Investigation of the steady regimes in a cross-shaped reactor by particle image velocimetry

In the chemical engineering area, impinging flow plays a significant role in process intensification and energy consumption reduction. Thoroughly revealing the formation and evolution of vortices within the reactor has emerged as a crucial scientific issue. This paper systematically studies the steady-state flow at low Re (1 <= Re <= 200, where Re is the Reynolds number) in a cross-shaped reactor by particle image velocimetry technology. The evolution, distribution, and intensity characteristics of vortices in the reactor chamber are focused on. We show that at 55 <= Re <= 120, the distribution of vorticity and shear rate in the chamber show unimodal and bimodal patterns, respectively, and the center of the chamber is a local area with high vorticity and low shear. In contrast, for 120 < Re <= 200, the distribution of vorticity turns into a bimodal pattern, and the shear rate develops into a trimodal pattern. The center of the chamber constitutes a local area characterized by low vorticity and high shear. Additionally, based on the modified monopole vortex model, the distributions of vorticity and velocity of vortices in the steady engulfment flow are accurately depicted.