CFD Investigation of Mutual Interaction between Hull, Propellers, and Rudders for an Inland Container Ship in Deep, Very Deep, Shallow, and Very Shallow Waters

A ship is generally characterized by three principal elements: the propulsive system, the steering system, and the hull geometry. The interaction between these elements is very strong; therefore, it is essential to be able to estimate the effect of this interaction for better control and prediction of the ship’s trajectory. This interaction is mostly affected by the drift angle, rudder angle, propeller rotation rate, and form of the stern hull. However, for ships navigating on inland waterways, the ratio, h/T, of the water depth, h, to the ship’s draught, T, can significantly affect this interaction. In this paper, we present the results of a full numerical study about the impact of the navigation environment (deep and shallow waters) on the hull–propeller–rudder interaction. A scaled inland container ship with twin propellers and quadruple rudders was selected to carry out this work. A steady computational fluid dynamics (CFD) code based on Reynolds-averaged Navier–Stokes (RANS) equations was validated and used to simulate the flow around the hull, propellers, and rudders. The flow was considered with a free surface and full turbulence. The influence of the confined environment on the force interaction was investigated by simulating various operating configurations of a ship; therefore, several values of the ship’s underkeel clearance, rudder angles, and propeller thrust loading were tested. The results of this work clearly show the influence of each parameter tested and confirm that the hull–propeller–rudder interaction is strongly impacted by waterway confinement.