Numerical evaluation of blood viscosity affecting pulse wave propagation in a fluid-structure interaction model

2015 ◽  
Vol 60 (1) ◽  
Author(s):  
Fan He ◽  
Lu Hua ◽  
Li-jian Gao
Keyword(s):  
Wave Propagation ◽  
Blood Viscosity ◽  
Pulse Wave ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Pulse Wave Propagation ◽  
Fluid Structure ◽  
Velocity Amplitude ◽  
Structure Interaction ◽  
Wave Characteristics

AbstractHigh blood viscosity often causes cardiovascular diseases, such as hypertension, atherosclerosis and thrombosis. It is proven that blood viscosity plays an important role in cardiovascular functions. In this paper, pulse wave characteristics with normal and high blood viscosities are presented in detail to evaluate how blood viscosity affects pulse wave propagation. A fluid-structure interaction is employed to solve for pulse wave characteristics. The results show that increased blood viscosity does not change the time delay of wave propagation. However, high viscosity reduces the velocity amplitude, while it enhances the pressure level. This study provides physical insight for evaluating blood viscosity leading potentially to pulse wave changes.

WALL SHEAR STRESSES IN A FLUID–STRUCTURE INTERACTION MODEL OF PULSE WAVE PROPAGATION

2014 ◽  
Vol 14 (02) ◽  
pp. 1450019 ◽  
Author(s):  
FAN HE
Keyword(s):  
Wave Propagation ◽  
Pulse Wave ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Elastic Tube ◽  
Tube Model ◽  
Pulse Wave Propagation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Internal Radius

In our prior paper, a fluid–structure interaction model of pulse wave propagation, called the elastic tube model, has been developed. The focus of this paper is wall shear stress (WSS) in this model and the effects of different parameters, including rigid walls, wall thickness, and internal radius. The unsteady flow was assumed to be laminar, Newtonian and incompressible, and the vessel wall to be linear-elastic isotropic, and incompressible. A fluid–structure interaction scheme is constructed using a finite element method. The results demonstrate the elastic tube plays an important role in WSS distributions of wave propagation. It is shown that there is a time delay between the WSS waveforms at different locations in the elastic tube model while the time delay cannot be observed clearly in the rigid tube model. Compared with the elastic tube model, the increase of the wall thickness makes disturbed WSS distributions, however WSS values are increased greatly due to the decrease of the internal radius. The results indicate that the effects of different parameters on WSS distributions are significant. The proposed model gives valid results.

scholarly journals Modeling Pulse Wave Propagation Through a Stenotic Artery With Fluid Structure Interaction: A Validation Study Using Ultrasound Pulse Wave Imaging

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Vittorio Gatti ◽  
Pierre Nauleau ◽  
Grigorios M. Karageorgos ◽  
Jay J. Shim ◽  
Gerard A. Ateshian ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wave Propagation ◽  
Arterial Wall ◽  
Pulse Wave ◽  
Fluid Structure Interaction ◽  
Clinical Findings ◽  
Pulse Wave Propagation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Wave Imaging

Abstract Pulse wave imaging (PWI) is an ultrasound-based method that allows spatiotemporal mapping of the arterial pulse wave propagation, from which the local pulse wave velocity (PWV) can be derived. Recent reports indicate that PWI can help the assessment of atherosclerotic plaque composition and mechanical properties. However, the effect of the atherosclerotic plaque's geometry and mechanics on the arterial wall distension and local PWV remains unclear. In this study, we investigated the accuracy of a finite element (FE) fluid–structure interaction (FSI) approach to predict the velocity of a pulse wave propagating through a stenotic artery with an asymmetrical plaque, as quantified with PWI method. Experiments were designed to compare FE-FSI modeling of the pulse wave propagation through a stenotic artery against PWI obtained with manufactured phantom arteries made of polyvinyl alcohol (PVA) material. FSI-generated spatiotemporal maps were used to estimate PWV at the plaque region and compared it to the experimental results. Velocity of the pulse wave propagation and magnitude of the wall distension were correctly predicted with the FE analysis. In addition, findings indicate that a plaque with a high degree of stenosis (>70%) attenuates the propagation of the pulse pressure wave. Results of this study support the validity of the FE-FSI methods to investigate the effect of arterial wall structural and mechanical properties on the pulse wave propagation. This modeling method can help to guide the optimization of PWI to characterize plaque properties and substantiate clinical findings.

scholarly journals Numerical Investigation of Pulse Wave Propagation in Arteries Using Fluid Structure Interaction Capabilities

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Hisham Elkenani ◽  
Essam Al-Bahkali ◽  
Mhamed Souli
Keyword(s):  
Wave Propagation ◽  
Pulse Wave ◽  
Regression Line ◽  
Computing Time ◽  
Fluid Structure Interaction ◽  
Elastic Tube ◽  
Contour Plot ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Constitutive Material Model

The aim of this study is to present a reliable computational scheme to serve in pulse wave velocity (PWV) assessment in large arteries. Clinicians considered it as an indication of human blood vessels’ stiffness. The simulation of PWV was conducted using a 3D elastic tube representing an artery. The constitutive material model specific for vascular applications was applied to the tube material. The fluid was defined with an equation of state representing the blood material. The onset of a velocity pulse was applied at the tube inlet to produce wave propagation. The Coupled Eulerian-Lagrangian (CEL) modeling technique with fluid structure interaction (FSI) was implemented. The scaling of sound speed and its effect on results and computing time is discussed and concluded that a value of 60 m/s was suitable for simulating vascular biomechanical problems. Two methods were used: foot-to-foot measurement of velocity waveforms and slope of the regression line of the wall radial deflection wave peaks throughout a contour plot. Both methods showed coincident results. Results were approximately 6% less than those calculated from the Moens-Korteweg equation. The proposed method was able to describe the increase in the stiffness of the walls of large human arteries via the PWV estimates.

An Investigation of the Aerodynamic and Vibration Behavior of a Helicopter Rotor Blade

2020 ◽  
Author(s):  
Mohammad Khairul Habib Pulok ◽  
Uttam K. Chakravarty
Keyword(s):  
Rotor Blade ◽  
Fluid Structure Interaction ◽  
Interaction Model ◽  
Scale Model ◽  
Helicopter Rotor ◽  
Small Scale ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerodynamic Analysis ◽  
Helicopter Rotor Blade

Abstract Rotary-wing aircrafts are the best-suited option in many cases for its vertical take-off and landing capacity, especially in any congested area, where a fixed-wing aircraft cannot perform. Rotor aerodynamic loading is the major reason behind helicopter vibration, therefore, determining the aerodynamic loadings are important. Coupling among aerodynamics and structural dynamics is involved in rotor blade design where the unsteady aerodynamic analysis is also imperative. In this study, a Bo 105 helicopter rotor blade is considered for computational aerodynamic analysis. A fluid-structure interaction model of the rotor blade with surrounding air is considered where the finite element model of the blade is coupled with the computational fluid dynamics model of the surrounding air. Aerodynamic coefficients, velocity profiles, and pressure profiles are analyzed from the fluid-structure interaction model. The resonance frequencies and mode shapes are also obtained by the computational method. A small-scale model of the rotor blade is manufactured, and experimental analysis of similar contemplation is conducted for the validation of the numerical results. Wind tunnel and vibration testing arrangements are used for the experimental validation of the aerodynamic and vibration characteristics by the small-scale rotor blade. The computational results show that the aerodynamic properties of the rotor blade vary with the change of angle of attack and natural frequency changes with mode number.

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