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turboelectric vehicle

Posted by Ed Ferris 
Re: turboelectric vehicle
April 21, 2019 09:04AM
Peter Brow Wrote:
> IC cars, and battery-electric cars, and
> ,IC-electric hybrid cars, will become extinct.
> Traditional steam cars, with Stanley-like engines,
> will replace them.
> Peter

I don't see any large car manufacturers spending much development money on anything but battery electric cars. It's only people on this forum (including me) that are still fascinated by the possibilities of small steam power.

The way to connect a turbine to a conventional CVT transmission is through a gear box that reduces the RPM to an acceptable value. Like electric motors, turbines have great low rpm torque. You might not even need more than a two speed gearbox.

We had the opposite problem for our record setting electric hydro. There the brushed motor the rules required had about 5000 rpm maximum, but the standard propellers for IC engines were designed for 10,000 rpm. We designed and built a quick change gear box that used standard quick change gears. That way we were able to adjust the propeller load to match the motor's characteristics.

Lohring Miller

Re: turboelectric vehicle
April 23, 2019 09:55AM
I have to note that not stacking power sources is really a rule of thumb that sometimes doesn't apply.

Electric generators and motors have reasonably high efficiency … there are losses in transmission but they aren't absolutely huge.

Heat engines, on the hand, often experience wide swings in efficiency depending on operating conditions. Otto cycle engines, for example, give best efficiency at high output --- in part because the pumping losses are minimized.

Gasoline/Electric hybrids capitalize on the fact that the gain in IC engine efficiency at high output is better than the loss in the electrical setup. The heat engine can operate intermittently, at best efficiency, with the excess power stored away in a battery for use by the electric motor. The overall efficiency is less than if the ICE were connected to the wheels, and the vehicle was running flat out, but it's better than you would find in a large operating band at partial engine load.

You can get higher overall efficiency if you have a gearbox mating the ICE to the wheels so that it can deliver power to the wheels, so that there are no electrical power losses in direct propulsion, with the excess sent to storage during the periods when the engine is offline.

It's a good rule of thumb, but you have to juggle all the numbers for any particular application.
Re: turboelectric vehicle
April 24, 2019 10:14AM
It's not only ICE's that have low efficiency under some conditions. A recip steam engine at long cutoff is very inefficient. In stop-and-go traffic it would get the Stanley's 5 mpg. So the hybrid might be worthwhile.
Another possibility is the Brayton or Stirling cycle, where the heat is recovered instead of rejected to the condenser. Since isochoric heat transfer is difficult, I would say the Brayton is the one to try.
One thing I've never heard of is recuperative braking, where the engine compresses steam back into the boiler. Seems a natural idea to me. Any examples?
Re: turboelectric vehicle
April 24, 2019 01:32PM
Doble looked at steam compression in the Ultimax engine. Reports are that it ran so rough --- and generated so much stress --- that the feature was disabled. That's understandable, look at how rough running some uniflow engines can get at lower speeds and realize that they aren't even beginning to compress the same amount of steam.
Re: turboelectric vehicle
April 24, 2019 02:20PM
Used to go down hill like that in the Stanley - don't remember ever recuperating any steam thoughsmiling smiley

Re: turboelectric vehicle
April 25, 2019 10:12AM
Turbines work exactly like torque converters. In fact a torque converter is a combination pump and turbine. That means that a turbine has favorable torque characteristics over a fairly wide range. It may only need a two or three speed transmission in a car. Of course efficiency at off design speed will be poor, but I doubt that efficiency would compete with modern IC engines in any case.

Lohring Miller
Re: turboelectric vehicle
April 25, 2019 11:20PM
Hmmmmm….I'd disagree about turbines working like torque converters and about them having favorable characteristics over a wide speed range. Torque converters work with a non-expanding and compressing medium, which steam is not. In the first case you are dealing with a purely mechanical process and in the second case it's thermodynamic.

To keep it simple, let's assume we're looking at a basic impulse turbine. The steam hits the turbine blade and is reversed in direction (well, reversed as much as possible) so that the impact moves the blade. A theoretically ideal turbine would rotate at exactly half the speed of the steam … if it did so, the steam leaving the blade would have zero velocity, having transferred all its momentum to the turbine. Of course, this is impossible, which we can realize by noting that absolutely zero velocity means that no steam leaves the vicinity of the turbine --- therefore the pressure climbs towards infinity. In the real world, actual turbine wheel velocity will be less than half the steam velocity, leaving some momentum in the steam.

For Curtis stages, the optimum efficiency is found at closer to 25% of steam velocity.

