scholarly journals Inhalation Induced Stresses and Flow Characteristics in Human Airways through Fluid-Structure Interaction Analysis

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Kittisak Koombua ◽  
Ramana M. Pidaparti
Keyword(s):  
Computational Model ◽  
Interaction Analysis ◽  
Airway Remodeling ◽  
Fluid Structure Interaction ◽  
Flow Characteristics ◽  
Fluid Structure ◽  
Tissue Properties ◽  
Structure Interaction ◽  
Simulation Results ◽  
Human Airways

Better understanding of stresses and flow characteristics in the human airways is very important for many clinical applications such as aerosol drug therapy, inhalation toxicology, and airway remodeling process. The bifurcation geometry of airway generations 3 to 5 based on the ICRP tracheobronchial model was chosen to analyze the flow characteristics and stresses during inhalation. A computational model was developed to investigate the airway tissue flexibility effect on stresses and flow characteristics in the airways. The finite-element method with the fluid-structure interaction analysis was employed to investigate the transient responses of the flow characteristics and stresses in the airways during inhalation. The simulation results showed that tissue flexibility affected the maximum airflow velocity, airway pressure, and wall shear stress about 2%, 7%, and 6%, respectively. The simulation results also showed that the differences between the orthotropic and isotropic material models on the airway stresses were in the ranges of 25–52%. The results from the present study suggest that it is very important to incorporate the orthotropic tissue properties into a computational model for studying flow characteristics and stresses in the airways.

scholarly journals FLUID-STRUCTURE INTERACTION ANALYSIS APPLIED TO OIL CONTAINMENT BOOMS

2005 ◽  
Vol 2005 (1) ◽  
pp. 585-588 ◽  
Author(s):  
Azin Amini ◽  
Maziar Mahzari ◽  
Erik Bollaert ◽  
Anton Schleiss
Keyword(s):  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Flow Characteristics ◽  
Two Phase ◽  
Ongoing Research ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Oil Slick ◽  
Flexible Barrier ◽  
Waves And Currents

ABSTRACT The most important aspect of the ongoing research project is to develop numerical coupled hydraulic-structural analysis models of oil containment booms. This should be later applicable for investigation of the efficiency limits of a new system of oil spill containment booms called Cavalli system. This system consists of surrounding the oil slick with a special boom and protecting it against waves and currents. It provides the possibility to divide the encircled area in several smaller circles and to increase the thickness of the oil slick inside. The whole system consists of a two-phase fluid (oil and water) and a boom that should be structurally stable for the pressure loads imposed by the fluids. It is finally important to evaluate the behaviour of the flexible skirt under different wave and current conditions, as almost all of existing research in the field have been undertaken for rigid barriers. To assess the behaviour of a flexible barrier fluid-structure interaction analysis is to be conducted. The problem is considered as a fluid-structure interaction problem as the boom usually undergoes large deformations and rotations, which modifies the flow characteristics during operation that is not the case for a rigid boom.

scholarly journals Fluid-structure interaction analysis of eccentricity and leaflet rigidity on thrombosis biomarkers in bioprosthetic aortic valve replacements

2022 ◽  
Author(s):  
David Oks ◽  
Mariano Vazquez ◽  
Guillaume Houzeaux ◽  
Constantine Butakoff ◽  
Cristobal Samaniego
Keyword(s):  
Aortic Valve ◽  
Computational Model ◽  
High Performance ◽  
Interaction Analysis ◽  
Thrombus Formation ◽  
Fluid Structure Interaction ◽  
Simulation Software ◽  
Fluid Structure ◽  
Structure Interaction

This work introduces the first 2-way fluid-structure interaction (FSI) computational model to study the effect of aortic annulus eccentricity on the performance and thrombogenic risk of cardiac bioprostheses. The model predicts that increasing eccentricities yield lower geometric orifice areas (GOAs) and higher normalized transvalvular pressure gradients (TPGs) for healthy cardiac outputs during systole, agreeing with in vitro experiments. Regions with peak values of residence time and shear rate are observed to grow with eccentricity in the sinus of Valsalva, indicating an elevated risk of thrombus formation for eccentric configurations. In addition, the computational model is used to analyze the effect of varying leaflet rigidity on both performance, thrombogenic and calcification risks with applications to tissue-engineered prostheses, observing an increase in systolic and diastolic TPGs, and decrease in systolic GOA, which translates to decreased valve performance for more rigid leaflets. An increased thrombogenic risk is detected for the most rigid valves. Peak solid stresses are also analyzed, and observed to increase with rigidity, elevating risk of valve calcification and structural failure. The immersed FSI method was implemented in a high-performance computing multi-physics simulation software, and validated against a well known FSI benchmark. The aortic valve bioprosthesis model is qualitatively contrasted against experimental data, showing good agreement in closed and open states. To the authors' knowledge this is the first computational FSI model to study the effect of eccentricity or leaflet rigidity on thrombogenic biomarkers, providing a novel tool to aid device manufacturers and clinical practitioners.

scholarly journals Fluid-Structure Interaction Analysis on Membrane Behavior of a Microfluidic Passive Valve

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 300 ◽  
Author(s):  
Zhen-hao Lin ◽  
Xiao-juan Li ◽  
Zhi-jiang Jin ◽  
Jin-yuan Qian
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Flow Characteristics ◽  
Microfluidic System ◽  
Membrane Behavior ◽  
Fluid Structure ◽  
Constant Flow Rate ◽  
Structure Interaction

In this paper, the effect of membrane features on flow characteristics in the microfluidic passive valve (MPV) and the membrane behavior against fluid flow are studied using the fluid-structure interaction (FSI) analysis. Firstly, the microvalve model with different numbers of microholes and pitches of microholes are designed to investigate the flow rate of the MPV. The result shows that the number of microholes on the membrane has a significant impact on the flow rate of the MPV, while the pitch of microholes has little effect on it. The constant flow rate maintained by the microvalve (the number of microholes n = 4) is 5.75 mL/min, and the threshold pressure to achieve the flow rate is 4 kPa. Secondly, the behavior of the membrane against the fluid flow is analyzed. The result shows that as the inlet pressure increases, the flow resistance of the MPV increases rapidly, and the deformation of the membrane gradually becomes stable. Finally, the effect of the membrane material on the flow rate and the deformation of the membrane are studied. The result shows that changes in the material properties of the membrane cause a decrease in the amount of deformation in all stages the all positions of the membrane. This work may provide valuable guidance for the optimization of microfluidic passive valve in microfluidic system.

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