Multifractality of Drop Breakup in Air-blast Nozzle Atomization Process

TL;DR

This paper investigates the multifractal properties of drop breakup in air-blast nozzle atomization, using experimental data and a new multifractal model to understand the spatial distribution fluctuations of drops.

Contribution

It introduces a random multifractal model with triangularly distributed multipliers to characterize drop breakup, aligning well with experimental spectra.

Findings

The model accurately reproduces the left part of the multifractal spectrum.

Negative dimensions indicate fluctuating spatial distribution of drops.

Intrinsic randomness causes momentary fluctuations in spray concentration.

Abstract

The multifractal nature of drop breakup in air-blast nozzle atomization process has been studied. We apply the multiplier method to extract the negative and the positive parts of the f(alpha) curve with the data of drop size distribution measured using Dual PDA. A random multifractal model with the multiplier triangularly distributed is proposed to characterize the breakup of drops. The agreement of the left part of the multifractal spectra between the experimental result and the model is remarkable. The cause of the distinction of the right part of the f(alpha) curve is argued. The fact that negative dimensions arise in the current system means that the spatial distribution of the drops yielded by the high-speed jet fluctuates from sample to sample. On other words, the spatial concentration distribution of the disperse phase in the spray zone fluctuates momentarily showing intrinsic randomness.