Dispersion of Vapor from LNG Spills -- Simulation in a Meteorological Wind Tunnel of Spills at China Lake Naval Weapons Center, California

Physical simulation of a series of four, six cubic meter Liquefied Natural Gas (LNG) spills on water was provided by the Meteorological Wind Tunnel facilities at Colorado State University. Field data were collected from spills performed at Naval Weapons Center, China Lake, California, in Fall 1978. The simulation test series was to provide field test planning information, extend the value of a limited set of field measurements, and validate the concept of physical modeling of LNG plume dispersion as a predictive hazard analysis tool. Two test series were conducted to aid in placement of field concentration measurement instrumentation. The first utilized 1:170 scale model of the China Lake site in the Meteorological Wind Tunnel and the second utilized 1:85 scale model in the Environmental Wind Tunnel. Dispersion data collected in the four field tests at China Lake were extended in two test series conducted in the Environmental Wind Tunnel over a 1:85 scale model. The following results were obtained: (1) Comparison between dispersion data for similar test parameters but at two different model scales, 1:85 and 1:170 produces similar concentration variation. (2) The China Lake surface roughness and topography causes the LNG vapor plume to disperse more rapidly than would be experienced over flat terrain. (3) For the four simulated LNG field tests the arrival time, peak concentration, maximum peak, etc., have been tabulated; peak ground level concentration contours have been determined; and normalized peak concentration coefficients vs. downwind distance have been plotted. (Author)