Viv Trafalgar: The topic today is Engines!
Jasper Kiergarten: I'm on chair duty, for those who don't already have one
Serafina Puchkina: There's tea and cake on the table. Please help yourself. Fresh pot of tea! For the record, I was present this time to record Bob's presentation but he was not here this month
Viv Trafalgar: we'll get started in just a few minutes –
Beq Janus notes that everyone is sitting further back than usual; clearly the two speakers' engine building escapades have taught many a lesson already
Kat Montpark waddles forward with her chair stuck to her bum.
Alyx Sands hobbles along too
Serafina Puchkina clears her throat to begin
Viv Trafalgar: we really should race these things sometime
Serafina Puchkina: Welcome, fine ladies, elegant gents, and intelligent urchins. Miss Viv Trafalgar and I welcome you all to the eighth Aether Salon: Engines!
The number 8 in Chinese culture carries great significance. It is an auspicious number, because the Mandarin word for "8" is similar to the word for "wealth" or "prosper." "88" sounds similar to "double joy." We are positive that today’s salon will bring great wealth and prosperity to you all -- just see Bob afterwards. (::notes Bob making himself scarce::)
We are so humbled by the support we receive from everyone in the community, and we thank you all. Many fine people have contributed to today’s salon; we are grateful to Miss Ceejay Writer, Miss Breezy Carver, Miss Redgrrl Llewellyn, Miss Canolli Capalini of Capalini Fine Furnishings for the chairs, and Albus Weka and Jasper Kiergarten who helped Viv create today’s craft - make-your-own toolbelts!
Miss Viv, my co-host, is incredibly talented, compassionate, intelligent, and funny. I treasure her close friendship and support.
Hold your questions until the end, and as a courtesy to all, please turn off everything that encourages lag - (sorry sir, that internal combustion engine must go for a bit), all HUDs, scripts, AOs and so on. Please, no weapons, bombs, or running with sharp objects.
Mark your calendars for upcoming salons: Fae! in June, a brief hiatus, then Airships! in September, and Haberdashery! in October.
Check out aethersalon.blogspot.com for edited and unedited transcripts of this and previous salons, a list of speakers, photos, and assorted witticisms in the “Overheard at the Salon” section. If you would like to join the Aether Salon group and receive notifications of future salon events, click the lower right hand corner of the large brown sign by the entrance. As a reminder, all speakers' fund donations go directly to the speakers.
After the question and answer period, today’s incredibly useful craft will be distributed.
Before we ask you to start your engines... Miss Viv has a few words to say about today's speakers –
Viv Trafalgar: Welcome everyone - and thanks to my co-host the wonderful Miss Serafina Puchkina
Elfod Nemeth is an avid builder (assembling, scripting and texturing) who accepts custom bespoke builds and sells occasional items of well-scripted goodness at his shop Steam Monks. His portfolio can be found at http://knol.google.com/k/elfod-nemeth/elfod-nemeth-second-life-portfolio/
Elfod's most eye-catching builds in New Babbage are Tiny Tim and Dagon's Pier. Both are resources for the use of any visitors to or residents of Babbage; however, Tiny Tim is also Elfod's home.
The Pier is a Victorian-style pier modeled after the famous Iron Bridge. It features entertainments (with more planned) and leads, via a pleasant walk, to the giant robot Tiny Tim. Tiny Tim is a 160m tall, hollow robot. Explorers who traverse its exterior and venture inside may discover a mushroom brewery and dance floor, a couples lounge chair with sea view, a Mars Expeditionary rocket, an avatar cannon, a games room, a mushroom shredder (that should not be touched!), a second, wet dance floor, a couples tree and many places to high-dive from and swim. Tiny Tin and Dagon's Pier can be found at http://slurl.com/secondlife/Vernian%20Sea/219/39/117
Greg Merryman is a renowned mechanologist who has forgotten more about engines than many of us will learn in a lifetime. Since arriving in Babbage, Mr. Merryman has created a number of builds that have caught the eye of the discerning traveller – from the Soap Factory of yore and the Fire Station (now the Ladies' Fire Brigade House), to the stunning steel mill in Iron Bay. Greg is however very humble, saying only, "I am a student of the art of mechanics I fix things and build things."
