Otto Cycle is the theoretical thermodynamic cycle which describes the working of a spark ignition engine. This type of spark ignition engines is the most common type of engines used in automobiles. Today we will attempt to study it and understand what comprises of this Otto Cycle.

The Otto cycle is the study of what happens to a mass of gas when it is subjected to changes in pressure, temperature, volume, adding heat and removing heat. The system is the term given to the mass of gas that is subjected to these changes. Otto Cycle also studies the effect of this system on the environment. The effect in question here is the net output or the work generated by the Otto Cycle to move the automobile in which the engine is installed.

otto cycle

The name Otto Cycle comes from the name of the person who has put forward the theory of this system.His name was Dr Nicolas August Otto.
The Otto Cycle comprises a top and bottom of the loop process which is called isentropic process. This process is frictionless and adiabatic. And an isochoric process which happens at left and right side of the loop and has the constant volume.

The reason we consider the Otto cycle as a theory is because of its premise that it operates in a completely efficient system where no energy is lost. However, we know that in reality, it is still not possible.

Also Read: Diesel Cycle vs Otto Cycle

The isentropic process implies that during compression cycle there will be no loss of mechanical energy and considers that no heat will either enter the system or leave it.
In theory, heat flows through the left pressurizing process and some of it passes back through the right depressurizing process. The difference of heat here gives the net mechanical work generated.

The Following Are The Four Processes In Otto Cycle-