Accession Number:

ADA621279

Title:

A New Semi-Implicit Time Integration Scheme for the Time-Dependent Atmospheric Boundary Layer Environment (ABLE) Model

Descriptive Note:

Final rept.

Corporate Author:

ARMY RESEARCH LAB ADELPHI MD COMPUTATIONAL AND INFORMATION SCIENCES DIRECTORATE

Report Date:

2015-09-01

Pagination or Media Count:

28.0

Abstract:

The time integration scheme demonstrated for the nonlinear shallow water equations has been extended to the 3-dimensional Navier-Stokes system and implemented as a time-dependent, finite-volume, convection-diffusion scheme in a new direct numerical simulation code. The model was compared with other simulation and laboratory results of lid-driven cavity flows with Reynolds numbers of Re1000, 3200, and 10,000 to assess simulation of boundary forced flows and generation of intermittent flow structures. The generation and shedding of the various flow vortices, including Taylor-Goertler like TGL vortices, impact the velocity variances and covariance as observed, though the vortex shedding frequency is greater than observed in the laboratory. The schemes low implicit diffusion, reduced need for explicit smoothing, and straightforward parallel implementation make it a good candidate for incorporating into finite-volume, large-eddy simulation for highly time-dependent atmospheric boundary layer flow.

Subject Categories:

  • Theoretical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE