scholarly journals Fluid–structure interaction and multi-body contact: Application to aortic valves

2009 ◽  
Vol 198 (45-46) ◽  
pp. 3603-3612 ◽  
Author(s):  
Matteo Astorino ◽  
Jean-Frédéric Gerbeau ◽  
Olivier Pantz ◽  
Karim-Frédéric Traoré
Keyword(s):  
Fluid Structure Interaction ◽  
Aortic Valves ◽  
Fluid Structure ◽  
Body Contact ◽  
Structure Interaction ◽  
Multi Body

Study of Critical Speed for a Flexible Drill String System Based on Fluid–Structure Interaction

2011 ◽  
Vol 105-107 ◽  
pp. 545-552
Author(s):  
Gui Jie Yu ◽  
Lei Fu ◽  
You Cai Yin
Keyword(s):  
Natural Frequency ◽  
Critical Speed ◽  
Fluid Structure Interaction ◽  
Drill String ◽  
Economic Returns ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Practical Engineering ◽  
Hoisting System ◽  
Multi Body

The TDS changed the drive mode and established a simple, flexible multi-body drill string system. The system consists of a derrick, a hoisting system, TDS, and a drill string system, and is inserted into a long, narrow borehole. The drill string then interacts with mud, the borehole wall, and the bottom hole, which generates resonance and increases the risk of drilling accidents. Natural frequency, which is related to the structure of the drill string, determines critical speed. In a vertical well, the transverse, torsional, and longitudinal fluid–structure interaction vibrations of the flexible multi-body drill string system within 1,700 m was analysed using the ANSYS. The natural frequency and the associated critical speed for different bottomhole assemblies (BHAs) were obtained. Results show that reasonably selecting the TDS rotation speed and optimizing BHA offer practical engineering applications for increasing drilling speed, reducing drilling accidents, and improving economic returns.

INVESTIGATION OF LEAFLET GEOMETRY IN A PERCUTANEOUS AORTIC VALVE WITH THE USE OF FLUID-STRUCTURE INTERACTION SIMULATION

2012 ◽  
Vol 12 (01) ◽  
pp. 1250003 ◽  
Author(s):  
K. H. J. VAN ASWEGEN ◽  
A. N. SMUTS ◽  
C. SCHEFFER ◽  
H. S. VH. WEICH ◽  
A. F. DOUBELL
Keyword(s):  
Aortic Valve ◽  
Fluid Structure Interaction ◽  
Von Mises Stress ◽  
Aortic Valves ◽  
Native Valve ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Prosthetic Valves ◽  
Significant Difference ◽  
Von Mises

Prosthetic aortic valves have been used for the replacement of dysfunctional native aortic valves in humans for more than fifty years. Current prosthetic valves have significant limitations and the development of improved aortic valve prostheses remains an important research focus area. This paper investigates one of the newer additions to the family of replacement valves, namely the stented percutaneous valve. An important design aspect of stented percutaneous valves, is the configuration of the leaflet's attachment to the surrounding stent. There are essentially two possible configurations: The first method is attaching the leaflets in a straight configuration, and the second method is to attach the leaflets in a curved configuration. Finite element models of both configurations were created, and the behavior of these configurations was then studied using a fluid-structure interaction (FSI) simulation. The FSI simulation was validated by means of comparing simulation results to actual measurements from a pulse duplicator using prototype valves of both configurations. The FSI results showed no significant difference between the valves' opening and closing behaviors. The von Mises stress distributions proved to be the largest differentiating and decisive factor between the two valves. The FSI simulations did however show that the leaflets that are attached in the straight configuration form folds that resembles that of the curved configuration as well as the native valve, but to a larger scale. The effect that these folds might have on valve tissue fatigue leaves room for future investigation.

Patient-Specific Valve Dynamics Using 3D Fluid-Structure Interaction Modeling: Comparison Between Bicuspid and Tricuspid Aortic Valves

2013 ◽  
Author(s):  
V. Govindarajan ◽  
J. Mousel ◽  
S. C. Vigmostad ◽  
H. S. Udaykumar ◽  
M. M. Levack ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Bicuspid Aortic Valve ◽  
Fluid Structure Interaction ◽  
Geometric Distortion ◽  
Patient Specific ◽  
Endothelial Lining ◽  
Aortic Valves ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Opening Phase

Aortic valve diseases such as congenital bicuspid aortic valve (BAV) and progressive calcification in tricuspid valves affect the hemodynamics in the aortic arch. In addition to leaflet calcification, BAVs are associated with other ailments such as aortic coarctation, aneurysm and dissection [1]. It has also been observed that progressive calcification is accelerated in the case of BAVs compared to normal tricuspid valves. While it is not yet known whether the geometric distortion in BAVs is the main cause of calcification [2] in these valves, the distortion in the leaflets may give rise to altered stresses during the deformation processes which might play a role in accelerating the calcification process in BAVs. In addition, the altered flow caused by the change in geometry could alter the local fluid stresses during the opening phase, which might affect the endothelial lining of the aortic wall. Analyzing and comparing BAV and tricuspid aortic valves as a fluid-structure interaction problem will help determine the stress distribution on the leaflets during opening phase, and enable the examination of altered flow dynamics in the ascending aorta. In this study, the opening phase of a patient-specific bicuspid aortic valve is analyzed at physiological conditions and compared with the opening phase of a tricuspid aortic valve.

Fully Coupled Fluid-Structure Interaction for Offshore Applications

2009 ◽  
Author(s):  
Rajeev K. Jaiman ◽  
Farzin Shakib ◽  
Owen H. Oakley ◽  
Yiannis Constantinides
Keyword(s):  
Mass Density ◽  
Fluid Structure Interaction ◽  
Stability And Convergence ◽  
Iterative Coupling ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Vortex Induced Vibrations ◽  
Low Mass ◽  
Density Ratios ◽  
Multi Body

CAD integrated tools are accelerating product development by incorporating various aspects of physics through coupling with computational aided engineering (CAE) packages. One of the most challenging areas is fluid-structure interaction (FSI) of low mass bodies such as flexible marine risers/cables with vortex-induced vibrations. The focus of this work is on the application of a new Multi-Iterative Coupling (MIC) procedure to couple AcuSolve (fluid solver) with Abaqus (structural solver). The proposed new scheme has superior stability and convergence properties as compared to conventional explicit staggered schemes, especially for low mass-density ratios of structure to fluid. Demonstrations and validation of the scheme are presented and discussed along with additional challenges associated with FSI in production environments. The addition of an FEA solver enables the modeling of the nonlinear aspects of flexible riser VIV, namely, contacts with gaps, multi-body dynamics, seabed interaction, geometric and/or material nonlinearities.

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