Problems in OTTO cycle

      The minimum pressure and temperature in an Otto cycle are 100 kPa and 27°C. The amount of heat added to the air per cycle is 1500 kJ/kg. 

    Determine the pressures and temperatures at all points of the air standard Otto cycle. Also calculate the specific work and thermal efficiency of the cycle for a compression ratio of 8 : 1.  Take for air: Cv = 0.72 kJ/kg K, and γ = 1.4.

Given:

P1  = 100 kPa = 105 N/m2 or 1 bar

T1 = 27 + 273 = 300 K

Heat added QS= 1500 kJ/kg;

r = 8 : 1 ; Cv = 0.72 kJ/kg ; γ = 1.4.

To Find:

(i) Pressure and temperature at all points

(ii) ηotto   and    (iii) Specific work

   

  Solution:

Result:

Specific work = 847 KJ/Kg

Air standard efficiency, ηotto = 56.47%

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