Research On Hydrodynamic Performance And Slamming Probability Of SWATH

China is a big maritime country. Because the Chinese coastal marine meteorological and hydrological environment is complex and diverse, it has demand for all types of military and civilian ships. SWATH as a new high performance vessel, its broad applicability, seakeeping and maneuverability all get widely promoted. It is very worthy of attention. Therefore, the study of SWATH wave load forecasting, the probability of occurrence of slamming in bad sea conditions and the mooring in anchorage is very meaningful.A SWATH with 5480 tons is used as the research object in this article. The distribution of the wave-induced loads at different speed along longitudinal and transverse direction of SWATH is studied in first time. At the same time, to analyze the impact of wave loads with different speed and the randomness of typical cross-section; In addition, the slamming occurrence probability with different speed in different sea conditions is studied. At the same time, slamming pressure are computed by formula; At last, the rational layout plan of SWATH mooring in the anchorage is studied. The specific contents of research are described as follows:(1) Mass model and wet surfaces model are built by distribution of mass and ship line drawings. Calculating the longitudinal and transverse wave load component transfer function at different speed and carrying out the short-term and long-term forecast to get the distribution of wave load along longitudinal and transverse direction respectively. At the same time, the randomness of wave loads has been analysed. It was found that during the calculation of wave induced load, environment simulation should be based on actual sea conditions to select the optimum wave spectrum. As a result,forecast values will be more reasonable.(2) Analysis of SWATH mooring in anchorage ground in the frequency domain and time domain. Obtaining SWATH variation regularity of added mass, RAO, first-order wave excitation force and steady drift force in different depths through the frequency domain analysis. Based on the analysis of frequency domain, it is researched that motion response and line tension in the six degrees of freedom, and analyzed the reasonable number in third and sixth sea condition, and discussed the influence of mooring by wind, waves and current,on this basis, combining the results of two typical condition, giving a reasonable mooring environmental condition(3) Study of slamming probability. Predicting relative motion and relative velocity value between ship and wave in one hour at different speed in different sea conditions.Calculating the occurrence probability of slamming at different speed in different sea conditions. At seven sea condition, the influence of slamming probability in different draft has been analyzed. The results showed that: Slamming the probability decreases with the increase of draft. At the same time, calculating slamming pressure according to empirical formula.