Assessment and numerical search for minimal Taylor–Aris dispersion in micro-machined channels of nearly rectangular cross-section

Callewaert, Manly; Malsche, Wim De; Ottevaere, Heidi; Thienpont, Hugo; Desmet, Gert

doi:10.1016/j.chroma.2014.09.009

Cited by 28 publications

(20 citation statements)

References 31 publications

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“…A value of 100 m was taken as an arbitrary depth of the channels for all types of flow distributors. In real world a chip consists of a top and a bottom part and band broadening can be easily transformed to other dimensions depending on the aspect ratio of the cross section of the channels [16,17]. When calculating the volume of the flow distributors and investigating the influence of different parameters on the variance, we kept the aspect ratio the same for all (but two, see below) of the designs considered.…”

Section: Hybrid Flow Distributormentioning

confidence: 99%

Optimization and evaluation of radially interconnected versus bifurcating flow distributors using computational fluid dynamics modelling

Davydova

Deridder

Eeltink

et al. 2015

Journal of Chromatography A

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Section: Hybrid Flow Distributormentioning

confidence: 99%

Optimization and evaluation of radially interconnected versus bifurcating flow distributors using computational fluid dynamics modelling

Davydova

Deridder

Eeltink

et al. 2015

Journal of Chromatography A

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“…The mathematical equations describing the solute concentration distribution along the long straight pipe are well studied. Callewaert [12] considers the numerical constant of the Taylor-Aris expression for the dispersion in a laminar flow and uses the MATLAB PDE toolbox for calculation. Wu [50] considers the longitudinal normality of mean concentration and explores the approach towards transverse uniformity of the solute concentration distribution.…”

Section: Tehuan Chen Chao Xu and Zhigang Renmentioning

confidence: 99%

Computational optimal control of 1D colloid transport by solute gradients in dead-end micro-channels

Chen¹,

Xu²,

Ren³

2018

Journal of Industrial &Amp; Management Optimization

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Diffusiophoresis is a common phenomenon that occurs when colloids are placed in the non-uniform solute concentration. It generates solute gradients which force the colloids to transfer toward or away from the higher solute concentration side. In this paper, we consider the input sequence control of the colloid transport in a dead-end micro-channel with a boundary solute concentration being manipulated, which has a wide range of applications such as drug delivery, biology transport, oil recovery system and so on. We model this process by a coupled system, which involves the solute diffusion equation and the colloid transport model. Then an optimal control problem is formulated, in which the goal is to minimize colloid density distribution deviation between the computational one and the target at a pre-specified terminal time. To solve this partial differential equation (PDE) optimal control problem, we first apply the control parameterization method to discretize the boundary control and transfer it into an optimal parameter selection problem. Then, using the variational method, the gradient of the objective function with respect to the decision parameters can be derived, which depends on the solution of the coupled system and the costate system. Based on this, we propose an effective computational method and a gradient-based optimization algorithm to solve the optimal control problem numerically. Finally, we give the simulation results to demonstrate that the objective function based on the proposed method is less nearly two orders of magnitude than that of a constant value control strategy, which well illustrates the effectiveness of the proposed method.

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“…parallel plate configuration), can be performed to increase the reactor volume preferentially without leaving the µm‐scale. However, this will often result in a larger axial dispersion . Keeping the channel width or depth constant the axial dispersion in a rectangular duct (Fig.…”

Section: Plug Flowmentioning

confidence: 99%

“…Increasing the aspect ratio will increase the axial variance maximum by roughly a factor of 4, this at the parallel plate configuration with side wall effect. To minimize the axial dispersion Callewaert et al studied different cross‐sectional designs. With an optimized pinched (P) cross‐sectional design in the middle of the channel (Fig.…”

Section: Plug Flowmentioning

confidence: 99%

“…Hence, at an aspect ratio of 45 or higher the axial dispersion with an optimal I‐shaped cross‐section (W and H) is a factor of 7–8 lower, than a rectangular cross‐section and a factor of 3–3.5 lower than a pinched one. Although the optimal pinched and I‐profile result in a reduced axial dispersion, caution should prevail, as these lower axial dispersion coefficients only occur when those optimal geometrical parameters are achieved . For instance, fabrication errors will inevitably result in geometrical parameters (P, H, W) that deviate from their optimum value.…”

Section: Plug Flowmentioning

confidence: 99%

See 1 more Smart Citation

Chromatography as an inspiration for microreactors

Hereijgers

Breugelmans

Malsche

2015

J. Chem. Technol. Biotechnol.

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In the shift from batch to continuous operations, microreactors, at least in academic research, have become an important segment. One of the next steps in process intensification is believed to be the reduction of axial dispersion, which will not only yield higher efficiencies but also allow integration of the reactor unit with downstream processing. Chromatographic (micro)devices are very interesting in this context as they successfully combine a narrow residence time distribution with a high separation factor. In the present review the low dispersion in microreactors is discussed, with emphasis on throughput, packing and flow distribution units. Subsequently, the relevance and progress during the last decade of combined reaction and separations in chromatographic and membrane based systems is treated. © 2015 Society of Chemical Industry

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Assessment and numerical search for minimal Taylor–Aris dispersion in micro-machined channels of nearly rectangular cross-section

Cited by 28 publications

References 31 publications

Optimization and evaluation of radially interconnected versus bifurcating flow distributors using computational fluid dynamics modelling

Optimization and evaluation of radially interconnected versus bifurcating flow distributors using computational fluid dynamics modelling

Computational optimal control of 1D colloid transport by solute gradients in dead-end micro-channels

Chromatography as an inspiration for microreactors

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