Experimental Investigation of Heat Transfer and Pressure Drop Through Deep Microchannels in a (110) Silicon Substrate

Harms, Todd M.; Kazmierczak, M.; Gerner, Frank M.; Hölke, A.; Henderson, H. Thurman; Pilchowski, J.; Baker, Karl W.

doi:10.1115/imece1997-0860

Cited by 16 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental friction factors were in rough agreement with the conventional theoretical predictions in . It can be found that the reported relative roughness was usually less than 1% in [40][41][42][43][44][45][46][47][48][49][50]. The roughness data were not reported in the others.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Experimental observations and lattice Boltzmann method study of the electroviscous effect for liquid flow in microchannels

Tang¹,

Li²,

He³

et al. 2007

J. Micromech. Microeng.

View full text Add to dashboard Cite

The existing experimental data in the literature on hydrodynamics for liquid flow in microchannels are analyzed and the reasons causing the diversities are discussed and summarized. The present experimental data for deionized water flow in glass microtubes with diameters ranging from 50 to 530 µm show that the friction factors and transition Reynolds numbers from laminar to turbulent flow are in good agreement with the conventional theoretical predictions. However, the friction factors in stainless steel microtubes with diameters of 119 and 172 µm are much higher than the conventional theoretical predictions. This discrepancy is attributed to the large surface relative roughness or dense roughness distribution in the stainless steel tubes. Numerical simulations taking into account the electroviscous effect are carried out by using the lattice Boltzmann method. The simulation results show that the electroviscous effect does not play a significant role in the flow characteristics for channel dimensions of the order of microns and hence it can be neglected in engineering applications for moderate electrical conductivity of the liquid and conductivity of the walls. From the literature review and the present test data, it is validated that for liquid flow in smooth microchannels the conventional theoretical prediction for flow characteristics should still be applied.

show abstract

Section: Introductionmentioning

confidence: 93%

“…Harms et al [40] tested the deionized water flow in a silicon channel of 251 µm wide and 1030 µm deep with ε/D h = 2%. The tested friction factors for the laminar and turbulent flows were in rough agreement with the conventional theory.…”

Section: Introductionmentioning

confidence: 99%

Experimental observations and lattice Boltzmann method study of the electroviscous effect for liquid flow in microchannels

Tang¹,

Li²,

He³

et al. 2007

J. Micromech. Microeng.

View full text Add to dashboard Cite

show abstract

“…38 In other cases, this value was lower than the expected f Re using the classical theory. This was found by Pfalher et al (0−30%), 39 Yu et al (19%), 40 Jiang et al (50−100%), 29 and Judy et al 41 In other cases, no significant differences were found with respect to the classical theory, for example, Harms et al, 42 Pfund et al, 34 and Webb and Zhang. 43 Different critical Reynolds numbers have been reported in the literature by several authors to determine the transition regime for different materials, geometries, and channel sizes (Table SI-1 in Supporting Information).…”

Section: ■ Results and Discussionmentioning

confidence: 74%

“…In other cases, this value was lower than the expected fRe using the classical theory. This was found by Pfalher et al (0–30%), Yu et al (19%), Jiang et al (50–100%), and Judy et al In other cases, no significant differences were found with respect to the classical theory, for example, Harms et al, Pfund et al, and Webb and Zhang…”

Section: Resultsmentioning

confidence: 77%

OpenFOAM Computational Fluid Dynamic Simulations of Single-Phase Flows in an Advanced-Flow Reactor

