood) - but I thought the project might be of
| interest to at least a few of the wreckers. snip
|
| Put it ta work.
| http://www.geocities.com/wastewatts/boatpage.html

I've been fascinated by stirling-powered boats; but don't have the
metalworking skills or tools to build anything other than the boat
itself. :-(

Of course, I'd want the boat to be solar-powered...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

Fri, Aug 25, 2006, 7:05pm (EDT-1) (Morris*Dovey) doth
sayeth:
I've been fascinated by stirling-powered boats; but don't have the
metalworking skills or tools to build anything other than the boat
itself. :-(
Of course, I'd want the boat to be solar-powered...

I think this one is even cooler.
http://www.geocities.com/Yosemite/Rapids/2068/JT.html

Just getcha a hacksaw and a wire welder, then buy tubing the right
size. No biggie. Personally, my thing is steam, more power.

Solar would be OK, if you were going to run a water pump, that
wouln't be expected to pump constantly, clouds you know, in a remote
location. Or, just wanted a toy. For a boat, or something serious,
you'd pretty much have to be in a desert to get sufficient sunlight to
run whatever, and there ain't that much water in deserts.

In a boat, I would consider solar a dream. Too many days with
clouds that would hamper the solar part, unless you had batteries as a
backup. Solar sounds very ecologically sound, but then you've got to
figure in the manufacturing processes required to make the solar panels
and/or batteries - some of them are very nasty. The tree huggers and
dandylion eaters never seem to factor any of that in when they applaud
solar and all.
If you were serious you'd pretty much have to use a gaseous,
liquid, or solid, fuel to get any useful work out of one. Why not go
for sawdust as fuel? Then you could tell your wife you'd have to do
more woodworking to get enough fuel to take her out joyriding in your
boat.

Me, I'm eventually planning on steam, Diesel or propane for fuel -
better control than solid fuel. Probably a side-wheeler - I like the
looks better, and much better for shallow water than a prop. Monotube
boiler of course. Definitely a wooden boat. Mind not made up on
engine(s) choice yet. I can get plans to make one from scratch, no
casting. Got several plans to make several versions from scratch,
machining needed. Or, convert something to steam. Many possibilities.
But other projects have precedance, for now.

May check out this for a propulsion option later, different boat of
course. http://www.rbbi.com/company/pursuit/pursuit.htm



JOAT
Justice was invented by the innocent.
Mercy and lawyers were invented by the guilty.

J T (in ) said:

| Fri, Aug 25, 2006, 7:05pm (EDT-1) (Morris Dovey)
| doth sayeth:
| I've been fascinated by stirling-powered boats; but don't have the
| metalworking skills or tools to build anything other than the boat
| itself. :-(
| Of course, I'd want the boat to be solar-powered...
|
| I think this one is even cooler.
| http://www.geocities.com/Yosemite/Rapids/2068/JT.html

I like that. My dream boat is (would be) a 50' sailing cat with fuel
cells for on-board power and stirling cycle backup auxillary engines.
I'd need an on-board workshop, of course.

| Solar would be OK, if you were going to run a water pump, that
| wouln't be expected to pump constantly, clouds you know, in a remote
| location. Or, just wanted a toy. For a boat, or something serious,
| you'd pretty much have to be in a desert to get sufficient sunlight
| to run whatever, and there ain't that much water in deserts.

You might be surprised. There are a number of major deserts that are
deserts precisely because all the water is unusably/inconveniently
below the surface.

| In a boat, I would consider solar a dream. Too many days with
| clouds that would hamper the solar part, unless you had batteries
| as a backup. Solar sounds very ecologically sound, but then you've
| got to figure in the manufacturing processes required to make the
| solar panels and/or batteries - some of them are very nasty. The
| tree huggers and dandylion eaters never seem to factor any of that
| in when they applaud solar and all.

I agree (unless someone points out that the breeze that pushes a
sailboat is just an indirect use of solar energy) - PV manufacturing
can be pretty clean; but I'm not as sure about batteries. We still
have a lot to learn about how to store energy.

