scholarly journals The dynamics and rheology of a dilute suspension of periodically forced neutrally buoyant spherical particles in a quiescent Newtonian fluid at low Reynolds numbers

2011 ◽  
Vol 43 (4) ◽  
pp. 045502 ◽  
Author(s):  
T R Ramamohan ◽  
I S Shivakumara ◽  
K Madhukar
Keyword(s):  
Newtonian Fluid ◽  
Reynolds Numbers ◽  
Spherical Particles ◽  
Low Reynolds Numbers ◽  
Dilute Suspension ◽  
Low Reynolds ◽  
Neutrally Buoyant

Lateral Migration of Neutrally-Buoyant Particles in a Square Microchannel at Low Reynolds Numbers

2009 ◽  
Author(s):  
Byung Rae Cho ◽  
Young Won Kim ◽  
Jung Yul Yoo
Keyword(s):  
Reynolds Numbers ◽  
Spherical Particles ◽  
Channel Cross Section ◽  
Microfluidic Channels ◽  
Lateral Migration ◽  
Low Reynolds Numbers ◽  
Low Reynolds ◽  
Square Microchannel ◽  
External Forces ◽  
Neutrally Buoyant

Lateral migration of particles has drawn a lot of attention in suspension community for the last 50 years. Since there is no need for extra external forces, lateral migration of particles plays an important role in constructing microfluidic devices in diverse engineering applications. In this paper, an experimental study on lateral migration of neutrally-buoyant spherical particles transported through a square microchannel is carried out using a fluorescent microscope at low Reynolds numbers. Fluorescent microspheres with diameters of d = 6 μm, 10 μm, and 16 μm are adopted as the test particles, which yield channel-to-particle size ratios of 13.3, 8 and 5, respectively. Spatial distributions of the particles in dilute suspension are visualized at different Reynolds numbers. It is shown that particles are uniformly distributed over the channel cross-section at relatively low Reynolds numbers. As the Reynolds number increases, however, particles migrate inward from the wall and away from the central axis of the channel, so that consequently they accumulate at an equilibrium position, exhibiting the so-called “tubular pinch effect”, first observed by Segre´ and Silberberg as early as in 1962. Experimental results obtained in this work offer design rules for microfluidic channels that play important roles of particle separation or particle focusing.

scholarly journals The Effects of a Constant Bias Force on the Dynamics of a Periodically Forced Spherical Particle in a Newtonian Fluid at Low Reynolds Numbers

2010 ◽  
Author(s):  
K. Madhukar ◽  
T. R. Ramamohan ◽  
I. S. Shivakumara ◽  
Theodore E. Simos ◽  
George Psihoyios ◽  
...  
Keyword(s):  
Spherical Particle ◽  
Newtonian Fluid ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Constant Bias ◽  
Low Reynolds

scholarly journals NON-NEWTONIAN FLUID FLOW IN A LIDDRIVEN CAVITY AT LOW REYNOLDS NUMBERS

2015 ◽  
pp. 90-99
Author(s):  
Maria Andreevna PONOMAREVA ◽  
◽  
Maria Petrovna FILINA ◽  
Vladimir Albertovich YAKUTENOK ◽  
◽  
...  
Keyword(s):  
Fluid Flow ◽  
Newtonian Fluid ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Low Reynolds

Investigation on the effect of leading edge tubercles of sweptback wing at low reynolds number

2020 ◽  
Vol 21 (6) ◽  
pp. 621
Author(s):  
Veerapathiran Thangaraj Gopinathan ◽  
John Bruce Ralphin Rose ◽  
Mohanram Surya
Keyword(s):  
Leading Edge ◽  
Reynolds Numbers ◽  
Sweep Angle ◽  
Laminar Separation ◽  
Low Reynolds Numbers ◽  
Flow Energy ◽  
Airplane Wing ◽  
Low Reynolds ◽  
Naca 0015 ◽  
Wing Performance

Aerodynamic efficiency of an airplane wing can be improved either by increasing its lift generation tendency or by reducing the drag. Recently, Bio-inspired designs have been received greater attention for the geometric modifications of airplane wings. One of the bio-inspired designs contains sinusoidal Humpback Whale (HW) tubercles, i.e., protuberances exist at the wing leading edge (LE). The tubercles have excellent flow control characteristics at low Reynolds numbers. The present work describes about the effect of tubercles on swept back wing performance at various Angle of Attack (AoA). NACA 0015 and NACA 4415 airfoils are used for swept back wing design with sweep angle about 30°. The modified wings (HUMP 0015 A, HUMP 0015 B, HUMP 4415 A, HUMP 4415 B) are designed with two amplitude to wavelength ratios (η) of 0.1 & 0.24 for the performance analysis. It is a novel effort to analyze the tubercle vortices along the span that induce additional flow energy especially, behind the tubercles peak and trough region. Subsequently, Co-efficient of Lift (CL), Co-efficient of Drag (CD) and boundary layer pressure gradients also predicted for modified and baseline (smooth LE) models in the pre & post-stall regimes. It was observed that the tubercles increase the performance of swept back wings by the enhanced CL/CD ratio in the pre-stall AoA region. Interestingly, the flow separation region behind the centerline of tubercles and formation of Laminar Separation Bubbles (LSB) were asymmetric because of the sweep.

Low Reynolds number flow around and heat transfer from a heated circular cylinder

2010 ◽  
Vol 1 (1-2) ◽  
pp. 15-20 ◽  
Author(s):  
B. Bolló
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Lift Coefficient ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Reynolds Number Flow ◽  
Two Dimensional Flow ◽  
Number Flow ◽  
Low Reynolds ◽  
Increasing Temperature

Abstract The two-dimensional flow around a stationary heated circular cylinder at low Reynolds numbers of 50 < Re < 210 is investigated numerically using the FLUENT commercial software package. The dimensionless vortex shedding frequency (St) reduces with increasing temperature at a given Reynolds number. The effective temperature concept was used and St-Re data were successfully transformed to the St-Reeff curve. Comparisons include root-mean-square values of the lift coefficient and Nusselt number. The results agree well with available data in the literature.

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