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Unsteady flow conditions and data reduction
The shock motion was imposed by sinusoidal downstream static pressure plane fhctuations. The amplitude and frequency of the perturbations are summarized in table 2 and the corresponding reduced frequency are presented in table 3. The reduced frequency based on the BL thickness is considered small enough to justify a quasi-steady response of the turbulence that is compatible with the turbulent model used.
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Table 3. Numerical reduced frequency
NB:ki = 2Tf/L with Ui = 231.2m/s or U2 = 248.3m/s |
The data reduction consisted in performing an harmonic analysis on both the unsteady pressure distribution and the shock motion. Similarly to experiments, the amplitude of each harmonic was divided by the amplitude of the fundamental at the outlet, and the phase angle value at the outlet reference location was subtracted to all signals, for each harmonic respectively.