Nieves‐Remacha

Kulkarni

Jensen

2015

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Computational fluid dynamic (CFD) simulations are carried out for single-phase flow in an advanced-flow reactor (AFR) using the open source software OpenFOAM. Excellent agreement of simulations with experimental pressure drop and residence time distribution (RTD) is obtained. Streamlines, stagnant zones, velocity profiles, and pressure fields are obtained at different flow rates ranging from 5 to 100 mL/min. A change in the flow behavior with the presence of recirculation zones is observed with a 40 mL/min flow rate. The extent of the recirculation zones increases with increasing flow rate from 40 to 60 mL/min and is limited further by the presence of a second cylindrical post inside the heart cell, remaining almost constant in the flow rate range of 60−100 mL/min. The RTD is also determined for all flow rates, and a comparison between different reactor designs (two-post, single-post, and low-flow-reactor-like single-post) is presented. The AFR shows a plug-flow behavior with a small degree of dispersion, which broadens the RTD. Symmetric RTD curves are obtained for the single-post designs, whereas the Gen 1 AFR design experiences asymmetry in the RTD at flow rates in the range between 20 and 60 mL/min. ■ INTRODUCTIONMicroreactors have been demonstrated to provide advantages over conventional process technologies for the synthesis of chemical compounds and kinetic studies at laboratory scale. 1 High heat and mass transfer rates, rapid mixing, and higher selectivities and conversions can be achieved in these microdevices thanks to the small characteristic dimensions, enabling the synthesis of compounds that cannot be synthesized in conventional reactors. In the past years, efforts have been directed toward the application of microreactor technology for production purposes, especially in the pharmaceutical and fine chemicals industry. 2−4 The challenge is how to get the benefit of the transport rates inherent to microreactors while increasing the throughput for production applications. Two approaches to increase production rate are possible: (a) scale-out by parallelization of units and (b) scaleup by increase in channel size and flow rates. Scale-out requires thousands of units to achieve kilogram per minute of production rates and development of very expensive and complex control systems to ensure identical operating conditions in each unit for a perfect and predictable overall reactor performance. In contrast, scale-up by increase in channel size risks losing mass and heat transfer performance. The advanced-flow reactor (AFR) manufactured by Corning, Inc., combines both approaches and is able to yield production rates of 10−300 g/min per module. 5 The AFR is formed by three layers, and the reaction mixture flows through the middle one. The reaction layer has a special design in the form of several rows of heart-shaped cells in series (Figure 1a) that form a sequence of convergent−divergent segments that enhance mass transfer rates. The height for this layer is 1.1 mm, and the minimum width is 1 mm (Figure 1b). T...

show abstract

“…It may be useful to fabricate complex structures that cannot be high-aspect-ratio Hard to fabricate multiple-depth structures micro-optical devices [11], angular with different thickness rate sensor [12], micro channel [13,14], comb structures [15,16]…”

Section: Introductionmentioning

confidence: 99%

A high-aspect-ratio comb actuator using UV-LIGA surface micromachining and (110) silicon bulk micromachining

Kim

Lee

Kim

2002

J. Micromech. Microeng.

View full text Add to dashboard Cite

A novel micromachining process based on the UV-LIGA process and (110) silicon anisotropic etching to fabricate a high-aspect-ratio comb actuator was developed. The comb electrodes were fabricated by (110) silicon anisotropic etching and the spring structures were fabricated using a UV-LIGA micromachining process. The (110) silicon comb structure was designed considering the etch-rate-ratio between the (110) and (111) planes and the lateral etch rate of a line-type structure. The fabricated structure was 400 μm thick and 18 μm wide comb electrodes separated by 7 μm and the height–gap ratio was approximately 57. In addition, the number, width, height and length of the spring structures were designed considering resonant frequency of the comb actuator and frequency-matching between the sensing and driving mode for gyroscope application. The electroplated gold springs on both sides of the seismic mass were 15 μm wide, 14 μm thick and 500 μm long. The fabricated comb actuator had a resonant frequency at 1430 Hz, which was calculated to be 1441 Hz. The proposed fabrication process can be applied to fabricating a high-aspect-ratio comb actuator for large displacement actuators and precision sensors. Moreover, this combined process enables the fabrication of a more complex structure, which cannot be fabricated by surface or bulk micromachining alone.

show abstract

Experimental Investigation of Heat Transfer and Pressure Drop Through Deep Microchannels in a (110) Silicon Substrate

Cited by 16 publications

References 0 publications

Experimental observations and lattice Boltzmann method study of the electroviscous effect for liquid flow in microchannels

Experimental observations and lattice Boltzmann method study of the electroviscous effect for liquid flow in microchannels

OpenFOAM Computational Fluid Dynamic Simulations of Single-Phase Flows in an Advanced-Flow Reactor

A high-aspect-ratio comb actuator using UV-LIGA surface micromachining and (110) silicon bulk micromachining

Contact Info

Product

Resources

About