Data and calculations of dispersion on 5 m/sup 3/ LNG spill tests

A series of liquefied natural gas (LNG) spill and dispersion experiments was carried out at the Naval Weapons Center at China Lake. These spills were nominally 5 m/sup 3/ of liquid spilled on a water pond under various wind conditions (3 to 10 m/s). The objective of the experiments was to evaluate sensors for field use in the detection of downwind hydrocarbon concentrations. The concentration data are shown as a function of time at various stations downwind from the spill point. These data are compared with calculations made by ATMAS, a computer model that uses wind field measurements as input then solves the advection diffusion equation for the downwind concentration as a function of time. The comparisons of data with ATMAS are quite good. It is concluded that ATMAS is a useful model; however, a more detailed description of the wind field (more measurements), a better model of the source (liquid pool spread and boil off of vapor), and the inclusion of variable density and temperature effects are required for better comparison with the data. The objective of the experiments, to evaluate sensors, was accomplished and has led to a selection of instruments to be placed in the field formore » larger (40 m/sup 3/ and more) spill and dispersion experiments to be conducted in the future.« less