His most recent creations include a new submarine and the tri-tanium airship, as well as scripting for the Iron Bay fleet. As for engines, they are a passion in this life and in RL. [14:11] Viv Trafalgar: Iron Bay can be found in Babbage New Babbage, http://slurl.com/secondlife/new%20babbage/101/52/102/.
Ladies and gentlemen, please put your hands together for Elfod Nemeth and Greg Merryman.
Elfod Nemeth: Good Evening all I'm going to give you a brief talk about Sterling Engines, followed by a more thorough talk covering many types of engines from Mr. Merryman.
In order to put the Sterling engine into historical context, lets look at when engines where perfected during the 19th century. When I say perfected I mean developed into a usable state where they could be put to practical use. As we can see, sterling engines where made practical in the early 19th century. The engines we see here all had their own quirks:
Steam engines were high pressure with steam as the fluid motivator (what pushes the piston), were dangerous due to poor understanding of metal fatigue, high power density generation and high maintenance. They were typically used in large applications - factories, ships, and trains.
Sterling Engines have low power density, run on ambient heat or cold source, use ordinary air as fluid motivator, extremely safe (impossible to explode), near silent operation and are very low maintenance.
Internal Combustion engines have higher density of power than ever before, use volatile explosive fuel, high maintenance and can be used in mobile applications. As a result they quickly went into went into mass production and have seen over 100 years of refinement
Viv Trafalgar: No exploding engines?
Elfod Nemeth: not from sterling engines, no
Viv Trafalgar: well hmph
Elfod Nemeth: Here we can see the relative merits of these engines in terms of efficiency. It's surprising just how efficient the sterling engine is. So why aren't we surrounded by Sterling engines today? In the 19th century sterling engines were made from cast iron, as were steam engines, and even though they weren't subject to the same metal fatigue as steam engines they were prone to burn out on one end due to oxidisation of the iron where the heat source was applied, creating a hole and resulting in pressure loss.
Elfod Nemeth: Here we simplest form of Sterling engine, what is more correctly termed a heat engine. A cylinder is heated at one end, then cooled at the other. This forces the air to rise, then cool, creating rising and falling air pressure within the cylinder. A piston, seen at the top here, is sucked and pushed as a result creating motive force. This is horrifically inefficient as we can see.
This development, still a heat engine, adds a displacer, a moving piece that shuttles back and forth within the cylinder. The displacer, loosely fitting, shunts the gas, usually aided by the fly wheel so the cooling and heating are applied faster. Amazingly this doubles the performance from 1% to an astonishing 2%! Heady stuff.
Here is where Robert Sterling comes in adding the innovation that made sterling engines practical. Along the side we can see a heat sponge otherwise know as a regenerator. This simple addition retains heat as the air in the cylinder passes between hot and cold states, heating and cooling the air faster, retaining heat that would otherwise be lost to the surrounding environment.
The model you see here (both are identical) display a form of alpha engine that doesn't have a displacer but does have a heat sponge regenerator in the form of a metal mesh. Heat is collected from the rising geothermal water on the right, heats the air in the tube, which passes through the regenerative mesh. The hot expanding air pushes up the cylinder exposing the air to the cooler part of the cylinder, cooled by the protruding heat sink vanes. The cooled air contracts passing though the heat sink warming as it passes to be heated again from the geothermal water and the cycle starts again.
So what happened to sterling engines?
Viv Trafalgar: Seriously - they seem like they'd be completely useful and clean
Elfod Nemeth: Because of poor materials (basic cast iron) sterling engines had a high failure rate, the iron simply oxidised after prolonged exposure to a heat source and perforated. Despite this tens of thousands of Sterling engines were used to power water pumps, run small machines, and turn fans, from the time of their invention up until about 1915.
Elfod Nemeth: As electricity became more widely available in the early 1900s, and as gasoline became readily available as a fuel for automobiles, electric motors and gasoline engines began to replace Sterling engines which never got the chance to fulfill their full potential.
Today Sterling Engines are seeing something of a revival, being used where there are abundant free sources of energy, such as geothermal vents, concentrated focused sunlight and even the excess heat from other engines.
