Shear Layer Instabilities In A Counter-Flowing Wall Jet

Counter-flowing wall jets are often used in heat transfer and combustion applications. While several experimental and numerical studies have been conducted to evaluate the characteristics of counter-flowing wall jets, their internal turbulence structure is not well understood. This paper presents the results of a three-dimensional, unsteady, Improved Delayed Detached Eddy Simulation conducted on a counter-flowing wall jet. The mean flow features captured by the simulation are presented with relevant discussions. The shear layer instabilities caused by the vortical structures in the recirculation zone are analyzed by examining the instantaneous flow field. The flow mechanism that causes the fluctuations in the penetration length is also evaluated. The results depict the complexity of the turbulence structure in a counter-flowing wall jet.