Question

An Otto cycle with air as the working fluid has a compression ratio of 8.2. The ambient temperature is 298K. The maximum temperature of the Otto cycle is 2000K. Under cold air standard conditions, the thermal efficiency of this cycle is ____

Answer 1

The correct answer is "57%".

Step-by-step explanation:

Given:

Temperature:

`T_a = 298 \ K`

`T_3 = 2000 \ K`

Compression ratio (r),

=
`8.2`

For Otto cycle, the thermal efficiency will be:

⇒
`\eta =1-(1)/((r)^(\\u-1))`

By substituting the values, we get

`=1-(1)/((8.2)^(1.4-1))`

`=1-(1)/((8.2)^(0.4))`

`=57` (%)