2. Modify problem 1 by increasing the pressure at the start of compression to 1.8 bar while keeping

the engine compression ratio, ratio of specific heats, pressure ratio at constant volume and volume

ratio at constant pressure, the same (note: you will have a different overall pressure ratio, pmax/pmin).

What effect will this change have on thermal efficiency and mean effective pressure?/n1. Three boosting schemes are considered to increase the power output of a compression ignition (CI)

engine operating on the air-standard dual cycle: constant-pressure turbocharging, variable-pressure

turbocharging, and supercharging. Determine the thermal efficiency and mep for each scheme

relative to the natural-induction dual-cycle engine. Take the following:

Ambient conditions

1 bar, 293K

Ratio of specific heats

7= 1.4

Compression ratio for base engine

12.5

Overall pressure ratio for boosted engines (Pmax/pmin) 82

Pressure ratio at constant volume

a=1.6

Volume ratio at constant pressure

B=1.3