Stratified flow distribution during gas–liquid downflow in the mesodomain

2021 ◽  
Vol 33 (11) ◽  
pp. 113317
Author(s):  
Amit Kumar ◽  
Srinivasa Rao Pujari ◽  
Subhabrata Ray ◽  
Gargi Das
Keyword(s):  
Flow Distribution ◽  
Stratified Flow

GAS-LIQUID FLOW DISTRIBUTION UNIFORMITY PARAMETERS IN UPWARD MULTI-PASS COMPACT EVAPORATOR

2016 ◽  
Vol 78 (10-3) ◽  
Author(s):  
Zuradzman Mohamad Razlan ◽  
Hazry Desa ◽  
Shahriman Abu Bakar ◽  
Khairunizam Wan ◽  
Ishak Ibrahim ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Water Distribution ◽  
Flow Distribution ◽  
Stratified Flow ◽  
Air Conditioner ◽  
Air Velocity ◽  
Inlet Condition ◽  
Automobile Air Conditioner ◽  
Distribution Uniformity ◽  
Gas Liquid Flow

The gas-liquid flow distributions in multi-pass upward parallel channels that simulate the evaporator for the automobile air-conditioner system were examined experimentally. In this paper, the attentions are (1) To study the influences of the backpressure condition at the branch outlets and of the flow-inlet condition at the header entrance on the gas-liquid distributions to the branches, (2) To discover the most influenced parameter to the flow distribution uniformity by using design of experiment method. Experiments were conducted in an isothermal air-water flow system. The influence of the backpressure condition on the flow distributions changed depending on the flow-inlet condition. In the stratified-flow inlet, the backpressure condition was highly influential in both the air and water distributions, and the uniform water distribution that was ideal for the evaporators could not be achieved even if air was distributed uniformly to all branches. In the mist-flow inlet, the water distribution was insensitive to the backpressure conditions and its uniformity was improved in comparison with that in the stratified-flow inlet. The flow distribution uniformity for gas phase is influenced mostly by superficial air velocity, and the flow distribution uniformity of liquid phase is mostly influence by 2-way interaction of parameters which are flow pattern and superficial air velocity.

Numerical Analysis of the VAD Outflow Cannula Positioning on the Blood Flow in the Patient–Specific Brain Supplying Arteries

2020 ◽  
Vol 22 (2) ◽  
pp. 619-636 ◽  
Author(s):  
Zbigniew Tyfa ◽  
Damian Obidowski ◽  
Krzysztof Jóźwik
Keyword(s):  
Blood Flow ◽  
Computer Aided Design ◽  
Volume Flow Rate ◽  
Flow Distribution ◽  
Primary Objective ◽  
Patient Specific ◽  
Blood Flow Distribution ◽  
Reconstruction Process ◽  
Outflow Cannula ◽  
The Brain

AbstractThe primary objective of this research can be divided into two separate aspects. The first one was to verify whether own software can be treated as a viable source of data for the Computer Aided Design (CAD) modelling and Computational Fluid Dynamics CFD analysis. The second aspect was to analyze the influence of the Ventricle Assist Device (VAD) outflow cannula positioning on the blood flow distribution in the brain-supplying arteries. Patient-specific model was reconstructed basing on the DICOM image sets obtained with the angiographic Computed Tomography. The reconstruction process was performed in the custom-created software, whereas the outflow cannulas were added in the SolidWorks software. Volumetric meshes were generated in the Ansys Mesher module. The transient boundary conditions enabled simulating several full cardiac cycles. Performed investigations focused mainly on volume flow rate, shear stress and velocity distribution. It was proven that custom-created software enhances the processes of the anatomical objects reconstruction. Developed geometrical files are compatible with CAD and CFD software – they can be easily manipulated and modified. Concerning the numerical simulations, several cases with varied positioning of the VAD outflow cannula were analyzed. Obtained results revealed that the location of the VAD outflow cannula has a slight impact on the blood flow distribution among the brain supplying arteries.

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