Simulation of low-Re pulsatile flow through bare 5 x 5 square arrayed rod bundles

2020 ◽  
Vol 129 ◽  
pp. 103487
Author(s):  
Ayodeji A. Ala ◽  
Sichao Tan ◽  
Abdelgadir Eltayeb ◽  
Thompson Appah
Keyword(s):  
Pulsatile Flow ◽  
Rod Bundles ◽  
Flow Through

Fluid Particle Motion and Lagrangian Velocities for Pulsatile Flow Through a Femoral Artery Branch Model

1987 ◽  
Vol 109 (1) ◽  
pp. 94-101 ◽  
Author(s):  
M. R. Back ◽  
Y. I. Cho ◽  
D. W. Crawford ◽  
L. H. Back
Keyword(s):  
Femoral Artery ◽  
Flow Separation ◽  
Pulsatile Flow ◽  
Reverse Flow ◽  
Branch Model ◽  
Flow Features ◽  
Flow Phase ◽  
Flow Through ◽  
Artery Flow ◽  
Artery Branch

A flow visualization study using selective dye injection and frame by frame analysis of a movie provided qualitative and quantitative data on the motion of marked fluid particles in a 60 degree artery branch model for simulation of physiological femoral artery flow. Physical flow features observed included jetting of the branch flow into the main lumen during the brief reverse flow period, flow separation along the main lumen wall during the near zero flow phase of diastole when the core flow was in the downstream direction, and inference of flow separation conditions along the wall opposite the branch later in systole at higher branch flow ratios. There were many similarities between dye particle motions in pulsatile flow and the comparative steady flow observations.

Experimental study of transient friction characteristics and velocity distribution of pulsatile flow in rod bundles

2020 ◽  
Vol 140 ◽  
pp. 107124 ◽  
Author(s):  
Xing Li ◽  
Peiyao Qi ◽  
Sichao Tan ◽  
Dongyang Li ◽  
Yitung Chen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Velocity Distribution ◽  
Pulsatile Flow ◽  
Rod Bundles ◽  
Friction Characteristics

Turbulent Flow Through Spacer Grids in Rod Bundles

1998 ◽  
Vol 120 (4) ◽  
pp. 786-791 ◽  
Author(s):  
Sun Kyu Yang ◽  
Moon Ki Chung
Keyword(s):  
Turbulent Flow ◽  
Laser Doppler Velocimetry ◽  
Hydraulic Characteristics ◽  
Rod Bundles ◽  
Spacer Grid ◽  
Spacer Grids ◽  
Rod Bundle ◽  
Turbulence Decay ◽  
Skewness Factor ◽  
Flow Through

The effects of the spacer grids with mixing vanes in rod bundles on the turbulent structure were investigated experimentally. The detailed hydraulic characteristics in subchannels of a 5 × 5 rod bundle with mixing spacer grids were measured upstream and downstream of the spacer grid by using a one component LDV (Laser Doppler Velocimetry). Axial velocity and turbulent intensity, skewness factor, and flatness factor were measured. The turbulence decay behind spacer grids was obtained from measured data. The trend of turbulence decay behaves in a similar way as turbulent flow through mesh grids or screens. Pressure drop measurements were also performed to evaluate the loss coefficient for the spacer grid and the friction factor for a rod bundle.

Highly resolved pulsatile flows through prosthetic heart valves using the entropic lattice-Boltzmann method

2014 ◽  
Vol 754 ◽  
pp. 122-160 ◽  
Author(s):  
B. Min Yun ◽  
L. P. Dasi ◽  
C. K. Aidun ◽  
A. P. Yoganathan
Keyword(s):  
Lattice Boltzmann Method ◽  
Pulsatile Flow ◽  
Lattice Boltzmann ◽  
Heart Valves ◽  
Prosthetic Heart Valves ◽  
Spatiotemporal Resolution ◽  
Jude Medical ◽  
High Spatiotemporal Resolution ◽  
Flow Through ◽  
Boltzmann Method

AbstractProsthetic heart valves have been widely used to replace diseased or defective native heart valves. Flow through bileaflet mechanical heart valves (BMHVs) have previously demonstrated complex phenomena in the vicinity of the valve owing to the presence of two rigid leaflets. This study aims to accurately capture the complex flow dynamics for pulsatile flow through a 23 mm St Jude Medical (SJM) Regent™ BMHV. The lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through the valve with the inclusion of reverse leakage flow at very high spatiotemporal resolution that can capture fine details in the pulsatile BMHV flow field. For higher-Reynolds-number flows, this high spatiotemporal resolution captures features that have not been observed in previous coarse resolution studies. In addition, the simulations are able to capture with detail the features of leaflet closing and the asymmetric b-datum leakage jet during mid-diastole. Novel flow physics are visualized and discussed along with quantification of turbulent features of this flow, which is made possible by this parallelized numerical method.

Three-dimensional pulsatile flow through a bifurcation

2002 ◽  
Author(s):  
Chain-Nan Yung ◽  
K.J. DeWitt ◽  
S. Subramanian ◽  
A.A. Afjeh ◽  
T.G. Keith
Keyword(s):  
Pulsatile Flow ◽  
Three Dimensional ◽  
Flow Through
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