Diesel engine Compression ignition Biodiesel Diesel Commentary

Rudolf Diesel thermodynamics

Diesel engine

• Rudolf Diesel had studied thermodynamics
• and tried to develop a Carnot Cycle engine
• with the best possible efficiency.
• Compression ignition and direct injection
• of oil into the cylinder instead of premixing
• a lighter gasoline with air simplified the cycle
• but the efficiency of the diesel engine
• compared to a gasoline engine is simply
• a result of its higher compression ratio.

Compression ignition

• It turns out that Diesel was not the first
• to build an engine with compression ignition.
• Diesel might have been inspired by the fire piston,
• which was patented in Europe in 1807 although
• it had been in use in South East Asia and the islands
• of the Pacific since ancient times. Nevertheless,
• Diesel was not the only person who was inspired.
• Herbert Akroyd-Stuart created an engine with
• compression ignition and direct fuel injection
• (not mixed with air) two years earlier; however,
• Akroyd-Stuart’s engine operated with lower compression
• and today is called a “heavy-oil” engine.
• At any event it shouldn’t be called a “diesel.”

Biodiesel

• The first working diesel ran on peanut oil
• and any diesel engine will run without modifcation
• on biodiesel, made of vegetable oil and animal fats
• by transesterification that separates the glycerin
• and leaves mono-alkyl esters of long chain fatty acids.

Diesel

• More bang for the buck
• moves more metal.
• Sure to be more
• to say about it.
• In the end it seems
• it all evens out.