Air Ejection in a Porous Pipe with Linear Cross-Flow Pattern

2015 ◽  
pp. 437-466
Keyword(s):  
Flow Pattern ◽  
Cross Flow ◽  
Porous Pipe ◽  
Air Ejection

Influence of Circuitry Arrangement on the Pressure Drops of Two-Row Finned Tube Evaporators

2000 ◽  
Vol 123 (1) ◽  
pp. 100-103 ◽  
Author(s):  
Chi-Chuan Wang ◽  
Min-Sheng Liu ◽  
Jin-Sheng Leu
Keyword(s):  
Pressure Drop ◽  
Flow Pattern ◽  
Cross Flow ◽  
Finned Tube ◽  
Parallel Flow ◽  
Pressure Drops ◽  
Heat Addition ◽  
Side Pressure ◽  
Flow Pattern Transition ◽  
Flow Circuit

This study experimentally investigates the effect of circuitry on the refrigerant-side pressure drops of plate finned tube evaporators. Experiments were performed with countercross, parallel-cross, and z-shape arrangements. The results showed that the parallel-cross-flow circuit gives a lower pressure drop than other arrangements. Generally, the refrigerant-side pressure drops increase with air frontal velocities. However, for G=200 kg/m2s˙s and parallel flow, the pressure drops decrease with increase of air frontal velocity. This unusual characteristic is most likely related to the flow pattern transition when subjected to heat addition.

Computer Modelling Of Multicomponent Gas Separation By Membranes

1998 ◽  
pp. 23-33
Author(s):  
Thomas S.Y Choong ◽  
Ramlan Abdul Aziz ◽  
Hamdani Saidi
Keyword(s):  
Flow Pattern ◽  
Gas Separation ◽  
Computer Modelling ◽  
Cross Flow ◽  
Cocurrent Flow ◽  
Countercurrent Flow ◽  
Feed System ◽  
Membrane Area ◽  
Chemical Process Industry ◽  
Multicomponent Gas

Gas separation using membrane is now an established unit operation in the chemical process industry. The performance of a single stage membrane permeator depends, among other things, on the feed and permeate flow pattern. In this paper, models for five different idealized flow patterns namely cocurrent flow, countercurrent flow, cross flow, perfect mixing and on-side mixing have been presented. A computer program written in Power Basic has also been developed. The models developed can be used for a binary mixture or multi-component gas feed system. A simple bisection method is used instead of the Newton iterative method originally suggested by Shindo et.al.[6] to solve the root finding-problem in order to ensure convergence. In this study countercurrent flow is found to be the most efficient flow pattern, giving the highest degree of separation and requiring the least membrane area.

scholarly journals Bacteriological evaluation of a laminar cross-flow tunnel for surgery under operational conditions

1974 ◽  
Vol 72 (2) ◽  
pp. 145-153 ◽  
Author(s):  
D. van der Waaij ◽  
P. J. Heidt ◽  
W. D. H. Hendriks
Keyword(s):  
Flow Pattern ◽  
Cross Flow ◽  
Surgical Team ◽  
Front Side ◽  
Air Velocity ◽  
Operational Conditions ◽  
Disappearance Time ◽  
Detectable Concentration ◽  
Bacteriological Evaluation ◽  
Stable Flow

SUMMARYA transportable surgery cross-flow unit has been tested under ‘operational conditions’. By the use of artificial aerosols and a volunteer surgical team, or dummies, it was found that, at an air velocity of 0·45 m./sec., a detectable transfer to above the table occurred only when quite highly concentrated aerosols (of more than 103·6 bacteria/m.3 of air or more) existed underneath the table. The short disappearance time under these conditions and the quite stable flow pattern above the table found when a surgical team was working, standing along both sides of the table, make it unlikely that an aerosol of detectable concentration can develop during surgery, at this site. The chance that particles, liberated from the heads of the surgical team, settle on the table, was found to be strongly reduced when a cross-flow tunnel operated at an air velocity of 0·45 m./sec. The transfer from outside the unit to the inside was prevented by closing the upper part of the open front side.

scholarly journals Properties of the flow around two rotating circular cylinders in side-by-side arrangement with different rotation types

2014 ◽  
Vol 18 (5) ◽  
pp. 1487-1492 ◽  
Author(s):  
Cheng-Xu Tu ◽  
Fu-Bin Bao ◽  
Long Huang
Keyword(s):  
Flow Pattern ◽  
Turbulence Intensity ◽  
Rotational Speed ◽  
Cross Flow ◽  
Type A ◽  
Shear Layers ◽  
Circular Cylinders ◽  
Flow Modification ◽  
Gap Flow ◽  
Optimal Value

The field characteristics of two side-by-side rotating circular cylinders in a cross-flow is investigated under different rotation types, at T/D = 1.11,1.6, and 3, respectively (T is the center spacing between the cylinders, and D is the cylinder diameter). A similar flow pattern which is the most efficient to narrow the lowpressure area is identified for rotation type A, independent of T/D ratio, and two typical flow patterns are found under different spacings for rotation type B and type C, respectively. It is confirmed that there is an optimal rotational speed of 1.7-2, under rotation type A to attenuate the vortices, velocity drop, and turbulence intensity tremendously. As rotational speed increases to the optimal value, both the velocity drop and turbulence intensity decrease and their distributions are smooth. The results indicate that the shear layers which are accelerated following the free-stream direction would have significant influence on the flow modification, and different rotation types actually arrange these shear layers in diverse ways to change the flow pattern. Pitch ratio is capable to transform the gap flow, which is usually including the shear layers referred, thus this parameter can modify the wake of the two cylinders at different rotation types.

scholarly journals Flow pattern determination for circular staggered cylinders in cross flow using CFD

2019 ◽  
Vol 5 (4) ◽  
pp. 82-95
Author(s):  
Ajitanshu Vedratnam ◽  
Balendra VS Chauhan ◽  
Virendra Pratap ◽  
Imran Sayyed
Keyword(s):  
Flow Pattern ◽  
Cross Flow ◽  
Pattern Determination
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