Hot-Wire Measurements of the Turbulence Structure in a Motored Spark-Ignition Engine.

摘要

Statistical techniques were developed for the processing of hot-wire anemometer signals digitally recorded in a motored Otto-cycle engine. Since engine flow processes are highly non-stationary,it is necessary to use ensemble-averaging procedures to define both the mean flow properties and turbulence structure. Statistical definitions and experimental results are presented for the mean velocity,turbulence intensity,skewness,kurtosis,probability density distribution,autocorrelation function,one-dimensional energy spectrum,and the micro-and integral-scales of turbulence. It is shown that these turbulence quantities are statistically well-behaved,such that an understanding and the eventual modeling of engine flow processes would appear to be an achievable goal.