Experimental Studies of a Ludwieg Tube High Reynolds Number Transonic Tunnel

AIAA Journal ◽  
1974 ◽  
Vol 12 (3) ◽  
pp. 267-268 ◽  
Author(s):  
R. F. STARR ◽  
C. J. SCHUELER
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Experimental Studies ◽  
Ludwieg Tube ◽  
High Reynolds

Characterization of dissimilar liquids mixing in T-junction and offset T-junction microchannels

2021 ◽  
pp. 095440892110154
Author(s):  
H Ringkai ◽  
KF Tamrin ◽  
NA Sheikh ◽  
P Barroy
Keyword(s):  
Reynolds Number ◽  
Sodium Chloride ◽  
Chloride Solution ◽  
High Reynolds Number ◽  
Sodium Chloride Solution ◽  
Experimental Studies ◽  
Low Flow ◽  
Mixing Process ◽  
Mixing Performance ◽  
High Reynolds

Micromixing process in microfluidic devices has been broadly employed in bio-, nano-, and environmental technologies using either miscible or immiscible liquids. However, there are limited experimental studies investigating the mixing process of different densities and viscosities liquids in relation to microfluidics. Therefore, the mixing process of propan-2-ol and water, water and sodium chloride solution, propan-2-ol and sodium chloride solution were experimented and reported at 5 ≤ Re ≤ 50 in T-junction and offset T-junction microchannels. For miscible mixing experiments, i.e. propan-2-ol and water, water and sodium chloride solution, both microchannels show mixing index for each Reynolds number is directly proportional to the mixing time. At low Reynolds number, higher molecular diffusion takes place while at low flow rate, the residence time of fluid is high. The mixing performance is relatively good at high Reynolds number of 40 and 50 due to the significant convection which is caused by the effect of stretching and thinning of liquid lamellae. For immiscible propan-2-ol and sodium chloride solution mixing, offset T-junction microchannel offers better mixing performance than T-junction microchannel at both low and high Reynolds number. The chaotic mixing happened at the intersection of the T-junction microchannel due to the direct interaction of two liquids entering the junction at high momentum.

Numerical Study of Wake-Induced Vibrations for Cylinders in Tandem With Different Diameters at High Reynolds Numbers

2016 ◽  
Author(s):  
Vinh-Tan Nguyen ◽  
Wai Hong Ronald Chan ◽  
Hoang-Huy Nguyen
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Experimental Studies ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
Geometrical Parameters ◽  
Tandem Arrangement ◽  
Wide Range ◽  
High Reynolds ◽  
Different Diameters

Wake induced vibration is a distinctive phenomena of fluid-elastic instability arising from interactions of a body in the wakes of another bluff body and characteristically different from the well-understood vortex induced vibrations. This work presents a fluid-structure interactions numerical model as an alternative tool for investigation of wake induced vibrations. In an attempt to better understand mechanisms of wake induced motions, a simplified model of two cylinders in tandem arrangement with different diameters under cross flow was considered in this work. Cross flow velocity conditions vary from moderate to high Reynolds number (Re = 2 × 103–5 × 104) in the same range as many experiment reported recently in literature. A hybrid detached eddy simulation approach is used for turbulence modelling at those high Reynolds number conditions in order to resolve complex near body flow features as well as in the wake regions. The proposed model is first validated through extensive benchmarking with experimental studies for responses of tandem cylinders at the same flow conditions as in physical experiment. With good agreement to experimental data, the model was extended for simulations of cylinders of different diameters in tandem arrangement. For different diameters between upstream and downstream cylinders, the fundamental frequencies of shedded vortices from the cylinders are essentially different. It is observed from the present study that responses of the downstream cylinder are characterized not only the geometrical parameters such as distances and diameter differences between the cylinders but also the Reynolds number. As contrast to many experimental studies, at constant Reynolds number, downstream cylinders are found to have multiple lock-in regions in a wide range of reduced velocities. This distinctive behaviour of the cylinders at constant Reynolds numbers and diameter ratios suggests strong evidence of complicated mechanism of wake-induced vibrations phenomena. Further analysis of results from high fidelity numerical simulations were carried out for detailed investigations of force amplitudes and frequencies. The current analysis revealed multiple frequency content of the force; thus explaining high response amplitudes of the downstream cylinder at high reduced velocity.

Modeling and Simulation of High Reynolds' Number Flows During Reaction Injection Mold Filling

1994 ◽  
Vol 9 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Rahima K. Mohammed ◽  
Tim A. Osswald ◽  
Timothy J. Spiegelhoff ◽  
Esther M. Sun
Keyword(s):  
Reynolds Number ◽  
Modeling And Simulation ◽  
High Reynolds Number ◽  
Mold Filling ◽  
Injection Mold ◽  
High Reynolds ◽  
Reynolds Number Flows
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