Heat Transfer Enhancement and Entropy Generation of Nanofluids Laminar Convection in Microchannels with Flow Control Devices
<p>Models of microchannels with flow control devices: (<b>a</b>) cross-sections of microchannels with cylinder, rectangle, and v-groove devices; and (<b>b</b>) flow domain of the microchannel with protrusions.</p> "> Figure 2
<p>Variation of <span class="html-italic">f/f<sub>0</sub></span> in different microchannels (nano2).</p> "> Figure 3
<p>Temperature contours (unit: K) and limiting streamlines on the modified heated surface (nano2, <span class="html-italic">Re</span> = 100): (<b>a</b>) cylinder; (<b>b</b>) rectangle; (<b>c</b>) protrusion; and (<b>d</b>) v-groove devices.</p> "> Figure 4
<p>Variation of <span class="html-italic">Nu/Nu<sub>0</sub></span> in different microchannels (nano2).</p> "> Figure 5
<p>Variation of <span class="html-italic">S′/S′<sub>0</sub></span> in different microchannels (nano2).</p> "> Figure 6
<p>Variation of <span class="html-italic">f/f<sub>0</sub></span> in a microchannel with protrusion devices.</p> "> Figure 7
<p>Temperature contours (unit: K) and limiting streamlines on the protruded surface (<span class="html-italic">Re</span> = 100): (<b>a</b>) nano1; and (<b>b</b>) nano2.</p> "> Figure 8
<p>Variation of <span class="html-italic">Nu/Nu<sub>0</sub></span> in microchannel with protrusion.</p> "> Figure 9
<p>Variation of <span class="html-italic">S′/S′<sub>0</sub></span> in the microchannel with protrusion devices.</p> "> Figure 10
<p>Variation of <span class="html-italic">S<sub>T</sub>′/S′<sub>0</sub></span> and <span class="html-italic">S<sub>F</sub>′/S′<sub>0</sub></span> in the microchannel with protrusion devices.</p> ">
Abstract
:1. Introduction
2. Physical Properties of Nanofluids
3. Numerical Method and Validation
3.1. Governing Equations
3.2. Geometrical Configuration of Models and Boundary Conditions
3.3. Data Reduction
3.4. Model Validation
4. Results and Discussions
4.1. Effects of Structures
4.2. Effects of Nanofluids Concentration
5. Conclusions
- (1)
- f/f0 of the microchannel with rectangle and protrusion ribs are much larger and smaller than others, respectively, and increase a little as Re increases. While, f/f0 of the microchannels with cylinder and v-groove ribs are medium, and increase quickly with the increase of Re. As the nanofluids concentration increases, f/f0 increases a bit, accordingly, and this trend is enhanced when Re increases.
- (2)
- Nu/Nu0 of the microchannel with cylinder ribs are larger than others, and, at low Re cases (Re = 50 and 100), Nu/Nu0 of the microchannel with protrusion ribs are a minimum, while, as Re further increases to 200 and 300, Nu/Nu0 of the microchannel with rectangle ribs are smaller than that of others. Nu/Nu0 of all the microchannels increase with the increase of Re, except that of the microchannel with rectangle ribs. For the microchannel with rectangle ribs, there is a transition point of Re for obtaining the largest heat transfer. Nu/Nu0 of the cases with larger nanofluids concentration are higher. The differences of Nu/Nu0 among different working substances increase with the increase of Re.
- (3)
- The microchannels with cylinder and v-groove ribs have the better heat flux transfer performance, especially at larger Re cases, while the microchannel with protrusion ribs is better from the perspective of entropy generation minimization. The variation of S′/S′0 is based on the change of ST′/S′0 and SF′/S′0, which are all influenced by not only the change of Nu/Nu0 and f/f0, but also the physical parameters of the working substances.
