Effect of the Number of Injectors on the Mixing Process in a Rapidly Mixed Type Tubular Flame Burner

Abstract

Three-dimensional simulations are performed to study the non-reactive mixing process in a rapidly mixed type tubular flame burner (RTFB). The current work examines the effect of the number of injectors (N= 2, 4 and 6) on the mixing process by focusing on three criterions (Flow structure, local swirl intensity and mixing layer thickness). The Discrete Phase Model (DPM) is used to track the particle trajectories. Validation of the numerical results is carried out by comparing the predicted particle trajectories, central recirculation zone (CRZ) and tangential velocity results to the experimental data. It is concluded that the model offers a satisfactory prediction of the flow field in a RTFB. Numerical results show that, for the same geometrical swirl number (Sw) and the same Reynolds number (ReT), the increasing of the number of injectors enhances the mixing process by generating a larger reverse flow and reducing the mixing layer thickness. It is also concluded that the local swirl intensity along of the RTFB can be correlated in terms of geometric swirl number and number of injectors.