I leave you with a rather poor picture from Robert Sterling's 1816 patent application of the air engine design which later came to be known as the Sterling Engine. And words of the man himself:
"…These imperfections have been in a great measure removed by time and especially by the genius of the distinguished Bessemer. If Bessemer iron or steel had been known thirty five or forty years ago there is a scarce doubt that the air engine would have been a great success … It remains for some skilled and ambitious mechanist in a future age to repeat it under more favourable circumstances and with complete success…" (written in the year 1876 by Dr. Robert Sterling [1790-1878])
Viv Trafalgar: We can take a couple of questions for Elfod – while Mr. Merryman gets set up
Greg Merryman: no questions for Elfod?
Viv Trafalgar: we can keep going and run questions at the end. I'll save mine on my List I have here...
Greg Merryman: ok
Viv Trafalgar: Thank you Elfod!
Greg Merryman: Hi, first I’d like to thank Viv and Sera for inviting me to speak at the very prestigious Aether Salon and to thank all of you for attending and I’d like to thank Mr Elfod Nemeth for his enlightening presentation of the Sterling engine and hopefully adding his wit and charisma to what would otherwise be my very dry and boring presentation.
Steam engines and sterling engines are both examples of external combustion engines; that is: engines whose heat source is on the outside of the engine rather than on the inside like the German gasoline engine created by Mr. Otto that you may have seen about.
The first known steam engine (the aeolipile) was invented in the first century AD by Hero of Alexandria but it was simply a novelty. I created an aeolipile for your viewing pleasure (to my left near the beverage dispenser) and feel free to get one from the box next to it (buy for 0L).
Steam technology lay dormant for nearly 1,500 years after Hero created his toy. It seems hard to believe something as important as steam power could have been lost for so long but it appears to the case.
Steam engines weren’t mentioned again in history until the prolific Muslim inventor Taqi al-Din Muhammad ibn Ma'ruf al-Shami al-Asadi (and no, I won’t go voice and pronounce that for you “) describes a steam engine and steam turbine in a book he had written named “The Sublime Methods of Spiritual Machines.” I'm not really sure what happened
Alyx Sands is a linguist and COULD pronounce it...
Greg Merryman makes a note of that fact.
Other inventors and tinkerers mention steam turbines and engines in their writings but it wasn’t until an English military engineer named Thomas Savery in 1698 invented one he called the Miner’s Friend, and even that wasn’t really what we’d call an engine. It was a pump used to pump water out of mines and it did not even have a flywheel or many moving parts.
We should stop and talk about the theory behind the early steam engines which applies to the sterling too, I guess. For the most part, when matter is heated it expands and when cooled it contracts. (Yes, your pipes burst when they freeze but that’s an odd case.)
Elfod Nemeth: unique too
Greg Merryman: This is also how an internal combustion engine works... gasoline explodes in the cylinder and the expanding gasses are what push the pistons. When we think of a steam engine we imagine very high pressure, hot, expanding steam pushing on engine cylinders to do work but many of the early steam engines did not work that way.
Most early steam engines only used the hot steam to return the cylinders back to where they started. It was the idea that things contract when they are cooled that did the actual heavy lifting. Engines that capitalize on the fact that when you cool off matter is contracts are known as "atmospheric engines," due to the fact that the atmosphere is doing the pushing into a much lower pressure vessel.
Basically what Mr Savery built was a large coffee percolator. All he did was shoot steam into a pipe that was down in some water at the bottom of a mine, then he shutoff the steam and waited for the lake too cool the pipe and condense the steam into the pipe back into water thereby creating a vacuum.
The atmosphere pushed the mine water into the very empty pipe, them he closed the valve at the bottom of the pipe.
Then he’d let steam back into the water filled pipe until it overflowed the water and then did it all over again, of course the fairly high pressure steam blasting into the relatively cold water in the pipe meant a lot of its energy was wasted needlessly heating up the water and the steam had to be fairly high pressure which is why they had so much trouble with the boilers exploding. It was terribly inefficient but it was somewhat better than horses or donkeys pulling a rope that had buckets tied to it.
Serafina Puchkina appreciates that both speakers are defining terms for non techies such as herself
Greg Merryman: It could only lift a column of water about 40 ft (12M) so deep mines had to have a series of these pumps one above the other. Oh and the boilers that generated the steam blew up fairly often, but he did do one thing incredibly right… he got a patent that covered the use of steam to make things move….and a law was passed that extended his patent for a total of 35 years.
