VIV Prediction of a Truss Spar Pull-Tube Array Using CFD

2011 ◽  
Author(s):  
Yiannis Constantinides ◽  
Weiwei Yu ◽  
Samuel Holmes
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Structural Model ◽  
Full Scale ◽  
Complex Flows ◽  
Single Cylinder ◽  
Structure Interaction ◽  
Cylinder Arrays ◽  
Truss Spar ◽  
Computational Fluid Dynamics Cfd

Complex flows through cylinder arrays, such as the case of pull-tubes located in the truss section of a truss spar, are very difficult to describe and analyze. It is especially difficult to predict and correct Vortex Induced Vibration (VIV) response using traditional tools that were developed to analyze single cylinder rather than arrays of cylinders. Computational Fluid Dynamics (CFD) offers the designer the ability to properly analyze these complex problems and increase the reliability of his design. In this study, a full scale truss spar with pull-tubes is modeled using CFD coupled with an FEA structural model of the pull-tubes for a fluid-structure interaction (FSI) computation. The VIV response of the pull-tubes is predicted and analyzed for different current headings and speeds.

Analysis of Turbulent Flows and VIV of Truss Spar Risers

2006 ◽  
Author(s):  
Yiannis Constantinides ◽  
Owen H. Oakley ◽  
Samuel Holmes
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Turbulent Flows ◽  
Full Scale ◽  
Complex Flows ◽  
Vortex Induced Vibration ◽  
Complex Problems ◽  
Truss Spar ◽  
Computational Fluid Dynamics Cfd ◽  
Vertical Risers

Complex flows through riser arrays, such as the case of risers located in the truss section of a truss spar, are very difficult to describe and analyze. It is especially difficult predict and correct Vortex Induced Vibration (VIV) response using traditional tools that were meant to analyze single risers rather than arrays of risers. Computational Fluid Dynamics (CFD) offers the designer the capability to properly analyze these complex problems, increasing the reliability of the design. In this study, a full scale truss spar with vertical risers is modeled using CFD. The VIV response of the risers is predicted and the effect of risers is correctly captured and compared with experiments.

Escort Tug Performance Prediction Using Computational Fluid Dynamics

2016 ◽  
Vol 60 (02) ◽  
pp. 61-77
Author(s):  
Brendan Smoker ◽  
Bart Stockdill ◽  
Peter Oshkai
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Separation ◽  
Travel Speed ◽  
Hydrodynamic Forces ◽  
Full Scale ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Thrust Forces ◽  
Steering Force

In this paper, we outline and validate a computational fluid dynamics (CFD) method for determining the hydrodynamic forces of an escort tug in indirect towing mode. We consider a range of yaw angles from 0° to 90° and a travel speed of 8 knots. We discuss the effects of scaling on prediction of flow separation and hydrodynamic forces acting on the vessel by carrying out CFD studies on both model and full-scale escort tugs performing indirect escort maneuvers. As the escort performance in terms of maximum steering forces is strongly dependent on the onset of flow separation from the hull and skeg of the tug, the model-scale simulations under-predict the maximum steering force by 12% relative to the full-scale simulations. In addition, we provide a method for converting the hydrodynamic forces of the CFD escort study into towline and thrust forces.

Hydrodynamic evaluation of a full-scale facultative pond by computational fluid dynamics (CFD) and field measurements

2014 ◽  
Vol 70 (3) ◽  
pp. 569-575 ◽  
Author(s):  
Ricardo Gomes Passos ◽  
Marcos von Sperling ◽  
Thiago Bressani Ribeiro
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Short Circuit ◽  
Field Measurements ◽  
Tracer Test ◽  
Full Scale ◽  
Cfd Model ◽  
Cfd Modelling ◽  
Hydraulic Behaviour ◽  
Computational Fluid Dynamics Cfd

Knowledge of the hydraulic behaviour is very important in the characterization of a stabilization pond, since pond hydrodynamics plays a fundamental role in treatment efficiency. An advanced hydrodynamics characterization may be achieved by carrying out measurements with tracers, dyes and drogues or using mathematical simulation employing computational fluid dynamics (CFD). The current study involved experimental determinations and mathematical simulations of a full-scale facultative pond in Brazil. A 3D CFD model showed major flow lines, degree of dispersion, dead zones and short circuit regions in the pond. Drogue tracking, wind measurements and dye dispersion were also used in order to obtain information about the actual flow in the pond and as a means of assessing the performance of the CFD model. The drogue, designed and built as part of this research, and which included a geographical positioning system (GPS), presented very satisfactory results. The CFD modelling has proven to be very useful in the evaluation of the hydrodynamic conditions of the facultative pond. A virtual tracer test allowed an estimation of the real mean hydraulic retention time and mixing conditions in the pond. The computational model in CFD corresponded well to what was verified in the field.

Perspective: Future Research Directions in Computational Fluid Dynamics

1994 ◽  
Vol 116 (2) ◽  
pp. 212-215 ◽  
Author(s):  
R. W. Douglass ◽  
J. D. Ramshaw
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Future Research ◽  
Complex Flows ◽  
Research Directions ◽  
Simulation Research ◽  
Current State ◽  
Future Research Directions ◽  
Computational Fluid Dynamics Cfd ◽  
Real Fluids

The current state of computational fluid dynamics (CFD) has yet to reach its full promise as a general tool for engineering design and simulation. Research in the areas of code robustness, complex flows of real fluids, and numerical errors and resolution are proposed as directions aiming toward that goal. We illustrate some of the current CFD challenges using selected applications.

