Study of Rivulet Flow Through Small Channels

2022 ◽  
pp. 359-366
Author(s):  
Zoheib Tufail Khan ◽  
Mohammad Saud Afzal
Keyword(s):  
Rivulet Flow ◽  
Flow Through ◽  
Small Channels

scholarly journals Spurious Current Suppression in VOF-CSF Simulation of Slug Flow through Small Channels

2014 ◽  
Vol 67 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Zhenhai Pan ◽  
Justin A. Weibel ◽  
Suresh V. Garimella
Keyword(s):  
Slug Flow ◽  
Flow Through ◽  
Small Channels

Scaling Roughness Effects on Pressure Loss and Heat Transfer of Additively Manufactured Channels

2016 ◽  
Author(s):  
Curtis K. Stimpson ◽  
Jacob C. Snyder ◽  
Karen A. Thole ◽  
Dominic Mongillo
Keyword(s):  
Heat Transfer ◽  
Metal Powder ◽  
Pressure Loss ◽  
Complex Flow ◽  
Roughness Effects ◽  
Flow Paths ◽  
Flow And Heat Transfer ◽  
Flow Through ◽  
High Temperature Components ◽  
Small Channels

Additive manufacturing (AM) with metal powder has made possible the fabrication of gas turbine components with small and complex flow paths that cannot be achieved with any other manufacturing technology presently available. The increased design space of AM allows turbine designers to develop advanced cooling schemes in high temperature components to increase cooling efficiency. Inherent in AM with metals is the large surface roughness that cannot be removed from small internal geometries. Such roughness has been shown in previous studies to significantly augment pressure loss and heat transfer of small channels. However, the roughness on these channels or other surfaces made from AM with metal powder has not been thoroughly characterized for scaling pressure loss and heat transfer data. This study examines the roughness of the surfaces of channels of various hydraulic length scales made with direct metal laser sintering (DMLS). Statistical roughness parameters are presented along with other parameters that others have found to correlate with flow and heat transfer. The pressure loss and heat transfer previously reported for the DMLS channels studied in this work are compared to the physical roughness measurements. Results show that the relative arithmetic mean roughness correlates well with the relative equivalent sand grain roughness. A correlation is presented to predict the Nusselt number of flow through AM channels which gives better predictions of heat transfer than correlations currently available.

Scaling Roughness Effects on Pressure Loss and Heat Transfer of Additively Manufactured Channels

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Curtis K. Stimpson ◽  
Jacob C. Snyder ◽  
Karen A. Thole ◽  
Dominic Mongillo
Keyword(s):  
Heat Transfer ◽  
Metal Powder ◽  
Pressure Loss ◽  
Complex Flow ◽  
Roughness Effects ◽  
Flow Paths ◽  
Flow And Heat Transfer ◽  
Flow Through ◽  
High Temperature Components ◽  
Small Channels

Additive manufacturing (AM) with metal powder has made possible the fabrication of gas turbine components with small and complex flow paths that cannot be achieved with any other manufacturing technology presently available. The increased design space of AM allows turbine designers to develop advanced cooling schemes in high-temperature components to increase cooling efficiency. Inherent in AM with metals is the large surface roughness that cannot be removed from small internal geometries. Such roughness has been shown in previous studies to significantly augment pressure loss and heat transfer of small channels. However, the roughness on these channels or other surfaces made from AM with metal powder has not been thoroughly characterized for scaling pressure loss and heat transfer data. This study examines the roughness of the surfaces of channels of various hydraulic length scales made with direct metal laser sintering (DMLS). Statistical roughness parameters are presented along with other parameters that others have found to correlate with flow and heat transfer. The pressure loss and heat transfer previously reported for the DMLS channels studied in this work are compared to the physical roughness measurements. Results show that the relative arithmetic mean roughness correlates well with the relative equivalent sand grain roughness. A correlation is presented to predict the Nusselt number of flow through AM channels, which gives better predictions of heat transfer than correlations currently available.

