Question

An ideal Otto Cycle with air as the working fluid has a compression ratio of10. The minimum temperature and pressure in the cycle are 25 degrees celsius and 100 kPa respectively. The highest temperature in the cycle is 1000 degrees celsius. Using the PG model for air with properties: k =1.4, c_p = 1 kJ.kg.K, c_v = 0.717 kJ/kg.K, determine the exhaust temperature (temperature at the end of the expansion stroke) in Kelvins.

Answer 1

`T_4`= 506.79 K

Step-by-step explanation:

Given that

Minimum temperature
`T_1`= 25 C

Pressure = 100 KPa

Highest temperature
`T_3`= 1000 C

Compression ratio r= 10

We know that for ideal Otto cycle

`(T_3)/(T_4)=r^(\gamma -1)`

Where
`T_3` is the exhaust temperature.

Now by putting the values

`(T_3)/(T_4)=r^(\gamma -1)`

`(1000+273)/(T_4)=10^(1.4-1)`

`T_4`= 506.79 K