Numerical Study of Pulsed Turbulent Plane Wall Jet by Low-Reynolds-Number k–ε Model

Abstract

The present study reports on the numerical characterization of the influence of an initial perturbation in the development of turbulent plane two-dimensional wall jets. At the nozzle exit, the pulsation is imposed by a vertical component velocity: u = u ₀[1 + Asin(ω t)]. In the configuration investigated, the jet may be either isothermal or submitted to various wall thermal boundary conditions: uniform temperature in mixed-convection regime or uniform heat flux in forced-convection regime. Numerical modeling of the pulsed wall jet is performed using a low-Reynolds number k–ε model. A finite-difference method, sing a staggered grid, is employed to solve the coupled governing equations associated to the inlet and boundary conditions. The effects of the parameters characterizing the pulsation, such as the amplitude and the frequency, on the dynamic, turbulent, and thermal characteristics of the turbulent wall jets are investigated in detail.