Three-dimensional Lagrangian transport phenomena in unsteady laminar flows driven by a rotating sphere

2013 ◽  
Vol 25 (9) ◽  
pp. 093602 ◽  
Author(s):  
N. R. Moharana ◽  
M. F. M. Speetjens ◽  
R. R. Trieling ◽  
H. J. H. Clercx
Keyword(s):  
Transport Phenomena ◽  
Three Dimensional ◽  
Laminar Flows ◽  
Lagrangian Transport ◽  
Rotating Sphere

scholarly journals Lagrangian Transport and Chaotic Advection in Three-Dimensional Laminar Flows

2021 ◽  
Author(s):  
Michel F. M. Speetjens ◽  
Guy Metcalfe ◽  
Murray Rudman
Keyword(s):  
Turbulent Flows ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Laminar Flows ◽  
Chaotic Advection ◽  
Systematic Analysis ◽  
Lagrangian Transport ◽  
Analysis And Design ◽  
Efficient Transport ◽  
Transport And Mixing

Abstract Transport and mixing of scalar quantities in fluid flows is ubiquitous in industry and Nature. Turbulent flows promote efficient transport and mixing by their inherent randomness. Laminar flows lack such a natural mixing mechanism and efficient transport is far more challenging. However, laminar flow is essential to many problems and insight into its transport characteristics of great importance. Laminar transport, arguably, is best described by the Lagrangian fluid motion ("advection") and the geometry, topology and coherence of fluid trajectories. Efficient laminar transport being equivalent to "chaotic advection" is a key finding of this approach. The Lagrangian framework enables systematic analysis and design of laminar flows. However, the gap between scientific insights into Lagrangian transport and technological applications is formidable primarily for two reasons. First, many studies concern two-dimensional (2D) flows yet the real world is three dimensional (3D). Second, Lagrangian transport is typically investigated for idealised flows yet practical relevance requires studies on realistic 3D flows. The present review aims to stimulate further development and utilisation of know-how on 3D Lagrangian transport and its dissemination to practice. To this end 3D practical flows are categorised into canonical problems. First, to expose the diversity of Lagrangian transport and create awareness of its broad relevance. Second, to enable knowledge transfer both within and between scientific disciplines. Third, to reconcile practical flows with fundamentals on Lagrangian transport and chaotic advection. This may be a first incentive to structurally integrate the "Lagrangian mindset" into the analysis and design of 3D practical flows.

scholarly journals Accumulation of motile elongated micro-organisms in turbulence

2013 ◽  
Vol 739 ◽  
pp. 22-36 ◽  
Author(s):  
Caijuan Zhan ◽  
Gaetano Sardina ◽  
Enkeleida Lushi ◽  
Luca Brandt
Keyword(s):  
Turbulent Flow ◽  
Three Dimensional ◽  
Laminar Flows ◽  
Marine Life ◽  
Prolate Spheroids ◽  
Linear Shear ◽  
Local Shear ◽  
Micro Organisms ◽  
Hydrodynamic Effects ◽  
Preferential Alignment

AbstractWe study the effect of turbulence on marine life by performing numerical simulations of motile micro-organisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-organisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react more slowly to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of micro-organisms that can vary their shape and their preferential orientation.

Transport Phenomena in Chaotic Laminar Flows

2012 ◽  
Vol 3 (1) ◽  
pp. 473-496 ◽  
Author(s):  
Pavithra Sundararajan ◽  
Abraham D. Stroock
Keyword(s):  
Transport Phenomena ◽  
Laminar Flows

THREE-DIMENSIONAL PHONON TRANSPORT SIMULATION FOR NANO/MICROSTRUCTURED MATERIALS

2008 ◽  
Vol 07 (02n03) ◽  
pp. 103-112 ◽  
Author(s):  
A. SAKURAI ◽  
S. MARUYAMA ◽  
A. KOMIYA ◽  
K. MIYAZAKI
Keyword(s):  
Radiative Transfer ◽  
Heat Transport ◽  
Characteristic Length ◽  
Transport Phenomena ◽  
Three Dimensional ◽  
Phonon Transport ◽  
Discrete Ordinates ◽  
Complex Geometries ◽  
Transport Mechanisms ◽  
Length Scales

The Discrete Ordinates Radiation Element Method (DOREM), which is radiative transfer code, is applied for solving phonon transport of nano/microscale materials. The DOREM allows phonon simulation with multi-dimensional complex geometries. The objective of this study is to apply the DOREM to the nano/microstructured materials. It is confirmed that significant changes of the heat transport phenomena with different characteristic length scales and geometries are observed. This study also discusses further variations for understanding of heat transport mechanisms.

