Pressure drop of laminar gas flows in a microchannel containing various pillar matrices

Vanapalli, Srinivas; Brake, ter Hjm Marcel; Jansen, Henricus V.; Burger, Johannes Faas; Holland, H.J.; Veenstra, T.T.; Elwenspoek, M.

doi:10.1088/0960-1317/17/7/021

Cited by 54 publications

(34 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Using water flow, they obtained a maximum heat transfer coefficient of around 55,000 W/m 2 C. John et al [35] compared the performance of square and circular pin fins and noted that the figure of merit, defined as the heat transfer performance to pressure drop penalty, was higher for circular pin fins at Re < 300, while reverse was true at higher Re. Vanapalli et al [36] studied additional fin shapes of ellipse and diamond in gas flow, but these have not been studied in liquid flows. Lee et al [37] studied their patented parallelogram cross-sectional fins with the side walls parallel to the flow and the oblique front and rear sides facing at an angle.…”

Section: Fins In Single-phase Liquid Flowmentioning

confidence: 99%

Heat Transfer in Microchannels—2012 Status and Research Needs

Kandlikar

Colin

Peles

et al. 2013

Journal of Heat Transfer

236

View full text Add to dashboard Cite

Heat transfer and fluid flow in microchannels have been topics of intense research in the past decade. A critical review of the current state of research is presented with a focus on the future research needs. After providing a brief introduction, the paper addresses six topics related to transport phenomena in microchannels: single-phase gas flow, enhancement in single-phase liquid flow and flow boiling, flow boiling instability, condensation, electronics cooling, and microscale heat exchangers. After reviewing the current status, future research directions are suggested. Concerning gas phase convective heat transfer in microchannels, the antagonist role played by the slip velocity and the temperature jump that appear at the wall are now clearly understood and quantified. It has also been demonstrated that the shear work due to the slipping fluid increases the effect of viscous heating on heat transfer. On the other hand, very few experiments support the theoretical models and a significant effort should be made in this direction, especially for measurement of temperature fields within the gas in microchannels, implementing promising recent techniques such as molecular tagging thermometry (MTT). The single-phase liquid flow in microchannels has been established to behave similar to the macroscale flows. The current need is in the area of further enhancing the performance. Progress on implementation of flow boiling in microchannels is facing challenges due to its lower heat transfer coefficients and critical heat flux (CHF) limits. An immediate need for breakthrough research related to these two areas is identified. Discussion about passive and active methods to suppress flow boiling instabilities is presented. Future research focus on instability research is suggested on developing active closed loop feedback control methods, extending current models to better predict and enable superior control of flow instabilities. Innovative high-speed visualization and measurement techniques have led to microchannel condensation now being studied as a unique process with its own governing influences. Further work is required to develop widely applicable flow regime maps that can address many fluid types and geometries. With this, condensation heat transfer models can progress from primarily annular flow based models with some adjustments using dimensionless parameters to those that can directly account for transport in intermittent and other flows, and the varying influences of tube shape, surface tension and fluid property differences over much larger ranges than currently possible. Electronics cooling continues to be the main driver for improving thermal transport processes in microchannels, while efforts are warranted to develop high performance heat exchangers with microscale passages. Specific areas related to enhancement, novel configurations, nanostructures and practical implementation are expected to be the research focus in the coming years.

show abstract

Section: Fins In Single-phase Liquid Flowmentioning

confidence: 99%

Heat Transfer in Microchannels—2012 Status and Research Needs

Kandlikar

Colin

Peles

et al. 2013

Journal of Heat Transfer

236

View full text Add to dashboard Cite

show abstract

“…Interestingly, it has been reported that the correlations used to predict the pressure drop for fluid flow across pin fin-tube bundles in conventional scale systems need to be modified for microscale counterparts [15]. These microscale hydrodynamic correlations have been developed in recent years for a variety of geometric fin configurations (aligned and staggered), fin types (tubular or non-tubular) and their aspect ratios (ratio of the height of a pin to its diameter) [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Low Reynolds number flow across an array of cylindrical microposts in a microchannel and figure-of-merit analysis of micropost-filled microreactors

