The Diesel Cycle

Robert Amirault

Objective: To establish the function, pros and cons and uses of a diesel engine.

Gasoline Engine

• Burns unleaded refined gasoline

• Lower compression ratio (8:1 to 12:1)

• Subject to “knocking” at high compression

• Mixes the fuel before injection

• Uses spark plugs

Diesel Engine

• Burns less refined diesel fuel

• High compression ratio (14:1 to 25:1)

• Low risk of “knocking” easy to turbo charge and supercharge

• Relies only on pressure to ignite fuel

• Uses glow plugs (larger engines do not)

• Injects the fuel directly into the cylinder

Benefits

• More energy is contained in diesel fuel– One gallon of diesel contains 155 MJ– One gallon of gasoline contains 132 MJ

• More efficient

• Cheaper fuel

Drawbacks

• More expensive to manufacture

• Noisier

• More pollutant

• Low acceleration due to high torque

• Required to run at lower RPM

The Diesel Cycle

• Definition– The diesel cycle is the combustion process of a type of internal

combustion engine in which the burning of the fuel is triggered not by a spark plug as in the Otto cycle, but rather by the heat generated in compressing the fuel-air mixture.

• Four parts– Intake– Compression– Injection/combustion– Exhaust

The Engine

• The dissected engine was a gasoline engine

• The spark plug shows that it is not diesel

• Diesel engines are most often found in large trucks, boats, trains and anything requiring a lot of power without much speed.

References• http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/diesel.html• http://www.google.ca/search?hl=en&lr=&safe=off&rls=GGGL,GGGL:2005-

09,GGGL:en&oi=defmore&defl=en&q=define:Diesel+cycle• http://auto.howstuffworks.com/diesel1.htm