scholarly journals ANÁLISE ESTRUTURAL DINÂMICA DE GRADE DE PROTEÇÃO DE TURBINA DE USINA HIDROELÉTRICA

e-xacta ◽  
2016 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Lucas Giovanetti ◽  
Carlos Alberto Chaves ◽  
Álvaro Manoel de Souza Soares
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Water Flow ◽  
Structural Model ◽  
Turbulent Regime ◽  
Floating Bodies ◽  
Structure Interaction ◽  
Hydroelectric Plants ◽  
Vertical Bars

<p>Grades são equipamentos de grande importância porque são responsáveis pela proteção das turbinas de usinas hidroelétricas contra impacto de corpos flutuantes. O objetivo do presente trabalho é analisar grades submetidas à ação de fluxo de água. Ou seja, analisar as respostas da estrutura e o comportamento do escoamento da água utilizando os cálculos de dinâmica de estruturas acopladas às técnicas de dinâmica de fluidos computacional (CFD), para um regime turbulento, mediante o uso do software comercial CFX versão 14. Tais análises são elaboradas mediante o processo de interação fluido-estrutura. Um modelo estrutural simplificado das barras verticais das grades é elaborado a partir de dados de projeto conhecidos. A partir desse modelo define-se um volume de controle que representa o escoamento do fluido. Devido ao número de Reynolds calculado, utiliza-se o modelo de turbulência para obtenção dos resultados tais como tensões e deslocamentos nas barras verticais; e perfil de velocidades do escoamento.</p><p>Abstract</p><p>Tashracks are very important equipment because they are responsible for protecting turbines of hydroelectric plants against floating bodies. The objective of this study is to analyze trashracks submitted by action of water flow. In other words, to analyze the responses of the structure and the behavior of water flow using dynamic of structures calculations coupled with computational fluid dynamics techniques (CFD) for a turbulent regime, through the use of commercial software CFX version 14. This analysis is elaborated by the process of fluid structure interaction. A simplified structural model of vertical bars is defined from other similar projects. For this model is defined a volume of control that represents fluid flow. Due to the Reynolds number calculated, it is utilized a turbulence model in order to obtain the results. These results are: stresses and displacements of vertical bars; and profile of velocities of flow. The results are analyzed and discussed.</p>

Investigating the effect of sparger configuration on the hydrodynamics of a full-scale membrane bioreactor using computational fluid dynamics

RSC Advances ◽  
2015 ◽  
Vol 5 (127) ◽  
pp. 105218-105226 ◽  
Author(s):  
Ershad Amini ◽  
Mohammad Reza Mehrnia ◽  
Seyyed Mohammad Mousavi ◽  
Hamed Azami ◽  
Navid Mostoufi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Membrane Bioreactor ◽  
Cfd Simulation ◽  
Full Scale ◽  
Hydrodynamic Parameters ◽  
Three Phase ◽  
Computational Fluid Dynamics Cfd

A three-phase computational fluid dynamics (CFD) simulation was carried out in a full-scale membrane bioreactor to investigate the effect of sparger configuration on various hydrodynamic parameters.

scholarly journals Advanced computational fluid dynamics (CFD)–multi-body simulation (MBS) coupling to assess low-frequency emissions from wind turbines

2018 ◽  
Vol 3 (2) ◽  
pp. 713-728 ◽  
Author(s):  
Levin Klein ◽  
Jonas Gude ◽  
Florian Wenz ◽  
Thorsten Lutz ◽  
Ewald Krämer
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Degrees Of Freedom ◽  
Structural Model ◽  
Low Frequency ◽  
Cfd Model ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Body

Abstract. The low-frequency emissions from a generic 5 MW wind turbine are investigated numerically. In order to regard airborne noise and structure-borne noise simultaneously, a process chain is developed. It considers fluid–structure coupling (FSC) of a computational fluid dynamics (CFD) solver and a multi-body simulations (MBSs) solver as well as a Ffowcs-Williams–Hawkings (FW-H) acoustic solver. The approach is applied to a generic 5 MW turbine to get more insight into the sources and mechanisms of low-frequency emissions from wind turbines. For this purpose simulations with increasing complexity in terms of considered components in the CFD model, degrees of freedom in the structural model and inflow in the CFD model are conducted. Consistent with the literature, it is found that aeroacoustic low-frequency emission is dominated by the blade-passing frequency harmonics. In the spectra of the tower base loads, which excite seismic emission, the structural eigenfrequencies become more prominent with increasing complexity of the model. The main source of low-frequency aeroacoustic emissions is the blade–tower interaction, and the contribution of the tower as an acoustic emitter is stronger than the contribution of the rotor. Aerodynamic tower loads also significantly contribute to the external excitation acting on the structure of the wind turbine.

scholarly journals Interaction Effect between Hull and Accommodation on Wind Drag Acting on a Container Ship

2020 ◽  
Vol 8 (11) ◽  
pp. 930
Author(s):  
Ngo Van He ◽  
Ngo Van Hien ◽  
Van-Thuan Truong ◽  
Ngoc-Tam Bui
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Interaction Effect ◽  
Full Scale ◽  
Ship Hull ◽  
Container Ship ◽  
Drastic Reduction ◽  
Aerodynamic Performances ◽  
Computational Fluid Dynamics Cfd

In this paper, we present our research on applying the commercial Computational Fluid Dynamics (CFD) code to investigate interaction effect between hull and accommodation on wind drag acting above the water hull surface of a full scale 1200 TEU container ship. With this purpose, aerodynamic performances and wind drag acting on the ship hull with and without accommodations have been computed. Analyzing the obtained CFD results, the interaction effect between hull and accommodation on aerodynamic performances and wind drag acting on the ship have been found. Various new accommodation shapes have been proposed for the original ship to reduce the interaction effect on wind drag. A drastic reduction in the interaction effect between hull and accommodation on wind drag acting on the ship has been achieved and the obtained results have been shown in this paper.

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