The Lattice Boltzmann Method with Applications in Acoustics
نویسنده
چکیده
in English An introduction is given to the lattice Boltzmann method and its background, with a view towards acoustic applications of the method. To make a larger range of acoustic applications possible, a point source method is proposed. This point source is applied to simulate cylindrical waves and plane waves, and is shown to give a very good numerical result compared with analytic solutions of viscously damped cylindrical and plane waves. Good results are found for simulations of Doppler effect, diffraction, and viscously damped standing waves. It is concluded that the lattice Boltzmann method could be suitable for simulating acoustics in complex flows, at ultrasound frequencies and very small spatial scales. The lattice Boltzmann method is shown to be unfeasible at lower frequencies or for larger systems. Abstract in Norwegianin Norwegian En introduksjon gis til lattice Boltzmann-metoden og dens bakgrunn, med henblikk p̊a akustiske anvendelser av metoden. For å muliggjøre flere forskjellige akustiske anvendelser foresl̊as en punktkildemetode. Denne punktkilden anvendes for å simulere sylinderog planbølger, og det vises at den gir et svært bra numerisk resultat sammenlignet med analytiske løsninger av viskøst dempede sylinderog planbølger. Gode resultater finnes for simuleringer av Dopplereffekt, diffraksjon og viskøst dempede st̊aende bølger. Det konkluderes med at lattice Boltzmann-metoden kan være passende for å simulere akustikk i komplekse strømninger, ved ultralydfrekvenser og svært sm̊a romlige skalaer. Lattice Boltzmann-metoden vises å være upraktisk ved lavere frekvenser og for større systemer.
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