Computational Fluid Dynamics Simulation of the Right Coronary Artery Moving With the Cardiac Wall

2002 ◽  
Author(s):  
H. Hayashi ◽  
T. Yamaguchi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Coronary Artery ◽  
Right Coronary Artery ◽  
Cfd Simulation ◽  
Dynamics Simulation ◽  
Cardiac Wall ◽  
Computational Fluid Dynamics Cfd ◽  
The Right ◽  
Heart Wall

The beating motion of the heart wall, to which the major coronary arteries are fixed, is interesting, due to its possible mechanical influence on the flow inside the artery, and hence its effect on atherogenesis [1–2]. In this study, we conducted a computational fluid dynamics (CFD) simulation using a simplified model of the right coronary artery, which deforms with heart contractions. The results are discussed with respect to the local hemodynamics characteristics, particularly the streamline pattern and the wall shear stress distribution.

Application of Computational Fluid Dynamics Simulation to Squeeze Film Damper Analysis

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Gil Jun Lee ◽  
Jay Kim ◽  
Tod Steen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Cfd Simulation ◽  
Design Guidelines ◽  
Dynamics Simulation ◽  
Squeeze Film ◽  
Computational Time ◽  
Small Clearance ◽  
Computational Fluid Dynamics Cfd

Squeeze film dampers (SFDs) are used in high-speed turbomachinery to provide external damping to the system. Computational fluid dynamics (CFD) simulation is a highly effective tool to predict the performance of SFDs and obtain design guidance. It is shown that a moving reference frame (MRF) can be adopted for CFD simulation, which saves computational time significantly. MRF-based CFD analysis is validated, then utilized to design oil plenums of SFDs. Effects of the piston ring clearances, the oil groove, and oil supply ports are studied based on CFD and theoretical solutions. It is shown that oil plenum geometries can significantly affect the performance of the SFD especially when the SFD has a small clearance. The equivalent clearance is proposed as a new concept that enables quick estimation of the effect of oil plenum geometries on the SFD performance. Some design practices that have been adopted in industry are revisited to check their validity. Based on simulation results, a set of general design guidelines is proposed.

Computational Fluid Dynamics Simulation of Steel Bars Cooling by Free Convection and Thermal Radiation

2015 ◽  
Vol 798 ◽  
pp. 170-174
Author(s):  
Paulo Henrique Terenzi Seixas ◽  
Paul Campos Santana Silva ◽  
Rudolf Huebner
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thermal Radiation ◽  
Cfd Simulation ◽  
Dynamics Simulation ◽  
Cfd Model ◽  
Computational Fluid Dynamics Simulation ◽  
Slow Cooling ◽  
Steel Bars ◽  
Computational Fluid Dynamics Cfd

In this article, the pilling process of hot steel bars is analyzed. During the loading three bars are placed over a wood surface, after those other three are placed over the previous for two times with 5 minutes intervals between them.They are all subject to a slow cooling by thermal radiation and free convection.A Computational Fluid Dynamics (CFD) model to predict the temperature profile of them is developed. Comparison between the CFD simulation results and experimental data yielded an average difference in the bars temperature between -0.3oC and 3.5oC.

scholarly journals Computational Fluid Dynamics Simulation to Predict the Airflow and Turbulence in a Wind Farm in Open Complex Terrain

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 33
Author(s):  
Amahjour Narjisse ◽  
Abdellatif Khamlichi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Farm ◽  
Cfd Simulation ◽  
Dynamics Simulation ◽  
Height Distribution ◽  
Wind Tunnel Data ◽  
Computational Fluid Dynamics Cfd ◽  
Neutral Conditions

The performance of a wind turbine depends on the characteristics of the airflow as well as the conditions of the atmospheric boundary layer (ABL). To evaluate accurately the amount of wind energy, it is required to have the exact height distribution of wind speed for the considered implementation site of a wind turbine. In this paper, computational fluid dynamics (CFD) simulation predictions provided by the standard k-ε turbulence model under neutral conditions were examined. The objective is to investigate the influence of hill slopes in the microscale wind farm on the airflow velocity to optimize the location of wind turbines. The results were validated by RUSHIL wind tunnel data and were compared with flat terrain.

Eulerian-Eulerian modelling and computational fluid dynamics simulation of wire mesh demisters in MSF plants

2014 ◽  
Vol 31 (7) ◽  
pp. 1242-1260 ◽  
Author(s):  
Hala Al-Fulaij ◽  
Andrea Cipollina ◽  
Giorgio Micale ◽  
Hisham Ettouney ◽  
David Bogle
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Wire Mesh ◽  
Dynamics Simulation ◽  
Cfd Modeling ◽  
Computational Domain ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Plant Data

Purpose – The purpose of this study is to focus on simulation of wire mesh demisters in multistage flash desalination (MSF) plants. The simulation is made by the use of computational fluid dynamics (CFD) software. Design/methodology/approach – A steady state and two-dimensional (2D) model was developed to simulate the demister. The model employs an Eulerian-Eulerian approach to simulate the flow of water vapor and brine droplets in the demister. The computational domain included three zones, which are the vapor space above and below the demister and the demister. The demister zone was modeled as a tube bank arrange or as a porous media. Findings – Sensitivity analysis of the model showed the main parameters that affect demister performance are the vapor velocity and the demister permeability. On the other hand, the analysis showed that the vapor temperature has no effect on the pressure drop across the demister. Research limitations/implications – The developed model was validated against previous literature data as well as real plant data. The analysis shows good agreement between model prediction and data. Originality/value – This work is the first in the literature to simulate the MSF demister using CFD modeling. This work is part of a group effort to develop a comprehensive CFD simulation for the entire flashing stage of the MSF process, which would provide an extremely efficient and inexpensive design and simulation tool to the desalination community.

scholarly journals Hemodynamics Study of Different Take-Off Angles of the Left Coronary Artery

2017 ◽  
Author(s):  
John J. Asiruwa ◽  
Aaron M. Propst ◽  
Stephen P. Gent
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Coronary Artery ◽  
Coronary Arteries ◽  
Aortic Root ◽  
Blood Circulation ◽  
Left Coronary Artery ◽  
Left Main ◽  
Computational Fluid Dynamics Cfd ◽  
The Right

Coronary arteries are located on the surface of the heart and supply oxygenated blood to the myocardium and other components of the heart. The two coronary arteries located above the aortic arch are the Left Coronary Artery (LCA) and Right Coronary Artery (RCA). The LCA branches into the Left Anterior Descending (LAD) and the Left Circumflex (LCx) while the RCA branches into the Right Marginal Artery (RMA) and Post Descending Artery (PDA). The coronary arteries are likened to a complex tube-like structure, and the motion of the heart cause changes in pressure, which allows proper blood circulation during the systolic and diastolic phases [1]. Since it is essential to understand the physiological and hemodynamical behavior of the heart and coronary arteries, numerous studies have been conducted at different artery locations in the heart. Most of the research has focused on the branches between the LAD and LCx, with little or no attention directed towards the take-off angle the LCA makes with the aortic root. Although it has been reported that certain take-off angles of left main (LM) can be considered anomalous, findings have documented that such take off angles can make the artery prone to atherosclerosis and sudanophilia diseases [2]. Computational Fluid Dynamics (CFD) has in recent years been used to solve a wide variety of fluid flow challenges, and can be used for this study. The goal of this study is to use CFD techniques to study the hemodynamics of the different take-off angles of the left coronary artery from the aortic root. This will help identify areas in the left coronary artery that could be prone to atherosclerosis buildup.

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