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该文发展了时变附加质量方法,并利用有限元方法模拟了水下飞行器的出水过程。基于出水过程中飞行器的振动模态试验数据,由于出水长度与一阶横向振动频率、出水长度与附加质量均有一一对应关系,所以该文在一定假设条件下,通过反演方法得到了随出水长度变化的横向时变附加质量,初步形成了将复杂流场载荷向飞行器表面等效的方法。该文完成了对水下飞行器出水过程动态性能的研究,考察了某截面上弯矩和剪力随时间变化的情况。在附加质量的影响下,结构的响应频率会低于无附加质量的情况,而响应幅值则因不同的外载荷条件而异。随着出水长度的增加和沾湿长度的减少,结构的振动频率逐渐升高,此计算结果也定性地说明了时变附加质量的合理性,并为对附加质量方法作进一步研究奠定了基础。
This paper develops a time-varying additional mass method and simulates the underwater vehicle’s effluent process using finite element method. Based on the experimental data of the vibration modes of the aircraft during the water discharge, the water length and the first-order transverse vibration frequency have a one-to-one correspondence with the additional mass. Therefore, under certain assumptions, The time-varying lateral mass of water changes in the length of the effluent, which initially forms a method of equating the complex flow field load with the aircraft surface. This paper has completed the research on the dynamic performance of the underwater craft’s water outlet and investigated the changes of the moment and the shear force over time on a section. Under the influence of additional mass, the response frequency of the structure will be lower than that without additional mass, while the response amplitude will vary with different external load conditions. With the increase of effluent length and the decrease of the wetting length, the vibrational frequency of the structure gradually increases. The calculation results also qualitatively illustrate the rationality of time-varying additional mass and lay a foundation for further study of the additional mass method.