Volumetric Efficiency And Clearance

The volumetric efficiency of an idealize compressor consists of an indicator diagram like the figure as shown below can be written directly as,

                                                                    Figure: Ideal Indicator Diagram

                                                  Figure: Effect of Clearance on Volumetric Efficiency

As (P₂/P₁)1/n is always bigger than unity, it is apparent that the volumetric efficiency of the idealized compressor reduces as the clearance rises and as the pressure ratio rises.