Next we come to Thomas Newcomen. In 1712 or so, Thomas Newcomen, another Englishman improved upon Savery’s design considerably. Mr Newcomen separated the engine from the water that was being pumped and figured out that if injected a small amount of cold water into the cylinder it would rapidly condense the steam back into water and create a powerful vacuum. This was a huge step forward and was much much more efficient than Savery’s engine.
Viv Trafalgar: Greg did you make these illustrations?
Greg Merryman: naw... borrowed them
Gizmo Theas: Nice animation
Greg Merryman: He used steam (the pink in the animation) to lift the cylinder back up, then he shot a little bit of cold water into the cylinder to condense the steam and create a partial vacuum, which sucked the engine-side of the beam downwards and lifted the plunger in the pump deep in the mine. That shot of water was the magic sauce, but there was a problem... Savery had locked up the steam pumping water out of the mine business with a patent. He installed over 100 steam engines all over Europe before his death.
A number of attempts were made to use the Newcomen steam engine to drive various machines rather than pumps, but they all failed due to the intermittent pulsing motion of the engine. The Newcomen engine was used pretty much as is for 50 years. This pic is one of the few surviving Newcomen engines.
James Watt a Scotsman came up with the idea to condense the steam in a separate vessel from the main engine cylinder. Newcomen injected water into the thick walled cast iron cylinder to condense the steam but it also cooled the engine off quite a bit. So the next injection of steam into the engine to start the next cycle had to re-heat the somewhat cooled off engine which wasted a lot of the energy that the steam contained.
After many false starts, Watt teamed up with a guy named Matthew Boulton who owned a foundry. They installed their first engine in 1776 which was still basically a pump. Boulton urged Watt to turn the reciprocating pump into a rotational engine. A man by the name of James Pickard held the patent for the crank (it seems the patent office was just as screwed up back then as today), one of Watt’s employees invented the Sun and planet gear to get around the patent on the crank. They had to turn the reciprocating motion into rotational motion using this... cause some guy patented the freaking crank of all things
He was the first to add a centrifugal governor to automatically regulate the speed of the steam engine. Now that's finally my idea of a steam engine.
Watt went on to create a double acting engine that used steam on both sides of the piston to move it back and forth. Watt was adamant about using only low pressure steam to power his steam engines. He felt (and rightfully so at the time) that high pressure steam was just too dangerous. Iron was not a very good material to use for boilers, cylinders etc. due to its brittleness…. Boilers made of iron would fail spectacularly rather than just develop a leak when something went wrong.
That blur is an example of a double acting piston. Steam pushes it both ways. Double action was a huge improvement. I built a steam engine is SL awhile back.... this was what I based it on. I don't think it would operate here with all the lag so I won't get it out. By this time the patent for the crank had expired.
Methods of smelting the iron improved and with the addition of coke (a by product of crude oil refining) into the iron as combustible, iron makers in the middle 1800s were actually making a crude from of steel which greatly improved the boilers.
My steel mill in the Iron Bay uses coke mixed in with the ore in the furnace
They did not get a good mix of steel this way though; some of the material was iron and some was steel.
Someone along the way got the brilliant idea to make a plug out of lead and put into the boiler. If the boiler ran out of water or built up too much pressure the lead plug would melt and blow relieving pressure on the boiler and directing the steam to hopefully a safe area rather than into one’s face. This is not unlike the re-useable pop off valve on today’s water heaters.
Low pressure steam (1 or 2 PSI) where much safer than higher pressure engines but they had to be quite large and heavy in order to get any work out of the low temp low pressure steam. A true Watt engine was far too large and heavy to be used in vehicles except for a steam locomotive which he patented in 1784.
You can see in this diagram they're starting to get more complicated.
Watt retired in 1800 the same year his original separate condenser patent ran out and many, many companies and inventors all over the world began to make steam engines. These next slides are photos of some of the post-watt engines.
Watt’s steam engine ushered in the Industrial revolution in Europe. No longer did factories have to built alongside rivers or rely on the intermittent wind to operate. Factories would generally have one large Watt engine that drove a series of pulleys that powered many devices in the factory. Grinders, saws lathes, sewing machines were just some of the tools that would get their power from an overhead pulley/belt that was powered by that one big steam engine.
