Question

A diesel engine operating on Air Standard Diesel cycle operates on 1 kg of air with an initial pressure of 98kPa and a temperature of 36°C. The pressure at the end of compression is 35 bar and cut off is 6% of the stroke. Determine (i) Thermal efficiency (ii) Mean effective pressure.

Answer 1

Given that :

m = 1 kg

P₁ = 98 kPa = 98 × 10³ Pa;

T₁ =36°C = 36 + 273 = 309 K, 

P₂ = 35 bar = 35 × 10⁵ Pa

V₃ – V₂ = 0.06VS

For air standard cycle P₁V₁ = mRT₁

98 × 10³ × V₁ = 1 × 287 × 309

V₁ = 1.10 m³; V₁ = V₂ + V₃ = 1.10

As process 1-2 is adiabtic compression process,

= 1539580 × 0.415 Pa = 6389257 Pa = 6389.3 KPa