Flow Structures of a Round Jet Evolving into a Cylindrical Cavity

摘要

This paper focuses on a study of the interaction of a turbulent round jet with a cylindrical cavity for Reynolds numbers ranging between 22 000 and 50 000. The distance between the jet exit and the front wall, L_f is varied from 2 to 30 jet diameters. The flow velocity field is measured with hot wire anemometry and calculated using the standard k-ε model for high Reynolds number in conjunction with a logarithmic wall function in the viscous region. For all these situations, a non-oscillatory and stable regime flow was observed. The flow in the cavity is composed of three principal zones: a zone of a free jet, a zone of interaction of the jet with the reverse flow and a semi-stagnant zone located at the bottom of the cavity.rnIt was also found that the model correlated well with the experimental mean velocity values but did not accurately predict the evolution of the radial kinetic energy particularly when L_f = 8d. The hypothesis of isotropy used in the model seemed to be invalid. Several circulation configurations were observed and documented for different L_f distances.