Problems in OTTO cycle

   An air standard Otto cycle has a volumetric compression ratio of 6, the lowest cycle pressure of 0.1MPa and operates between temperature limits of 27°C and 1569°C. 

     Calculate:

    (i) the temperature and pressure after the isentropic expansion (ratio of specific heats = 1.4). (ii) Since it is observed that values in (i) are well above the lowest cycle operating conditions, the expansion process was allowed to continue down to a pressure of 0.1 MPa. Which process is required to complete the cycle? Name the cycle so obtained. 

    (iii) Determine by what percentage the cycle efficiency has been improved.

   Given:

                r = 6;       γ = 1.4.     P1  = 0.1 MPa = 1 bar;            T1  = 27 + 273= 300 K;                                            

                 T3  = 1569 + 273 = 1842 K;  

    To Find:

Temperature & Pressure and efficiency.

   Solution:

 

Composed by:  R.Satheesh, M.E., Asso Prof., email: rsatheeshemail@gmail.com.