Sara Zahedi – Post Doctoral

Research

My research concerns development of accurate numerical methods for solving partial differential equations where parameters and solutions may be discontinuous across interfaces. These interfaces are typically moving. The main application I am working with is multiphase flows. Immiscible fluids, that may have different densities and viscosities, are separated by interfaces. At the interfaces surface tension forces act and surfactants (surface active agents) may be present, changing the surface tension. Surface tension effects and the discontinuities in the viscosity results in discontinuities in the pressure and the derivatives of the velocity field. How to accurately represent the singular surface tension force, the interface geometry, and solve the PDEs used to model multiphase flow phenomena are the questions I try to answer in my research.

Publications

• Numerical Methods for Fluid Interface Problems, Sara Zahedi, Doctoral Thesis in Applied and Computational Mathematics, TRITA-CSC-A 2011:07, ISSN 1653-5723 (2011)

• A uniformly well-conditioned, unfitted Nitsche method for interface problems: Part II, Eddie Wadbro, Sara Zahedi, Gunilla Kreiss, and Martin Berggren submitted

• A uniformly well-conditioned, unfitted Nitsche method for interface problems: Part I, Sara Zahedi, Eddie Wadbro, Gunilla Kreiss, and Martin Berggren submitted

• Spurious currents in finite element based level set methods for two phase flow, Sara Zahedi, Martin Kronbichler and Gunilla Kreiss, published online

• Delta function approximations in level set methods by distance function extension, Sara Zahedi and Anna-Karin Tornberg, J. Comput. Phys. 229, 2199-2219 (2010)

• A Conservative Level Set Method for Contact Line Dynamics, Sara Zahedi, Katarina Gustavsson and Gunilla Kreiss, J. Comput. Phys. 228, 6361-6375 (2009)

• Numerical Modeling of Fluid Interface Phenomena, Sara Zahedi, Licentiate Thesis in Numerical Analysis, TRITA-CSC-A, ISSN 1653-5723 (2009)

• Computation of interior eigenvalues in electronic structure calculations facilitated by density matrix purification, Emanuel H. Rubensson, Sara Zahedi, J. Chem. Phys. 128, 176101 (2008)

• A conservative level set method for two phase flow II, Elin Olsson, Gunilla Kreiss and Sara Zahedi, J. Comput. Phys. 225, 785--807 (2007)