Unsteady blood flow through severe stenosis in an artery under the effects of gravitational forces

2015 ◽  
Author(s):  
Yan Bin Tan ◽  
Norzieha Mustapha
Keyword(s):  
Blood Flow ◽  
Severe Stenosis ◽  
Gravitational Forces ◽  
Flow Through ◽  
Unsteady Blood Flow

scholarly journals Numerical and Analytical Study of Two-Layered Unsteady Blood Flow through Catheterized Artery

PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0161377 ◽  
Author(s):  
Akbar Zaman ◽  
Nasir Ali ◽  
M. Sajid ◽  
Tasawar Hayat
Keyword(s):  
Blood Flow ◽  
Analytical Study ◽  
Catheterized Artery ◽  
Flow Through ◽  
Unsteady Blood Flow

NUMERICAL SIMULATION OF SISKO MODEL FOR UNSTEADY BLOOD FLOW THROUGH A VESSEL

2019 ◽  
Vol 16 (1) ◽  
pp. 107-124
Author(s):  
Ida Wahidah ◽  
Sumardi ◽  
Imam Solekhudin ◽  
Lina Aryati
Keyword(s):  
Numerical Simulation ◽  
Blood Flow ◽  
Flow Through ◽  
Unsteady Blood Flow

scholarly journals Case Studies in Physiology: Ventilation and perfusion in a giraffe–does size matter?

2016 ◽  
Vol 121 (6) ◽  
pp. 1374-1378 ◽  
Author(s):  
Görel Nyman ◽  
Bengt Röken ◽  
Eva-Maria Hedin ◽  
Göran Hedenstierna
Keyword(s):  
Blood Flow ◽  
Inert Gas ◽  
Arterial Oxygenation ◽  
Lung Collapse ◽  
Gravitational Forces ◽  
Flow Through ◽  
Lung Blood Flow ◽  
Size Matter ◽  
Ventilation And Perfusion ◽  
Dead Space Ventilation

The trachea in the giraffe is long but narrow, and dead space ventilation is considered to be of approximately the same size as in other mammals. Less is known about the matching between ventilation and lung blood flow. The lungs in the giraffe are large, up to 1 m high and 0.7 m wide, and this may cause considerable ventilation/perfusion (VA/Q) mismatch due to the influence of gravitational forces, which could lead to hypoxemia. We studied a young giraffe under anesthesia using the multiple inert gas elimination technique to analyze the VA/Q distribution and arterial oxygenation and compared the results with those obtained in other species of different sizes, including humans. VA/Q distribution was broad but unimodal, and the shunt of blood flow through nonventilated lung regions was essentially absent, suggesting no lung collapse. The VA/Q match was as good as in the similarly sized horse and was even comparable to that in smaller sized animals, including rabbit and rat. The match was also similar to that in anesthetized humans. Arterial oxygenation was essentially similar in all studied species. The findings suggest that the efficiency of VA/Q matching is independent of lung size in the studied mammals that vary in weight from less than 1 to more than 400 kg.

scholarly journals A Numerical Analysis of Pressure Pulsation Characteristics Induced by Unsteady Blood Flow in a Bileaflet Mechanical Heart Valve

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 232 ◽  
Author(s):  
Xiao-gang Xu ◽  
Tai-yu Liu ◽  
Cheng Li ◽  
Lu Zhu ◽  
Shu-xun Li
Keyword(s):  
Blood Flow ◽  
Heart Valves ◽  
Pressure Pulsation ◽  
Flow Direction ◽  
Mechanical Heart Valve ◽  
Opening Angle ◽  
Trailing Edges ◽  
Main Flow Direction ◽  
Flow Through ◽  
Unsteady Blood Flow

The leaflet vibration phenomenon in bileaflet mechanical heart valves (BMHVs) can cause complications such as hemolysis, leaflet damage, and valve fracture. One of the main reasons for leaflet vibration is the unsteady blood flow pressure pulsation induced by turbulent flow instabilities. In this study, we performed numerical simulations of unsteady flow through a BMHV and observed pressure pulsation characteristics under different flow rates and leaflet fully opening angle conditions. The pressure pulsation coefficient and the low-Reynolds k-ω model in CFD (Computational Fluid Dynamics) software were employed to solve these problems. Results showed that the level of pressure pulsation was highly influenced by velocity distribution, and that the higher coefficient of pressure pulsation was associated with the lower flow velocity along the main flow direction. The influence of pressure pulsation near the trailing edges was much larger than the data obtained near the leading edges of the leaflets. In addition, considering the level of pressure pulsation and the flow uniformity, the recommended setting of leaflet fully opening angle was about 80°.

scholarly journals Numerical Study on Three-Dimensional Unsteady Blood Flow through an Artery with a Small Side Branch.

1999 ◽  
Vol 42 (3) ◽  
pp. 673-679 ◽  
Author(s):  
Masahide NAKAMURA ◽  
Toshinori EBA ◽  
Margot R. ROACH ◽  
Ralph G. KRATKY ◽  
Masahiro OTOMO
Keyword(s):  
Blood Flow ◽  
Numerical Study ◽  
Three Dimensional ◽  
Side Branch ◽  
Flow Through ◽  
Unsteady Blood Flow ◽  
Small Side

scholarly journals Numerical Simulation of Magnetohydrodynamic Influences on Casson Model for Blood Flow through an Overlapping Stenosed Artery

2021 ◽  
pp. 1016-1024
Author(s):  
Ahmed Bakheet ◽  
Esam A. Alnussairy
Keyword(s):  
Blood Flow ◽  
Flow Characteristics ◽  
Correction Method ◽  
Casson Fluid ◽  
Governing Equations ◽  
Finite Difference Technique ◽  
Stenosed Artery ◽  
Flow Phenomena ◽  
Flow Through ◽  
Unsteady Blood Flow

Magnetohydrodynamic (MHD) effects of unsteady blood flow on Casson fluid through an artery with overlapping stenosis were investigated. The nonlinear governing equations accompanied by the appropriate boundary conditions were discretized and solved based on a finite difference technique, using the pressure correction method with MAC algorithm. Moreover, blood flow characteristics, such as the velocity profile, pressure drop, wall shear stress, and patterns of streamlines, are presented graphically and inspected thoroughly for understanding the blood flow phenomena in the stenosed artery.

Sign in / Sign up

Export Citation Format

Share Document