Numerical investigation of the cavitating flow and the cavitation-induced noise around one and two circular cylinders

In this work, we simulated a two-phase cavitating flow around one and two circular cylinders with the density based homogeneous mixture model. We discretized the governing equations with employing a high-order compact finite-difference scheme incorporating filtering scheme to account for the numerical instabilities and physical discontinuities. We applied a shock capturing sensor for discontinuities detection and switching between the second-order and high-order filtering and computed the far-field acoustic by the Ffowcs WilliamsHawkings surface integral method. We studied the flow features in the wake of a circular cylinder and two cylinders for noncavitating regime and cavitating conditions. In addition, we analyzed the cavitating flow for various gaps of two side-by-side cylinders. Results revealed that the shock waves due to the collapse of the cavity moving downstream of the cylinders is the main mechanism for the generation of the acoustic impulses. The results also showed that the noise peak can occur at lower frequencies for the smaller gap between the two cylinders. Furthermore, the wakes behind the side-by-side cylinders were merged together and a single vortex street was generated by the reduction of the gap between two cylinders.