PIV experiment and large eddy simulation of turbulence characteristics in a confined impinging jet reactor

Abstract

Abstract Confined impinging jet reactor (CIJR) is a typical process intensification device used in the chemical industry. In this study, two dimensional Particle Image Velocimetry (PIV) and Large Eddy Simulation (LES) method were used to investigate the flow field in a CIJR with jets of diameter 3 mm under highly turbulent condition. The results showed LES can predict the velocity and Turbulence Kinetic Energy (TKE) distributions in the reactor well by comparing with the PIV results. In the CIJR, the stagnation point fluctuates with the turbulence, and its instantaneous position accords with the normal distribution. Three methods, including s–t representation, Lumley–Newman triangle and A–G representation, were used to compare the turbulence anisotropy in the mixing chamber. It was found that the anisotropy in the impinging area and at the edge of impinging jet was strong and the maximum deviation was up to 40%. The results from 2D PIV would lead to an overestimation of the turbulent kinetic energy as much as 20% to 30% than the results from the three dimensional numerical simulation.