A Spray Model for an Adaptive Mesh Refinement Code

Sara D. Bauman
Under the supervision of Prof. Christopher J. Rutland
At the University of Wisconsin-Madison




Abstract:

A spray model has been implemented into an existing low Mach number, Navier-Stokes code utilizing adaptive mesh refinement. The integration of a spray model with a fluid code possessing the ability to control the resolution of the computational grid attempts to address the problem of insufficient solution resolution when the cell size of fixed grids is compromised in order to achieve reasonable run times in high-pressure spray simulations.

The implementation of the spray model involves the creation and development of a suitable data structure to store spray variables, routines to control the behavior of the parcels of spray droplets, and routines to control the interaction between the ambient fluid and the spray. The spray model includes submodels for aerodynamic drag, droplet oscillation and distortion, turbulence effects, droplet breakup, evaporation, and droplet collision and coalescence. Special provisions for the treatment of spray droplet parcels within the adaptive mesh refinement framework have also been developed.

The performance of individual spray submodels has been validated by comparing single grid results to theory and experimental results from the literature. The performance of the complete spray model has been explored by comparing results calculated using grid adaptation to experimental results from the literature. The effect of adaptation on spray simulation has also been explored and discussed.




dailey@cs.wisc.edu
Mon June 1, 1998