Effects of Obstacle Geometry on Jet Mixing for Releases of Silane

Abstract

Releases of silane into air and the effects of obstacles were modeled with the Computational Fluid Dynamics (CFD) code, FLUENT. First the CFD code simulated the release of a free turbulent jet of silane into air to assure that the code agreed with established trends for turbulent jets. Then FLUENT was used to model the flow of silane when confined due to a wall, or impinged by an obstacle such as a flat plate. Computer simulated concentration profiles of a silane air mixture were analyzed to determine mixture volumes between the mixture explosive limits. From each volume of an explosive mixture, the masses of silane and air were determined. The volume of the flammable mixture and the amount of silane within the flammable mixture were determined as functions of plate radius and plate distance. The volumes decrease if the plate is close to nozzle where the radial contribution dominates, and the volumes increase with increasing plate distance where the axial contribution dominates. The volumes increase, decrease, or remain constant depending on the plate diameter.