10. Physiological Fluid Dynamics: A General Survey

1975 ◽  
pp. 199-209
1972 ◽  
Vol 52 (3) ◽  
pp. 475-497 ◽  
Author(s):  
M. J. Lighthill

Section 1 is in the nature of a general survey of fluid flows within the human body : including the lungs (airflow in the airways and the special characteristics of the pulmonary blood circulation), the general systemic circulation of the blood, and the urinary tract. Problems of the microcirculation, including blood flow in the narrower capillaries, gas exchange with the terminal airways (alveoli), and exchange of gas and nutrients with peripheral tissue, are treated in the more specialized second section, which describes in some detail modern views concerning peripheral resistance.


Author(s):  
Jiafeng Zhang ◽  
Pei Zhang ◽  
Kate Fraser ◽  
Bartley P. Griffith ◽  
Zhongjun J. Wu

Heart disease affects millions of people each year. However, only a limited number of people benefit from a heart transplant due to the scarce supply of donor hearts. Ventricular assist devices (VADs) provide an alternative way to augment or replace the function of one or more chambers of a failing heart. Fluid dynamics in these devices plays a key role in their function and blood biocompatibility. Although current devices are more biocompatible than their forerunners, they still cause blood damage, such as hemolysis, platelet activation, thrombosis and embolization, which may result in serious clinical events and are directly related to fluid dynamics and artificial materials of these devices. Significant research efforts have been devoted to studying the device-blood interactions and minimizing these non-physiological fluid dynamic conditions to improve the functional characteristics and bio/hemo-compatibility of these medical devices.


Author(s):  
Carlo Conti ◽  
Umberto Morbiducci ◽  
Matteo Nobili ◽  
Giuseppe Passoni ◽  
Costantino Del Gaudio ◽  
...  

Clinical reports indicate that mechanical heart valves are still unable to eliminate problems mainly related to a non physiological fluid dynamics like thrombosis and coagulation complications [1]. Advanced experimental technique such as laser doppler anemometry (LDA) and particle image velocimetry (PIV), used to investigate the fluid dynamics of these devices, suffer from some intrinsic limitations (eg. access difficulties, light reflection, low resolution) [2]. In parallel with the increased performance at computing, the use of computational fluid dynamics has gained relevance as a powerful tool able to provide meaningful information of clinical and design aspects [3]. Key parameters in the assessment of blood damage potency (velocity patterns and turbulence, among them) are related to the behaviour of the valve in the flow field. The application of fluid structure interaction (FSI) models moves in the direction of greater accuracy in the reproduction of realistic flow condition in order to reach more in-depth insight into the hemodynamic of the virtual prototypes. The aim of this study is the investigation, in silico, of the bileaflet mechanical valve dynamics during the whole systolic phase. A 3D direct numerical simulation (DNS) was performed and an implicit fluid structure interaction model was used [4,5]. The results of the dynamics of the valve were validated with an experimental counterpart.


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