The greenies are just like everyone else - they see what they want to
see and ignore the rest until it bumps 'em in the nose. I think their
intentions are good - but they seem as prone as anyone to not consider
what the consequences would be if all their dreams came true.

| If you were serious you'd pretty much have to use a gaseous,
| liquid, or solid, fuel to get any useful work out of one. Why not
| go for sawdust as fuel? Then you could tell your wife you'd have
| to do more woodworking to get enough fuel to take her out joyriding
| in your boat.

This is a non-problem. The x decided I was too boring and left. I work
wood (to pay the bills) or sail as /I/ choose.

| Me, I'm eventually planning on steam, Diesel or propane for
| fuel - better control than solid fuel. Probably a side-wheeler - I
| like the looks better, and much better for shallow water than a
| prop. Monotube boiler of course. Definitely a wooden boat. Mind
| not made up on engine(s) choice yet. I can get plans to make one
| from scratch, no casting. Got several plans to make several
| versions from scratch, machining needed. Or, convert something to
| steam. Many possibilities. But other projects have precedance, for
| now.

I enjoy sailing in deep water and I enjoy paddling my kayack in
shallow water.

| May check out this for a propulsion option later, different
| boat of course. http://www.rbbi.com/company/pursuit/pursuit.htm

Interesting! I wonder how efficient it is...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

Sat, Aug 26, 2006, 12:00am (EDT-1) (Morris*Dovey)
reports back thusly:
I like that. My dream boat is (would be) a 50' sailing cat with fuel
cells for
on-board power and stirling cycle
backup auxillary engines. I'd need an
on-board workshop, of course.

Ah, that's a bit different story. Haven't kept up with fuel
cells, but I don't think they're far enough along for that, or at least
not at a reasonable price. Stirling power for on-board power I think
could well work, maybe even your solar way. Just not for propulsion.
Been some recent advances using Diesel fuel for cooking, heading,
refigeration, et al, if you opted to go that way..

You might be surprised. There are a
number of major deserts that are
deserts precisely because all the water is unusably/inconveniently
below the
surface.

Yeah, I knew a bout the underground water. It's a real bitch tho,
getting to the launch ramps.

I agree (unless someone points out that the breeze that pushes a
sailboat is just an indirect use of solar energy) - PV
manufacturing can be pretty clean; but
I'm not as sure about batteries. We still have a lot to learn about
how to store
energy.

The key word is indiret. Clean manufacturing, but production of a
lot of nasty waste. And things like sulferic acid aren't nice to
be/have around.

The greenies are just like everyone else - they see what they want
to see and
ignore the rest until it bumps 'em in the nose. I think their
intentions are good -
but they seem as prone as anyone to
not consider what the consequences
would be if all their dreams came true.

The daisy eaters have a right to their own opinion. I guess. It's
when they start doing things like spiking trees they should have their
right to an opinion taken away. Besides the rist of injuring or killing
unsuspecting loggers, who have families to support, spikes are not good
for the trees they're so worried about. I guess they figure the end
justifies the means. A lot of them are also anti-hunters, who don't
realize the game conservation funds come from the taxes on hunting and
sporting equipment and licenses.

This is a non-problem. The x decided I
was too boring and left. I work wood (to pay the bills) or sail as
/I/ choose.

Ah, exes. Different subject altogether. A subject for a different
time and place.

Interesting! I wonder how efficient it is..

Supposedly quite. With a monotube boiler there'd be no problem of
producing steam for long periods. Any flammable fuel could be used.
Wood, grass, corn stals, charcoal, coal, used oil, vegetable oil,
propane, etc. Make a combo boiler, that would use a gaseous and/or
liquid fuel, and then could use driftwood in a pinch. Or, just use
driftwood, period. Many options. I've skimmed over the info and think
it should do fine (I'm no marine engineeer tho). If water jet power can
work, why not? Or a water pump.
http://www.belljar.net/jetboatdevel1.htm



JOAT
Justice was invented by the innocent.
Mercy and lawyers were invented by the guilty.

