Abstract: The acoustic performance for the nanoporous frustule of the diatom is studied based on the computational fluid dynamics theory and acoustic theory involved. Representative Coscinodiscus sp. frustule is observed through the scanning electron microscope and modeled by the commercial software Solidworks. Further, the acoustic performance for the Coscinodiscus sp. frustule is studied at the varied depth, diameter or interval of the pore, as well as the film thickness of the fluid surrounding the Coscinodiscus sp. frustule. The numerical results show that, when the upper and lower pore diameters are separately 200 and 300 nm, the upper and lower pore depths are separately 200 and 250 nm, and both the pore interval and fluid film thickness are 500 nm, the elaborate nanoporous structure of Coscinodiscus sp. frustule can lower its acoustic power level by 17.49%, compared with that without porous structure. Meanwhile, the double-layer pore of Coscinodiscus sp. frustule can decrease its acoustic power level by 12.69%, compared with its single-layer pore structures.

Key words: Acoustic performance , · Nanoporous structure , · Diatom , · Computational fluid dynamics