The emphasis was put on the study of the effect of 8 mm diameter air bubbles arranged at different spatial positions on the rear wake flows and their interactions.

The flow model of wakes for bluff body was established, based on the cold experiments, the results of wakes for bluff body with rough surface were obtained, and the results were compared with the one of bluff body with smooth surface.

The author of this paper proposes a four zone partition behind a bluff body, namely, recirculation, primary jet flow, wakes recovery and sufficient development.

The numerical analysis of time-space structures in the large turning angle axial cascade with a certain large attack angle condition suffered from unsteady incoming wake excitation has been carried out.

Two-dimensional model,where the influence of wall boundary layers is neglected and inlet jet-wake velocity patterns are prescribed,was applied to simulate one vanless diffuser with large width-radius(ratio.

Assuming that the flow inside the vaneless diffuser was incompressible two dimensional flow,a state matrix model was established and analysis was made on the jet-wake type disturbance at the inlet of the diffuser based on published literatures.