采用CFD方法计算目标螺旋桨的敞水性能,通过Fourier变换得到轴承激振力的频域特性.结合舰艇推进轴系的一般结构形式,建立桨—轴—艇耦合系统纵向振动动力学模型,将先前计算所得的螺旋桨激励特性与振动能量传递相结合,讨论了纵向振动形式下螺旋桨激励振动功率流的传递和振动能量传递耗散的特性,从能量角度分析纵向振动在系统耦合振动中的影响,进而基于模拟工况探讨振动能量在轴系耦合振动中的传递机理.

对于舰船推进轴系的螺旋桨激励,由于其工作环境和结构条件的限制,很难在实际工况下进行直接测量.通过测量轴系的振动响应对螺旋桨激励进行估计是一种可行的方法.本文根据激励反演理论,从推进轴系的一般结构形式出发,提出了适用于由轴系振动响应估计螺旋桨激励的理论模型.由等截面均匀轴入手,通过轴段的波动解来分析纵向振动;结合边界条件,推导了波幅系数递推关系,进而建立了推进轴系纵向振动的一般波导模型.根据振动响应和建立的波导模型来识别波幅系数,并反演螺旋桨纵向激励.将模态法与波导法相结合,对一般的变截面非均质轴段的波导模型和轴段间波导传递关系进行了论证.结果表明,模态法与波导法结合,可作为一般方法,根据实测振动响应对复杂轴系结构的波导模型进行识别.

Affected by some difficult factors such as bearing stiffness and lubricant film stiffness and so on, the calculation of the lateral vibration response of the ship shafting is difficult to guarantee high calculation accuracy. A mathematical model of the propulsion system-submarine hull coupling bending vibration was established by mathematical physics, and the bearing excitation of the propeller was calculated. A mathematical model of the bending vibration response of the propulsion shaft system and the transmission of vibrational power to the hull was established to calculate the transmitted power flow. The vibration response and bending vibration power flow of the shafting under the lateral excitation of the propeller were solved. Through MATLAB simulation calculation and analysis, the influence of system parameter variation on the bending vibration flow transmission of each node in the power flow transmission path was obtained.