Numerical Analysis Of Response Characteristics Of Stationary Small Vessel Under KCS Ship Waves

When a ship is sailing,it will be influenced by the wave environment of the water it is in,causing various motion responses such as rolling and pitching of the ship’s hull.Due to the complex environment of the navigable waters of the diversion,the number of vessels coming and going,the speed of the vessels is fast,and the ship traveling waves have different degrees of influence on the small boats operating in the vicinity,which may lead to the capsizing of small boats when the lateral distance is close.To address these problems,this thesis uses the numerical calculation method based on viscosity theory,adopts the overlapping mesh technique to realize the large scale motion of the ship,adopts the SDOF method to calculate the motion response of small ships with six degrees of freedom,and studies the motion response characteristics of small ships under the influence of ship travel waves,optimizes the formula for calculating the transverse rocking amplitude of small ships under the influence of ship travel waves,and completes the following research work.To verify the accuracy of the ship wave numerical simulation method used in this article,the numerical simulation results are compared with the results of tank tests.The results show that the ship wave obtained from the numerical simulation method is highly consistent with the results of the tank tests.Subsequently,the formation process,longitudinal attenuation,and lateral attenuation characteristics of KCS ship waves were studied and analyzed.It was found that the lateral attenuation of the ship waves was more severe within 2 times the ship width,and the wave attenuation became slower as the ship speed increased.The KCS ship waves at different Froude numbers were studied,and the morphological changes of the ship waves under different ship speeds were analyzed.By introducing the ship type factor to improve the empirical formula for the lateral attenuation of ship waves,the influence of ship type on the lateral attenuation of ship waves was further reflected.The attenuation curve obtained can accurately reflect the lateral attenuation of KCS ship waves.By establishing a numerical wave tank model of the hydrodynamic interference of KCS ship waves,the hydrodynamic interference and motion response of small vessels under the influence of single factors,such as different ship speeds,transverse distance between two ships,and wave direction angles,were analyzed.The motion response rules of small vessels under the influence of single factors were summarized.Subsequently,the orthogonal experimental method was used to analyze the significance of small vessel motion response under the influence of multiple factors.The results showed that the ship speed and transverse distance between two ships of the direct sailing ship significantly affected the roll motion response of small vessels.Since the empirical formula only considers the rigid characteristics of the ship,the hydrodynamic characteristics of the ship,such as fluid resistance and flow field disturbance,are not considered,resulting in errors between the calculated and actual values.Therefore,in this thesis,the empirical formulas for the response amplitude of transverse hydrodynamic and transverse rocking motion of small ships subjected to numerical simulations are optimized to improve the accuracy of calculating the transverse rocking amplitude of small ships,and the generalizability of the optimized formulas is tested.