7,226 research outputs found
Perspectives on the simulation of micro gas and nano liquid flows
Micro- and nano-scale fluid systems can behave very differently from their macro-scale counterparts. Remarkably, there is no sufficiently accurate, computationally efficient, and — most importantly — generally agreed fluid dynamic model that encapsulates all of this important behaviour. The only thing that researchers can agree on is that the conventional Navier-Stokes fluid equations are unable to capture the unique complexity of these often locally non-thermodynamic-equilibrium flows. Here, we outline recent work on developing and exploring new models for these flows, highlighting, in particular, slip flow as a quintessential non-equilibrium (or sub-continuum) phenomenon. We describe the successes and failures of various hydrodynamic and molecular models in capturing the non-equilibrium flow physics in current test applications in micro and nano engineering, including the aerodynamic drag of a sphere in a rarefied gas, and the flow of water along carbon nanotubes
Dynamics of heat and mass transport in a quantum insulator
The real time evolution of two pieces of quantum insulators, initially at
different temperatures, is studied when they are glued together. Specifically,
each subsystem is taken as a Bose-Hubbard model in a Mott insulator state. The
process of temperature equilibration via heat transfer is simulated in real
time using the Minimally Entangled Typical Thermal States algorithm. The
analytic theory based on quasiparticles transport is also given.Comment: small clarifying changes, 3 references adde
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