As the 19th century progressed many inventors continued to improve upon the steam engine. The created multiple cylinder engines that extracted work from the waste steam from the preceding cylinder to further increase efficiency. Europe was afraid of high pressure stream engines due to the problems they had seen with them in the past but the US had no experience with exploding boilers, etc., so Americans quickly surpassed the gun-shy Europeans in the creation of high pressure steam engines.
beth India: It was incredibly dangerous in the large factories though; many children and adult were killed by these machines
Greg Merryman: yes.... limbs were lost too. No belt guards or OSHA back in those days.
Canolli Capalini: because that's where children and women belong, on the factory floors.
Viv Trafalgar whispers to Canoli... 'don't make the urchins mad... they've been holding meetings....'
Greg Merryman: This is a very efficient engine... it uses waste steam from the first cylinder to power the second and so on. This type of engine would have been used on ships for instance. Very high pressure/hot hot steam. Building a steam engine in SL is easy.... scripting it is hard.
My most successful attempt used llSetAlpha to turn on and off a series of 8 axles, 8 pushrods and 8 pistons. The steam engine at Kandace's lighthouse moved the prims by doing some pretty heavy math that is beyond me.
That concludes my presentation
Serafina Puchkina: Are there questions for our speakers?
Elfod Nemeth: for those who live in the UK you can see a very early bem engine and other excellent steam engines at the science museum London: http://www.sciencemuseum.org.uk/objects/motive_power/1920-124.aspx
beth India: When do you think the decline of the steam engine started and what was the biggest factor in that?
Boh Benoir: Greg, where is that engine build of yours that you mentioned?
Viv Trafalgar: Beth first and then Boh
Greg Merryman: It was slow to start compared to the new gasoline engine. The Stanley steamer bested the gasoline engines in races, but it had to warm up for 20 minutes before you could use it.
Viv Trafalgar: ((after questions I'll put the craft box out - but they have to be GOOD questions! ::smiles sweetly::))
beth India: The SS Great Britain always amazed my, but I guess the size and weight also counted against steam engines?
Greg Merryman: I've got the steam engine for sale in my store in the canals but it's not out. There's one up in the rafters of the steel mill.
Jedburgh30 Dagger: What about horsepower to weight ratios Greg?
Greg Merryman: yeah... steam was heavier for sure.... had lots of torque though. There's a ton of power in a small amount of gasoline, and it should be pointed out that about 80% of our electricity comes from steam.
Canolli Capalini: Are Sterling engines being looked at more in modern times now?
Greg Merryman: Steam turbines.... which I did not cover cause I thought people might get bored or need coffee to stay awake :) are in use today. Nuclear power plants heat water to make steam to make a turbine go.
Elfod Nemeth: yes, they are being looked at particularly as an alternate to solar panels in countries with good sunshine.
Boh Benoir: Steam heats & cools most of my RP city's downtown
Elfod Nemeth: the sun is focused, via a parabolic mirror onto a sterling engine to generate electricity.
Greg Merryman: Sterling engines have me fascinated in RL
Elfod Nemeth: here's a video on the excellent TED website about using sterling engines to generate electiricity (and where I pinched some of my slides from): http://www.ted.com/index.php/talks/bill_gross_on_new_energy.html
Jasper Kiergarten: on the multiple piston engines, is there more stress on the later cylinders, since they take the waste steam off of the previous cylinders such that they wear unevenly?
Greg Merryman: I don’t know.... I did notice they got larger the further down the chain that they went. I imagine the larger size is due to the lower power steam to balance it all out
Elfod Nemeth: I presume they got longer because as the steam progresses it looses pressure, therefore more surface area is needed to provide sufficient motive force
Saffia Widdershins: One of the most interesting uses of steam power I saw was in Tuscany
Elfod Nemeth: Also, there is a giant aeoliophle ride on my pier in the Vernian sea, should have mentioned it earlier
Saffia Widdershins: where they use the thermal power of hot springs in an area of Southern Tuscany.
Viv Trafalgar: what do they use it for Ms Widdershins?
Saffia Widdershins: supplying power in the local villages. The hills and roads are all crossed by these huge tubes. Bright yellow.
Aeolus Cleanslate: lots of that going on in Hawaii too - geothermal driving steam turbines producing electricity
Aeolus Cleanslate raises his hand
Viv Trafalgar: Yes Mr. Cleanslate?
