This presentation describes the present status and future perspectives of the computational aeroacoustics, by showing several applications to flow-related industrial products. In particular, it focuses on the sound generated in relatively low-speed flows. Aerodynamic sound originates from the fluctuations in the fluid flows, and therefore, it can be predicted by combined computations of fluid-flow and sound propagation, provided that the source fluctuations in the fluid flows can be accurately predicted. Due to the remarkable speed up of the computer performance, the affordable number of the grids for fluid-flow computations has already reached to several tens billion, and will probably reach several hundred billion within five years. This number of the computational grids allows us to accurately predict fluid motion in micro-meter scales, which contributes to the generation of sound in frequency range of several thousand hertz. Therefore, it is almost certain that we will be able to predict, with a sufficient accuracy, source fluctuations in the fluid flows, and hence, the method for predicting sound propagation will become more important.
