Atomization and Sprays

IMPINGEMENT FLUX UNIFORMITY IN NOZZLE SPRAYING FOR INDUSTRIAL APPLICATIONS

ABSTRACT

The spray volume flux on the impingement or target surface from a nozzle is inherently not uniform even with a short impingement distance. A technique that only requires a special one-dimensional (1D) array arrangement of spray nozzles is developed to provide a uniform overall flux on a large impingement surface with the existing commercially available nozzles. Experiments and analyses were first conducted to assess how well the measured spray flux profiles can be correlated or fitted to a Gaussian function. The corresponding coefficient of determinations (R²) and standard deviations were specifically computed to quantify the deviation of the correlations or the data fitting accuracy. It was found that the measured spray flux data agreed extremely well with the Gaussian function. Based on this finding, the technique to assemble the overall flux profile from the 1D arrayed nozzles was analytically developed and experimentally illustrated. By adjusting the array pitch or nozzle spacing, the profile of the overall (overlapped) spray volume flux could be controlled and predicted. The uniformity criteria for assembling a uniform overall flux profile, including the threshold pitch, uniformity ratio, and flux peak intensity, were then analyzed and experimentally confirmed.