scholarly journals Simulation of 2-Way Fluid Structure Interaction in a 3D Model Combustor

2012 ◽  
Author(s):  
Mina Shahi ◽  
Jim B. W. Kok ◽  
P. R. Alemela
Keyword(s):  
Flue Gas ◽  
Fluid Structure Interaction ◽  
Operating Conditions ◽  
Limit Cycle Oscillation ◽  
Structural Domain ◽  
Pressure Oscillations ◽  
Fluid Structure ◽  
Thermoacoustic Instability ◽  
Structure Interaction ◽  
Computational Fluid Dynamics Analysis

The liner of a gas turbine combustor is a very flexible structure that is exposed to the pressure oscillations that occur in the combustor. These pressure oscillations can be of very high amplitude due to thermoacoustic instability, when the fluctuations of the rate of heat release and the acoustic pressure waves amplify each other. The liner structure is a dynamic mechanical system that vibrates at its eigenfrequencies and at the frequencies by which it is forced by the pressure oscillations to which it is exposed. On the other hand the liner vibrations force a displacement of the flue gas near the wall in the combustor. The displacement is very small but this acts like a distributed acoustic source which is proportional to the liner wall acceleration. Hence liner and combustor are a coupled elasto-acoustic system. When this is exposed to a limit cycle oscillation the liner may fail due to fatigue. In this paper the method and the results will be presented of the partitioned simulation of the coupled acousto-elastic system composed of the liner and the flue gas domain in the combustor. The partitioned simulation uses separate solvers for the flow domain and the structural domain, that operate in a coupled way. In this work 2-way fluid structure interaction is studied for the case of a model combustor for the operating conditions 40–60 kW with equivalence ratio of 0.625. This is done in the framework of the LIMOUSINE project. Computational fluid dynamics analysis is performed to obtain the thermal loading of the combustor liner and finite element analysis renders the temperature, stress distribution and deformation in the liner. The software used is ANSYS workbench V13.0 software, in which the information (pressure and displacement) is also exchanged between fluid and structural domain transiently.

The Ocean Cleanup System 001 Performance During Towing and Seakeeping Tests

2019 ◽  
Author(s):  
Joost Sterenborg ◽  
Nicola Grasso ◽  
Rogier Schouten ◽  
Arjen Tjallema
Keyword(s):  
Fluid Structure Interaction ◽  
Model Tests ◽  
Operating Conditions ◽  
Image Correlation ◽  
Plastic Pollution ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Wave Basin ◽  
Floating System ◽  
Floating Systems

Abstract One of the aims of The Ocean Cleanup is to develop technologies to extract plastic pollution from the world’s oceans. Several concepts of passive floating systems were considered that are supposed to confine plastics to ease their collection. Such concepts consist of a floating member and a submerged flexible skirt and have in common that their span is generally more than 500 meters. Consequently, fluid-structure interaction plays an important role in the response of such a floating system. To support numerical simulations, MARIN carried out extensive model tests on a 120 meter system section of the final concept, with focus on the fluid-structure interaction (FSI) of the submerged skirt in operating conditions and in towing configuration. The ability to capture plastics was not investigated in these model tests. Novel for wave-basin tests were non-intrusive measurements using underwater Digital Image Correlation (DIC) to obtain the displacements and deformations of the flexible skirt. DIC proved to be a capable measurement technique for this type of structure in combination with a wave basin. Detailed quantitative data on skirt motions and deformations were delivered and the last concept of the cleanup system was tested in the towing configuration and operational configuration.

scholarly journals NUMERICAL SIMULATION OF FLUID-STRUCTURE INTERACTION BETWEEN FISHING WOBBLER AND WATER

2020 ◽  
pp. 665
Author(s):  
Miroslav Mijajlović ◽  
Sonja Vidojković ◽  
Dušan Ćirić ◽  
Dragan Marinković
Keyword(s):  
Fluid Structure Interaction ◽  
Computational Time ◽  
Structural Domain ◽  
Time Step ◽  
Water Stream ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Solid Bodies ◽  
Computer Resources ◽  
Mutual Structure

