A General, Mass-Preserving Navier-Stokes Projection Method

The conservation of mass is common issue with multiphase fluid simulations. In this work a novel projection method is presented which conserves mass both locally and globally. The fluid pressure is augmented with a time-varying component which accounts for any global mass change. The resulting system of equations is solved using an efficient Schur-complement method. Using the proposed method four numerical examples are performed: the evolution of a static bubble, the rise of a bubble, the breakup of a thin fluid thread, and the extension of a droplet in shear flow. The method is capable of conserving the mass even in situations with morphological changes such as droplet breakup.Comment: Submitted to Computer Physics Communication

Level Set Jet Schemes for Stiff Advection Equations: The SemiJet Method

Many interfacial phenomena in physical and biological systems are dominated by high order geometric quantities such as curvature. Here a semi-implicit method is combined with a level set jet scheme to handle stiff nonlinear advection problems. The new method offers an improvement over the semi-implicit gradient augmented level set method previously introduced by requiring only one smoothing step when updating the level set jet function while still preserving the underlying methods higher accuracy. Sample results demonstrate that accuracy is not sacrificed while strict time step restrictions can be avoided

Ordering of metallic quantum dots

This letter proposes a mechanism for the ordering of metallic quantum dots without coherent lattice or lattice mismatch with the substrate so that elasticity may not account for the phenomena. The authors show that contact potential induces repulsive charge clouds in the substrate. The size-dependent repulsion and van der Waals attraction lead to ordered nanoscale structures.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87805/2/073105_1.pd