We first proved that it makes sense to pay attention in reducing broadband noise in vaccum units as its broadband noise contribution to total noise is not negligible. After
that, we started looking for a parameter of numerical simulations, which is related to broadband noise. We tackled this by performing a simple experiment with minimal
environmental influences. Air flowed through the cylinder under different conditions. After that, we numerically recreated the experiment, looking for simulation output
variables whose trend and even absolute value correspond to the noise trends in the experiment. Therefore, we determined in the thesis which of the output parameters in numerical simulations is related to broadband noise. We also compared these parameters with the noise on the real problem of broadband noise generation on suction unit impellers. For this purpose, we measured the noise of the suction units in the deaf room and removed the prominent peaks of the amplitude frequency spectrum. Using the analysis of both experiments, which were supported by numerical simulations, we found thatthe following output parameters are most related to noise: the volume integral of turbulent kinetic energy and the logarithm of the volume integral
of acoustic sound power.
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