A torque converter turbine spins at a velocity directly proportional to the impeller velocity, and does so with high efficiency across the spectrum. A steam turbine spins at a velocity proportional to the velocity of the steam leaving the nozzle, which is approximated by the equation V = 223.8 * sqrt (h1 - h2) with V equaling velocity in feet per second. The variables h1 and h2 represent the enthalpy of the steam entering and leaving the nozzle, measured in BTU per pound.

At this point we can see that, unlike the torque converter, the turbine works most effectively at a speed which is related to the temperature and pressure of the steam entering and leaving the nozzle. We can throttle the steam flow to regulate power but this also dramatically changes turbine efficient operating speed. In other words, efficient high power operation occurs at high rpm and efficient low power operation at lower rpm with pressure following rpm in both instances … but not in a linear fashion since enthalpy occurs in curves. This is very un-torque converter-like.

Edited 1 time(s). Last edit at 04/25/2019 11:23PM by frustrated.
Re: turboelectric vehicle
April 27, 2019 04:53AM
Hi Ed & Lohring,

I agree, except for the bit about "the Stanley's 5 mpg". There are probably Stanleys -- especially pre-1914 models with lower superheat, and most with no "hookup"/early-cutoff, stuck at ~63% cutoff -- that get 5 mpg, but almost all reports from 1920s Stanley [700F steam temp, ~28% early-cutoff setting] operators which I have seen come in around 10 mpg. Some, like David Nergaard's late condensing Stanley, are reported to get around 10-12mpg in short-trip, stop/go running, with an approx. 4000 lb vehicle, 6-7 feet tall.

I daily-drive a 4000 lb, ~7-ft tall, 2016 Dodge Ram 1500 pickup truck, and boy howdy would I like to get 10-12 mpg in short-trip stop/go running. Actually i get more like 8-9 mpg, according to the digital/computer display on the dashboard. And yep, that's with the A/C off, and an empty cargo bed. I ain't driving around with 2000 lbs of bricks out back. My truck has variable valve timing, computer control of fuel mix and ignition timing, cylinder deactivation under low-load conditions, and computer-controlled 8-speed automatic transmission. This truck has every hyper-advanced computer-controlled trick in the modern gas car book. Air drag in my 2016 RAM 1500 is far lower than in boxy "parachute-aerodynamics" 1920's Stanleys. If my latest-tech IC truck's powerplant efficiency were better, then it should be getting better fuel mileage than a 1920s Stanley. But it ain't. It just ain't. Sorry to contradict anyone's firmly-held and happily reassuring beliefs, but I watch the actual fuel-mileage readouts on my truck dashboard every single day. If it was showing 20-25mpg all the time, I'd "admit defeat", and admit that Stanleys use 2x or more as much fuel as an IC vehicle of comparable weight and air drag per mile, but that simply is not the case.

I think it probably happens, but come to think of it, over 40 years of steam car research I have not ever personally seen any reports of any Stanleys getting 5 mpg. Anyone who gets 5 mpg from any Stanley, and there are probably some, probably has serious malfunctions in their vehicle. Badly-worn/leaky engine, pump leaks, bad boiler/engine modifications, and so on.

5 mpg for a Stanley, sounds to me like "an estimate based on IC/steam comparative optimum-conditions test bench tests", rather than on real-world road-driving result reports. Change the numbers to fit the "theory", rather than basing conclusions on the actual results.

Kinda funny how I spent many years arguing against the view that "10-12mpg Stanley fuel mileage proves that they are ridiculously inefficient", and now, magically, it's "5 mpg Stanley fuel mileage proves they are no good".

It looks like my old argument comparing modern IC pickup trucks to 1920s Stanleys finally hit home, and the other side now tacitly admits defeat, by resorting to imaginary fuel economy numbers.

I am hoping that these comments will not "conveniently disappear" through the marvelous mysterious magic of "moderator editing".

If they do, then that will explain the future complete lack of posts [and SACA membership renewals] by me.

I don't mind people disagreeing with me, but I do have a problem with having my point of view simply "officially disappeared", as if it never existed in the first place, and conveniently replaced with pure-fantasy fuel economy numbers which no actual operator of a reasonably-original, properly-tuned Stanley has ever publicly reported in actual road driving.

I apologize for my recent grumpy posts, now apparently conveniently [and happily] disappeared. Those were the result of grumpiness generated by serious and frustrating design/engineering problems with my vaporizing-burner cleanout system. Those problems have now been resolved. The above comments, IMO, are not ad-hominem or otherwise abusive or objectionable, but solidly impersonal, factual, and "on-topic" [steam vehicle vs IC vehicle fuel economy] in nature. I understand that they may offend some people, but I do not post them here with the intent of offending anyone. I post these comments simply to explain the reasoning behind my own steam automobile design approach. Actually, I regret the fact that my views may offend many folks. I do not wish to offend anyone. I would be much happier if my comments were welcomed with agreement and praise. But there are many different points of view on modern steam automobile design, and I think that it is reasonable and beneficial for the SACA Forum to reflect that fact.

