1. Using the parameters from the experiment, the predicted sound power reduction is also computed to validate the accuracy of the model. The cut-on frequencies of the first radial modes (w=7, n=0,l,2,3) are 374, 1084, 1736, and 2381 Hz, respectively. Therefore, there are 3 propagating modes at a BPF lower than 2381 Hz. The amplitudes of these first three fan modes have been experimentally determined for a BPF of 2320 Hz. These amplitudes were used in the model for a frequency range from 2100 to 2380 Hz. Since the amplitude of the fourth radial mode, cut-on at 2381 Hz, is unknown, the analysis was not performed abovethis frequency.
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