ID 43

A Hybrid Approach for Modeling Fully Resolved Liquid Film Formation by Converting Lagrangian Particles to Eulerian VOF Structures

 

Abstract:

Liquid atomization based on shearing a thin film along a solid surface is receiving focus in gas turbine combustors with an objective of staging the evaporation of the fuel to control the flame temperature and thus the emission. Gas turbine combustors often have a hybrid-atomization feature with pressure swirl atomization from the nozzle and airblast re-atomization of a liquid film at the trailing edge of a wall. The process involves interaction of different length scales. Thus, multiscale modeling approaches, transitioning large scale structures like ligaments to droplets and small scale structures like droplets to a film are recommended to perform high-fidelity simulations. In the current work we propose a hybrid approach involving Eulerian Volume of Fluids and Lagrangian droplet tracking to model the overall jet breakup and the spray formation process. Additionally, the transition of droplets to a film by impingement of droplets on a filming wall is captured by the conversion of Lagrangian droplets back to liquid phase in the Eulerian Volume of Fluid model. The proposed approach is validated against experimental data in the form of film thickness measurements available in literature [1]. The results compare well with the experimental values and the proposed model-transition approach is accurate as well as computationally affordable.

[1] Shedd, T., Corn, M. L., Arienti, M., and Soteriou, M. C., 2009, “Liquid Jet Breakup by an Impinging Air Jet,” Forty-Seventh AIAA Aerospace Sciences Meeting. Paper No. AIAA-2009-0998