I think it was our rightly esteemed President and Magazine-Editor Emeritus, Tom Kimmel -- who no longer writes me due to my grossly intemperate/scary emails over some "tempest in a teapot" controversy a decade or so ago -- who once said that "if you ask 10 steam car guys about anything, you'll get 11 different opinions". As R. Crumb's underground-comics character Mr. Natural once said, "Twas ever thus". And always will be. But such disagreements and controversy are the fire from which progress is forged, in any field, including the apparently and widely/officially-[& IMO incorrectly]-believed-to-be-extinct field of steam automobile development.


Edited 2 time(s). Last edit at 04/27/2019 06:19AM by Peter Brow.
Re: turboelectric vehicle
April 27, 2019 05:47AM
Re: turboelectric vehicle
April 27, 2019 09:51AM
The "5 mpg and 5 mpg on water" figure I quoted was from some writer on the subject. I've never owned or driven a Stanley.
I recently had a Camry which seldom got the advertised mileage. It would return 20 mpg on short trips in the city. We've all heard how manufacturers tune their test cars for the EPA mileage loop.
Horsepower figures are also not comparable. Maybe the Camry did put out 200+ hp at 6000 rpm, but I never revved it that high. A 20-hp steam or electric car would be fully sufficient for everyday use.
Another story I heard in Emeryville was about a Doble E or F that was being driven on the freeway near there. The driver in front slammed on his brakes and the Doble driver realized he couldn't stop in time. So he threw the quadrant into Reverse. He said it was like running into a pillow. It did stop the car rapidly enough.
Re: turboelectric vehicle
April 27, 2019 09:52AM
LOL Feel free to be grumpy. I consider myself to be a cranky old man as well. On the turbine as a torque converter, how many gears did Jim Cranks land speed record car use? I think it only had a single speed transmission. It had to operate over a larger speed range than the average car.

Lohring Miller
Re: turboelectric vehicle
April 27, 2019 01:19PM
Jim Crank told me that he had single speed gearbox with a massive stepdown ratio. He also broke the transmission a number of times because he was trying to deal with such a wide operating range and such a massive stepdown.

His original intent had been to convert an aluminum 353 "Jimmy" Detroit Diesel into a 3 cylinder uniflow engine. Lear had grown disillusioned with the steam bus program and offered Jim a million plus dollars of hardware development for something like a hundred bucks, and Jim had taken it. He told me that the turbine was problematic and that the off peak efficiency was horrible, necessitating a drastically oversized boiler. His conclusion was that his initial idea of using the Jimmy was superior and that he wouldn't have considered the turbine if he had to do the whole project over again.
Re: turboelectric vehicle
April 27, 2019 02:27PM
I am going to throw this out there once again...

self cooling DC motor

We have a DC traction motor, that can drive an EV directly it has a turbine component to cool winding's for full torque as the motor is spinning liquid cooling thru centrifugal force is forced thru the winding cooling in a helix arrangement.. The working fluid steam or Freon can drive an auxiliary electronic alternator to supplement charging of the batt bank. Its not much but the arrangement is HIGHLY EFFICIENT in nature. It supplements the charging to batt bank at maybe %30.

So we have the best of both worlds. the traction motor can directly operate under all conditions that a vehicle requires. The heat generation of the working fluid heat is reclaimed as best as possible. Maintaining max torque output...

As I have read this post a different strategy is a better to use.
Re: turboelectric vehicle
April 27, 2019 05:54PM
Click on the PDF if you like what you see let me know and post more I think there are 21 pictures

Edited 2 time(s). Last edit at 04/27/2019 06:36PM by Jeremy Holmes.
open | download - 01a.pdf (31.1 KB)
Re: turboelectric vehicle
April 27, 2019 06:57PM
Outside ex

