파수-주파수 변환을 이용한 선체 벽면 압력으로부터 선박 추진기 압축성 압력 추출

Abstract

Underwater radiated noise (URN) is a compressible pressure component that propagates in the far-field from sources. Therefore, compressible pressure separation is required as a first step in developing a far-field URN monitoring technique based on hull surface pressure. In this study, a numerical method of decomposing surface total pressure induced by an underwater propeller into compressible and incompressible pressure was proposed using wavenumber-frequency transformation (WFT). First, a compressible multiphase Delayed Detached Eddy Simulation (DDES) of the hydrodynamic flow field was computed. Acoustic pressure caused by cavitation from the underwater propeller was predicted using the Ffowcs Williams？Hawkings (FW？H) integral equation and compared with the measured data to validate the numerical simulation. Finally, the compressible pressure was extracted from the total surface pressure on the stern part by using the WFT decomposition technique. In the high-frequency range, the compressible pressure appeared to be relatively high compared to the incompressible pressure in this study.