This paper deals with modeling, discretization, and numerical analysis of the two-way fluid-structure interaction between a fishing wobbler and a water stream. The structural domain is an assembly of several bodies that have multiple mutual structure-to-structure interactions. These interactions are mostly nonlinear contacts that significantly influence the time step used in simulations. As a result of these nonlinearities, the numerical solving of such a model requires significant computer resources and a long computational time. The paper also presents the creation and numerical simplifications of the model. However, the model remains very realistic. It is concluded that solving the structural domain in a model that retains the interaction between solid bodies is more computationally sensitive and more demanding than solving the fluid domain.

A Coupled Two-Way Fluid-Structure Interaction Analysis for the Dynamics of a Partially Confined Cantilevered Pipe Under Simultaneous Internal and External Axial Flow in Opposite Directions

2021 ◽  
Author(s):  
Farhang Daneshmand ◽  
Tahereh Liaghat ◽  
Michael Paidoussis
Keyword(s):  
Interaction Analysis ◽  
Velocity Ratio ◽  
Fluid Structure Interaction ◽  
Axial Flow ◽  
Internal Flow ◽  
Structural Domain ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Cantilevered Pipe ◽  
Central Pipe

Abstract This paper presents the results of a coupled two-way fluid-structure interaction analysis of a slender flexible vertical cantilevered pipe hanging concentrically within a shorter rigid tube forming an annulus. The pipe is subjected to internal and annular flows simultaneously. This system has applications in brine production and salt-cavern hydrocarbon storage. In the present study, the fluid-structure problem is solved with a finite-volume-based CFD code for the fluid domain coupled to a finite-element-based CSM code for the structural domain. The numerical results obtained for the free-end displacement of the central pipe versus the annular/internal flow velocity ratio U_o/U_i are presented and compared with those obtained from experiment. The capability of the numerical model to predict the onset of the experimentally observed flutter instability in the system is also examined. This provides a better insight into the dynamics of the system.

scholarly journals Spontaneous oscillation and fluid–structure interaction of cilia

2018 ◽  
Vol 115 (17) ◽  
pp. 4417-4422 ◽  
Author(s):  
Jihun Han ◽  
Charles S. Peskin
Keyword(s):  
Motor Proteins ◽  
Phase Synchronization ◽  
Fluid Structure Interaction ◽  
3D Structure ◽  
Immersed Boundary ◽  
Limit Cycle Oscillation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dynein Motor ◽  
Fluid Environment

The exact mechanism to orchestrate the action of hundreds of dynein motor proteins to generate wave-like ciliary beating remains puzzling and has fascinated many scientists. We present a 3D model of a cilium and the simulation of its beating in a fluid environment. The model cilium obeys a simple geometric constraint that arises naturally from the microscopic structure of a real cilium. This constraint allows us to determine the whole 3D structure at any instant in terms of the configuration of a single space curve. The tensions of active links, which model the dynein motor proteins, follow a postulated dynamical law, and together with the passive elasticity of microtubules, this dynamical law is responsible for the ciliary motions. In particular, our postulated tension dynamics lead to the instability of a symmetrical steady state, in which the cilium is straight and its active links are under equal tensions. The result of this instability is a stable, wave-like, limit cycle oscillation. We have also investigated the fluid–structure interaction of cilia using the immersed boundary (IB) method. In this setting, we see not only coordination within a single cilium but also, coordinated motion, in which multiple cilia in an array organize their beating to pump fluid, in particular by breaking phase synchronization.