hit the attachment

Edited 1 time(s). Last edit at 04/27/2019 06:59PM by Jeremy Holmes.
open | download - oil1.pdf (17.6 KB)
Re: turboelectric vehicle
April 27, 2019 07:13PM
open | download - oil8.pdf (18.9 KB)
Re: turboelectric vehicle
April 27, 2019 07:15PM
Armature assy
open | download - oil10.pdf (33.4 KB)
Re: turboelectric vehicle
April 28, 2019 10:07AM
Since we're not trying for a land speed record, I think the ordinary motors used in hybrid cars will be satisfactory. I must admit I don't even know if they're AC or DC; since my Prius has a big inverter I think it's AC.
I once had a SAAB 93 with a Bosch DC generator. It was on an auxiliary shaft with the water pump, of all things, and would regularly get sprayed when the pump seal failed.
Re: turboelectric vehicle
April 28, 2019 10:27AM
All modern electric cars use an AC motor driven by a solid state speed control that converts DC battery voltage to a variable three phase AC for the motor. That's the most efficient setup. We ran a brushed DC motor in our hydro because the rules required it in 2008. It was the least expensive option at the time and was driven by a 2000 amp chopped DC solid state speed control. Today I would look for the battery, speed control, and motors from a wrecked Tesla.

That's what I thought about Jim Crank's car. The fact that a turbine could work at all in this setup gives an idea about its torque characteristics. Of course efficiency goes down the tubes at low rpm. A piston steam engine would have better characteristics. I can't imagine that a small steam turbine would be as efficient as a piston engine of similar power. At this point, I don't think we are worrying about the efficiency of a small steam power plant. IC engines in cars have been more efficient for a long time and modern electrics are even better.

Lohring Miller
Re: turboelectric vehicle
April 28, 2019 11:10AM

and modern electrics are even better.

Sure like to see some real efficiency numbers on this, not the made up EPA equivalents used to promote EVs.
Re: turboelectric vehicle
April 29, 2019 09:03AM
My Tesla model 3 performance version gets around 350 to 375 watt hours per mile when I drive in "fun mode" on my 120 mile commute. That means driving 65 mph over the coast range with occasional bursts to 90+ mph while passing log trucks and 75 mph down the freeway. Yesterday that trip used 274 watt hours per mile driving a little more conservatively over all two lane roads at around 60 mph maximum. Electricity costs around $.06 per kilowatt hour here. So at most that trip cost $2.70. Yesterday it cost under $2.00. I have over 8,000 miles on the car. All I do is plug it in at home. No gas or oil change stops.

My Subaru BRZ on the same trip used around 4 gallons of premium gasoline at around $3.72 per gallon. That means it cost around $14.90 or around 6 to 7 times as much for the same trip. It would have needed an oil change with synthetic oil by now. The Subaru was a great handling 2700 pound, 200 hp car. The Tesla is a great handling 4000 pound car with as much as 500 hp on tap. There's no comparison. You have to drive one to understand how quick the car is. Of course the Tesla cost 3 times as much. But then there's the Autopilot system that keeps getting better with every update.

Lohring Miller

Edited 1 time(s). Last edit at 04/29/2019 09:09AM by lohring.
Re: turboelectric vehicle
April 30, 2019 07:35AM
It suddenly hit me that I forgot one last, important bit of information about turbines. The formula for spouting speed holds true only for velocities below that of the speed of sound through the steam at the given temperatures and pressures. The speed of sound through steam, at the given temperature and pressure, is the limiting velocity because shock waves are set up in the nozzle. This also means that you can't push more steam through a given size nozzle once you reach Mach one. You can determine this velocity using the calculator at NIST Chemistry Web Book SRD69

Edited 1 time(s). Last edit at 04/30/2019 07:37AM by frustrated.
Re: turboelectric vehicle
May 03, 2019 01:27PM
The speed of sound through steam, at the given temperature and pressure, is the limiting velocity because shock waves are set up in the nozzle. This also means that you can't push more steam through a given size nozzle once you reach Mach one.

Inst this Reynolds Number
Re: turboelectric vehicle
May 03, 2019 02:31PM
Nope, it's a different number, the Reynolds number defines turbulence at different rates of flow across different types of surfaces.
Re: turboelectric vehicle
May 03, 2019 08:59PM
Dam you got me Ken...

I remember when you posted on [www.fieldlines.com] I own the site now and your correction of Reynolds number owns a new theory with relations of home brew turbines.

I did a search but I didn't not find an application that Im comforting converting with, .
Re: turboelectric vehicle
May 03, 2019 11:58PM
Thanks Ed, yep, the 5 mpg Stanley water/fuel mileage report which you read was probably completely honest, actual results. But I bet a bunch of experienced Stanley operators here could tune up that old chuffer to 10 mpg or better -- or the owner could, with a bit of info and advice.

Said info implying "join SACA and get to know/chat with knowledgeable/experienced Club members on the topic".