Morris Dovey wrote:
...

It's be like winning the lottery if someone could explain to me (in
terms I could understand) why and how (with formulas!) the darn thing
works so I could do some actual design.
...



If you brouse the engineering texts at your local University Library
you can probably find an explanation of the underlying theroy--if you
don't find it online.I remember covering it and the professor demoed
a sterno powered desktop unit in the classroom. It has been too
long for me to remember much about it though.

Also many years ago a friend told me that the had seen a solar-
powered Stirling engine powered water pump that had been
designed for farm use--similar to the wind powered uints. It
may have been a manufactured unit.

I'll bet it was similar to your design. One problem I see with
the simple open loop design is that evaporation and condensation
will transfer water from the engine to the pump resevoir. It will
require periodic repriming.

Maybe that could be done automatically.

Thanks for posting.

--

FF

(in
) said:

| Morris Dovey wrote:
||
|| It's be like winning the lottery if someone could explain to me (in
|| terms I could understand) why and how (with formulas!) the darn
|| thing works so I could do some actual design.
|
| If you brouse the engineering texts at your local University Library
| you can probably find an explanation of the underlying theroy--if
| you don't find it online.I remember covering it and the professor
| demoed a sterno powered desktop unit in the classroom. It has been
| too long for me to remember much about it though.

I've had two "toy" sterlings - one was heated by a small alcohol
burner and the other used a small parabolic dish. Both engines had two
pistons separated by 90 degrees tied to a common crankshaft. They were
fascinating; but not particularly educational. As far as I was
concerned, they may as well have been PFM-powered.

| Also many years ago a friend told me that the had seen a solar-
| powered Stirling engine powered water pump that had been
| designed for farm use--similar to the wind powered uints. It
| may have been a manufactured unit.

I wish I'd seen it!

| I'll bet it was similar to your design. One problem I see with
| the simple open loop design is that evaporation and condensation
| will transfer water from the engine to the pump resevoir. It will
| require periodic repriming.
|
| Maybe that could be done automatically.

Perhaps. I'll just have to get the darned thing built and see how much
fluid loss there actually is. I may be able to get by with just a few
drops of oil or some styrofoam beads/fluff in the open column.

| Thanks for posting.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto

Morris Dovey wrote:
(in
) said:
...
I've had two "toy" sterlings - one was heated by a small alcohol
burner and the other used a small parabolic dish. Both engines had two
pistons separated by 90 degrees tied to a common crankshaft. They were
fascinating; but not particularly educational. As far as I was
concerned, they may as well have been PFM-powered.

You can't tell much by looking at the outside of the engine.


| Also many years ago a friend told me that the had seen a solar-
| powered Stirling engine powered water pump that had been
| designed for farm use--similar to the wind powered uints. It
| may have been a manufactured unit.

I wish I'd seen it!


Quite possibly a patent desclosure could be located at the US
Patent Office. I don't know if you can search century-old patents
online.

BTW, I found that places that sell aquarium supplies, like the major
Pet store chains, have very small inexpensive check valves.

Also, did you get my email?

--

FF

(in
) said:

| Quite possibly a patent desclosure could be located at the US
| Patent Office. I don't know if you can search century-old patents
| online.

I'm not sure; but think expired patents would be valuable in terms of
"prior art".

| BTW, I found that places that sell aquarium supplies, like the major
| Pet store chains, have very small inexpensive check valves.

I hadn't (and probably wouldn't have) thought of that.

| Also, did you get my email?

I did (two of them from you and a batch from other people). I've been
frying my circuits trying to absorb all the input!

Your second e-mail suggests that what I have may actually be a
steam/stirling hybrid, and I'm still working my way through what that
means in terms of modeling not-yet-built engines.

Several other people also suggested cold-side cooling, something I
hadn't concerned myself with, and I'm taking a look at low cost ways
to do that.

I was fairly comfortable watching the little desktop unit run; and now
I'm beginning to sympathize with the centipede asked to tell how he
walks with all those legs. :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto