Isothermal Predictions of Recirculating Turbulent Flow fields of Confined Dual Coaxial Jets Behind an Axisymmetrec Bluff Body

Abstract

Finite-difference numerical computations are presented to predict the isothermal, turbulent, recirculating flowfields in a centerbody combustor configuration which involves confined dual coaxial jet mixing in the near-wake region of an axisymmetric bluff body. The calculations based upon the Reynolds-averaged Navier-Stokes equations and the k-epsilon turbulence model consider the influence of the annular and central flow rates on the nature of the flowfield downstream of the bluff body. Other questions addressed include the effects of inlet turbulence length scales and streamline curvature. The recirculating flowfield structure is studied by examining the axial and radial distributions of the mean and rms velocity fields, the centerline stagnation points, the vortex center, and the zero mean axial velocity contour. The present numerical results demonstrate the complex nature of the flowfield interactions in the near-wake region and refine the understanding of the centerbody combustor flowfields.