INCINERATOR RELATED FLOWS - AN EXPERIMENTAL AND NUMERICAL STUDY OF TURBULENT-FLOW OVER AN OBSTACLE

To study the suitability of numerical simulations for predicting incin erator-related flows, an experimental and computational study of an ob stacle flow with some of the features of incinerator flows is performe d. Results of LDV measurements from a water channel experiment on the flow over a triangular obstacle and from a concurrent FEM simulation u sing the standard k-epsilon turbulence model are compared. The reattac hment length predicted by the computations agrees to within 3% with th e experimentally determined value. The mean velocity profiles and the shapes of the turbulent kinetic energy profiles show good agreement. A more realistic model of the flow in an incinerator is studied briefly and provides information on the appropriate choice of outflow boundar y conditions for computing flows in truncated domains. The standard k- epsilon model was found to be useful in making predictions of separate d flows with similarities to those found in incinerators. Special exit boundary conditions which allow for a pressure variation independent of the viscous normal stresses were found to predict realistic outflow velocity profiles.