The effects of plate impingement on the flammable mixture produced by a fuel jet release were modeled with a commercial computational fluid dynamics (CFD) code. First, the CFD code was used to simulate the release of a free turbulent jet to assure that the code agreed with established trends. Equations were derived to determine the volume of the free jet above the lower flammable limit. The code was then used to model a jet confined by a,wall or a circular plate. Computer simulated concentration Profiles of the source fluid and air mixtures were analyzed to determine mixture volumes above the lower flammable limit. The flammable mixture volume was normalized and determined as a function of plate radius and distance.