Investigation on the effect of bow configuration on motion and green water for tumblehome vessels based on cartesian grid finite difference method

The special bow design of the tumblehome vessel makes it easy to produce green water, resulting in serious damage to the superstructure. However, the harsh environment numerical studies supported by experimental data on the bow configuration of tumblehome vessels are few. Based on the Cartesian Grid Finite Difference Method (CGFDM), this paper studied the motion response of the ship and the green water characteristics in regular waves under different bow configurations. The Finite Difference Method (FDM) based on a fixed regular staggered Cartesian grid system is used to solve the flow field, and the Tangent of Hyperbola for Interface Capturing with Slope Weighting (THINC/SW) scheme is used to capture the severe free surface flow. At the same time, the immersed boundary method is used to effectively solve the problem of the large motion of the object. The numerical simulation results were compared with the experimental values, showing good consistency. The calculation results show that the bow configuration has little effect on the motion response of the tumblehome vessel in regular waves and only shows some local differences in some wave conditions. Macroscopically, the change of stem angle has little effect on the green water degree of the ship. However, under high wave conditions, the change of stem angle greatly influences the height of green water and the slamming pressure characteristics of the ship. Compared with the bow configuration schemes with stem angles of 30 degrees and 60 degrees, the ship with the stem angle of 45 degrees has a better comprehensive load performance when green water occurs. This study can provide a suitable reference for selecting ship types and structural designs of tumblehome vessels.