Fluid-Structure-Acoustic Interaction of a Towed Sonar Array System
* Presenting author
Towed sonar arrays are designed as long thin circular cylinders utilized as underwater sound receivers. These arrays usually have a very large ratio of length to radius, in the order of 10^5. When fluid flows parallel to such a cylindrical geometry an axisymmetrical turbulent boundary layer (ATBL) develops that has a turbulent boundary layer thickness much larger than the cylinder radius. In such flows, curvature effects become significant, leading to changes in the turbulent boundary layer (TBL), especially on mean velocity profiles and turbulent fluctuations, causing higher skin-friction coefficients and different characteristics of wall-pressure fluctuations compared to the planar case (TBL of a flat plate or channel flow). The special features of the ATBL are interesting for sonar array designers because the performance of these devices is usually limited by the noise generated by the turbulent fluctuations around the surface of the array. Therefore, one-way coupled fluid-structure-acoustic interaction computations are carried out for a simplified sonar array geometry. The approach and the first results are presented.