Experimental and numerical investigation on effects of air compressibility on dynamic performance of the damaged ship

This paper presents a detailed test procedure, including the test facilities, the design of the ship model and the releasing mechanism of the damaged opening. The aim is to analyze the effects of air compressibility on the flooding process and motion responses of the damaged ship. To assist in the explanation of the test results, necessary numerical simulations are performed. Through carrying out series of model tests, it was found that the limited ventilation level not only delays the flooding process but also affects the dynamic responses of the damaged ship. In addition, the test results verify the assumption of 10% full ventilation publihsed by the International Maritime Organization (IMO) while analyzing the applicability of this assumption to the single flooding compartment. The results also show that ensuring a proper ventilation level in the flooding compartments can mitigate gas-liquid interactions and thus improve the dynamic response of the damaged ship. Based on the research results in this paper, an 8% ventilation ratio can be preliminarily used as a reference standard for similarventilation designs. Finally, the obtained experimental data in this paper can be used as a benchmark for future reliability analysis of the numerical methods.