Airfoil Deterministic Lateral Displacement for High-Throughput Particle Separation in Viscous Fluids

2020 ◽  
Author(s):  
Brian Senf ◽  
Kawkab Ahasan ◽  
Jong-Hoon Kim
Keyword(s):  
High Throughput ◽  
Biological Sample ◽  
Particle Trajectory ◽  
Lateral Displacement ◽  
Particle Separation ◽  
Reynolds Numbers ◽  
Deionized Water ◽  
Fluid Viscosity ◽  
Deterministic Lateral Displacement ◽  
Low Reynolds Numbers

Abstract Deterministic Lateral Displacement (DLD) is an inertial size-based particle separation technique with great possibilities for use with biological sample preparation. Recently it has been shown that particle shift of a DLD is highly dependent on the Reynolds number. Additionally, particle trajectory has been characterized in a high throughput airfoil array DLD with varying Angle of Attack (AoA) in Deionized water. The AoA can be shifted negatively assisting in particle trajectory increases at low Reynolds numbers. With variations in fluid viscosity, particle trajectories compared to Reynolds value should theoretically have a constant and similar slope. In this work, various viscosities are tested in a DLD with a neutral and negative AoA to eventually characterize non-Newtonian fluids within a DLD. Due to higher viscosities increasing the internal pressure of the device, the negative AoA DLD shows promising results at higher range viscosities due to its ability to shift particles at lower Reynolds numbers.

scholarly journals Accelerated Particle Separation in a DLD Device at Re > 1 Investigated by Means of µPIV

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 768 ◽  
Author(s):  
Jonathan Kottmeier ◽  
Maike Wullenweber ◽  
Sebastian Blahout ◽  
Jeanette Hussong ◽  
Ingo Kampen ◽  
...  
Keyword(s):  
Lateral Displacement ◽  
Fluid Dynamic ◽  
Particle Diameter ◽  
Reynolds Numbers ◽  
Field Pattern ◽  
Cfd Simulations ◽  
Deterministic Lateral Displacement ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Microparticle Image Velocimetry

A pressure resistant and optically accessible deterministic lateral displacement (DLD) device was designed and microfabricated from silicon and glass for high-throughput fractionation of particles between 3.0 and 7.0 µm comprising array segments of varying tilt angles with a post size of 5 µm. The design was supported by computational fluid dynamic (CFD) simulations using OpenFOAM software. Simulations indicated a change in the critical particle diameter for fractionation at higher Reynolds numbers. This was experimentally confirmed by microparticle image velocimetry (µPIV) in the DLD device with tracer particles of 0.86 µm. At Reynolds numbers above 8 an asymmetric flow field pattern between posts could be observed. Furthermore, the new DLD device allowed successful fractionation of 2 µm and 5 µm fluorescent polystyrene particles at Re = 0.5–25.

Limits of Parabolic Flow Theory in Microfluidic Particle Separation: A Computational Study

2013 ◽  
Author(s):  
Ryan S. Pawell ◽  
Tracie J. Barber ◽  
David W. Inglis ◽  
Robert A. Taylor
Keyword(s):  
Computational Study ◽  
Lateral Displacement ◽  
Particle Separation ◽  
Flow Profile ◽  
Flow Rates ◽  
Deterministic Lateral Displacement ◽  
Flow Development ◽  
Separation Threshold ◽  
Parabolic Flow ◽  
Size Based Separation

Microfluidic particle separation technologies are useful for enriching rare cell populations for academic and clinical purposes. In order to separate particles based on size, deterministic lateral displacement (DLD) arrays are designed assuming that the flow profile between posts is parabolic or shifted parabolic (depending on post geometry). The design process also assumes the shape of the normalized flow profile is speed-invariant. The work presented here shows flow profile shapes vary, in arrays with circular and triangular posts, from this assumption at practical flow rates (10 < Re < 100). The root-mean-square error (RMSE) of this assumption in the circular post arrays peaked at 0.144. The RMSE in the triangular post array peaked at 0.136. Flow development occurred more rapidly in circular post arrays when compared to triangular post arrays. Additionally, the changes in critical bumping diameter (DCB) the DLD design metric used to calculate the size-based separation threshold were examined for 10 different row shift fractions (FRS). These errors correspond to a DCB that varies as much as 11.7% in the circular post arrays and 15.1% in the triangular post arrays.

Study of Angle-of-Attack (AoA) for Airfoil in Deterministic Lateral Displacement (DLD)

2019 ◽  
Author(s):  
Kawkab Ahasan ◽  
Jong-Hoon Kim
Keyword(s):  
High Throughput ◽  
Lateral Displacement ◽  
Angle Of Attack ◽  
Critical Diameter ◽  
Control Flow ◽  
Flow Rates ◽  
Deterministic Lateral Displacement ◽  
Potential Applications ◽  
High Reynolds ◽  
Flow Symmetry

Abstract Deterministic lateral displacement (DLD) is a method of inertial size-based particle separation with potential applications in high throughput sample processing, such as the fractionation of blood or the purification of target species like viral particles or circulating tumor cells. Recently, it has been shown that symmetric airfoils with neutral angle-of-attack (AoA) can be used for high-throughput design of DLD device, due to their mitigation of vortex effects and preservation of flow symmetry under high Reynolds number (Re) conditions. While high-Re operation with symmetric airfoils has been established, the effect of AoA for airfoil on the DLD performance has not been characterized. In this study, we present a high-Re investigation with symmetric airfoil-shaped pillars having positive and negative 15 degree AoA. Both positive and negative AoA configurations yield significant flow anisotropy at higher flow rates. The stronger shift of the critical diameter (Dc) was observed with negative AoA, but not in positive AoA device. The most likely contributor may be the growing anisotropy that develops in the AoA device at higher flow rates. This study shows that high-Re DLD design with airfoil shaped pillars requires significant consideration for pillar orientation to control flow symmetry.

Investigation on Drag Reduction Through Dimple Machining

2018 ◽  
Author(s):  
Majid TabkhPaz ◽  
Lindsay Howell ◽  
Zachary Kockerbeck ◽  
Simon Park ◽  
Ron Hugo
Keyword(s):  
Drag Reduction ◽  
Silicone Oil ◽  
Reynolds Numbers ◽  
System Capacity ◽  
Micro Milling ◽  
Fluid Viscosity ◽  
Low Reynolds Numbers ◽  
Milling Tool ◽  
Transmission Pipeline ◽  
Surface Patterns

High friction between a fluid and a pipe wall results in increased pumping requirements. This friction contributes to lower production rates and reduced system capacity. Thermal heating, fluid blending, and drag reducing agents (DRA) are commonly used methods for decreasing pressure drop in pipelines. Surface patterns inscribed onto internal pipe walls have also been shown to reduce fluid friction. In this paper, the effects of different surface patterns on the shear between a fluid and a wall are studied. Surfaces with different dimple patterns are investigated. Micro-dimpled patterns on the surface are created using an inclined, flat end micro-milling tool. The surfaces with different dimpled patterns are characterized and tested through morphological, contact angle, and viscosity measurement studies. The effects of the surface patterns are also studied through simulation. A Power Law relationship and apparent fluid viscosity is determined for the low Reynolds numbers investigated. The deepest dimpled surfaces investigated (0.2 mm dimple depth) result in a drag reduction of approximately 20% for silicone oil. Further research and application of the results to transmission pipeline systems are discussed.

Sign in / Sign up

Export Citation Format

Share Document