Stirling, NASA, helium

Thread Starter

Motanache

Joined Mar 2, 2015
512
NASA has created a Stirling truck.

This car is more economical at fuel consumption,
Healthier for the environment.

If we say we want to protect the environment, why don't we promote it?

It certainly has disadvantages.

This car has efficiency (I think) 40%, diesel car 33%, and gasoline car 30%.
Or is it free piston?

I did NOT understand, how did they use helium and made this gas not escape between the piston and the cylinder?


I realized that what NASA does is not a simple thing, and that's why I wanted a discussion with you!
 
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Wendy

Joined Mar 24, 2008
22,328
I've wondered for years why they don't use a Stirling Engine (SE)for a hybrid as it would support the strengths of the engine and minimize its weaknesses. A SE has lousy throttle control, running at a constant speed suits it best. A hybrid needs 2 speeds from a SE, on/off to recharge the battery.
 

nsaspook

Joined Aug 27, 2009
8,163
2021 called back to 1983, so what happened??
https://ntrs.nasa.gov/api/citations/19830019654/downloads/19830019654.pdf
https://ntrs.nasa.gov/api/citations/19880002196/downloads/19880002196.pdf

https://www.stirlingengine.com/why-not-popular/
The Curse of Carnot
When I was taking my first physics class in Joliet, Illinois, I came across a sentence in my physics text book that said:

Stirling engines had the same theoretical efficiency as the Carnot cycle and the Carnot cycle has the maximum possible theoretical efficiency.

I thought to myself, “if these are so great, why are they not being used?”

It’s probably the same question that brought you to this page.
 

Thread Starter

Motanache

Joined Mar 2, 2015
512

3:39 "125 miles for just 2 bucks"

3-4 hours the tank is full.
These are exaggerated. I don't think it's that useful
But it's an interesting idea.
 

Thread Starter

Motanache

Joined Mar 2, 2015
512
There are many Stirling engines on the market but for toy cars!

Please post ideas to build for hobby a 10-20 horsepower Stirling engine.

I just found a woman on youtube who opened an air compressor and wants to turn it into a stirling.

I don't think air compressor pistons and cylinders are a good idea.
I would like pistons and cylinders from cars junkyards! To withstand the combustion temperature of the fuel

Please come up with ideas, diy projects, Succeed or not, we will accumulate knowledge of thermodynamics

The beauty is that the stirling cycle is also reversible. You give it mechanical work and you have a refrigerator


 

Thread Starter

Motanache

Joined Mar 2, 2015
512
I worked in auto engineering through a written exam. I know how it is! It is human inertia!
They try to improve what they have to make the final product more attractive to the customer.

The Stirling engine cannot be obtained by improving what already exists.

Another example is the field effect transistor it was invented about 20 years before the bipolar transistor.Although the inventor presented it to several factories, they did not want to give up the tubes
 

nsaspook

Joined Aug 27, 2009
8,163
I worked in auto engineering through a written exam. I know how it is! It is human inertia!
They try to improve what they have to make the final product more attractive to the customer.

The Stirling engine cannot be obtained by improving what already exists.

Another example is the field effect transistor it was invented about 20 years before the bipolar transistor.Although the inventor presented it to several factories, they did not want to give up the tubes
The real reason for the FET 20 years lag was the the physical processing needed to make actual devices didn't exist in the 20s, 30s and barely existed in the 40s. This idea that people don't want improved X because of human inertia is a misguided view of technological progress. The idea not only has to be possible in some theoretical sense or prototype, it needs to be practical, profitable and useful (or fun) to Joe Six-pack too.
 

crutschow

Joined Mar 14, 2008
26,740
I did NOT understand, how did they use helium and made this gas not escape between the piston and the cylinder?
If you look at the operating of a Stirling engine you will see that it is a closed-cycle. The internal mechanism can be sealed from ambient (of course there needs to be a seal on the rotating shaft to contain the helium, which could be a magnetic coupling through the wall).
 

Wendy

Joined Mar 24, 2008
22,328
Hydrogen could also be used, though more dangerous it can be far cheaper and can be made at home. The trick is to find a gas with really low viscosity. Viscosity is equivalent to friction in a SE.
 

Thread Starter

Motanache

Joined Mar 2, 2015
512
One gram of practice makes as much as a ton of theory!
Kidding!!

