[01] A. Helmy, Mechanical Power Engineering Department, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt. [02] S. Wilson, Mechanical Power Engineering Department, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt. [03] A. Siam, Mechanical Power Engineering Department, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt. [04] A. Balabel, Mechanical Engineering Department, Faculty of Engineering, Taif University, Taif, Saudi Arabia.

Effervescent atomizers have showed to work well in terms of lower droplets size at relatively low injection pressure. In effervescent atomizer, a type of internal-mixing twin-fluid atomizer, the gas is bubbled in the liquid to form bubbly mixture upstream atomizer exit. The flow nature upstream atomizer exit affects the atomizer performance to great extent. In literature, several studies were done to simulate internal flow. Few results have used volume of fluid method. In the current study the two phase flow inside the atomizer was numerically simulated using the volume of fluid model. Validation with experimental work was performed first. The results were found in close agreement with the experimental correlation. The main purpose of the current study is to investigate the application of effervescent atomizer in aviation gas turbine and to investigate the internal flow evolution inside the atomizer. The fuel used is Jet-A1 commercial aviation fuel. The present results showed that the gas to liquid mass ratio (GLR) is one of the major contributory factors affecting the atomizer performance. The two phase flow was identified as slug flow in the discharge passage at low GLR (0.08%). The flow evolved to slug- annular flow at GLR= 0.5%. At high GLR (0.8%) the annular flow was distinguished. The mixing between phases was augmented with increasing GLR. Finally the liquid film thickness at the atomizer outlet was calculated. The results showed that the liquid film thickness decreased with increasing GLR. Lower GLRs affect liquid film thickness sharply than higher GLRs.

Effervescent Atomizer, Liquid Film Thickness, Numerical Modelling, Two-Phase Flow, Volume of Fluid

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