Yeom

Agonafer

Han

et al. 2009

J. Micromech. Microeng.

View full text Add to dashboard Cite

The design, fabrication and characterization of a silicon microheater for an integrated MEMS gas preconcentrator Junghoon Yeom, Christopher R Field, Byunghoon Bae et al. Numerical modeling of three-dimensional compressible gas flow in microchannnels V Jain and C X Lin Modeling of liquid-gas meniscus for textured surfaces: effects of curvature and local slip length Anvesh Gaddam, Mayank Garg, Amit Agrawal et al. Experimental observations and lattice Boltzmann method study of the electroviscous effect for liquid flow G H Tang, Zhuo Li, Y L He et al. Stokes flow through a rectangular array of circular cylinders C Y Wang Low Reynolds number flow across an array of cylindrical microposts in a microchannel and figure-of-merit analysis of micropost-filled microreactors AbstractMicropost-filled reactors are commonly found in many micro-total analysis system applications because of their large surface area for the surrounding volume. Design rules for micropost-filled reactors are presented here to optimize the performance of a micro-preconcentrator, which is a component of a micro-gas chromatography system. A key figure of merit for the performance of the micropost-filled preconcentrator is to minimize the pressure drop while maximizing the surface-area-to-volume ratio for a given overall channel geometry. Several independent models from the literature are used to predict the flow resistance across the micropost-filled channels for low Reynolds number flows. The pressure drop can be expressed solely as a function of a couple of design parameters: β = a/s, the ratio of the radius of each post to the half-spacing between two adjacent posts, and N, the number of microposts in a row. Pressure drop measurements are performed to experimentally corroborate the flow resistance models and the optimization scheme using the figure of merit. As the number of microposts for a given β increases in a given channel size, a greater surface-area-to-volume ratio will result for a fixed pressure drop. Therefore, increasing the arrays of posts with smaller diameters and spacing will optimize the microreactor for larger surface area for a given flow resistance, at least until Knudsen flow begins to dominate.

show abstract

“…However, employing the existing models may lead to significant inaccuracy in the analysis of flow through low aspect ratio cylinders embedded inside channels. The experimental results reported by Kosar et al [3], Vanapalli et al [14], and Yeom et al [15] revealed that in the case of low aspect ratio cylinders, these two-dimensional models failed. Therefore, a more general model should consider the channel walls' effects in the analysis in order to successfully predict the flow through the cylinder array.…”

Section: Introductionmentioning

confidence: 95%

Moderate Reynolds number flow through microchannels filled with arrays of micro-cylinders

Tamayol

Yeom

Hooman

et al. 2012

AIP Conference Proceedings

View full text Add to dashboard Cite

Abstract. Moderate Reynolds number flow pressure drop of ordered arrays of cylinders embedded inside microchannels is studied experimentally and analytically. The array of microcylinders is modeled as a porous medium embedded inside the channel. The pressure drop is expressed as a function of the involved geometrical parameters such as micro-cylinder diameter, spacing between adjacent cylinders, channel height, and its width. To verify the developed models, 15 silicon/glass samples are fabricated using the Deep Reactive Ion Etching (DRIE) technique. Pressure drop measurements are performed over a wide range of nitrogen flow rates spanning from 0.1 sccm to 50 sccm (velocity range of 0.004 m/s to 2 m/s). The experimental data shows a parabolic relationship between the pressure drop and the volumetric flow rate in moderate Reynolds number flow. In addition, the proposed model captures the experimental data.

show abstract

Pressure drop of laminar gas flows in a microchannel containing various pillar matrices

Cited by 54 publications

References 15 publications

Heat Transfer in Microchannels—2012 Status and Research Needs

Heat Transfer in Microchannels—2012 Status and Research Needs

Low Reynolds number flow across an array of cylindrical microposts in a microchannel and figure-of-merit analysis of micropost-filled microreactors

Moderate Reynolds number flow through microchannels filled with arrays of micro-cylinders

Contact Info

Product

Resources

About