Droplet ratio deformation model in combination with droplet breakup onset modeling

Abstract

Droplet deformation and breakup in the continuously accelerated flowfield generated by an incoming airfoil have been studied. The upper limit of droplet deformation and the minimum distance to the airfoil model at which the breakup onset takes place have been modeled. Three analytical equations have been developed based on the combination of two models: a droplet deformation and trajectory model for droplets in a continuously accelerated flowfield, and a breakup model for droplets in the vicinity of a leading edge of an airfoil model. The verification was made using experimental data obtained for water droplets whose diameters were in the range from 400 to 1800 μm impinging on airfoils of three different chord sizes moving at velocities from 50 to 90 m/s90 m/s. The rotating arm facility at National Institute of Aerospace Technology was used for this purpose. The analytical equations of the model were in good agreement with the experimental data. The upper limit of droplet deformation was verified by 95.40% of the tested experimental cases, and the minimum distance to the airfoil was verified in 99.65% of the cases.