An Analytical Investigation of Fluid Cargo Vapor Dispersion.

Means for analytical prediction of the dispersion field of toxic or combustible vapor vented from a tanker are critically evaluated. Particular emphasis is given the conservative delineation of the flammable surface separating spatial domains outside of which dangerous combustion is unlikely and inside of which it is (and an analogous toxic surface) in the light of normal available data and the uncertainties therein. Approximate analyses covering buoyancy and jet momentum effects are included. The problem of assignment of appropriate flammability limits in a turbulent and inhomogeneous mixture is reviewed. Experimental and analytical means of dealing with flow past obstacles and other geometrically complex phenomena are evaluated. The effects of helicopter downwash on vapor dispersion is also briefly analyzed. Finally, the procedure for analysis of vapor dispersion within tanks is outlined.