Event Type:

Applied Mathematics and Computation Seminar

Date/Time:

Friday, February 27, 2009 - 04:00

Location:

Gilkey 113

Guest Speaker:

Sourabh Apte

Institution:

Department of Mechanical Engineering

Abstract:

A hybrid Lagrangian-Eulerian (hLE) scheme, combining a particle-based, mesh-free technique with a finite-volume flow solver, is developed for direct simulations of two-phase flows. The approach uses marker points around the interface and advects the signed distance to the interface in a Lagrangian frame. The kernel–based derivative calculations typical of particle methods are used to extract the interface normal and curvature from unordered marker points. This approach allows computation of topological changes in the interface and merges the naturally adaptive nature of particle-based schemes, for efficient representation of the interface between two fluids, with the relative flexibility offered by grid-based solvers for complex flows. The fluid flow equations are solved on a background, fixed mesh using a co-located grid finite volume solver together with balanced force algorithm (Francois et al. JCP, 2006) for surface tension force. The numerical scheme is first validated for standard test cases: (i) parasitic currents in a stationary spherical drop, (ii) capillary waves on droplet surface, and (iii) gravity waves to show good accuracy. Extension of the approach to three-dimensions is conceptually straight forward, however, poses challenges for parallel implementation. A domain-decomposition based on balancing the number of grid points per processor gives rise to load–imbalance due to uneven distribution of the marker points. A dual–constraint partitioning balancing the marker points and the grid control volumes is being investigated.