Study of non-reactive isothermal turbulent asymmetric jet with variable density

摘要

In the present study, the effects of inlet isothermal jet geometry on the mixing process with variable density have been investigated numerically. Four density ratios were considered, namely R ρ =7.2, 1.8,1 and 0.66 for He-air, CH4-air, Air-air and CO2-air mixtures respectively. The jets are produced through rectangular and elliptic nozzles with aspect ratio Ar = 2:1. The elliptic and rectangular nozzles have approximately the same exit area as the circular nozzle. A second-order Reynolds stress model (RSM) is used to investigate variable density effects in asymmetric turbulent jets. Comparative studies are presented for the calculations of the variables such as the longitudinal velocity, the longitudinal fluctuating velocity and the turbulent kinetic energy. The results indicate that the asymmetric geometry noticeably enhances mixing in comparison with the axisymmetric case. Typical phenomenon of 3D jets is observed.