ONR Tumblehome (ONRT) – Course Keeping in Waves

The aim of this test case is to assess the capability of free-running CFD to predict the course keeping ability and motions of a ship in regular head and stern quartering waves. Special attention is given the CFD setup (mass properties, GM, and roll decay) and validation of the surge and sway forces and the yaw moment as well as to the propeller and rudder loads. The ONR Tumblehome (ONRT) model 5613 is a preliminary design of a modern surface combatant, which is publicly accessible for fundamental research. The 1/48.935 scaled ship model is appended with a centreline skeg and bilge keels. The model has a wave piercing hull design with tumblehome sides and transom stern. The model also has spade rudders, shafts and propellers with propeller shaft brackets. No full-scale ship exists.