Diesel engines have the ability to retain their efficiency at low loading. As already mentioned, about the only thing you can do is reduce spurious losses. If the generator is belted you can change pulleys to reduce engine RPM.
Or use an inverter generator. They allow engine RPM to be...
Hemi Agree the post isn't clear. What I was trying to say is; when a CI engine is cold it has long ignition delay. When the fuel does ignite it tends to burn all at once like detonation in a SI engine.
The rapid energy release makes for a high peak temperature which gets into a temperature...
Jmc41 Thanks for the interesting post. No doubt you observed that more compression (more heat and pressure) lowered NOx. But there is more going on. One of the big things in CI engines is ignition delay. The fuel is injected then sometime there after it burns all at once giving the well...
There have been some interesting historic attempts at a hyperbaric two cycle.
The Kettering designed Detroit Diesel used a single port at the bottom of the cylinder and an exhaust valve in the head. It needed a blower or supercharger to work. This engine is no longer used because of oiling...
"Elsewhere it is claimed that the layout permits higher working temperatures in the hot cylinder. This tends to have the effect of INCREASING NOx emissions."
Probably what the author meant to say was that compression is done in a cooler cylinder hence the compression stroke requires less...
This is a Brayton cycle first proposed and patented by George Brayton, Philadelphia in 1875.
The major difference is the end on pistons and the use of a poppet valve for exhaust.
The original Brayton engines used a port in the bottom of the high temperature cylinder for exhaust.
The Brayton...
You do not need batteries for the differential/electric counter method. That is what the second motor is for. But still we must agree that an aeronautical application is not ideal for this technique.
In aeronautical applications it seems like turbo compounding would be the better approach...
Excellent thread. Many thanks to wwest and Brian for their insight.
Internal combustion engines are at a similar point to where electric motors were 25 years ago.
High efficiency units are now available but we quickly find that the higher efficiency motors have preferred areas of operation...
Probably at idle the residence volume left over from the exhaust stroke is a significant percentage of the charge. You are not getting enough stokeometric mixture out to the edge of the cylinder to the ignition point.
Three things come to mind.
1. Any grove you could get in there probably would not make much difference.
2. You are removing material in a critical area needed for cooling conduction and strength.
3. Today's diesels are highly optimized. Any change in induction would probably get you off the...
Good point SonyAD.
But how about going a little more into the way out. How about using water based lubricant in the crank case? This fluid would serve for both crank case lubricant and heat exchange. I feel that new engine designs may tend to high temperature top end, even approaching...
The maximum gas velocity is for a given pressure drop is given by Toricelli's formula which is a subset of the Bernoulli equation.
The difference you are seeing is probably because when the engine breathes combustion air in, the air is starting with zero kinetic energy. All air movement has...
In my first post I was trying to keep it simple and just answer the op. But since there seems to be interest, here is more info. This is speaking of the USA.
The electronic service station came in about 20-25 years ago when the Feds mandated tank gaging to detect leaking tanks. Oddly enough...
Dicer writes:
The elimination of O2 with EGR.
Less compression.
Cooler combustion.
Less heat means less power extracted from the fuel so more fuel is needed to do the same job.
This is mostly right. The EGR reduces the percentage of O2 in the charge.
They may have less mechanical compression...
