Question

In an ideal Otto cycle, air is compressed from 25 C and 2 L to 0.16 L, and its temperature increases by an additional 800 C during the heat addition process. Determine the thermal efficiency of the cycle. Account for the constant specific heats at room temperature. Assume Cp = 1.005 kJ/kg.K and k=1.4.

Answer 1

η = 0.635 or 63.5 %

Step-by-step explanation:

Given that

T₁=25 C

V₁= 2 L

V₂=0.16 L

We know that compression ratio(r) in Otto cycle given as

r= V₁ /V₂

r= 2 / 0.16

r=12.5

We know that efficiency to cycle given as

tex]\eta =1-\dfrac{1}{r^{k-1}}[/tex]

By putting the values

`\eta =1-(1)/(12.5^(1.4-1))`

η = 0.635 or 63.5 %