Analysis of the interrow flow field within a transonic axial compressor: Part 2 - Unsteady flow analysis

An analysis of the experimental data, obtained by laser two-focus anemometr y in the IGV-rotor interrow region of a transonic axial compressor, is pres ented with the aim of improving the understanding of the unsteady flow phen omena. A study of the IGV wakes and of the shock waves emanating from the l eading edge of the rotor blades is proposed. Their interaction reveals the increase in magnitude of the wake passing through the moving shock. This re sult is highlighted by the streamwise evolution of the wake vorticity. More over, the results are analyzed in terms of a time-averaging procedure and t he purely time-dependent velocity fluctuations that occur are quantified. I t may be concluded that they are of the same order of magnitude as the spat ial terms for the inlet rotor flow field. That shows that the temporal fluc tuations should be considered for the three-dimensional rotor time-averaged simulations.