The problem of expansion of a dilute granular gas consisting of smooth, inelastic hard spheres into vacuum was investigated by three different methods: both (1) analytical and (2) computational (CFD) treatments of a hydrodynamic model, and (3) by Discrete Element Method (DEM) simulation. Furthermore, the systems were followed for long times, over which the granular kinetic energy decreases by s...

We present a scheme for coarse-graining hydrodynamic interactions in an isolated flexible homopolymer molecule in solution. In contrast to the conventional bead-spring model that employs spherical beads of fixed radii to represent the hydrodynamic characteristics of coarse-grained segments, we show that our procedure leads naturally to a discrete model of a polymer molecule as a chain of orient...

The convective hydrodynamic model of semiconductor devices is analyzed employing parallel and stabilized finite element methods. The stabilized finite element method for the two-carrier hydrodynamic equations and the parallel computational model are briefly described. Numerical results are shown for a bipolar transistor. A comparison of drift-diffusion, energy-transport and the hydrodynamic mod...

Anomalous output characteristics are observed in hydrodynamic simulations of partially depleted SOI MOSFETs. The effect that the drain current reaches a maximum and then decreases is peculiar to the hydrodynamic transport model. It is not observed in drift-diffusion simulations and its occurance in measurements is questionable. An explanation of the cause of this effect is given and a solution ...

An introduction to the hydrodynamic model for semiconductor devices is presented. Special attention is paid to classifying the hydrodynamic PDE’s and analyzing their nonlinear wave structure. Numerical simulations of the ballistic diode using the hydrodynamic device model are presented, as an illustrative elliptic problem. The importance of nonlinear block iterative methods is emphasized. Argum...

An anomalous output characteristics is observed in hydrodynamic simulations of partially depleted SOI MOSFETs. The effect that the drain current reaches a maximum and then decreases is peculiar to the hydrodynamic transport model. It is not present in drift-diffusion simulations and its occurance in measurements is questionable. An explanation of the cause of this effect is given, and a solutio...

Keywords: Micro-swimming Micro-flows Resistive force theory Hydrodynamic interaction Bio-inspired robots Surrogate models a b s t r a c t Research on micro-swimming robots without tether is growing fast owing to their potential impact on minimally invasive medical procedures. Candidate propulsion mechanisms of robots are vastly based on microorganisms with rotating helical tails. For design of ...

Mathematically, the typical difference of Discrete Boltzmann Model (DBM) from the traditional hydrodynamic one is that the Navier-Stokes (NS) equations are replaced by a discrete Boltzmann equation. But physically, this replacement has a significant gain: a DBM is roughly equivalent to a hydrodynamic model supplemented by a coarse-grained model of the Thermodynamic Non-Equilibrium (TNE) effects...