In this paper, a CFD-based procedure for the evaluation of the performance characteristics of the well-known PPTC propeller, at model scale, is presented in detail. Results are obtained using one of the Local Correlation based Transition Models (LCTM), namely, the 𝛾 −𝑅𝑒̃ 𝜃𝑡 transition model in combination with the 𝑘 − 𝜔 SST turbulence model in a RANS-based numerical procedure to predict transition over the blade surface. The aim of using the 𝛾 − 𝑅𝑒̃ 𝜃𝑡 transition model is to predict the onset of transition and its influence on the propeller’s overall performance and on the flow behavior. Another aim of the work is to investigate the influence of the laminar-turbulent transition on the propeller’s flow. With the transition model, the constrained streamlines reflect an improvement in the flow pattern as compared to that of the model used for fully turbulent flow. Results also show an accurate prediction of the propeller’s global coefficients when the transition model is applied. Finally, a comparison between the results of the different transition models is conducted showing privilege of the 𝛾 −𝑅𝑒̃ 𝜃𝑡 over other transition models in terms of predicting the overall performance of the propeller.

The hull-propeller interaction has a significant impact on the propulsion performance of ships. The interaction parameters are mostly investigated under the assumption of calm water conditions, although in real operation, the influence of the waves and ship motion may be significant. The aim of the study is to determine the influence of head-waves on the interaction between the hull, the propeller, and the rudder as well as on the overall propulsive efficiency. In this numerical study, the viscous flow on the KRISO Container ship (KCS) model is calculated in calm water and in head-waves. The required power and propeller performance are estimated at different steepnesses of the incoming waves. The RANS code STAR-CCM+ is applied to evaluate the propulsion performance of the KCS fitted with the KP505 propeller in model scale. A PID controller is applied to keep the ship speed constant in calm water and in waves. The propeller flow is simulated using two approaches, namely, the virtual actuator disk (AD) and the discretized propeller (DP). The numerical setup is validated using published data for propulsion tests at different speeds. The obtained results show that the wave-induced velocity components change the wake field significantly. The increase in the wave steepness leads to a strong fluctuation in the wake velocity field and the required thrust as well as to higher power losses Furthermore, the results obtained confirm that the presence of the rudder behind the propeller leads to an improvement in propulsion efficiency not only in calm water but also in waves.

An acceleration maneuver may have critical operating phases where the propeller is subjected to unsteady flow conditions in addition to gradual or sudden changes in the number of revolutions per second (RPS). In the present study, a control model is developed to assist the acceleration maneuver of underwater vehicles in calm water under various operating conditions, in which the increase in propeller speed is precisely controlled to ensure the avoidance of tip vortex cavitation and to enable a reduction in the non-cavitating noise radiated by the propeller during the acceleration maneuver. As a test case for the study, the DARPA SUBOFF geometry (Defense Advanced Research Projects Agency) in combination with the CNR-INM E1619 propeller is selected. The numerical simulations are conducted using the RANSE-solver STAR-CCM+. The hybrid method, which combines CFD and P-FWH is applied to calculate the acoustic pressure and estimate the propeller radiated noise. The provided control model shows that the inception of the tip vortex cavitation can be avoided during the acceleration maneuver. In addition, the noise radiation can be reduced when the control model is activated.