Prediction of Flow-generated Noise produced by In-duct spoilers

摘要

Flow-generated noise is the noise that generated by continuities in a ductwork system. The prediction of flow-generated is of engineering importance in the design of ventilation system. Flow-generated noise, produced by strip spoilers in an air duct of a ventilation system have been measured in 1/3 octave band sound power spectra. The individual 1/3 octave band sound power measurements are satisfactorily collapsed with the aid of derived prediction methods. The results for a single flow spoiler agreed with the previous works of Nelson and Morfey. The results also show that predicted results for multiple spoilers agree well with the experimental results. The normalized spectra presented, together with the predicted equations and measurable engineering parameters, permit generalized predictions of the level and spectral distribution of flow generated noise produced by in-duct spoilers.