Underwater Radiated Noise as a Propeller Design Constraint

The evaluation of underwater radiated noise using high-fidelity Navier-Stokes solvers involves high computational costs that makes it unsuitable for optimization algorithms. Hence, the use of potential flow solvers, coupled with acoustic analogy methods, has garnered keen interest within the propeller design community. The low computational cost makes it ideal to be incorporated into design optimization algorithms, as well as to evaluate the various design aspects that critically affect the noise behavior. This paper focuses on the latter part, wherein various design aspects are analyzed for their influence on the overall noise characteristics. Within the current study, ESPPRO a potential flow solver based on the Boundary Element Method (BEM), is coupled with an acoustic analogy solver based on the Ffowcs-Williams Hawkings (FWH) method. This enables the prediction of the tonal noise, for any given propeller design and operating condition. Systematic variation of field parameters, such as ship wake field distribution and propeller blade loading distribution, is undertaken. The influence of critical wake field parameters are evaluated using a parametric definition of the ship wake field. Geometry variants of propeller blade pitch and skew are used to assess the influence of blade loading distribution. The outcome of the work can be extended towards application in design optimization algorithms and/or data-based prediction methods.