How to start with practice?
What to start with?
It should be cheap so I don't feel sorry if it doesn't work.

It should be cheap so I don't feel sorry if it doesn't work.

https://www.stirlingengine.com/diagram/

1615637865691.png



https://www.researchgate.net/figure/Schematic-of-an-alpha-type-Stirling-engine_fig1_328510776

A V-motor can be converted to Stirling. But it has:

Metal contact with good thermal conduction between the hot and cold cylinder, I would like a thermal insulator between the two cylinders.
 

Thread Starter

Motanache

Joined Mar 2, 2015
512
" Stirling came up with a first air engine in 1816 " => 1816

The first DC electric motor capable of turning machinery was invented by British scientist William Sturgeon in 1832

"After 14 years of research and development Otto succeeded in creating the compressed charge internal combustion engine May 9, 1876 " => 1876
" In early summer 1893, Diesel's first prototype engine was built in Augsburg. " =>1893




Can someone tell me how much the efficiency decreases if helium is not used but air?
 
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Thread Starter

Motanache

Joined Mar 2, 2015
512
Stirling for the car is ruled out because it's too much for diy.

I'll start with an electric generator.

I could buy this little generator. But what to do with it? I can charge a smart watch:
https://www.aliexpress.com/item/400...earchweb0_0,searchweb201602_,searchweb201603_
1616153490949.png

But what to do with the smart watch?..... At least a laptop to power!

Who has the details and can help me build the next generator?

I think it has 40% efficiency?



0:50 Was it used for educational purposes for thermodynamic laws? And now it doesn't need to be used for educational purposes, because they gave it?
 
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Thread Starter

Motanache

Joined Mar 2, 2015
512
https://www.microgen-engine.com/engines/
Where can I buy this electric generator?
I hope it has an affordable price.

It is the 2016 version.
I was expecting a fantastic efficiency of 40%.

But its efficiency is only 26%

It has 1KW power.
You can think a lot with a stirling engine, including solar energy

I read that they have a contact email. But if they do not answer we will find other sources from where it can be bought.
 

Sensacell

Joined Jun 19, 2012
2,757
With the cost of solar panels around $2.5 a watt, the sterling business is deader than ever.

That company is probably bankrupt.
Nobody can make any money selling engines, the market is too small and the engines are too difficult to design and manufacture.
 

Thread Starter

Motanache

Joined Mar 2, 2015
512
Some in their fantasies say that the stirling will replace gasoline.
In fact, they say it will replace many others, it will revolutionize the technique/

This is as wrong as can be.

But for people with money and no technical knowledge it seems credible. And frightening.
Why?
1. - NASA studied and made such an engine and put it on a truck. Consume less than gasoline engines. It's easier to do.It has fewer parts, so it breaks down harder.
It can work with any kind of fuel.
They test with a truck with which they traveled a lot and everything is perfect

2. The Stirling engine is theoretically as efficient as Carnot, the highest efficiency known.


This is like the one who created the panic like CERN Geneva that creates a black hole with their experiments and this black hole will swallow us all.

What to say to those who do not know about the collision of protons ....

The rage continued and many thought about how to stop the CERN experiments as soon as possible


The reality about stirling:
- The highest Stirlingg efficiency I've found is the one above 26% less than diesel 33% and gasoline 30%
- The stirling engine was invented before the Diesel and Otto engine. If it had been practical, it would have been imposed since then.
The electric motor exists to make a hybrid motor

- - I read on stirling use - it is only - is a stove on wood or central heating system that has a stirling motor that circulates water to the radiator
Or a stove that has a stirling motor to charge the phone. This could also be done with a thermoogenerator and made no noise.

- NASA is testing engines that run out of air on other planets. Using only one heat source..
Hence the stirling.
They do not say that the truck will have problems accelerating on the spot.
The Stirlinng engine needs to warm up, it doesn't start immediately.

Let's say we make it hybrid.
If you make short trips in the city, you will need to leave the car in the parking lot with the engine running to charge the batteries.
Hybrid petrol cars can start their heat engine much faster than Stirling starts

Who will want to leave the car in the parking lot with the engine running?
Isn't it easier to turn the key in the ignition when you start and stop the engine in the parking lot?

- The Stirling engine was designed as an alternative to the steam engine but does not emit steam.
Who still uses a steam engine today? Only hobbyists like us!
Same with Stirling.
 
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