High compression
Re: High compression
As you know this is the site of the Stirling engine.
The Stirling engine is, first of all, an external combustion engine.
This poses several problems and some advantages.
The advantages are that the combustion is continuous, so potentially perfect, something that can not physically be in diesel engines, unless they are VERY big and slow, as some marine engines.
The problems are due to transfer heat (external) into the engine.
Then there is a problem that is rarely mentioned in textbooks: the engine produces a pulse cyclic "natural", that being without valves can not have high gradients, (so I said: short stroke, and high RPM).
I personally think that the Stirling engine has little chance of achieving high overall efficiencies.
Instead I think that might be interesting for alternative fuels (wood, twigs, coal, straw, sawdust, dried cow dung, peat, rice hulls, nut shells, ....not all in the world have diesel oil), or solar or heat sewage not otherwise used.
The Stirling engine is, first of all, an external combustion engine.
This poses several problems and some advantages.
The advantages are that the combustion is continuous, so potentially perfect, something that can not physically be in diesel engines, unless they are VERY big and slow, as some marine engines.
The problems are due to transfer heat (external) into the engine.
Then there is a problem that is rarely mentioned in textbooks: the engine produces a pulse cyclic "natural", that being without valves can not have high gradients, (so I said: short stroke, and high RPM).
I personally think that the Stirling engine has little chance of achieving high overall efficiencies.
Instead I think that might be interesting for alternative fuels (wood, twigs, coal, straw, sawdust, dried cow dung, peat, rice hulls, nut shells, ....not all in the world have diesel oil), or solar or heat sewage not otherwise used.
Re: High compression
I only came to this site, as an answer to a question while 'inventing' a different type of engine. It uses tried and tested technology, but with a modern twist. I remembered from my past a compressor for Hydrogen liquification, with a piston inside another. I had never quite understood the reason for this, but thought the piston idea cold perhaps be used in my prototype. Since then I have found out why the pistons are like this, but think I will use my first idea which is less elegant, as I'm not sure that it can withstand the pressures involved. I will put it on the back burner for the 2nd prototype, if the first one needs it.
Re: High compression
A piston moving within another moving piston can be sealed just as they would be in a piston moving in a stationary cylinder. If high compression is proven in Diesel your materials need to have the capacity to hold the compression to these rates. Don't know of any examples that use piston within piston sealing for high compression but you have an answer that the seal can be made.
Re: High compression
Thank you Longboy,
I thought this might be true as it seems logical.
I am slowly working towards designing my engine design. I have never done this before, so it is a sharp learning curve.
Initially I was trying to find a prototype model maker, but it's quite hard to find someone who can work with me perhaps changing things as I 'invent' them.
I thought this might be true as it seems logical.
I am slowly working towards designing my engine design. I have never done this before, so it is a sharp learning curve.
Initially I was trying to find a prototype model maker, but it's quite hard to find someone who can work with me perhaps changing things as I 'invent' them.