Modifications to the Lagrangian particle dipsersion model

Technical Report · Tue Apr 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/469150· OSTI ID:469150

Buckley, R L; O`Steen, B L

An advanced stochastic Lagrangian Particle Dispersion Model (LPDM) is used by the Atmospheric Technologies Group to simulate contaminant transport. The model uses time-dependent three-dimensional fields of wind and turbulence to determine the location of individual particles released into the atmosphere. Improvements to the LPDM from both operational and scientific standpoints are discussed by comparing results obtained from the original code with those from a revised version. Memory requirements are decreased by using dynamic memory allocation for many of the code`s larger arrays, while more efficient vectorization of portions of the code produces a two-fold reduction in computational time for large particle releases. In addition, the original version contained a routine for calculating random turbulent velocity components which produced anomalously large variations in particle distributions depending on the sequence in which the random numbers were selected. A revision to the technique which eliminates this sensitivity is discussed along with the improved results.

• Research Organization: Westinghouse Savannah River Co., Aiken, SC (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC09-89SR18035
• OSTI ID: 469150
• Report Number(s): WSRC-TR--97-0059; ON: DE97005960
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
99 GENERAL AND MISCELLANEOUS
ATMOSPHERIC CIRCULATION
COMPUTER CODES
CONTAMINATION
DIFFUSION
EARTH ATMOSPHERE
L CODES
MATHEMATICAL MODELS
MODIFICATIONS
TURBULENCE