Numerical investigation of the ship propeller load under reversed propulsion condition

Abstract

Stopping maneuver is an important research topic in ship maneuverability. The stopping ability of ship is not only related to the hydrodynamic characteristics of hull, rudder and propeller, but also related to the capacity of main engine. However, there are few researches on the capacity of main engine under reversed propulsion condition. In the paper, a numerical water tank is established to simulate the propeller loads using the computational fluid dynamics (CFD) software STAR CCM+. The numerical model is firstly validated by experimental data, and then is used to investigate the propeller loads on a full-scale model with different ship speed and propeller speed. By dimensionless, the relations between the advance coefficient and the load coefficients are shown as J - K T curves and J - K Q curves. Furtherly, the flow structures near the propeller and the pressure on the propeller with different J values are investigated. The simulations reveal that the flow velocities induced by the reversed propulsion of the propeller is similar to the wake flow by ship with J = -0.49. That is the reason for the minimum points of J - K T and J - K Q curve occurring in cases with J = -0.49. Subsequently, the capacity of the main engine and the output load of the propeller are considered comprehensively. The relations between the ship speeds and the maximum output loads on the propeller are discussed in details.