千配列の熱交換器管群における気流騒音特性

概要

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Experimental investigations were carried out on the characteristics of air flow noise for practically used heat exchanger tube banks. The tube banks are usually composed of bare tube, solid fin tubes or serrated fin tubes. For clarifying the air flow noise characteristics, the experimental data without resonant condition are used. The test tube banks were installed in the duct connected to a silent wind tunnel. The whole experimental setup was installed in an anechoic room. Sound pressure emitted from each test tube bank was measured by microphones on the duct wall and at the duct outlet. The experimental results were used to evaluate its RMS value, dominant frequencies and coherence against flow velocity for each kind of test tube banks. It is found that the rms pressure level of the airflow noise for each test tube bank is proportional to the 3rd power of flow velocity, and the acoustic pressure coefficient is mainly dependent on pitch-to-diameter ratio and tube bank depth. Thus, the airflow noise is concluded to be predicted by the acoustic pressure coefficients when they are experimentally determined for various tube banks used in industry.
社団法人日本機械学会の論文
1999-07-25