Determining and understanding the performance characteristics of marine propellers by experiments is quite a complex and costly task. Numerical predictions using computational fluid dynamics simulations could be a valuable alternative provided that the laminar-to-turbulent transition flow effects are fundamentally understood with the suitable numerical models developed. Experience suggests that the use of classical turbulent flow models may lead to high discrepancies especially at low rotational speeds where the effects of fluid flow transition from the laminar to the turbulent state may influence the predicted propeller's performance. This article proposes a complete and detailed procedure for the computational fluid dynamics simulation of non-cavitating flow over marine propellers using the ''k-kl-v'' transition-sensitive turbulence model. Results are evaluated by ''ANSYS FLUENT 16'' for the ''INSEAN E779A'' propeller. Comparisons against the fully turbulent standard ''k-e'' model and against experiments show improved agreement in way of flow transition zones at lower rotational speeds, that is, at low Reynolds numbers.

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The aim of this paper is to compare the heave and pitch motions for the S175 containership, travelling in head regular waves, obtained from frequency domain linear and time domain partly nonlinear potential flow analyses. The frequency domain methods comprise the pulsating and the translating, pulsating Green’s function methods, with the relevant source distribution over the mean wetted surface of the hull. The time domain method uses the radiation and diffraction potentials related to the mean wetted surface, implemented using Impulse Response Functions (IRF), whilst the incident wave and restoring actions are evaluated on the instantaneous wetted surface. The calculations are carried out for a range of Froude numbers, and in the case of the partly nonlinear method for different wave steepness values. Comparisons are made with available experimental measurements. The discussion focuses on the necessity for a nonlinear approach for predicting the radiation potential and the possible numerical methods for its formulation.

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