A NUMERICAL STUDY OF CONFINED TURBULENT JETS

A numerical investigation is reported of turbulent incompressible jets confined in two ducts, one cylindrical and the other conical with a 5 deg divergence. In each case, three Craya-Curtet numbers are consider ed which correspond, respectively, to flow situations with no, moderat e, and strong recirculation. Turbulence closure is achieved by using t he K-epsilon model and a recently proposed realizable Reynolds stress algebraic equation model. Calculations are carried out with a finite-v olume procedure. Second-order accurate differencing schemes and suffic iently fine grids are used to ensure numerical accuracy. The calculate d results are compared with experimental data. It is shown that the nu merical methods presented are capable of capturing the essential flow features observed in the experiments and that the realizable Reynolds stress algebraic equation model performs better than the K-epsilon mod el for this class of flows.