Acknowledgments
Author Contributions
Conflicts of Interest
Nomenclature
Cp | Fluid special heat (J·kg−1·K−1) |
D | Dimple/Protrusion print diameter (μm) |
Dh | Characteristic length |
f | Fanning friction factor |
H | Microchannel height (μm) |
h | Heat transfer coefficient (W·m−2·K−1) |
k | Fluid thermal conductivity (W·m−1·K−1) |
m | Flow rate (kg·s−1) |
Nu | Nusselt number |
P | Fluid pressure (Pa) |
q′ | Heat transfer rate per unit length (W·m−1) |
q″ | Surface heat flux rate (W·m−2) |
Re | Reynolds number |
S′ | Entropy generation (W·K−1·m−1) |
SF′ | Friction induced entropy generation (W·K−1·m−1) |
ST′ | Heat transfer induced entropy generation (W·K−1·m−1) |
T | Temperature (K) |
Uave | Average velocity of inlet (m·s−1) |
ΔP | Pressure drop (Pa) |
ΔT | Mean temperature difference (K) |
Greek symbols
δ | Dimple/protrusion depth (μm) |
ϕ | Nanoparticle volume fraction (%) |
ρ | Fluid density (kg·m−3) |
Subscripts
h | Hydraulic |
w | Wall |
o | Baselines condition |
References
- Wang, X.Q.; Mujumdar, A.S. Heat transfer characteristics of nanofluids: A review. Int. J. Therm. Sci. 2007, 46, 1–19. [Google Scholar] [CrossRef]
- Xu, J.; Bandyopadhyay, K.; Jung, D. Experimental investigation on the correlation between nano-fluid characteristics and thermal properties of Al2O3 nano-particles dispersed in ethylene glycol-water mixture. Int. J. Heat Mass Transf. 2016, 94, 262–268. [Google Scholar] [CrossRef]
- Hussien, A.A.; Abdullah, M.Z.; Moh’d, A.A.N. Single-phase heat transfer enhancement in micro/minichannels using nanofluids: Theory and applications. Appl. Energy 2016, 164, 733–755. [Google Scholar] [CrossRef]
- Lo, K.J.; Weng, H.C. Convective heat transfer of magnetic nanofluids in a microtube. Smart Sci. 2015, 3, 56–64. [Google Scholar]
- Heris, S.Z.; Etemad, S.G.; Esfahany, M.N. Experimental investigation of oxide nanofluids laminar flow convective heat transfer. Int. Commun. Heat Mass 2006, 33, 529–535. [Google Scholar] [CrossRef]
- Barzegarian, R.; Moraveji, M.K.; Aloueyan, A. Experimental investigation on heat transfer characteristics and pressure drop of BPHE (brazed plate heat exchanger) using TiO2-water nanofluid. Exp. Therm. Fluid Sci. 2016, 74, 11–18. [Google Scholar] [CrossRef]
- Andreozzi, A.; Manca, O.; Nardini, S.; Ricci, D. Forced convection enhancement in channels with transversal ribs and nanofluids. Appl. Therm. Eng. 2016, 98, 1044–1053. [Google Scholar] [CrossRef]
- Sun, B.; Zhang, Z.; Yang, D. Improved heat transfer and flow resistance achieved with drag reducing Cu nanofluids in the horizontal tube and built-in twisted belt tubes. Int. J. Heat Mass Transf. 2016, 95, 69–82. [Google Scholar] [CrossRef]
- Hsieh, S.S.; Liu, H.H.; Yeh, Y.F. Nanofluids spray heat transfer enhancement. Int. J. Heat Mass Transf. 2016, 94, 104–118. [Google Scholar] [CrossRef]
- Tsai, C.Y.; Chien, H.T.; Ding, P.P.; Chan, B.; Luh, T.Y.; Chen, P.H. Effect of structural character of gold nanoparticles in nanofluid on heat pipe thermal performance. Mater. Lett. 2004, 58, 1461–1465. [Google Scholar] [CrossRef]
- Sarafraz, M.M.; Hormozi, F. Heat transfer, pressure drop and fouling studies of multi-walled carbon nanotube nano-fluids inside a plate heat exchanger. Exp. Therm. Fluid Sci. 2016, 72, 1–11. [Google Scholar] [CrossRef]
- Lee, P.S.; Garimella, S.V.; Liu, D. Investigation of heat transfer in rectangular microchannels. Int. J. Heat Mass Transf. 2005, 48, 1688–1704. [Google Scholar] [CrossRef]
- Hung, T.C.; Yan, W.M. Optimization of a microchannel heat sink with varying channel heights and widths. Numer. Heat Transf. A 2012, 62, 722–741. [Google Scholar] [CrossRef]
- Mohammed, H.A.; Gunnasegaran, P.; Shuaib, N.H. Influence of channel shape on the thermal and hydraulic performance of microchannel heat sink. Int. Commun. Heat Mass Transf. 2011, 38, 474–480. [Google Scholar] [CrossRef]
- Gunnasegaran, P.; Mohammed, H.A.; Shuaib, N.H.; Saidur, R. The effect of geometrical parameters on heat transfer characteristics of microchannels heat sink with different shapes. Int. Commun. Heat Mass Transf. 2010, 37, 1078–1086. [Google Scholar] [CrossRef]
- Liu, J.; Xie, G.N.; Simon, T.W. Turbulent flow and heat transfer enhancement in rectangular channels with novel cylindrical grooves. Int. J. Heat Mass Transf. 2015, 81, 563–577. [Google Scholar] [CrossRef]
- Liu, J.; Song, Y.; Xie, G.N.; Sunden, B. Numerical modeling flow and heat transfer in dimpled cooling channels with secondary hemispherical protrusions. Energy 2015, 79, 1–19. [Google Scholar] [CrossRef]
