Laser Diagnostic Development and Measurement and Modeling of Turbulent Flowfields of Jets and Wakes. Part 2. Numerical Predictions of Isothermal Flowfields in a Ducted Centerbody Combustor

摘要

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. 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. The reported isothermal modeling calculations are performed with the 'Teaching Elliptic Axisymmetrical Characteristics Heuristically' (TEACH) Code. Numerical results show the influence of the annular and central jet flow rates on the distributions of the mean and rms velocity fields and centerline locations of stagnation points. The sensitivity of the predicted results to several aspects of the modeling is considered. The predicted results demonstrate the complexity of flowfield interactions in the near-wake region and refine the understanding of the centerbody combustor flowfields. The character of the recirculating flowfield emerging from the numerical predictions when the near-wake is dominated by the annular jet is in conformity with experimental observations.