NESC9739 2DFLOW. (Abstract last modified 13-FEB-1987)
1.
NAME OR DESIGNATION OF PROGRAM - 2DFLOW. 2.
COMPUTER FOR WHICH PROGRAM IS DESIGNED AND OTHER MACHINE VERSION PACKAGES AVAILABLE -
To request or retrieve programs click on the one of the active versions below.
A password and special authorization is required. Explanation of the status codes.
Machines used:
Package-ID Orig.Computer Test Computer
NESC9739/01 DEC VAX 11/780 DEC VAX 11/780
3.
DESCRIPTION OF PROGRAM OR FUNCTION - 2DFLOW is a vertically integrated dynamical drainage flow model developed from conservation equations for momentum and mass in a terrain following coordinate system. Wind fields from the dynamical model drive a Monte Carlo transport and diffusion model. The model needs only topographic data, an Eulerian or Lagrangian time scale, and a surface drag coefficient for input data; it can be started with a motionless atmosphere.
4.
METHOD OF SOLUTION - The system of dynamical equations is solved numerically with a second-order finite difference scheme. Advection of mass and momentum is calculated by the second upwind differencing or "donor cell" method.
5.
RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - 6.
TYPICAL RUNNING TIME - 7.
UNUSUAL FEATURES OF THE PROGRAM - 2DFLOW has the following features which make it attractive as a practical tool for estimating the concentrations of pollutants released into nocturnal drainage winds: 1) No wind or temperature data are needed. A surface drag coefficient and Eulerian or Lagrangian time scale are required, but the model is not sensitive to their exact value. High resolution topographic data are required. 2) The model has been successfully tested at sites with rugged mountainous terrain and at a site with gently rolling terrain. 3) The model is two-dimensional (vertically integrated) so its computational requirements are moderate. 4) Maximum pollutant concentrations are predicted to within factors of 2 to 10 at specific points, based on observed and simulated concentration time series.
8.
RELATED AND AUXILIARY PROGRAMS - 9.
STATUS 10.
REFERENCES - 11.
MACHINE REQUIREMENTS - 500K bytes. 12.
PROGRAMMING LANGUAGE(S) USED - 13.
OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED - 14.
OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS - 15.
NAME AND ESTABLISHMENT OF AUTHORS - 16.
MATERIAL AVAILABLE - 17.
CATEGORIES - Keywords: AIR POLLUTION, DIFFUSION, FLOW MODELS, MONTE CARLO METHOD, SURFACE AIR, TOPOGRAPHY, TURBULENCE, WEATHER
Program-name Package-ID Status
2DFLOW NESC9739/01 Tested
NESC9739/01:
NEA-DB executed the test case included in this package on a VAX-11/780 computer in 8 minutes, 17 seconds of CPU time.
NESC9739/01: 13-FEB-1987 Tested at NEADB
NESC9739/01:
- A.J. Garrett and F.G. Smith:
Two-Dimensional Simulations of Drainage Winds and Diffusion
Compared to Observations.
Reprinted from "Journal of Climate and Applied Meteorology",
Vol. 23, No. 4, pp. 597-610 (April 1984)
NESC9739/01: FORTRAN-77
NESC9739/01:
VMS V4.3 (VAX-11/780).
A.J. Garrett
Savannah River Laboratory
Aiken, South Carolina 29808
NESC9739/01:
NESC9739_01.001 Information file 79 records
NESC9739_01.002 2DFLOW Source Program 776 records
NESC9739_01.003 2DFLOW test case input data 20 records
NESC9739_01.004 2DFLOW topographical data library 59 records
NESC9739_01.005 2DFLOW sample output (concentrations data) 159 records
NESC9739_01.006 2DFLOW sample output (winds data) 289 records
- R. Environmental and Earth Sciences
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