Thermodynamic Diesel Cycle: Air Standard Cycle

Thermodynamic Diesel cycle corresponds to the four stroke internal combsution diesel engines used by us in our vehicles and machines. In these engines the air is compressed to high pressures and then combustion of fuel takes place, hence they are also called as Compression Ignition (CI) engines.

Introduction

Apart from Otto cycle, thermodynamic Diesel cycle is one of the most popularly used cycles. The internal combustion diesel engines that are fitted in your cars and others machines run on the principle of Diesel cycle. Like petrol engine running on the principle of Otto cycle, the Diesel engines also comprise of four strokes: suction of fuel, compression of fuel, combustion and expansion of fuel and exhaust of burnt fuel. The four stroke engine has been described in details in article: How Four-Stroke Compression Ignition Engines Work

In diesel engine initially only air is inducted inside the cylinder and it is compresses to very high pressures. Thereafter the diesel fuel is injected inside the cylinder and its combustion takes place to high temperature of the compressed air. Since the combustion of fuel takes place due to compression of air, the diesel engine is also called Compression Ignition (CI) engine.

Four stroke Diesel cycle was invented by Rudolf Diesel in the year 1897. The principle of Diesel cycle is used in the compression ignition (CI) type of internal combustion engines using diesel as the fuel. Originally when Rudolf Diesel discovered this engine, it was meant to run on the coal dust.