Three-Dimensional Numerical Calculations of a Jet in an External Cross Flow: Application to Pollutant Dispersion

The paper presents a three-dimensional numerical simulation of a circular turbulent jet issuing transversely into a uniform air stream. In the first part an air-helium jet is considered and the three-dimensional structure of the flow field is discussed. Then, a comparison between the numerical results of four turbulence closure models (three first-order models and a second-order one) are presented and compared with the experimental data given by Crabb et al. [7] and Andreopoulos et al. [9]. Although the different models render identical results in the upstream and far downstream regions of the jet, only the second order model is shown to give good results in the exit region and in the trailing zone of the jet. Based on this last model, the dynamic and scalar fields of a fume turbulent jet issuing transversely with velocity v0 into a uniform air flow with velocity u are then examined as functions of the ratio R=v0/u∞ in order to simulate pollutant dispersion from industrial chimneys.