System properties were normalized systematically: engine properties by displacement into mean effective pressures
, transmission data by input torque capacity, vehicle road load data to coast down deceleration rates, and drive cycle traction power requirement to P/M or Vehicle Specific Power.
The engine operations at different throttle conditions showed a varied range of rich and lean misfiring limits around a reference equivalence ratio that corresponds to the respective maximum indicated mean effective pressure.
The coefficient of variation of indicated mean effective pressure at the reference equivalence ratio remained within 10 percent.
The variation of brake thermal efficiency with respect to the brake mean effective pressure under various compression ratios is shown in the Fig.
The variation of CO emission on volumetric basis with respect to brake mean effective pressure for the various fuel blends and neat diesel are shown in Fig.
6 shows the variation of hydrocarbon emission with brake mean effective pressure under various compression ratios.
Mean effective pressure (mep) where nR is the number of crank revolutions for each power stroke per cylinder (two for four-stroke, one for two-stroke cycles) as:
In addition, indicated horse power, break mean effective pressure and specific fuel consumption calculated from the experiments.
These smaller engines operate at higher cylinder mean effective pressures
across the load range than the engines they supersede.
The integration of the measured cylinder pressure curves throughout a work cycle gives the internal work done, which applied to the piston displacement gives the (IMEP) indicated mean effective pressure .
The brake mean effective pressure (BMEP) for a four stroke engine is given according to the following equation:
This simulation requires engine geometry, cylinder wall temperatures, a heat transfer model, estimation of friction mean effective pressure
and a proper set of both boundary and initial conditions.