1407 Numerical Analysis on Three-dimensional Detonation with Transport Phenomena

2014 ◽  
Vol 2014 (0) ◽  
pp. _1407-1_-_1407-2_
Author(s):  
Katsuhito KOZAWA ◽  
Hiroki YOKOE ◽  
Tadayoshi SUGIMURA ◽  
Yoshihiro TAKI
Keyword(s):  
Numerical Analysis ◽  
Transport Phenomena ◽  
Three Dimensional

On Three‐Dimensional Transport Phenomena in CVD Processes

1987 ◽  
Vol 134 (10) ◽  
pp. 2552-2559 ◽  
Author(s):  
S. Rhee ◽  
J. Szekely ◽  
O. J. Ilegbusi
Keyword(s):  
Transport Phenomena ◽  
Three Dimensional

DIFFUSION-LIMITED AGGREGATION IN LAMINAR FLOWS

2003 ◽  
Vol 14 (09) ◽  
pp. 1171-1182 ◽  
Author(s):  
R. M. H. MERKS ◽  
A. G. HOEKSTRA ◽  
J. A. KAANDORP ◽  
P. M. A. SLOOT
Keyword(s):  
Flow Direction ◽  
Cluster Structure ◽  
Three Dimensional ◽  
Laminar Flows ◽  
Diffusion Field ◽  
Diffusion Limited Aggregation ◽  
Diffusion Limited ◽  
Advection Diffusion ◽  
Multiple Particles ◽  
Dla Model

In the diffusion-limited aggregation (DLA) model, pioneered by Witten and Sander (Phys. Rev. Lett.47, 1400 (1981)), diffusing particles irreversibly attach to a growing cluster which is initiated with a single solid seed. This process generates clusters with a branched morphology. Advection–diffusion-limited aggregation (ADLA) is a straightforward extension to this model, where the transport of the aggregating particles not only depends on diffusion, but also on a fluid flow. The authors studying two-dimensional and three-dimensional ADLA in laminar flows reported that clusters grow preferentially against the flow direction. The internal structure of the clusters was mostly reported to remain unaffected, except by Kaandorp et al. (Phys. Rev. Lett.77, 2328 (1996)) who found compact clusters "as the flow becomes more important". In the present paper we present three-dimensional simulations of ADLA. We did not find significant effects of low Reynolds-number advection on the cluster structure. The contradicting results by Kaandorp et al. (1996) were recovered only when the relaxation into equilibrium of the advection–diffusion field was too slow, in combination with the synchronous addition of multiple particles.

A Finite Element Computer Model for the Application of Electrokinetics to Contaminated Land

2003 ◽  
Author(s):  
Simon Kwong ◽  
Alan Paulley ◽  
Alex Bond
Keyword(s):  
Finite Element ◽  
Chemical Speciation ◽  
Three Dimensional ◽  
Computer Code ◽  
Test Cases ◽  
Coupled Flow ◽  
Lagrangian Transport ◽  
Chemical Gradients ◽  
Flow Transport ◽  
Element Approach

The computer code TRAFFIC incorporating three-dimensional (3-D) electrokinetic capabilities, coupled flow, transport and chemical speciation, using a finite element approach has been used to replicate published laboratory scale experiments [1, 2]. Two test cases have been presented using TRAFFIC with chemical speciation options and the Euler-Lagrangian transport formulation. The first of these (Case A with graphite anode) provided useful insights into the capabilities of the code to simulate realistic and complex problems, while the second (Case B with iron anode) closely reproduced the experimental results. It was also shown that the Euler-Lagrangian transport scheme was much better in coping with the steep chemical gradients, whereas the standard Euler scheme is less stable. Given the good results of these test cases, it is concluded that the code has been verified and partially validated.

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