• Nuclear Engineering and Technology
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• 제41권5호
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• pp.649-654
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• 2009

The finite element based lattice Boltzmann method (FELBM) has been developed to model complex fluid domain shapes, which is essential for studying fluid-structure interaction problems in commercial nuclear power systems, for example. The present study addresses a new finite element formulation of the lattice Boltzmann equation using a general weighted residual technique. Among the weighted residual formulations, the collocation method, Galerkin method, and method of moments are used for finite element based Lattice Boltzmann solutions. Different finite element geometries, such as triangular, quadrilateral, and general six-sided solids, were used in this work. Some examples using the FELBM are studied. The results were compared with both analytical and computational fluid dynamics solutions.

• Coupled systems mechanics
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• 제1권2호
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• pp.133-154
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• 2012

In this paper a bridge flutter prediction is performed by using advanced numerical simulation. Two novel approaches were developed simultaneously by utilizing the ANSYS v12.1 commercial software package. The first one is a fluid-structure interaction simulation involving the three-dimensional elastic motion of a bridge deck and the fluid flow around it. The second one is an updated forced oscillation technique based on the dynamic mode shapes of the bridge. An aeroelastic wind tunnel model was constructed in order to validate the numerical results. Good agreement between the numerical results and the measurements proves the applicability of the novel methods in bridge flutter assessment.

• International Journal of Fluid Machinery and Systems
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• 제9권2호
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• pp.143-149
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• 2016

In this study, a method for the multi-objective optimization of an impeller for a centrifugal compressor using fluid-structure interaction (FSI) and response surface method (RSM) was proposed. Numerical simulation was conducted using ANSYS CFX and Mechanical with various configurations of impeller geometry. Each design parameter was divided into 3 levels. A total of 15 design points were planned using Box-Behnken design, which is one of the design of experiment (DOE) techniques. Response surfaces based on the results of the DOE were used to find the optimal shape of the impeller. Two objective functions, isentropic efficiency and equivalent stress were selected. Each objective function is an important factor of aerodynamic performance and structural safety. The entire process of optimization was conducted using the ANSYS Design Xplorer (DX). The trade-off between the two objectives was analyzed in the light of Pareto-optimal solutions. Through the optimization, the structural safety and aerodynamic performance of the centrifugal compressor were increased.

• 동력기계공학회지
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• 제5권4호
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• pp.38-43
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• 2001

This paper describes the effect of dynamic characteristics in tube line by external vibration conveying fluid with the power steering system. By the experimental analysis we found out that the factor of system vibration is the fluid-structure interaction of tube line. In fluid-filled tube system we study on the influence that the natural frequency of system and the frequency of wave motion produce upon through experiment. Experiments are modal test, frequency response function in continuous system, and vibrating tests when the system is driving with bolted clamping joint condition. From the results of the experimental studies, we obtained that the natural frequencies of system are very important than the wave induced vibrations. And we found that the tendency of system vibration level was decreased by bolting force, bolting condition and clamping distance.

• Advances in Computational Design
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• 제1권2호
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• pp.195-206
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• 2016

Dams play a vital role in the development and sustainment in a country. Failure of dams leads to the catastrophic event with sudden release of water and is of great concern. Hence earthquake-resistant design of dams is of prime importance. The present study involves static, modal and transient analyses of dam-reservoir-foundation system using finite element software ANSYS 15. The dam and the foundation are modeled with 2D plane strain element "PLANE 42" and the reservoir by fluid acoustic element "FLUID 29" with proper consideration of fluid-structure interaction. An expression for the fundamental period of concrete dams is developed based on modal analysis. Seismic response of gravity dams subjected to earthquake acceleration is evaluated in terms of peak displacement and stress.

• 동력기계공학회지
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• 제14권5호
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• pp.48-55
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• 2010

When a large ship is advancing in waves, ship undergoes the hydroelastic response, which has influences on structural stability and the fatigue destruction etc. of the ship. Therefore, to predict accurate hydroelastic response, it is necessary to analyze hydroelastic response including fluid-structure interaction. In this research, a ship is divided into many hull elements to calculate the fluid forces and wave exciting forces on each elements using three-dimensional source distribution method. The calculated fluid forces and wave exciting forces are assigned to nodes of hull elements. The neighbor nodes are connected with elastic beam elements. We analyzed hydroelastic responses, and those are formulated by using finite element method. Particularly, to estimate the influence of forward speed on the hydroelastic responses, we use two different methods : Full Hull Rotation Method(FHRM) and Sectional Hull Rotation Method(SHRM).

• 한국안전학회지
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• 제15권3호
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• pp.45-51
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• 2000

This paper studies the effect of vibrational characteristics of the various tubes analyzed though experiment. By an experiment analysis we found out that the factor of system vibration is fluid-structure interaction of tube line. In fluid-filled tube system we study on the influence that the natural frequency of system and the frequency of wave motion produce upon through three experiments. Three experiments are modal test on each tube, FRF in continuous system, and vibrating tests when the system is driving on. From the results of the experimental studies, we obtained that the natural frequencies of system are very important than wave induced vibrations. and according to the variation of configuration, the frequencies are different each other. And we found that though fluid passed away through the tube, the tendency of system vibration level was similar with the mode shape at the simple system.

• 동력기계공학회지
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• 제9권4호
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• pp.65-70
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• 2005

A liquid storage rectangular tank structures are used in many fields of civil, mechanical and marine engineering. Especially, Ship structures have many tanks in contact with inner or outer fluid, like ballast, fuel and cargo tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tank structures. Many authors have studied vibration of cylindrical and rectangular tanks structures containing fluid. Few research on dynamic interaction among tank walls through fluid are reported in the vibration of rectangular tanks recently. In case of rectangular tanks, structural coupling between adjacent panels and effect of vibration modes of multiple panels on added mass have to be considered. In the present paper, coupling effect between panels of tank structure on added mass of containing fluid, the effect of structural constraint between panels on each vibration mode for fluid region have investigated numerically and experimentally.

• Journal of Mechanical Science and Technology
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• 제19권2호
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• pp.625-633
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• 2005

A finite element vibration analysis of thin-walled cylindrical shells conveying fluid with uniform velocity is presented. The dynamic behavior of thin-walled shell is based on the Sanders' theory and the fluid in cylindrical shell is considered as inviscid and incompressible so that it satisfies the Laplace's equation. A beam-like shell element is used to reduce the number of degrees-of-freedom by restricting to the circumferential modes of cylindrical shell. An estimation of frequency response function of the pipe considering of the coupled effects of the internal fluid is presented. A dynamic coupling condition of the interface between the fluid and the structure is used. The effective thickness of fluid according to circumferential modes is also discussed. The influence of fluid velocity on the frequency response function is illustrated and discussed. The results by this method are compared with published results and those by commercial tools.

• 대한토목학회논문집
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• 제14권3호
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• pp.463-472
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• 1994

Random 지반운동에 대한 면진수조구조물 응답의 추계학적 해석방법을 연구하였다. 유연한 벽체와 내부유체간의 유체구조물 상호작용은 유체운동의 유한요소 모델링에 의하여 얻어지는 부가질량행렬 형태로 고려되었다. 정상(定常)(Stationary)지반운동으로는 수정된 Clough-Penzien Spectral Model이 사용되었으며, 비정상(非定常)(Nonstationary)지반운동으로는 상기모델에 포락함수를 적용한 모델을 사용하였다. 운동을 지배하는 Lyapunov Covariance Matrix 미분방정식의 해를 구하여 두 종류 면진시스템의 정상응답 및 비정상응답을 해석하였다.