Developing convective heat transfer in deep rectangular microchannels

Harms, Todd M.; Kazmierczak, M.; Gerner, Frank M.

doi:10.1016/s0142-727x(98)10055-3

Cited by 314 publications

(153 citation statements)

References 16 publications

Supporting

Mentioning

135

Contrasting

Unclassified

Order By: Relevance

“…Heat transfer results obtained in a number of experimental studies on microchannels have been compared in the literature [13,22,33] against the numerical results of Wibulswas [21], to assess the applicability of a conventional analysis. Simultaneously developing as well as thermally developing flows in channels of rectangular cross-section were considered in [21], both with T (constant wall temperature) and H1 (constant wall heat flux with circumferentially constant wall temperature) boundary conditions [28].…”

Section: Numerical Analysismentioning

confidence: 99%

“…Nusselt numbers from this analysis were reported as functions of the channel aspect ratio and dimensionless axial position, as shown in Table 2. Later studies [13,22] have used curve-fits to these numerical results for predictive purposes. The main limitation in the analysis of [21] was that the results covered only four particular aspect ratios ( = 1, 2, 3 and 4), and the computational resources available at the time of the work necessitated very coarse computational meshes.…”

Section: Numerical Analysismentioning

confidence: 99%

“…Based on comparison with these conventional correlations, various conclusions have been drawn regarding their applicability to microchannel heat transfer [1,12,13,14,15,[29][30][31][32][33][34][35][36][37]. Table 4 summarizes the conditions considered in these past microchannel studies, the conventional correlations against which results were compared, the conclusions that were drawn regarding applicability of conventional correlations, and any new correlations that were proposed.…”

Section: Alternative Prediction Approachesmentioning

confidence: 99%

“…Although deviations were observed for the smallest channel size studied, the paucity of data under these conditions precluded firm conclusions from being drawn. Harms et al [13] studied convective heat transfer of water in rectangular microchannels of 251 m width and 1000 m depth. In the laminar regime of Reynolds number investigated, the measured local Nusselt numbers agreed well with classical developing-flow theory.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Investigation of heat transfer in rectangular microchannels

Lee

Garimella

Liu

2005

International Journal of Heat and Mass Transfer

716

295

View full text Add to dashboard Cite

An experimental investigation was conducted to explore the validity of classical correlations based on conventional-sized channels for predicting the thermal behavior in single-phase flow through rectangular microchannels. The microchannels considered ranged in width from 194 m to 534 m, with the channel depth being nominally five times the width in each case. Each test piece was made of copper and contained ten microchannels in parallel. The experiments were conducted with deionized water, with the Reynolds number ranging from approximately 300 to 3500. Numerical predictions obtained based on a classical, continuum approach were found to be in good agreement with the experimental data (showing an average deviation of 5 percent), suggesting that a conventional analysis approach can be employed in predicting heat transfer behavior in microchannels of the dimensions considered in this study. However, the entrance and boundary conditions imposed in the experiment need to be carefully matched in the predictive approaches.

show abstract

Section: Numerical Analysismentioning

confidence: 99%

Section: Numerical Analysismentioning

confidence: 99%

Section: Alternative Prediction Approachesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of heat transfer in rectangular microchannels

Lee

Garimella

Liu

2005

International Journal of Heat and Mass Transfer

716

295

View full text Add to dashboard Cite

show abstract

“…Some of these studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] are summarised in Table 1 and reference is made to the fluid used, cross-sectional channel shape, inlet type, channel material, whether a single channel or multiple parallel channels were investigated, the applied thermal boundary, diameter range considered, the relative roughness of the channel wall, the reported critical Reynolds number and whether conventional macro-channel theory over predicted (>), under predicted (<), or correctly predicted (=) the measured friction factor and Nusselt number. It could be noted that a wide range of critical Reynolds numbers were reported and that there are inconsistencies amongst the reported results for macro channel conformance.…”

Section: Introductionmentioning

confidence: 99%

Inlet flow effects in micro-channels in the laminar and transitional regimes on single-phase heat transfer coefficients and friction factors

Dirker

Meyer

Garach

2014

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

An experimental investigation of heat transfer and pressure drop in rectangular micro-channels was conducted for water in the laminar and transitional regimes for three different inlet configurations.The inlet types under consideration were the sudden contraction, bellmouth, and swirl inlet types, and hydraulic diameters of 0.57 mm, 0.85 mm, and 1.05 mm were covered. It was found that the critical Reynolds number and the transitional behaviour in terms of heat transfer coefficients and friction factors were influences significantly by the inlet type. For the sudden contraction inlet type, which were investigated for both adiabatic, as well as diabatic cases, adiabatic friction factors were predicted well by the laminar Shah and London correlation, while diabatic friction factors were decreased with an increase in wall heat flux. The sudden contraction inlet critical Reynolds numbers were found to be between 1 800 and 2 000 for adiabatic cases, while for diabatic cases the transition regime commenced at a Reynolds number of about 2 000. The bellmouth and swirl inlet types were investigated for diabatic cases only with swirl inlet tests limited to the 1.05 mm channel. Laminar 2 friction factors were approximately similar to those of the sudden contraction inlet type, however, after the commencement of transition both inlet types exhibited higher friction factors than the sudden contraction inlet. Minor transition occurred as early as at Reynolds numbers of 1 200 and 800 for the bellmouth and swirl inlet types respectively while major transition occurred at Reynolds numbers of approximately 1 800 and 1 500 respectively. Critical Reynolds numbers were found not be significantly influenced by the channel to diameter to length ratio considered in this study. Laminar Nusselt numbers were predicted well by conventional macro-channel thermal entry correlations. The swirl inlet type exhibited the highest friction factors and Nusselt numbers in the transitional regime followed by the bellmouth inlet type. During transition while compared with the sudden contraction inlet, both the bellmouth and swirl inlet types exhibited larger enhancement in heat transfer than increases in the friction factor penalty. Based on the experimental data obtained in this study, a set of correlations were developed which describes the relation between the friction factor and Colburn jfactor. Depending on the inlet type, the correlations predicted between 94% and 100% of the results to within 10% of the experimental measurements.

show abstract

Microreactors - Modeling and Simulation

Hardt

2006

Ullmann's Encyclopedia of Industrial Chemistry

View full text Add to dashboard Cite

Developing convective heat transfer in deep rectangular microchannels

Cited by 314 publications

References 16 publications

Investigation of heat transfer in rectangular microchannels

Investigation of heat transfer in rectangular microchannels

Inlet flow effects in micro-channels in the laminar and transitional regimes on single-phase heat transfer coefficients and friction factors

Microreactors - Modeling and Simulation

Contact Info

Product

Resources

About