1018 Evaluation of correlation between blade angle and flow pattern in an open type cross-flow turbine

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.

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Computer Modelling Of Multicomponent Gas Separation By Membranes

Jurnal Teknologi ◽

10.11113/jt.v29.1092 ◽

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.

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Effect of Exit Blade Angle on the Performance of Cross Flow Hydro Turbine: A Numerical Study

10.1115/gtindia2021-76037 ◽

2021 ◽

Author(s):

Nur Alom ◽

Bikash Kumar Sarkar

Keyword(s):

Power Plants ◽

Numerical Study ◽

Cross Flow ◽

Low Flow ◽

Maximum Efficiency ◽

Blade Angle ◽

Hydraulic Power ◽

Ansys Fluent ◽

Low Head ◽

Hydro Turbines

Abstract Cross-flow hydro turbines (CFHTs) are generally used in micro hydraulic power plants due to their simplicity in design and fabrication, moderate efficiency, ease of maintenance. The CFHT can be used in low flow and low head conditions with an efficiency of around 90% at rated conditions. However, the efficiency of the CFHT can further be improved by changing its geometric parameters Hence, in the present investigation, 3D unsteady simulations are performed in order to locate the exit blade angle (β2) with the intention is to improve the efficiency of the turbine. In the proposed investigation, the multi-physics FVM solver ANSYS Fluent has been used with the help of the SST k-ω turbulence model to carry out the unsteady simulations. The 3D unsteady simulations are performed by varying the exit blade angle (β2) from 60° to 90° to improve its efficiency when the rotational speed is fixed with the number of blades being 20. From the unsteady simulations, the maximum efficiency of the CFHT is at the exit blade angle (β2) = 80°.

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Effect of Blade Angle on Performance and Flow Field of an Undershot Cross-Flow Water Turbine with Straight Blades

The Proceedings of Ibaraki District Conference ◽

10.1299/jsmeibaraki.2019.27.307 ◽

2019 ◽

Vol 2019.27 (0) ◽

pp. 307

Author(s):

Mikihiro Shindo ◽

Yasuyuki NISHI ◽

Yuichiro YAHAGI ◽

Ryota SUZUKI ◽

Terumi INAGAKI

Keyword(s):

Flow Field ◽

Cross Flow ◽

Blade Angle ◽

Water Turbine

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

Journal of Hygiene ◽

10.1017/s0022172400023330 ◽

1974 ◽

Vol 72 (2) ◽

pp. 145-153 ◽

Cited By ~ 4

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.

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