Seismic Analysis of a Nuclear Reactor With Fluid-Structure Interaction

2005 ◽  
Author(s):  
Jean-Franc¸ois Sigrist ◽  
Daniel Broc ◽  
Christian Laine
Keyword(s):  
Internal Structure ◽  
Pressure Vessel ◽  
Nuclear Reactor ◽  
Seismic Analysis ◽  
Mass Operator ◽  
Fluid Structure Interaction ◽  
Added Mass ◽  
Operating Conditions ◽  
Fluid Structure ◽  
Structure Interaction

The present paper is related to a seismic analysis of a naval propulsion ground prototype nuclear reactor with fluid-structure interaction modeling. Many numerical methods have been proposed over the past years to take fluid/structure phenomenon into account [14] in various engineering domains, among which nuclear engineering in seismic analysis [15]. The purpose of the present study is to apply general methods on a global approach of the nuclear reactor. A simplified design of the pressure vessel and the internal structure is presented; fluid-structure interaction is characterized by the following effects: • added mass effects are highlighted with the calculation of an added mass operator, obtained from a finite element discretisation of the coupled problem. The numerical model is developed within the CASTEM code using an axi-symmetric model of the industrial structure; • coupling effects between the external and internal structure via the confined inner fluid are also illustrated and numerically described with the added mass operator; • added stiffness effects are taken into account with an added stiffness matrix describing pre-stress effects due to a static pressure loading simulating the actual operating conditions of the reactor. The expected fluid-structure interaction effects on the nuclear pressure vessel and their numerical modeling leads to the definition of a global coupled model which can be used to perform a seismic analysis. A modal analysis is first performed and classical linear methods (static, spectral and temporal) are then applied on the studied structure with taking fluid-structure into account.

Numerical Evaluation of Deformation and Stress in Impellers of Multistage Pumps by Means of Fluid Structure Interaction

2013 ◽  
Author(s):  
Andreas Schneider ◽  
Björn-Christian Will ◽  
Martin Böhle
Keyword(s):  
Numerical Evaluation ◽  
Fluid Structure Interaction ◽  
Hydrodynamic Pressure ◽  
Operational Reliability ◽  
Operating Conditions ◽  
Design Parameters ◽  
Centrifugal Pumps ◽  
Fluid Structure ◽  
Structural Part ◽  
Structure Interaction

The operational reliability of centrifugal pumps strongly depends on an adequate structural design of every single component. Therefore, the design process requires trustworthy information about the expected stresses and deformations. The numerical evaluation of the deformations and the stresses in the impellers of multistage centrifugal pumps is the topic of this report. The loads acting on the impeller under operating conditions can be subdivided into structural and hydrodynamic components, which are considered by means of one-way coupled fluid-structure interaction (FSI) simulations. For the investigations, an exemplary multistage pump with a specific speed of nq = 30 has been chosen. The hydrodynamic pressure loads on the impeller are derived from the CFD solution for a single stage of the pump. These pressure loads are imposed on the impeller in the structural part of the simulation. In order to determine the resulting deformations and stresses of the impeller, static structural analyses are performed. Different operating conditions, i.e. flow rates and temperatures, are analyzed. Furthermore, the influence of structural impeller design parameters on the resulting deformations and stresses is investigated in detail. The thickness of the impeller shrouds as well as the fillet radii between the blades and the shrouds are considered as design parameters.

Study of coating's effects on mechanical performances for sleeve of cotton picker with fluid–structure interaction method

2014 ◽  
Vol 228 (17) ◽  
pp. 3057-3068 ◽  
Author(s):  
FM Meng ◽  
ZW Chen
Keyword(s):  
Elastic Modulus ◽  
Poisson’S Ratio ◽  
Fluid Structure Interaction ◽  
Operating Conditions ◽  
Poisson's Ratio ◽  
Interaction Method ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Cotton Picker ◽  
Mechanical Performances

A sleeve and its matched spindle are key components of a cotton picker, whose performances affect picking cotton efficiency directly. To enhance the sleeve strength and wear resistance, it is desired to add coatings on the inner surface of the sleeve. In this paper, influences of the coatings on the mechanical performances of the sleeve are investigated with fluid–structure interaction method. Mechanical performances of the sleeve are studied at the varied elastic modulus, Poisson's ratio, and thickness of the coating and different operating conditions. The numerical results show that both the amplitude and position of the von Mises stress and strain of the coated sleeve depend on the varied elastic modulus, Poisson's ratio, and thickness of coating. The coating effect on the sleeve is significant at a big eccentricity ratio or high rotational speed of the spindle.

