STUDY ON THE PIPING SYSTEM INHERENT CHARACTERISTICS AFFECTED BY THE FLOW VELOCITY AND PRESSURE

摘要

Along with the developed trend to the speed is more and more bigger and the depth is more and more deeper for submarines in the future, the piping system is also the main noise resource for quite submarine, so it is very necessary to study the piping system inherent characteristics affected by the flow velocity and pressure for submarines. The fluid-solid interaction vibration differential equation of piping system is obtained according to the Hamilton principle in this paper, the approximate analytic formulations of natural frequency is derived by using the Galerkin method, and we find that the instability factor of the pipeline working is 2m_fv(({partial deriv}~2y)/({partial deriv}t{partial deriv}x), the limit velocity is ((EI(π/L)~2+AP)/m_f))~(1/2). The calculated results show that the natural frequency of the piping system reduces as the flow velocity increases, and slightly increases as the flow pressure increases.