Calculation Approach Validation for Airblast Atomizers

Abstract

In order to formulate a common approach that could provide the spray parameters of airblast atomizers, various processes of liquid preparation, breakup, and secondary atomization have been included in a semi-analytical calculation procedure. The air velocity components in the atomizer flow field are provided by mathematical expressions, and the spray droplets are considered to form at ligament breakup through a disturbance wave growth concept. The validation of the developed approach included the application to six atomizers that significantly varied in concept, design, and size. They represented both prefilming and plain-jet types, and the data utilized in the present effort were obtained with six different liquids. Satisfactory agreement between the measurements and the predictions has been achieved under wide ranges of air/fuel ratio and air pressure drop for various test liquids. The results of this investigation indicate the potential of using such an approach in the early phases of airblast atomizer design, and may be followed by more detailed calculations using analytical tools.