Evolution of vortical structures in a curved artery model with non-Newtonian blood-analog fluid under pulsatile inflow conditions

2016 ◽  
Vol 57 (6) ◽  
Author(s):  
Mohammad Reza Najjari ◽  
Michael W. Plesniak
Keyword(s):  
Vortical Structures ◽  
Curved Artery ◽  
Inflow Conditions

Experimental Study of Large-Scale Flow Structures in an Aneurysm

2018 ◽  
Author(s):  
Paulo Yu ◽  
Vibhav Durgesh
Keyword(s):  
Large Scale ◽  
Flow Structures ◽  
Pump System ◽  
Vortical Structures ◽  
Abnormal Growth ◽  
Image Velocimetry ◽  
Large Scale Flow ◽  
The Impact ◽  
Inflow Conditions ◽  
Aneurysm Model

An aneurysm is an abnormal growth in the wall of a weakened blood vessel, and can often be fatal upon rupture. Studies have shown that aneurysm shape and hemodynamics, in conjunction with other parameters, play an important role in growth and rupture. The objective of this study was to investigate the impact of varying inflow conditions on flow structures in an aneurysm. An idealized rigid sidewall aneurysm model was prepared and the Womersley number (α) and Reynolds number (Re) values were varied from 2 to 5 and 50 to 250, respectively. A ViVitro Labs pump system was used for inflow control and Particle Image Velocimetry was used for conducting velocity measurements. The results showed that the primary vortex path varied with an increase in α, while an increase in Re was correlated to the vortex strength and formation of secondary vortical structures. The evolution and decay of vortical structures were also observed to be dependent on α and Re.

Three-dimensional vortical structures and wall shear stress in a curved artery model

2019 ◽  
Vol 31 (12) ◽  
pp. 121903 ◽  
Author(s):  
Christopher Cox ◽  
Mohammad Reza Najjari ◽  
Michael W. Plesniak
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Three Dimensional ◽  
Vortical Structures ◽  
Curved Artery ◽  
Wall Shear

DNS of the Flow Near the Endwall in a Linear Low Pressure Turbine Cascade With Periodically Passing Wakes

2014 ◽  
Author(s):  
Denis Koschichow ◽  
Jochen Fröhlich ◽  
Ilker Kirik ◽  
Reinhard Niehuis
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Direct Numerical Simulations ◽  
Experimental Setup ◽  
Turbine Cascade ◽  
Vortical Structures ◽  
Low Pressure Turbine ◽  
Turbulent Inflow ◽  
Inflow Conditions

Direct numerical simulations (DNS) were used to study the effects of periodic incoming wakes on the flow near the endwall in a linear turbine cascade T106. The moving cylindrical bars generating the wakes in the experiment were represented by means of appropriate unsteady turbulent inflow conditions. In the simulations, two cases, with and without incoming wakes, were conducted at a Reynolds number of 90,000 based on chord length and outlet velocity. The results were validated with experimental data. Due to constructive limitations of the experimental setup, the incoming boundary layer is very thin, so that some features of the secondary flow are absent or small. Employing phase-averaging, however, the periodic formation of vortical structures caused by the wakes can be identified in the vicinity of the endwall.

A STUDY OF VORTICAL STRUCTURES PAST THE LOWER PORTION OF THE AHMED CAR MODEL

2012 ◽  
Vol 19 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Giancarlo Alfonsi ◽  
Agostino Lauria ◽  
Leonardo Primavera
Keyword(s):  
Lower Portion ◽  
Vortical Structures ◽  
Car Model
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