Numerical investigation of cavitation noise of the submarine propellers using DDES technique and quadrupole corrected FW-H equation

The acoustic waves caused by cavitation in the flow driven by an underwater propeller of a submarine are investigated by numerically solving the incompressible two-phase Navier-Stokes (NS) equations. Especially, to reproduce the tip-vortex cavitation of the underwater propeller with high resolution, the Delayed Detached Eddy Simulation (DDES) technique and the adaptive grid-refinement methods are employed for the numerical solver. The Schnerr-Sauer cavitation model is used for the homogenous mixture model. To improve the accuracy of acoustic prediction, the quadrupole-corrected FW-H integral equation is used as the acoustic solver. The underwater propeller, named HSP17, is newly designed and manufactured to provide benchmarking data, especially for the effects of the skew angles on the tip-vortex cavitation. Besides, the entire body of submarine is also included to account for the effects of the boundary layer flow of the body upstream on the tip-vortex cavitating flow of the HSP17 downstream. The experiments with the same conditions as those of the simulation are also carried out in the Large Cavitation Tunnel (LCT) in the Korean Research Institute of Ships and Ocean Engineering (KRISO). The acoustic pressure spectrum predicted using the current numerical methods is compared with the measured one. There is an excellent agreement between the two results.