Fluid-Structure Interaction Simulation Of Simply Supported Plate With Large Deformation Subjected To Axial Flow

Fluid-structure interaction vibration and instability of plate-shell thi n-walled structure is often encountered in many practical engineering fields a nd it is a problem needed to resolve. The in-depth study of fluid-structure inte raction vibration problems of thin plate structure and the fluid is not only bene ficial to reveal the vibration mechanism of board structure with the fluid indu ced, but also to some extent creates engineering design and application. Under standing the structure vibration caused by fluid-structure interaction in practic al engineering, and applying related theory to engineering practice, which has important theoretical value and practical significance on the study of this prob lem. This paper using numerical simulation software to simulate simply suppo rt elastic thin plate in the large deflection fluid-structure interaction system wi th the axial flow, and using the moving grid control technology and the nonlin ear fluid-structure interaction function of finite element analysis software —A DINA. This paper combined with the existing theoretical research methods an d results to provide the reference for all related engineering field on flow indu ced vibration, the prediction and control of instability, experimental study andtheoretical calculation, etc. The main content and achievements are as follows:1. The numerical simulation model of a single simply-supported elastic thin plate in axial flow is established. The dynamic response and flow field characteristics of fluid structure interaction system of simply-supported elastic thin plates with large deformation subjected to axial flow are studied numerically. The structural dynamics equation is discretized by displacement-based finite elements. The fluid domain is governed by two-dimensional incompressible viscous Navier-Stokes equations, which are discretized by the finite volume method. Based on this and combined with dynamic grid control technology, the two-dimensional numerical model of simply-supported elastic thin plate in the axial flow with two-way fluid-structure interaction is built. By using this numerical model, the flow-induced vibration characteristics of a single plate as well as the vibration stability of the large deflection structure are studied, Pitchfork bifurcation curve and Hopf bifurcation curve of nonlinear system structure have been obtained respectively. Due to the influence of the plate vibration, karman vortex street occurs at the downstream. By comparing the vorticity, pressure and velocity at given flow velocity, the fluid and structure interaction system is explained vividly.2. Established a numerical model of two parallel simply-supportedelastic thin plate in the axial flow. The flow vibration characteristics are gained through the numerical simulation of two simply supported parallel plate with different spacing and constant axial flow velocity. With the different distance between the two parallel plates, the characteristic of three different limit-cycle oscillations modes are found: in-phase oscillation,out-of-phase oscillation, and indefinite oscillation. In addition, the plate boundary layer shed from its free end and wake stream change rule are obtained under the in-phase and out-of-phase modes respectively; In the transition stage from in-phase mode to out-of-phase mode of changing plate spacing the numerical simulation, the two plates show beating effect.