Plume databases

Reduction of combustion-generated noise from high-speed jet flows is the topic discussed in Section 2. Fundamental research and novel noise-reduction techniques are presented. These include detailed experimental and computational studies of jet-plume noise, as well as precise measurements. A narrow-band acoustic database generated from actual aircraft landing practice is used as a benchmark for the development of the effective noise-suppression technology. 

So as to predict precisely the near-field behaviour for long-term performance analysis by inclusion of the near-field chemical evolution, we need to extend the interactive model from chemical process to other processes. In the near-future, we will introduce databases focused on chemical effects, e.g. high-pH plume by cementitious materials, on other processes through experimental studies on-going by JNC. We strongly believe numerical experiments on the coupled T-H-M-C processes will decrease the gap among the laboratory, in-situ experiment and performance assessment, and will increase confidence in performance assessment. 

Two different databases provided ehlorinated solvent site data. The first database, the Hydrogeologic Database (HGDB), provided information on plume length, plume width, plume thickness, and highest solvent eoneentration for 109 chlorinated solvent sites. The second database condensed extensive site characterization data from 17 Air Force chlorinated solvent sites, with information on parent compounds vs. progeny products concentrations, competing electron acceptors, hydrogen, and metabolic by-products. 

Table 23.1.10. Characteristics of chlorinated solvent plumes from HGDB database...

Evans (1999) discusses the use of the ALOHA model to model this incident. The author points out that oleum is a mixture of two chemicals (sulfur trioxide and sulfuric acid), but ALOHA is (as of 1999) designed to model release and dispersion of pure chemicals only. Therefore, oleum was not in the ALOHA database. The user may still model the release as sulfur trioxide, but ALOHA displayed a warning message saying that sulfur trioxide reacts with any water to produce sulfuric acid and water, and therefore ALOHA cannot model chemically reactive substances and cannot accurately predict the air hazard. Fortunately, in this incident the plume cloud escaping from the oleum tankcar was clearly visible. Visual observation allowed responders to track its movements more accurately than any air dispersion model could. 

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