scholarly journals Fluid-structure interaction of a pulsatile flow with an aortic valve model: A combined experimental and numerical study

2018 ◽  
Vol 34 (4) ◽  
pp. e2945 ◽  
Author(s):  
Julien Sigüenza ◽  
Desiree Pott ◽  
Simon Mendez ◽  
Simon J. Sonntag ◽  
Tim A.S. Kaufmann ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Pulsatile Flow ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Valve Model

Modeling of aortic valve stenosis using fluid-structure interaction method

Perfusion ◽  
2021 ◽  
pp. 026765912199854
Author(s):  
Mohammad Javad Ghasemi Pour ◽  
Kamran Hassani ◽  
Morteza Khayat ◽  
Shahram Etemadi Haghighi
Keyword(s):  
Blood Flow ◽  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Relaxation Phase ◽  
Exercise Condition ◽  
Time Dependent Domain ◽  
Comparison Of The Results

Background and objectives: Fluid structure interaction (FSI) is defined as interaction of the structures with contacting fluids. The aortic valve experiences the interaction with blood flow in systolic phase. In this study, we have tried to predict the hemodynamics of blood flow through a normal and stenotic aortic valve in two relaxation and exercise conditions using a three-dimensional FSI method. Methods: The aorta valve was modeled as a three-dimensional geometry including a normal model and two others with 25% and 50% stenosis. The geometry of the aortic valve was extracted from CT images and the models were generated by MMIMCS software and then they were implemented in ANSYS software. The pulsatile flow rate was used for all cases and the numerical simulations were conducted based on a time-dependent domain. Results: The obtained results including the velocity, pressure, and shear stress contours in different systolic time sequences were explained and discussed. The maximum blood flow velocity in relaxation phase was obtained 1.62 m/s (normal valve), 3.78 m/s (25% stenosed valve), and 4.73 m/s (50% stenosed valve). In exercise condition, the maximum velocities are 2.86, 4.32, and 5.42 m/s respectively. The maximum blood pressure in relaxation phase was calculated 111.45 mmHg (normal), 148.66 mmHg (25% stenosed), and 164.21 mmHg (50% stenosed). However, the calculated values in exercise situation were 129.57, 163.58, and 191.26 mmHg. The validation of the predicted results was also conducted using existing literature. Conclusions: We believe that such model are useful tools for biomechanical experts. The further studies should be done using experimental data and the data are implemented on the boundary conditions for better comparison of the results.

Computational Modeling of Aortic Stenosis with a Reduced Degree-Of-Freedom Fluid-Structure Interaction Valve Model

2021 ◽  
Author(s):  
Chi Zhu ◽  
Jung-Hee Seo ◽  
Rajat Mittal
Keyword(s):  
Aortic Stenosis ◽  
Pressure Fluctuations ◽  
Fluid Structure Interaction ◽  
Degree Of Freedom ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Deceleration Phase ◽  
Wall Pressure Fluctuations ◽  
Two Parameters ◽  
Valve Model

Abstract In this study, a novel reduced degree-of-freedom (rDOF) aortic valve model is employed to investigate the fluid-structure interaction and hemodynamics associated with aortic stenosis. The dynamics of the valve leaflets are determined by an ordinary differential equation with two parameters and this rDOF model is shown to reproduce key features of more complex valve models. The hemodynamics associated with aortic stenosis is studied for three cases: a healthy case and two stenosed cases. The focus of the study is to correlate the hemodynamic features with the source generation mechanism of systolic murmurs associated with aortic stenosis. In the healthy case, extremely weak flow fluctuations are observed. However, in the stenosed cases, simulations show significant turbulent fluctuations in the asending aorta, which are responsible for the generation of strong wall pressure fluctuations after the aortic root mostly during the deceleration phase of the systole. The intensity of the murmur generation increases with the severity of the stenosis, and the source locations for the two diseased cases studied here lies around 1.0 inlet duct diameters ($D_o$) downstream of the ascending aorta.

Fluid-structure interaction computational analysis and experiments of tsunami bore forces on coastal bridges

2021 ◽  
Vol 31 (5) ◽  
pp. 1373-1395
Author(s):  
Iman Mazinani ◽  
Mohammad Mohsen Sarafraz ◽  
Zubaidah Ismail ◽  
Ahmad Mustafa Hashim ◽  
Mohammad Reza Safaei ◽  
...  
Keyword(s):  
Tsunami Wave ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Indian Ocean Tsunami ◽  
Fluid Structure ◽  
Content Type ◽  
Coastal Bridges ◽  
Structure Interaction ◽  
Wave Flume ◽  
Wave Heights

Purpose Two disastrous Tsunamis, one on the west coast of Sumatra Island, Indonesia, in 2004 and another in North East Japan in 2011, had seriously destroyed a large number of bridges. Thus, experimental tests in a wave flume and a fluid structure interaction (FSI) analysis were constructed to gain insight into tsunami bore force on coastal bridges. Design/methodology/approach Various wave heights and shallow water were used in the experiments and computational process. A 1:40 scaled concrete bridge model was placed in mild beach profile similar to a 24 × 1.5 × 2 m wave flume for the experimental investigation. An Arbitrary Lagrange Euler formulation for the propagation of tsunami solitary and bore waves by an FSI package of LS-DYNA on high-performance computing system was used to evaluate the experimental results. Findings The excellent agreement between experiments and computational simulation is shown in results. The results showed that the fully coupled FSI models could capture the tsunami wave force accurately for all ranges of wave heights and shallow depths. The effects of the overturning moment, horizontal, uplift and impact forces on a pier and deck of the bridge were evaluated in this research. Originality/value Photos and videos captured during the Indian Ocean tsunami in 2004 and the 2011 Japan tsunami showed solitary tsunami waves breaking offshore, along with an extremely turbulent tsunami-induced bore propagating toward shore with significantly higher velocity. Consequently, the outcomes of this current experimental and numerical study are highly relevant to the evaluation of tsunami bore forces on the coastal, over sea or river bridges. These experiments assessed tsunami wave forces on deck pier showing the complete response of the coastal bridge over water.

Numerical study of active control by piezoelectric materials for fluid–structure interaction problems

2018 ◽  
Vol 435 ◽  
pp. 23-35 ◽  
Author(s):  
Shigeki Kaneko ◽  
Giwon Hong ◽  
Naoto Mitsume ◽  
Tomonori Yamada ◽  
Shinobu Yoshimura
Keyword(s):  
Active Control ◽  
Numerical Study ◽  
Piezoelectric Materials ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction

scholarly journals Validation and Extension of a Fluid–Structure Interaction Model of the Healthy Aortic Valve

2018 ◽  
Vol 9 (4) ◽  
pp. 739-751 ◽  
Author(s):  
Anna Maria Tango ◽  
Jacob Salmonsmith ◽  
Andrea Ducci ◽  
Gaetano Burriesci
Keyword(s):  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Fluid Structure ◽  
Structure Interaction
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