FEM3: a finite-element model for the simulation of heavy-gas dispersion and incompressible flow. User's manual

Technical Report · Tue Feb 01 04:00:00 EST 1983

OSTI ID:6286485

Chan, S T

FEM3 is a numerical model developed primarily to simulate heavy gas dispersion in the atmosphere, such as the gravitational spread and vapor dispersion that result from an accidental spill of liquefied natural gas (LNG). The model is based on solving the time-dependent, multidimensional conservation equations of mass, momentum, energy, and species. To accommodate large density changes and yet preclude sound waves, a generalized anelastic approximation is employed (i.e., the fluid is considered to be basically incompressible but to have variable density). A modified Galerkin finite element method (GFEM) with eight-node isoparametric hexahedron elements (four-node quadrilaterals in two dimensions) is used for spatial discretization, and a modified forward Euler method is employed for time integration. The discretized Poisson equation for pressure is solved implicitly by means of a skyline solver. In this report, the theoretical and numerical aspects of the model are described briefly, user's guides for using the model are given, and a numerical example is presented to illustrate the use of the model.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6286485
• Report Number(s): UCRL-53397; ON: DE83013496
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030800* -- Natural Gas-- Environmental Aspects
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
COMPUTER CODES
DIFFUSION
DISTRIBUTION
DOCUMENT TYPES
EARTH ATMOSPHERE
ENERGY SOURCES
F CODES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GAS SPILLS
GASES
LIQUEFIED GASES
LIQUEFIED NATURAL GAS
MANUALS
MATHEMATICAL MODELS
NATURAL GAS
SPATIAL DISTRIBUTION