Transmitral Flow Analysis by Means of Computational Fluid Dynamics on Unstructured Grids

2020 ◽  
pp. 593-600
Author(s):  
C. Capozzolo ◽  
F. M. Denaro ◽  
F. Sarghini
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Unstructured Grids ◽  
Flow Analysis ◽  
Transmitral Flow

Computed tomography angiography as an adjunct to computational fluid dynamics for prediction of oxygenator thrombus formation

Perfusion ◽  
2020 ◽  
pp. 026765912094410
Author(s):  
Robert G Conway ◽  
Jiafeng Zhang ◽  
Jean Jeudy ◽  
Charles Evans ◽  
Tieluo Li ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computed Tomography ◽  
Computational Fluid Dynamics ◽  
Computed Tomography Angiography ◽  
Thrombus Formation ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Region Of Interest ◽  
Computational Fluid Dynamics Analysis ◽  
Clot Burden

Introduction: Extracorporeal membrane oxygenation circuit performance can be compromised by oxygenator thrombosis. Stagnant blood flow in the oxygenator can increase the risk of thrombus formation. To minimize thrombogenic potential, computational fluid dynamics is frequently applied for identification of stagnant flow conditions. We investigate the use of computed tomography angiography to identify flow patterns associated with thrombus formation. Methods: A computed tomography angiography was performed on a Quadrox D oxygenator, and video densitometric parameters associated with flow stagnation were measured from the acquired videos. Computational fluid dynamics analysis of the same oxygenator was performed to establish computational fluid dynamics–based flow characteristics. Forty-one Quadrox D oxygenators were sectioned following completion of clinical use. Section images were analyzed with software to determine oxygenator clot burden. Linear regression was used to correlate clot burden to computed tomography angiography and computational fluid dynamics–based flow characteristics. Results: Clot burden from the explanted oxygenators demonstrated a well-defined pattern, with the largest clot burden at the corner opposite the blood inlet and outlet. The regression model predicted clot burden by region of interest as a function of time to first opacification on computed tomography angiography (R2 = 0.55). The explanted oxygenator clot burden map agreed well with the computed tomography angiography predicted clot burden map. The computational fluid dynamics parameter of residence time, when summed in the Z-direction, was partially predictive of clot burden (R2 = 0.35). Conclusion: In the studied oxygenator, clot burden follows a pattern consistent with clinical observations. Computed tomography angiography–based flow analysis provides a useful adjunct to computational fluid dynamics–based flow analysis in understanding oxygenator thrombus formation.

Investigation of Air Entrainment: A Numerical Approach

2003 ◽  
Author(s):  
J. T. Kshirsagar ◽  
S. G. Joshi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Vortex Formation ◽  
Flow Analysis ◽  
Air Entrainment ◽  
Numerical Approach ◽  
Test Cases ◽  
Two Phase ◽  
Root Cause ◽  
Model Study

The air entrainment in sumps (Pump Intake) is a commonly observed phenomenon at low water level and high Froude number corresponding to flow rates higher than the rated flow. The air entrainment initiates with the formation of small vortex like structure on the surface with its position varying in the vicinity of Pump intake portion. Normally it calls for two-phase flow analysis (and possibly transient also) to correctly predict the air entrainment phenomenon using computational fluid dynamics approach. We at CRED, Kirloskar Brothers Limited could predict the root cause for air entrainment by studying the vortex formation well within the flow. A single-phase steady state flow was analyzed. Two test cases were studied. IOWA University had published a sump case with results from computational fluid dynamics studies. The other case was the actual sump model study carried out using experimental setup wherein the air entrainment was observed. The paper presents the comparison of the predictions with results from these two test cases.

Air Flow Simulation in High-Pressure Fan with Splitter Blade

2013 ◽  
Vol 805-806 ◽  
pp. 1730-1735
Author(s):  
Xiao Lin Wang ◽  
Ding Hua Yang ◽  
Gen Sheng Yang ◽  
Zhong Li ◽  
Jian Feng Li ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Pressure ◽  
Total Pressure ◽  
Unstructured Grids ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Turbulent Model ◽  
Centrifugal Blower ◽  
The Mean

In the process of fans design, splitter blades could be adopted in the middle of rotator to improve the performance of fan. In order to understand the flow pattern in the high-pressure centrifugal blower of 9-26type with splitter blade thoroughly, computational fluid dynamics Fluent is applied and the three dimensional air flows in the fan is numerically simulated and analyzed. The calculating results showed that under the same condition, the flux of the fan was improved 5%approximately and the mean total pressure at outlet of the fan was improved 10% because of the splitter blade, the length of the splitter blade affected the flux either. Standard turbulent model and unstructured grids are applied in computation. The results of calculation can good helpful for people to improve the performance of the fan.

COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF FABRICATED MICRONOZZLE FOR SUPERSONIC PARTICLE DEPOSITION

2010 ◽  
Vol 17 (01) ◽  
pp. 45-49
Author(s):  
KYUBONG JUNG ◽  
WOOJIN SONG ◽  
DOO-MAN CHUN ◽  
JUN-CHEOL YEO ◽  
MIN-SAENG KIM ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particle Deposition ◽  
Room Temperature ◽  
Flow Analysis ◽  
Dynamics Analysis ◽  
Nanoparticle Deposition ◽  
Computational Fluid Dynamics Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results

A micronozzle was applied in nanoparticle deposition system (NPDS) for supersonic deposition. To determine whether suitable behavior of supersonic fluid can be produced or not, computational fluid dynamics (CFD) flow analysis was used. Ni particles were successfully deposited using the fabricated micronozzle in NPDS at room temperature. It was found that shorter micronozzle with larger side profile deposits wide and thick film compared to the deposition using long micronozzle with smaller side profile. These experimental results agree with the simulation results.

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