Strength Evaluation of LNG Containment System Considering Fluid-Structure Interaction Under Sloshing Impact Pressure

2007 ◽  
Author(s):  
Bo Wang ◽  
Jang Whan Kim
Keyword(s):  
Comparative Method ◽  
Fluid Structure Interaction ◽  
Operating Conditions ◽  
Impact Pressure ◽  
Acoustic Medium ◽  
Strength Evaluation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Containment System ◽  
Membrane Type

As LNG carriers become larger and new operating conditions are being designed, it is essential to develop a new procedure for the strength evaluation of a membrane-type LNG containment system under sloshing loads. The conventional comparative method based on existing service experiences and previous damage cases is currently used in most cases, but this method is only valid for designing new LNG carriers with similar size and type of existing ones. In this study, an analytical solution of acoustic-solid interaction has been derived and a simple 2D coupled acoustic-solid model has been simulated to investigate hydro-elastic effects for the verification purpose. After validation of FE modeling, a coupled model considering the fluid-structure interaction between LNG and containment system has been developed for structural analysis of LNG Mark III containment system. For LNG Mark III containment system, nonlinear dynamic FE analysis under sloshing impact pressure has been conducted using the fluid-structure coupling model. In FE simulations, the hydro-elastic effect in structural response has been studied through considering LNG as an acoustic medium, foam as a visco-elastic material, plywood as an orthotropic material, and mastic as an isotropic material. Parametric study has also been done to investigate the effects of material properties and loading patterns on hydro-elastic response in the coupled fluid-structure model. Based on FE results and experimental data, the strength of LNG Mark III containment system has been evaluated in terms of acceptance criteria. Finally, the new procedure has been developed for the strength evaluation of membrane-type LNG containment systems.

The Simulation of Dual Layer Fuel Tank During the Impact With the Ground Based on Parallel Computing

2007 ◽  
Vol 2 (4) ◽  
pp. 366-373 ◽  
Author(s):  
Li Zheng ◽  
Jin Xiang-long ◽  
Chen Xiang-dong
Keyword(s):  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Fuel Tank ◽  
Woven Fabric ◽  
Structural Domain ◽  
Arbitrary Lagrangian Eulerian ◽  
Fluid Structure ◽  
Bisection Algorithm ◽  
Structure Interaction ◽  
The Impact

The crashworthiness of a dual layer fuel tank, with the outer layer made of metal and the inner layer made of woven fabric composite material, is fundamental for the survivability of an impact with the ground in emergency. In this research, the simulation of a three-dimensional dual layer fuel tank in the impact with the ground is achieved through the multimaterial arbitrary Lagrangian-Eulerian (ALE) finite element method because of its ability to control mesh geometry independently of geometry. At the same time, the naked flexible tank in the impact with the ground is simulated for the evaluation of the outer metal tank. The ALE description is adopted for the fluid domain, while for the structural domain the Lagrangian formulation is considered. The computation of the fluid-structure interaction and the impact contact between the tank and the ground are realized by the penalty-based coupling method. Then, the dynamic behaviors of the dual layer fuel tank and the naked flexible tank in the impact are analyzed. In the meantime, the parallelism of the dual layer fuel tank is discussed because the computation of the fluid-structure interaction and the impact contact is quite time consuming. Based on domain decomposition, the recursive coordinate bisection (RCB) is improved according to the time-consuming characteristics of fluid-filled tank in the impact. The result indicates, comparing with the RCB algorithm, that the improved recursive coordinate bisection algorithm has improved the speedup and parallel efficiency.

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