Abstract
A completely submerged underwater vehicle is modeled as a conical-cylindrical-spherical combined shell, the vibro-acoustic response near free surface of which is rarely analyzed in existing studies. In this paper, a Ritz-Legendre spectral method is proposed to analyze the vibro-acoustic response of combined shells under different submerged depths from the free surface. A theoretical structural model is established based on the Love shell theory, virtual spring technology and coordination relationship between displacements and rotation angle of adjacent subshells. The half-space external acoustic field model with the free surface is formulated by the Legendre spectral method, image method and Kirchhoff–Helmholtz boundary integral equation. The unified displacement admissible function of each subshell is expanded as Legendre orthogonal polynomial along generatrix direction and Fourier series along circumferential direction. The free surface treated as an ideal infinite acoustic soft boundary is substituted into acoustic wave equation and the half-space Green's function is obtained. The key technology to construct final coupled governing equation is how to expand the half-space Green's function with two-dimensional Fourier transform. Computed results are compared with those of the references and finite element method. The convergence, applicability, and correctness of the present method are verified. Influence of the free surface on the vibration and far-field acoustic radiation of combined shells under different submerged depths is analyzed, providing engineering significance for predicting external acoustic radiation of complicated combined shells with free surface.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
