55.How main engine is working

- The working principle is based on dual cycle.

-The dual combustion cycle  is a thermal cycle that is a combination of the Otto cycle and the Diesel cycle

 It consists of two adiabatic and two constant volume and one constant pressure processes.

  

The dual cycle consists of following operations:

• Process 1-2: Isentropic compression
• Process 2-3: Addition of heat at constant volume.
• Process 3-4: Addition of heat at constant pressure.
• Process 4-5: Isentropic expansion.
• Process 5-1: Rejection of heat at constant volume.

 Heat is added partly at constant volume (isochoric) and partly at constant pressure (isobaric),^[2] the advantage of which is that more time is available for the fuel to completely combust