螺旋桨诱导的船体表面力预报新方法

在已知船舶的质量、刚度、阻尼以及实测尾端振动速度的条件下,反推出螺旋桨叶频激振力.这是属于结构动力学的反问题即载荷识别问题.在深入研究国内外螺旋桨激振力计算方法以及综合分析影响螺旋桨激振力的各种要素后,采用载荷识别方法,提出计算空泡螺旋桨诱导的船体表面力的新公式,用该公式预报了四条船的表面力并与国外有关方法进行比较,预报的螺旋桨激振力与脉动压力值均在国外各公式预报值之间.用该公式预报的5.2万吨多用途货船的脉动压力值与空泡水筒中的实验值相比误差为21.8%;预报了30万吨超大型油船的激振力并由该激振力算出的尾端振动速度值与实测值相比误差仅为3.64%.

New prediction method for the vibration response of hull girder by propeller excitation

Under the condition of knowing the mass,stiffness,damping and the real vibration response of stern,the propeller pressure impulses of blade frequency are deduced,these belong to structure dynamics problem that is loading identification problem.Basing on deeply studying the domestic and overseas propeller fluctuating pressure calculation method,and comprehensively analyzing diversified element factors which influence propeller exciting force,the predigested loading recognition method is adopted to get a new formula for predicting the surface force which induced by the cavitations propeller.Then apply this formula to predict 4 vessels,the result compared with other overseas methods is within the scope of them.The prediction error percentage of the 52000t all-purpose cargo ship compared with the model test result is 21.8%,300000t VLCC compared with the measured value is merely 3.64%.