Thanks very much, Lohring, for being cool with me getting grumpy now and then. That means a lot to me. But I don't _want_ to be grumpy, or old. Of course I'm getting used to the latter, but I'd rather be the "cheerful old coot" type of old guy, instead of doing the "grumpy old guy" thing. I'm working on it. Somewhere around 1990 AD/CE, as part of my lifelong quest for "da 411", to use somewhat[?] current vernacular,,29-year-old me attended a talk by psychadelic guru Timothy Leary, at which time/space coordinates, among other fascinating, thought-provoking, and hilarious comments the infamous "Dr. Tim" stated that "senility is wasted on the old". He also said that senility, and the states of mind induced by weird modern sci-fi/fantasy TV/movies and bizarre TV commercials/pop culture, were exactly what "1960s drug-culture people" were trying to achieve, so there's no need for any one to take mind-altering drugs any more. This, from the formerly famous/infamous #1 advocate of "mind expansion" via psychadelic drugs like LSD. #mindblown. AKA go figure. LOL

The point being... wait a minute, was there supposed to be a point? I don't remember now. LOL

Edited 5 time(s). Last edit at 05/04/2019 04:01AM by Peter Brow.
Re: turboelectric vehicle
May 04, 2019 01:35AM
None of my foregoing comments should be interpreted as an attempt to discourage building/testing the original idea in this thread, a steam turbine driving an automobile via an electric/hybrid drive system. Design/build and test it, and let's see the results.

My "grumpy old steam car guy" smiling smiley opinion that a Stanley-like steam engine, by virtue of its inherent advantages, will eventually replace all other road vehicle engines is an entirely separate topic, not relevant here. No batteries, no motors, no generators, no clutches, no change-speed gearsets, 2 cylinders, 2 valves, 2 main bearings, minimum distance between cranks and PTO, no right-angle final drive, no drive shaft, light engine frame based on high tensile strength steel rods, and overall simpler and more cost-effective drive train, and many other issues, are issues for a different thread, a very complex discussion which I do not have time to start or pursue at present.

Re: turboelectric vehicle
May 06, 2019 10:28AM
Worth a Thousand Words. Instrument panel display, Chevy Cruze TD hatchback at refueling stop enroute to home from Berrien Springs meet. Average speed on Interstate, 63 mph (including construction zones). Vehicle curb weight, empty: 3,229 pounds.

Edited 2 time(s). Last edit at 05/06/2019 10:31AM by frustrated.

Re: turboelectric vehicle
May 07, 2019 08:47AM
It would be very hard to beat that mileage with any steam car, but I bet a steam car could be built to out accelerate it. A Doble has gone from 0 to 75 in 10 seconds. The best electric cars will get close to double the equivalent mileage and get from 0 to 60 in around half the time.

Lohring Miller
Re: turboelectric vehicle
May 07, 2019 10:48AM
Actually, this photo was posted to show that the government mpg numbers are not unrealistic. Obviously, they can't give a few numbers that reflect all different vehicle loads, weather conditions, road conditions, driver temperament and so on. On the other hand, this car is rated at 50 mpg and had no trouble beating the EPA figure. At one point, when traffic was about 62 mph, but steady, the economy was running nearly 61.5 … then the construction caused regular changes in speed, increasing the fuel burn.

Every vehicle I have owned is capable of matching or exceeding the EPA figures when driven conservatively. The allegation that auto companies use specially tweaked cars is generally false (and I'm sure a billion or two dollars in penalties has caused Volkswagen to get religion). It isn't as though you just show up with a car and they record the numbers. The tests are extensive and include close inspection by the manufacturer, government and interested third parties like the SAE. I'm sure some on here will argue the point but, being in the business, they will need a lot of proof to convince me since my experience is otherwise.

Again, I agree that the right steamer could beat the acceleration of the Cruze ...but this car wasn't meant to go like spit on the griddle; it's an economy sedan. However, I'd bet it would beat a Doble up a long stretch on the Rockies, given how Crank said his steam pressure dropped drastically on long, steep grades (and that Doble factory demonstrators were losing pressure on steep grades in San Francisco). An "apples to apples" comparison of acceleration of a performance oriented product built by the same company is the ZR-1, which can go from zero to 60 mph in 2.85 seconds and 0-100 mph in 6.0 seconds.
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File Name File Size   Posted by Date  
Motor with Gearbox.JPG 498.4 KB open | download lohring 04/21/2019 Read message
01a.pdf 31.1 KB open | download Jeremy Holmes 04/27/2019 Read message
oil1.pdf 17.6 KB open | download Jeremy Holmes 04/27/2019 Read message
oil8.pdf 18.9 KB open | download Jeremy Holmes 04/27/2019 Read message
oil10.pdf 33.4 KB open | download Jeremy Holmes 04/27/2019 Read message
2018 Cruze TD panel1.png 115.8 KB open | download frustrated 05/06/2019 Read message