Effect of asymmetric swirl induction on swirl-center dynamics and turbulence in a confined swirl flow

Two-dimensional, two-component particle image velocimetry has been used to investigate the effect of port configuration on bulk flow statistics and turbulence in a confined swirl flow. Three different port configurations were examined to assess the effects of port geometry and combinations on the evolution of swirl flow. The axial variation of the flow field was investigated by velocity measurements in different axial planes. A swirl center analysis was performed to understand the bulk flow fluctuations and orientation in the engine cylinder. The cycle-resolved ensemble flow field was extracted to study the cycle-to-cycle variations in the bulk flow. The in-plane turbulent kinetic energy was estimated using the conventional ensemble averaging method and the window averaging method, and the results were compared. The findings suggested that the characteristics of the port location affected the bulk flow structure. Variations in swirl ratio across port configurations also yielded different levels of cyclic flow variability in the cylinder.