Time-based analysis of phase Do

摘要

Abstract: spectral density estimation was performed to detect characteristic velocity fluctuations in the surrounding air flow field of a air-assisted spray flame. Measurements were carried out using randomly spaced in time velocity data obtained from a phase Doppler instrument. A fast algorithm enabled large numbers of data points to be analyzed in a relatively short time. An unbiased estimate was made of the power spectral density that considered the variable measurement times of individual realizations. The measured droplet arrival times from the phase Doppler particle sizer were used to determine the appropriateness of the Poisson distribution in describing droplet arrival times. The results indicate that the variance in droplet arrival statistics is larger than would be expected for a Poisson process. In addition, several positions in the spray have bimodal distributions which limits the utility of the Poisson process.!15