scholarly journals Flow Through Very Small Channels

Nature ◽  
1946 ◽  
Vol 157 (3975) ◽  
pp. 24-24 ◽  
Author(s):  
J. REEKIE
Keyword(s):  
Flow Through ◽  
Small Channels

Flow Through Very Small Channels

Nature ◽  
1946 ◽  
Vol 157 (3975) ◽  
pp. 24-24
Author(s):  
O. P. SCARFF
Keyword(s):  
Flow Through ◽  
Small Channels

scholarly journals A computational study of trajectories of micro- and nano-particles with different shapes in flow through small channels

2014 ◽  
Vol 8 (2) ◽  
pp. 14-28 ◽  
Author(s):  
V. Isailović ◽  
M. Kojić ◽  
M. Milošević ◽  
N. Filipović ◽  
N. Kojić ◽  
...  
Keyword(s):  
Computational Study ◽  
Nano Particles ◽  
Flow Through ◽  
Different Shapes ◽  
Small Channels

Complex Biological Fluid Flow Through Microfabricated Polysilicon Microneedles

2000 ◽  
Author(s):  
Jeffrey D. Zahn ◽  
Dorian Liepmann
Keyword(s):  
Fluid Flow ◽  
Biological Fluid ◽  
Biological Fluids ◽  
Sample Extraction ◽  
Flow Through ◽  
Complex Features ◽  
Small Channels ◽  
Biological Solutions ◽  
Phosphate Buffered Saline ◽  
Fahraeus Effect

Abstract Microneedles can be used for sample extraction or injection for biomedical applications. It is important to understand how complex biological fluids behave within the needles because non-newtonian effects are associated with fluid flow of concentrated biological solutions. Different concentrations of sheep blood diluted with phosphate buffered saline (PBS) were investigated in different planar needle geometries. Only slight shear thinning behavior was observed, and only slight changes in apparent viscosity were recorded even at higher hematocrit levels. This is hypothesized to be a result of the Fahraeus effect in which cells are excluded from the wall regions in small channels. Microneedles with complex features clogged easily whereas needles with larger hydraulic radii allowed higher concentrations of blood to flow through them. However, at higher hematocrit levels (>25%) even the lower resistance needle clogged. Further investigations are needed to correlate how geometry affects flow of complex cellular suspensions.

Development of apical pits in chloride cells of the gills of Pimephales promelas after chronic exposure to acid water

1983 ◽  
Vol 41 ◽  
pp. 462-463
Author(s):  
Richard L. Leino ◽  
Jon G. Anderson ◽  
J. Howard McCormick
Keyword(s):  
Confidence Interval ◽  
Chronic Exposure ◽  
Lake Superior ◽  
Pimephales Promelas ◽  
Chloride Cells ◽  
Fathead Minnows ◽  
Secondary Lamellae ◽  
Untreated Water ◽  
Water Ph ◽  
Flow Through

Groups of 12 fathead minnows were exposed for 129 days to Lake Superior water acidified (pH 5.0, 5.5, 6.0 or 6.5) with reagent grade H2SO4 by means of a multichannel toxicant system for flow-through bioassays. Untreated water (pH 7.5) had the following properties: hardness 45.3 ± 0.3 (95% confidence interval) mg/1 as CaCO3; alkalinity 42.6 ± 0.2 mg/1; Cl- 0.03 meq/1; Na+ 0.05 meq/1; K+ 0.01 meq/1; Ca2+ 0.68 meq/1; Mg2+ 0.26 meq/1; dissolved O2 5.8 ± 0.3 mg/1; free CO2 3.2 ± 0.4 mg/1; T= 24.3 ± 0.1°C. The 1st, 2nd and 3rd gills were subsequently processed for LM (methacrylate), TEM and SEM respectively.Three changes involving chloride cells were correlated with increasing acidity: 1) the appearance of apical pits (figs. 2,5 as compared to figs. 1, 3,4) in chloride cells (about 22% of the chloride cells had pits at pH 5.0); 2) increases in their numbers and 3) increases in the % of these cells in the epithelium of the secondary lamellae.

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