Decomposition of cylindrical wave modes of fine-scale turbulence noise

Decomposition of the sound field into cylindrical waves is one of the effective methods to understand the noise-generation process. In the present paper, a new mathematic function describing the dependence of cylindrical-wave modes of finescale turbulence noise on difference frequencies with Tam and Auriault's theory model is developed. Both axisymmetric and non-axisymmetric jets are analysed by the method of cylindrical wave decomposition. It turns out that the number of the dominant cylindrical wave modes is linearly related to the frequencies, which allows cutting down the computational time apparently. Comparisons between the calculated results with fewer cylindrical waves and experimental measurements operating subsonically through supersonically are carried out. Good agreements are observed over a wide range of frequencies and observation positions. Results of these comparisons indicate that the method of cylindrical wave decomposition is capable of predicting the far-field radiated noise accurately and efficiently.