## Abstract

Fractal scaling of the exponential type is used to establish the cumulative volume (V) distribution applied through agricultural spray nozzles in size x droplets, smaller than the characteristic size X. From exponent d, we deduced the fractal dimension (D_{f}) which measures the degree of irregularity of the medium. This property is known as `self-similarity'. Assuming that the droplet set from a spray nozzle is self-similar, the objectives of this study were to develop a methodology for calculating a D_{f} factor associated with a given nozzle and to determine regression coefficients in order to predict droplet spectra factors from a nozzle, taking into account its own D_{f} and pressure operating. Based on the iterated function system, we developed an algorithm to relate nozzle types to a particular value of D_{f}. Four nozzles and five operating pressure droplet size characteristics were measured using a Phase Doppler Particle Analyser (PDPA). The data input consisted of droplet size spectra factors derived from these measurements. Estimated D_{f} values showed dependence on nozzle type and independence of operating pressure. We developed an exponential model based on the D_{f} to enable us to predict droplet size spectra factors. Significant coefficients of determination were found for the fitted model. This model could prove useful as a means of comparing the behavior of nozzles which only differ in not measurable geometric parameters and it can predict droplet spectra factors of a nozzle operating under different pressures from data measured only in extreme work pressures.

Original language | English |
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Journal | Scientia Agricola |

Volume | 69 |

Issue number | 1 |

Pages (from-to) | 6-12 |

Number of pages | 7 |

ISSN | 0103-9016 |

Publication status | Published - 2012 |