scholarly journals Holding Force and Vertical Vibration of Emergency Gate in the Closing Process: Physical and Numerical Modelling

2021 ◽  
Vol 11 (18) ◽  
pp. 8440
Author(s):  
Yanzhao Wang ◽  
Guobin Xu ◽  
Fang Liu
Keyword(s):  
Numerical Model ◽  
Fluid Structure Interaction ◽  
Great Influence ◽  
Vertical Vibration ◽  
Physical Model Test ◽  
Force Coefficient ◽  
Fluid Structure ◽  
Flow Discharge ◽  
Structure Interaction ◽  
Outflow Boundary Condition

A two-dimensional unsteady fluid–structure interaction numerical model was established, based on the physical model test, to investigate the influence of vertical vibration on the holding force of an emergency gate in the closing process. Gate motion was controlled by the user-defined function in Fluent. Attention was paid to the relationship between the vertical vibration, hydrodynamic loads and flow discharge. The experiment results show that holding force has three typical forms in the closing process and it is related to the service gate height. The numerical model can reflect the gate vertical vibration and the gate-closing displacement in the form of steps. Gate vertical vibration in the closing process is a motion-induced vibration caused by gate active falling. Moreover, the transition from full-flow to open-flow behind the emergency gate has a great influence on the gate vertical vibration. With a small gate opening, gate vertical vibration makes the flow discharge fluctuation increase. Furthermore, flow discharge has an influence on the gate body loads, which is mainly concentrated in the upstream plate and gate bottom. Finally, the lift force coefficient at the gate bottom is different from the standard and is mainly controlled by the outflow boundary condition. The simulation result is in good agreement with the experiment and the relative error meets engineering requirements, suggesting that the numerical model can successfully simulate the gate fluid–structure interaction and reproduce the characteristics of physical quantities in the closing process.

Fluid-Structure Interaction Approach for Numerical Investigation of a Flexible Hydrofoil Deformations in Turbulent Fluid Flow

2018 ◽  
Author(s):  
M. Benaouicha ◽  
S. Guillou ◽  
A. Santa Cruz ◽  
H. Trigui
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Stokes Equations ◽  
Fluid Structure Interaction ◽  
Time Step ◽  
Fluid Structure ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Structure Interaction ◽  
Ale Formulation

The study deals with a 3D Fluid-Structure Interaction (FSI) numerical model of a rectangular cantilevered flexible hydrofoil subjected to a turbulent fluid flow regime. The structural response and dynamic deformations are studied by analyzing the oscillations frequencies and amplitudes, under a hydrodynamics loads. The obtained numerical results are confronted with experimental ones, for validation. The numerical model is performed in the same geometric, physical and material conditions as the experimental set-up carried out in a hydrodynamic tunnel. A polyacetal (POM) flexible hydrofoil NACA0015 with an angle of attack of 8° is considered to be immersed in a fluid flow at a Reynold number of 3 × 105. The structure is initially at rest and then moved by the action of the fluid flow. The numerical model is based on a strong coupling procedure for solving the Fluid-Structure Interaction problem. The Arbitrary Lagrangian-Eulerian (ALE) formulation of the Navier-Stokes equations is used and an anisotropic diffusion equation is solved to compute the fluid mesh velocity and position at each time step. The finite volume method is used for the numerical resolution of the fluid dynamics equations. The structure deformations are described by the linear elasticity equation which is solved by the finite elements method. The Fluid-Structure coupled problem is solved by using the partitioned FSI implicit algorithm. A good agreement between numerical and experimental results for the hydrodynamics coefficients and hydrofoil deformations, maximum deflection and frequencies is obtained. The added mass and damping are analyzed and then the FSI effect on the dynamic deformations of the structure is highlighted.

