Question

An ideal diesel engine has a cylinder diameter

150 mm and stroke 200 mm. The clearance

volume is 10% of swept volume, cut-off takes

place at 6% of the stroke. Calculate the

compression ratio and air standard efficiency of

the engine.​

Answer 1

2.An air compressor cylinder has 150mm bore and 150mm stroke and the clearance is

15%. It operates between 1 bar, 27oC and 5 bar. Take polytrophic exponent n=1.3 for

compression and expansion processes find?

i. Cylinder volume at the various salient points of in cycle.

ii. Flow rate in m3

/min at 720 rpm and .

iii. The deal volumetric efficiency.

Given

D = 15010-3m P2 = 5105 N/m2

L = 15010-3 m T1 = 27+273 = 300K

Vc =0.15Vs N = 720rpm

P1 = 1105 N/m2

pv

n = Cn=1.3

Find

i. V1, V2, V3, V4

ii. FAD (Va)

iii. v

Solution

V1 = Vc + Vs

Vs = (0.15) .0.15 720 1.9085 /min

4

.

4

2 2 3 D L N     m

 

Vc = 0.15 Vs

=0.151.9085

Vc= 0.2862 m3

/min

V1 = Vc + Vs

= 0.2862 + 1.9085

m

3

/min

n

2 2

n

P1V1  P V

V2 = V1

n

P

P

1

2

1

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