Potential -flow and CFD investigations of bow-flare slamming on a container ship in regular heading waves

This study numerically and experimentally investigates the ship motions and slamming pressures of a 10,000 TEU container ship in regular heading waves. A modified Stavovy-Chuang model that considers the influence of the wave-ship encounter time and asymmetric rolling motions is proposed as the potential-flow method to solve symmetric and asymmetric flare slamming calculations. Instantaneous ship motions from a nonlinear six degree of freedom unified model are adopted to simulate the pressure. The ship flare-wave encounter time determines the duration of the slamming. The commercial software STAR CCM+ is utilised for computational fluid dynamics (CFD) simulations of the slamming and motions. The modified Stavovy-Chuang model, CFD technology, and segmented model tests are used for the first time to predict asymmetric slamming accompanied by parametric rolling. Empirical formulas for various classification society rules are adopted for the cross-validation of the symmetric impact forces. In conclusion, the occurrence of slamming is dominated by the normal impact velocity and the relative positions of the ship and waves. The duration of the slamming, especially under parametric rolling conditions, mainly depends on the rolling period and encountering wave. Under parametric rolling conditions, the magnitude of the slamming pressure decreases and the impact duration increases as the wavelength increases. In simulations of symmetric slamming, only the duration increases as the wavelength increases, and the American Bureau of Shipping and International Association of Classification Societies results are similar to the test results.

Automated summary

The study investigates ship motions and slamming pressures of a 10,000 TEU container ship in regular waves through numerical and experimental methods. A modified model is proposed to solve symmetric and asymmetric flare slamming calculations, considering wave-ship encounter time and asymmetric rolling motions. Computational fluid dynamics simulations, empirical formulas, and segmented model tests contribute to predicting slamming behavior and duration under various conditions. The occurrence and duration of slamming are influenced by normal impact velocity, relative positions of the ship and waves, rolling period, and encountering wave, with different behaviors observed under different wave conditions.