How Do Diesel Engines Work?

The diesel engine working principle was completed by the inventor, Rudolf Diesel, in 1892, and the first prototype was created in 1897. In the years following, he continued to work on improving his theory, and others soon realized the potential of this invention and started making their own versions. One of the people to recognize the importance of the diesel engine was Clessie Lyle Cummins. In 1919, He founded Cummins Engine Company with a goal of improving diesel technology and producing the world’s finest engines. Thanks to his vision, Cummins Inc. is now a global leader, producing advanced diesel engines for applications ranging from heavy-duty trucks and consumer pickups to industrial mining and oil drilling.

How does a diesel engine work?

Rudolf Diesel built his internal combustion engine based on the Carnot cycle, an idealized model of how a theoretical engine could maximize efficiency. In reality, this model doesn’t work since factors like friction make maximal efficiency impossible. However, the diesel engine applies this theoretical principle in a very practical way.

In general, a diesel engine works by using a piston to compress air to increase the temperature in the cylinder and then injecting atomized diesel fuel into this cylinder. When the fuel comes into contact with the high temperature, it ignites, creating energy that drives the piston down transferring energy to the crankshaft and through the powertrain. This process is repeated over and over again at a high speed, making a diesel engine a powerful piece of technology. Different types of diesel engines will have varying compression ratios. The compression ratio of the diesel engine impacts how much power the engine puts out. The higher the ratio, the more power is generated.

One common question about how diesel engines work is; why don’t diesel engines have spark plugs? The simple answer is that a diesel engine doesn’t need spark plugs because the fuel is ignited by the compression of air. Don’t get confused because there are certain parts of a diesel engine called “glow plugs.” When comparing a glow plug to a spark plug, you’ll find their purpose is different. A spark plug is used to ignite fuel in a gasoline or natural gas engine. The glow plug does not ignite the fuel but is basically a small heater that helps with heating up the compressed air in the cylinder. Glow plugs, among other key advantages to diesel engines, are especially useful when starting a cold engine.