Simulation of free turbulent particle-laden jet using Reynolds-stress gas turbulence model

摘要

Free two-phase flows occur in many practical applications, such as sprays or particle drying and combustion. This paper deals with mathematical modelling of a free turbulent two-phase jet. A steady, axisymmetric, dilute, monodisperse, particle-laden, turbulent jet injected into a still environment, has been considered. The model treats the gas-phase from an Eulerian standpoint and the motion of particles from a Lagrangian one. Closure of the system of time averaged transport equations has been accomplished by using a Reynolds-stress turbulence model. The particles-fluid interaction has been considered by the PSI-Cell concept. Both the effect of interphase slip and the effect of particle dispersion have been taken into account. Results of the model have been compared with experimental data for axial and radial profiles of gas-phase mean and turbulent quantities and solid-phase mean velocity. Accuracy of model predictions of particle-laden free jet time averaged characteristics as well as turbulence correlation coefficients have been improved. The modelling of observed turbulence anisotropy levels and correlation coefficients need to be carried out with special care. The model has provided insight into the turbulence structure and aerodynamic characteristics of the particle-laden free jet. A brief sensitivity study has been performed as well, indicating that the specification of inlet boundary conditions exerts pronounced effects on predictions. In this paper, the study refers to the effect of the turbulence kinetic energy dissipation rate, while the other inlet boundary conditions have been applied with respect to the referent measurements.