A stochastic-experimental investigation of the cyclic pressure variation in a di single-cylinder diesel engine

This paper presents an analysis of the cycle-by-cycle combustion variation as reflected in the pressure indicator diagram of a single-cylinder, naturally aspirated, four-stroke, direct-injection, Lister LV1 diesel engine. A measuring set-up consisting of piezoelectric transducers with charge amplifiers, in the cylinder and the fuel injection pipeline, and a fast data-acquisition board installed on an IBM-compatible microcomputer was used to gather the data of 650 successive combustion cycles of the cylinder, under various combinations of injection timing and load conditions. The measured data were corrected for drift, and the top dead centre of each cycle is determined thermodynamically. The data obtained by this technique were analysed for the peak pressure, the peak rate of pressure rise, the crank angles at which these maximum values occur, and for the injection timing and ignition delay. The groups of parameters have been further statistically analysed for averages, standard deviations, probability density functions, autocorrelations and power spectra. Crosscorrelation runs were also performed to observe any cause relationship between cyclic pressure variations and the fuel-injection-system operation. The results of the stochastic analysis technique have proved to be very useful for the investigation and interpretation of the existence of fluctuation phenomena in the diesel internal combustion engine and their cause relationships, thereby aiding the correct interpretation of the relevant experimental results and their associated errors.

[1]  Charles A. Amann,et al.  Cylinder-Pressure measurement and Its Use in Engine Research , 1985 .

[2]  Russell V. Fisher,et al.  Digital Data Aquisition with Emphasis on Measuring Pressure Synchronously wih Crank Angle , 1975 .

[3]  Iwao KOIZUMl,et al.  Study on the Cycle-by-Cycle Variation in Diesel Engines , 1976 .

[4]  R. D. Wing.  The Rotary Fuel-Injection Pump as a Source of Cyclic Variation in Diesel Engines, and its Effect on Nitric Oxide Emissions , 1975 .

[5]  Dimitrios T. Hountalas,et al.  Thermodynamic analysis of indirect injection diesel engines by two-zone modeling of combustion , 1990 .

[6]  H. Saunders.  Literature Review : RANDOM DATA: ANALYSIS AND MEASUREMENT PROCEDURES J. S. Bendat and A.G. Piersol Wiley-Interscience, New York, N. Y. (1971) , 1974 .

[7]  C. D. Rakopoulos,et al.  Influence of ambient temperature and humidity on the performance and emissions of nitric oxide and smoke of high speed diesel engines in the Athens/Greece region , 1991 .

[8]  Warren C. Strahle.  COMBUSTION RANDOMNESS AND DIESEL ENGINE NOISE: THEORY AND INITIAL EXPERIMENTS , 1977 .

[9]  Donald J. Patterson,et al.  Mixture Turbulence - A Key to Cyclic Combustion Variation , 1973 .

[10]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[11]  A. Douaud,et al.  DIGITAP-An On-Line Acquisition and Processing System for Instantaneous Engine Data-Applications , 1977 .

[12]  C. D. Rakopoulos,et al.  An experimental-stochastic and theoretical analysis of the density wave instability in a helical monotube vapour generator , 1980 .

[13]  N. Watson,et al.  Turbocharging the internal combustion engine , 1982 .

[14]  John H. Lienesch,et al.  An Engine Diagnostic Package (EDPAC) - Software for Analyzing Cylinder Pressure-Time Data , 1978 .

[15]  Constantine D. Rakopoulos,et al.  Phasing cylinder pressure to crank angle in a direct injection diesel engine, by simulation of compression curve and elaboration of measured pressure data , 1991 .

[16]  Roger B. Krieger,et al.  A Statistical Analysis of the Influence of Cyclic Variation on the Formation of Nitric Oxide in Spark Ignition Engines , 1976 .