Suzuki Takashi

The experiment which have been made clear the effect of turbulence caused by combustion analyzed in the second paper was done by this paper. The experiments let equivalence ratio of supplied air-fuel mixture, pressure, configuration of combustion chamber and location of ignition plug change using constant volume combustion chamber. As a result of experiments, it became clear that the turbulence caused by combustion was in proportion to the density of supplied air-fuel mixture and mean velocity of flame propagation. The empirical formula is shown next. The calorific value calculated using this empirical formula became small around 8% value with mean than theoretical calorific value. And also it became clear that the dispersion of estimation was small comparatively because a value of correlation coefficient was 0.98.

When the power or specific fuel consumption is estimated in design process, thermodynamic consideration for the estimation is generally insufficient. Hence, a theory that can estimate these performances accurately is investigated in this paper. As a result of investigation, it is clear that the effect of pumping loss in wide-opene throttle valve operation has to be excluded from the mechanical loss which is measured in the motoring test. It also becomes clear that a new coefficient called pumping loss coefficient ηP has to be considered for the negative work for pumping. From the foregoing, theoretical formulas for estimating the net power Pe and net specific fuel consumption be. which are formed with various efficiencies and coefficients are as follows: It is verified that the estimation from these formulas agree well with the experimental test values using stoichiometric mixture ratio. By using these formulas, the mechanism for improvement of specific fuel consumption in the lean burn engine is also examined by analyzing the effect of air/fuel ratio on Pe and be. © Copyright 1996 Society of Automotive Engineers, Inc.