AN INTEGRAL MODEL OF TURBULENT JETS IN A CROSS-FLOW .1. GAS DISPERSION

In this, the first part of a two part study of turbulent jets in a cro ss-flow, a mathematical model for predicting the dispersion of a jet i n the atmospheric boundary layer is described. The model is based on s olutions of integral forms of the fluid dynamic equations, with air en trainment rates into the jet being determined by summing contributions representing entrainment due to longitudinal and transverse shear. Th e model contains a one-dimensional formulation of the k-epsilon turbul ence model, and is capable of predicting both the mean and fluctuating concentration field within a jet. In order to assess the ultimate use fulness of the model for predicting the consequences associated with a ccidental and operational releases of flammable gases, solutions of th e model are compared with data derived from experiments carried out at both laboratory and field scales. Predictions of the model are shown to be in good agreement with the available experimental data. The comp lete model is applicable to releases of gas at subsonic and sonic velo cities, and with computer run times of less than one minute is ideal f or routine use in performing consequence and risk assessments.