Elfod Nemeth: nuclear power stations use steam turbines too Greg?
Greg Merryman: yes
Viv Trafalgar: ahh Mr. Cleanslate and then Mr. Nemeth
Aeolus Cleanslate: forgive me if you covered this earlier, but early steam engines seem to have alternated between vertical and horizontal boilers. Is one better than another? Or does one work better in certain circumstances?
Greg Merryman: I don't know
Aeolus Cleanslate: it might just be a form factor thing for railroads. It’s easier to make bigger boilers longer than taller.
Elfod Nemeth: shouldn't make any difference really, it's just pressure that would apply equally regardless of shape, no?
Greg Merryman: most of the early ones were for pumping water out of mines, so a vertical orientation would certainly make sense there.
Jasper Kiergarten: well I'm reminded of the slant 6 engine and the theory behind that
Greg Merryman: good point
Jasper Kiergarten: perhaps there's something to orientation indeed
Greg Merryman: the early engines were beam engines.... so they had to be vertical
Viv Trafalgar: realizes that the boys are going to take over the salon courtyard long after dark.
Viv Trafalgar: Have the size issues for steam engines been overcome? Most seem so enormous - and combustion engines can be so small
Greg Merryman: pretty much yes
Aeolus Cleanslate: I've seen some pretty tiny steam engines - and the little ones still seem pretty powerful
Greg Merryman: now that we have better materials to work with we can use high pressure steam safely. Low pressure requires lots of surfaced area to push on
Elfod Nemeth: you can get sterling engines now that will run from a tea candle flame or if dipped in coffee
Aeolus Cleanslate: speaking of which - I re-read the old Steamboy novel the other day and wondered about *storing* steam
Breezy Carver: umm sort of the like the motion of the ocean so to speak smiles ...
Aeolus Cleanslate: if you could reduce the temperature loss, couldn't you theoretically build a steam *battery*?
Greg Merryman: one of the big Sterling projects stores heat in molten salt underground
Viv Trafalgar: I'm going to pause the questions for just a second, and then open the floor back up to whomever wishes
Greg Merryman: what's the name of the super light insulating material.... called frozen smoke
Beq Janus: there was a nanotech steam engine made; pistons at 5 microns I think. http://www.google.co.uk/url?sa=t&source=web&ct=res&cd=2&url=http%3A%2F%2Fwww.auburn.edu%2F~rainerk%2Fnano.ppt&ei=ZI0QSqvDGZGUjAew8LnCBg&usg=AFQjCNFce6I8UhwknLTSbNmizTYfJCjaoQ&sig2=u46o8sVM4ZiFf-6zSQEKhQ
Viv Trafalgar: Sera and I would like to thank each and every one of you for fighting the grid to be here today! From the emails and IMs I've received a number of Salon fans were locked out or unable to TP. Please let them know that we will be publishing the entire transcript at http://aethersalon.blogspot.com
As is our custom, we offer a craft towards the end of each salon. This month the craft is DIY steampunk toolbelts, as suggested by Mr. Gatsby Szuster.
Serafina Puchkina: Edited and unedited versions will be posted
Beq Janus: easier URL www.auburn.edu/~rainerk/nano.ppt
Viv Trafalgar: I will put the boxes out - I beg you to please read the instructions (RTFM!) so that you do not end up with a screwdriver in an uncomfortable place. I return you all to the questions session - and keep talking!
Greg Merryman: the aeolipile to my left is a freebie too
Viv Trafalgar: I would like to thank our speakers profusely - the work you did today and the information you provided was extraordinary! Please join us again next month - and join the salon group as well!
Elfod Nemeth: and a comfy sofa too
Viv Trafalgar: lol I've always wanted someone to give a salon lying down
Canolli Capalini coughs at Elfod "traitor"
Serafina Puchkina: Thank you Elfod and Greg
Beq Janus: a special cheer for Elfod our most relaxed speaker ever
Elfod Nemeth grins at Olli
Serafina Puchkina: Goodnight to those leaving now and thanks for coming!
Viv Trafalgar: I am thrilled to announce that I am splitting the speakers fund of over 5K L with Greg and Elfod now. (That is, they're splitting it - I'm not gettin any.) 5630L to be exact, thank you Herr Baron!
Girl Genius for Friday, May 24, 2013
2 days ago