Dear Sir: Can anyone provide me information/references regarding noise induced by airflow through ventilation vents, grills, diffuser etc? I have already arrived good CFD data in velocity, K, Ep, TI etc. Should I try the LES?

Thanks,

ML Tu

(1). There are a couple of old handbooks in the library:a)HandBook of Noise Control, Cyril M. Harris, 1957 McGraw-Hill, b) Noise & Vibration Control, Edited by Leo. L. Beranek, 1971, McFraw-Hill, c) Noise & Fluid Engineering, Editor, Robert Hickling, General Motor Lab, 1977,ASME. (2). The noise measurement instrument is rather small and easy to use. You may want to get one and do it yourself. And also check AIAA journal for some recent CFD related acoustic calculations.

Real-Time frequency analysators are very expensive and not easy to use You have to know very well what are you doing.

(1). I think, there are probably many different kind of instrument for noise analysis. (2). The one I have used in the design of low noise fan was direct reading, hand-held, direct PC interface type. It was very effective in the design process. (3). It does not give you db vs frequency distribution, which is only useful in identifying the specific source of noise in complex environment. If you are designing something, then you already know the main source of noise. So, the direct measurement of db is the goal.