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 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.

scholarly journals High-speed prediction of computational fluid dynamics simulation in crystal growth

CrystEngComm ◽  
2018 ◽  
Vol 20 (41) ◽  
pp. 6546-6550 ◽  
Author(s):  
Yosuke Tsunooka ◽  
Nobuhiko Kokubo ◽  
Goki Hatasa ◽  
Shunta Harada ◽  
Miho Tagawa ◽  
...  
Keyword(s):  
Machine Learning ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Cfd Simulation ◽  
Large Diameter ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
High Quality ◽  
Speed Prediction

The combination of the CFD simulation and machine learning thus makes it possible to determine optimized parameters for high-quality and large-diameter crystals.

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 Computational Fluid Dynamics (CFD) Simulation on Mixing in T-Shaped Micromixer

2020 ◽  
Vol 932 ◽  
pp. 012006
Author(s):  
S N A Ahmad Termizi ◽  
C Y Khor ◽  
M A M Nawi ◽  
Nurlela Ahmad ◽  
Muhammad Ikman Ishak ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Computational Fluid Dynamics Cfd

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

CFD Leakage Predictions of Unworn and Worn Labyrinth Seals With and Without Tooth Axial Offset

2017 ◽  
Author(s):  
Hasham H. Chougule ◽  
Alexander Mirzamoghadam
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Modeling ◽  
Steady State ◽  
Flow Field ◽  
Labyrinth Seals ◽  
Small Clearance ◽  
Total Leakage ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Deflection

The objective of this study is to develop a Computational Fluid Dynamics (CFD) based methodology for analyzing and predicting leakage of worn or rub-intended labyrinth seals during operation. The simulations include intended tooth axial offset and numerical modeling of the flow field. The purpose is to predict total leakage through the seal when an axial tooth offset is provided after the intended/unintended rub. Results indicate that as expected, the leakage for the in-line worn land case (i.e. tooth under rub) is higher compared to unworn. Furthermore, the intended rotor/teeth forward axial offset/shift with respect to the rubbed land reduces the seal leakage. The overall leakage of a rubbed seal with axial tooth offset is observed to be considerably reduced, and it can become even less than a small clearance seal designed not to rub. The reduced leakage during steady state is due to a targeted smaller running gap because of tooth offset under the intended/worn land groove shape, higher blockages, higher turbulence and flow deflection as compared to worn seal model without axial tooth offset.

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