Numerical investigation of thermo-fluid dynamics of two triangular jets

Abstract

This paper addresses the numerical simulation of thermo-fluid characteristics of triangular jets. The results of spatially developing, three dimensional jets from isosce les and equilateral nozzles at different Reynolds numbers and distances between jets are presented. The system of governing equations, subject to the proper boundary condi tions is solved with the finite volume method with collo cated grid arrangement. SIMPLEC algorithm was used for the pressure-velocity coupling to discrete the governing equations of flow and energy. The turbulent stresses are approximated using k - e  model. The velocity and tempera ture fields are presented and rates of their decay at jet cen terline are noted. The velocity vectors of main flow and secondary flow are illustrated. Also, the effect of different vertex angles on mixing in triangular cross-section jets is considered. The vertex angles that were considered for this work were 30 to 120 degree. The results showed that the jet entrains more with equilateral cross sections. Special attention has been drawn to the influence of the Reynolds number (based on hydraulic diameter) as well as the inflow conditions on the evolution of the triangular jet. The inflow conditions have considerable influence on the jet character istics. The flow pattern results show strong mixing and flow entrainment from free boundaries into the jet. In comparison with single triangular jet mass entrainment from free boundaries is larger and also potential core is smaller.

http://dx.doi.org/10.5755/j01.mech.17.2.330