Diesel motors are great...but?

[Egon]

I believe Egon should have the last word in aircraft AC, since he has supplied a definitive source.

No no no. Areo knowledge is not a strong point in my narrow domain. Did talk to fellow who flew 747's once though.

 

[Rock knocker]

But your referenced link was definitive

 

[John_Mc]

Piston aircraft engines are pretty basic low tech machines but they cost just about as much as near luxury car that is way more complex. Is it a possible liability expense built in the price or it is because of market will pay the price or what else it can be?

Liability is part of the cost. The cost of certification for aircraft use if part of it. A really big part of it is that 1000 units is a big run for aviation (as compared to 100s of thousands run for automotive).

 

[DarkBlack]

But your referenced link was definitive

Definitive no, athoritive yes. Using the cold air for heat exchangers makes sense. I thought someone posted air conditioning ie compressors etc. I noticed they will reduce the air loss so they don't need to compress so much. Makes sense for economy.

 

[Dalmatian90]

Why have they never been used in airplanes (WW2 or so)?

One thing I didn't see mentioned is logistics -- especially at the refinery level, but also at the airfield side.

Big Caveat: This is informed speculation, I haven't read up on the topic, but these are the questions I'd go looking for answers for.

Did we have the capacity to produce enough diesel to power all those aircraft? Different grades of oil have different yields of gasoline v. diesel, and then the refinery has the ability within a fairly limited range to determine how much goes to each. If the refineries were built to emphasize gasoline, you might not get more diesel without major rebuilding projects to add capacity on the diesel side. And the diesel would be coming off the heavier side, which might be cutting into your heavier fuels for industrial and marine applications.

If you were Germany, and external oil supplies cut off you might be more interested in pressing vegetable oil to cut your diesel with.

As it heads down to the airfield, did you want to deal with two supply streams and how much of each you needed, or a single grade of aviation gas?

Start combining the logistics stuff with the technical stuff and you'd probably have a better picture of the reasoning.

 

[flyerdan]

The current versions of aircraft 'diesel' engines are designed to burn jet fuel; since Jet A is available worldwide it would provide less availability problems that avgas now, as it will cease to exist as we know it in a few years. Several refineries are working on a replacement, which a lot of operators are following closely, as it appears that a lot of the same problems we experience with older engines not liking corn gas might migrate to the aircraft as well.

 

[Egon]

Wondering how the diesel flows at 35,000 ft.

 

[buickanddeere]

As alluded to. The difference in refining capacity would not be a hurdle to refine all compression ignition fuel into Jet A-1 and drop #2 diesel all together. No more winter gelling from wax.
All other factors identical. Jet A-1 burns cleaner than #2 diesel. Operators of puttering around Tier IV diesel equipment will notice fewer re-gens if operating on Jet A-1 instead of diesel.

 

[ksbrdmkr]

Let the engineers loose and most anything can fly. This state of the art UAV (Unmanned Aerial Vehicle) is equipped with a liquid-hydrogen propulsion system that powers two four-cylinder truck engines. Darryl Davis, president of Boeing Phantom Works explains,
"It's basically a Ford Ranger truck engine converted to burn liquid and gaseous hydrogen."
The engines each provide 150 horsepower, combined with a 150 ft wingspan, allow the UAV to cruise at approximately 150 knots while carrying a 450 lb payload. This highly efficient aircraft is also capable of staying aloft at 65,000 ft for up to four days and it's only byproduct is water.

 

[MossRoad]

Let the engineers loose and most anything can fly. This state of the art UAV (Unmanned Aerial Vehicle) is equipped with a liquid-hydrogen propulsion system that powers two four-cylinder truck engines. Darryl Davis, president of Boeing Phantom Works explains,
"It's basically a Ford Ranger truck engine converted to burn liquid and gaseous hydrogen."
The engines each provide 150 horsepower, combined with a 150 ft wingspan, allow the UAV to cruise at approximately 150 knots while carrying a 450 lb payload. This highly efficient aircraft is also capable of staying aloft at 65,000 ft for up to four days and it's only byproduct is water.

Pictures and links man! :laughing: