A numerical study on the effects of anisotropic turbulence on the behaviors of impinging sprays

Abstract

The present study performs an extensive numerical study for analyzing the anisotropic turbulence effects on spatial and temporal behaviors of diesel sprays after wall impingement. The Durbin (P. A. Durbin, Int. J. Heat Fluid Flow, vol. 14, no. 4, pp. 316-323, 1993) k-epsilon-v(2) model is used to simulate the anisotropic turbulence effects and its results are compared with the predictions by the k-epsilon model based on the isotropic assumption. In the present study, the Lee and Ryou (S. H. Lee and H. S. Ryou, Atomization and Sprays, vol. 11, pp. 85-105, 2001) model is used for the calculation of the spray-wall interactions. The predicted results by two turbulence models are compared with several experimental data for both the overall structure of impinging sprays and the internal structure, for which the main parameters are the radius and height of impinging sprays, the local velocities and the Sauter mean diameter of droplets, the local velocities of gas-phases, and so on. The k-epsilon-v(2) model considering the anisotropy of turbulence predicts both gas and droplet tangential velocities better than the k-epsilon model does. It is concluded that the anisotropy of turbulence should be considered in simulating impinging diesel sprays.