A Hybrid Numerical Model to Address Fluid Elastic Structure Interaction

2016 ◽  
Author(s):  
Manoj Kumar Gangadharan ◽  
Sriram Venkatachalam
Keyword(s):  
Numerical Model ◽  
Fluid Structure Interaction ◽  
Breaking Waves ◽  
Elastic Structure ◽  
Navier Stokes ◽  
Breaking Wave ◽  
Ocean Engineering ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction

Hydroelasticity is an important problem in the field of ocean engineering. It can be noted from most of the works published as well as theories proposed earlier that this particular problem was addressed based on the time independent/ frequency domain approach. In this paper, we propose a novel numerical method to address the fluid-structure interaction problem in time domain simulations. The hybrid numerical model proposed earlier for hydro-elasticity (Sriram and Ma, 2012) as well as for breaking waves (Sriram et al 2014) has been extended to study the problem of breaking wave-elastic structure interaction. The method involves strong coupling of Fully Nonlinear Potential Flow Theory (FNPT) and Navier Stokes (NS) equation using a moving overlapping zone in space and Runge kutta 2nd order with a predictor corrector scheme in time. The fluid structure interaction is achieved by a near strongly coupled partitioned procedure. The simulation was performed using Finite Element method (FEM) in the FNPT domain, Particle based method (Improved Meshless Local Petrov Galerkin based on Rankine source, IMPLG_R) in the NS domain and FEM for the structural dynamics part. The advantage of using this approach is due to high computational efficiency. The method has been applied to study the interaction between breaking waves and elastic wall.

Fluid Structure Interaction Simulation on the Seagull Airfoil of the Small Wind Turbine

2012 ◽  
Vol 546-547 ◽  
pp. 160-165
Author(s):  
Li Min Qiao ◽  
Xue Shan Liu ◽  
Yong Bo Yang ◽  
Yong Gang Jia ◽  
Xiao Lin Quan
Keyword(s):  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Great Influence ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Transition Prediction ◽  
Small Wind Turbine ◽  
Interaction Simulation ◽  
Low Reynolds ◽  
Turbine Design

For the blades of the small wind turbine working under the conditions of Low-Reynolds, the air viscosity has relatively great influence on them. The design and calculation on thickness of airfoils were studied in order to raise its life and reduce weight. In the premise of strength, the lighter, the better. This paper studied the aerodynamic performance of the airfoil under the Low-Reynolds and analyzed fluid-structure interaction effect at Reynolds number 600,000 under three different attack angles. The numerical simulation approach addresses unsteady Reynolds-averaged N-S solutions and covers transition prediction for unsteady mean flows. The computational result and the analysis show that the fluid-structure interaction is an important issue to consider while designing the wind turbine blade. The results may provide technical reference for the further wind turbine design.

Numerical Method to Estimate Fluid-Structure Interaction Effect of Ships Under Severe Wave Condition

2018 ◽  
Author(s):  
Tomoki Takami ◽  
Kazuhiro Iijima
Keyword(s):  
Natural Frequency ◽  
Interaction Effect ◽  
Fluid Structure Interaction ◽  
Structural Response ◽  
Vertical Vibration ◽  
Coupling Method ◽  
Wave Condition ◽  
Fluid Structure ◽  
Strongly Coupled ◽  
Structure Interaction

In this study, for the sake of evaluating the structural response taking account of the fluid-structure interaction effect of a ship under severe wave condition, a method for coupling the CFD and 3D FEA in a sequentially staggered manner, is developed. The elastic deformation of the ship is taken over, not only to the following FEA stages but also to the following CFD stages. In order to validate the developed two-way coupling method, and to investigate into the fluid-structure interaction effect on the ship, the comparisons among the straightforward (one-way) coupling method, the experimental results and the developed two-way coupling method are carried out, in terms of the wave-induced loads exerted on the ship, and the hydroelastic response. Both the weakly and strongly coupled methods are investigated. The fluid-structure interaction effect is found as a decrease of the natural frequency of vertical vibration mode of the ship; the natural frequency predicted from the developed two-way coupling method is slightly lower than that from the one-way coupling method.

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