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Advisor(s)
Abstract(s)
The 3D incompressible Navier-Stokes equations are coupled with the CLSVOF method and employed to numerically simulate the phenomena of single droplet impact onto liquid films. A solution-adaptive mesh refinement tool, based on the gradient of the volume fraction scalar, is adopted in order to reduce computational cost. Three different fluids are taken into account: 100% jet fuel and 75%/25% and 50%/50% of jet fuel and biofuel, respectively. Quantitative analysis of the crown height and outer diameter is performed for different impact conditions, such as the influence of the impact velocity and dimensionless thickness, between experimental and numerical results, and the qualitative analysis includes the occurrence of splashing and overall crown evolution. Numerical results show that the crown outer diameter measurements are in good agreement with the experimental cases, presenting a slight discrepancy for the lower liquid film thickness of h*= 0.2. The crown height measurements are under-predicted for the current model, maintaining a similar trend for dimensionless thicknesses of h*= 0.5 and h*= 1 while, for the lower thickness, the crown disintegrates at earlier stages. The crown curvature and rim instabilities exhibit significant differences, and the splashing phenomenon occurs for both the experimental and numerical outcomes.
Description
Keywords
Droplet impact Thin Liquid Layers CLSVOF method Numerical Secondary atomisation Biofuels Crown evolution
Citation
Publisher
American Institute of Aeronautics and Astronautics Inc, AIAA