Accession Number:

ADA505291

Title:

A Hierarchical Multiscale Particle Computational Method for Simulation of Nanoscale Flows on 3D Unstructured Grids

Descriptive Note:

Final rept. 15 Mar 2006-31 May 2009

Corporate Author:

WORCESTER POLYTECHNIC INST MA

Personal Author(s):

• Gatsonis, Nikolaos A.

Report Date:

2009-08-14

Pagination or Media Count:

40.0

Abstract:

This research addresses mathematical and computational issues of particle methods for the three-dimensional simulation of flows at the nanoscale. The research addresses also the multi-scale physical phenomena in nanoscale flows that can be found in micronano fluidic devices and processes. The developments of an unstructured 3D Direct Simulation Monte Carlo U3DSMC method are presented, including a methodology for subsonic boundary conditions as well as the analysis of statistical fluctuations and errors in sample-averaged macroscopic flow properties obtained from U3DSMC simulations. The effects of number of samples, computational particles in a Delaunay cell, and Mach number on statistical fluctuations are investigated for uniform and pressure-driven nanoscale flows. A parametric investigation of supersonic flows into nanochannels examines the effects of Knudsen number, aspect ratio, and freestream Mach number. The computational implementation of a three-dimensional smooth dissipative particle dynamics method is presented along with a new solid-wall boundary condition methodology. Simulations of pressure driven flows show minimal density fluctuations in the proximity of walls and a good agreement with analytical results.

Descriptors:

• *FLUIDICS
• *NANOTECHNOLOGY
• MICROSTRUCTURE
• MONTE CARLO METHOD
• PARTICLES
• FLUID FLOW
• COMPUTERIZED SIMULATION
• MATHEMATICAL MODELS
• BOUNDARIES

Subject Categories:

• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE