DOI: 10.1615/TSFP5
STUDY OF TURBULENT PASSIVE SCALAR DISPERSION WITHIN A REGULAR ARRAY OF OBSTACLES
摘要
In this paper, we study the turbulent dispersion of a passive scalar released from a transient point source within an obstacle array using an unsteady Reynolds-averaged Navier-Stokes (URANS) method. The numerical results are validated against a set of high-quality water channel measurements. A modification to the modelled transport equation for the turbulence kinetic energy (TKE) is suggested, which leads to significant improvements in the prediction of the TKE levels within and above the obstacle array. The temporal and spatial evolution of the concentration cloud spread is investigated. A new closure model for the scalar dissipation rate is proposed for the transport equation of the concentration variance, and predictions of the concentration variance in a dispersing cloud are compared with the experimental measurements.