Diesel Engines

A powerful machine, diesel engine (also known as a compression-ignition engine and sometimes capitalized as Diesel engine) is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber during the final stage of compression. This is totally contrast to spark-ignition engines such as a petrol engine (gasoline engine) or gas engine (using a gaseous fuel as opposed to gasoline), which uses a spark plug to ignite an air-fuel mixture. The diesel engine works according to the cycle called the Diesel cycle. The thermodynamic cycle and the engine were both developed by Rudolf Diesel in 1897.

It is provided with the highest thermal efficiency of any regular internal or external combustion engine due to its very high compression ratio. Low-speed but heavy diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) often have a thermal efficiency which exceeds 50 percent.

Power And Fuel Economy:

Even though it is more economic compared to the petrol engine, the diesel engine has a poorer power-to-weight ratio than the petrol engine. This is probably because the diesel engine must operate at lower speeds and because it needs heavier, stronger parts to resist the operating pressure caused by the high compression ratio of the engine and the large amounts of torque generated to the crankshaft. In addition to that, diesel engines are often built with stronger parts to give them a longer lives and better reliability, important considerations in industrial applications.

Diesel engines have longer stroke lengths in order to achieve the necessary compression ratios. The connecting rods and piston are heavier and more force must be transmitted through the connecting rods and crankshaft to change the momentum of the piston. This is the reason that a diesel engine must be stronger for the same power output as a petrol engine.

With a diesel engine, boost pressure is essentially unlimited. It is possible to run as much boost as the engine will physically stand before breaking apart.