Session Ca - Turbulent Jets & Wakes.
ORAL session, Sunday, November 23
301, Moscone Center
Planar and round jets are typical turbulent shear flows which are of interest in combustion, propulsion, and environmental flows. The evolution of these flows from an essentially symmetric structure near the jet nozzle to the antisymmetric structure which is dominant in the jet column is not fully understood. However, the existance and control of this large scale restructuring of the flow can have a significant impact on the mixing and entrainment of the jet. Numerical simulations can be used to expand on the existing experimental data, as well as characterize and understand the mixing and entrainment properties of these flows. In this study, time-dependent direct numerical simulations of the near field of three-dimensional planar jets has been performed to investigate the evolution from the shear layer dominated region near the nozzle into the jet flow downstream of the potential core. In these simulations, high accuracy time integration and spatial derivative schemes are utilized on a nonuniform grid in conjunction with nonreflecting boundary conditions. Results will be presented showing the evolution of the flow structure as well as a passive scalar. The mean and fluctuating quantities, as well as the spectral evolution, will be compared with existing experimental data.