THREE-DIMENSIONAL NUMERICAL INVESTIGATION ON SWIRLING JETS AND ELLIPTIC JETS WITH DIFFERENT ASPECT RATIO

This paper deals with the three-dimensional numerical simulation of aerodynamic characteristics of turbulent jets issuing from two diffusers configuration with different geometries. The first diffuser configuration is an elliptical shape with different aspect ratios AR = a/b, where a and b are the diffuser height and width varied from 1, 2, 4 and 8, while the second diffuser configuration generates the swirling jet through a diffuser provided with 60 degrees inclined vanes. The comparison of the numerical results of the swirling jet and those of the elliptical jets, keeping the same equivalent diameter of the diffusers and the same flow conditions to the ambient environment, has been discussed. The numerical simulation is performed using two turbulences model, the standard k-epsilon model and the Reynolds stress model (RSM). The finite volume method with an unstructured tetrahedral mesh type has been used in this investigation. In the light of the results, we find that the swirling jet provides an improved flow mixing with large transversal velocities spreading in all sections of the resultant jet, compared to all studied elliptic jets.