- Khan, A.A.; Kim, S.M.; Kim, K.Y. Performance Analysis of a microchannel heat sink with various rib configurations. J.Thermophys. Heat Transf. 2015, 29, 1–9. [Google Scholar] [CrossRef]
- Hong, F.; Cheng, P. Three dimensional numerical analyses and optimization of offset strip-fin microchannel heat sinks. Int. Commun. Heat Mass Transf. 2009, 36, 651–656. [Google Scholar] [CrossRef]
- Sui, Y.; Teo, C.J.; Lee, P.S.; Chew, Y.T.; Shu, C. Fluid flow and heat transfer in wavy microchannels. Int. J. Heat Mass Transf. 2010, 53, 2760–2772. [Google Scholar] [CrossRef]
- Lan, J.B.; Xie, Y.H.; Zhang, D. Flow and heat transfer in microchannels with dimples and protrusions. J. Heat Transf. 2012, 134, 021901. [Google Scholar] [CrossRef]
- Bi, C.; Tang, G.H.; Tao, W.Q. Heat transfer enhancement in mini-channel heat sinks with dimples and cylindrical grooves. Appl. Therm. Eng. 2013, 55, 121–132. [Google Scholar] [CrossRef]
- Silva, C.; Park, D. Optimization of fin performance in a laminar channel flow through dimpled surfaces. J. Heat Transf. 2009, 131, 021702. [Google Scholar] [CrossRef]
- Wei, X.J.; Joshi, Y.K.; Ligrani, P.M. Numerical simulation of laminar flow and heat transfer inside a microchannel with one dimpled surface. J. Electron. Packag. 2007, 129, 63–70. [Google Scholar] [CrossRef]
- Li, P.; Zhang, D.; Xie, Y.H. Heat transfer and flow analysis of Al2O3-water nanofluids in microchannel with dimple and protrusion. Int. J. Heat Mass Transf. 2014, 73, 456–467. [Google Scholar] [CrossRef]
- Xie, Y.H.; Shen, Z.Y.; Zhang, D.; Lan, J.B. Thermal performance of a water-cooled microchannel heat sink with grooves and obstacles. J. Electron. Packag. 2014, 136, 021001. [Google Scholar] [CrossRef]
- Hung, T.C.; Yan, W.M.; Wang, X.D.; Chang, C.Y. Heat transfer enhancement in microchannel heat sinks using nanofluids. Int. J. Heat Mass Trans. 2012, 55, 2559–2570. [Google Scholar]
- Ho, C.; Chen, W.C.; Yan, W.M. Correlations of heat transfer effectiveness in a minichannel heat sink with water-based suspensions of Al2O3 nanoparticles and/or MEPCM particles. Int. J. Heat Mass Transf. 2014, 69, 293–299. [Google Scholar] [CrossRef]
- Kuppusamy, N.R.; Mohammed, H.; Lim, C. Numerical investigation of trapezoidal grooved microchannel heat sink using nanofluids. Thermochim. Acta 2013, 573, 39–56. [Google Scholar] [CrossRef]
- Tokit, E.M.; Mohammed, H.A.; Yusoff, M. Thermal performance of optimized interrupted microchannel heat sink (IMCHS) using nanofluids. Int. Commun. Heat Mass Transf. 2012, 39, 1595–1604. [Google Scholar] [CrossRef]
- Chun, B.H.; Kang, H.U.; Kim, S.H. Effect of alumina nanoparticles in the fluid on heat transfer in double-pipe heat exchanger system. Korean J. Chem. Eng. 2008, 25, 966–971. [Google Scholar] [CrossRef]
- Manca, O.; Nardini, S.; Ricci, D.; Tamburrino, S. Numerical investigation on mixed convection in triangular cross-section ducts with nanofluids. Adv. Mech. Eng. 2012, 4, 139370. [Google Scholar] [CrossRef]
- Manca, O.; Mesolella, P.; Nardini, S.; Ricci, D. Numerical study of a confined slot impinging jet with nanofluids. Nanoscale Res. Lett. 2011, 6, 1–16. [Google Scholar] [CrossRef] [PubMed]
- Maiga, S.E.B.; Palm, S.J.; Nguyen, C.T.; Roy, G.; Galanis, N. Heat transfer enhancement by using nanofluids in forced convection flows. Int. J. Heat Fluid Flow 2005, 26, 530–546. [Google Scholar] [CrossRef]
- Duangthongsuk, W.; Wongwises, S. An experimental study on the heat transfer performance and pressure drop of TiO2-water nanofluids flowing under a turbulent flow regime. Int. J. Heat Mass Transf. 2010, 53, 334–344. [Google Scholar] [CrossRef]
- Vajjha, R.S.; Das, D.K. Experimental determination of thermal conductivity of three nanofluids and development of new correlations. Int. J. Heat Mass Transf. 2009, 52, 4675–4682. [Google Scholar] [CrossRef]
- Mahian, O.; Kianifar, A.; Kleinstreuer, C.; Moh’d, A.A.N.; Pop, I.; Sahin, A.Z.; Wongwises, S. A review of entropy generation in nanofluid flow. Int. J. Heat Mass Transf. 2013, 65, 514–532. [Google Scholar] [CrossRef]
- Ko, T.H.; Ting, K. Entropy generation and optimal analysis for laminar forced convection in curved rectangular ducts: A numerical study. Int. J. Therm. Sci. 2006, 45, 138–150. [Google Scholar] [CrossRef]
- Bejan, A. General criterion for rating heat-exchanger performance. Int. J. Heat Mass Transf. 1978, 21, 655–658. [Google Scholar] [CrossRef]
- Bejan, A. A study of entropy generation in fundamental convective heat transfer. J. Heat Trans. 1979, 101, 718–725. [Google Scholar] [CrossRef]
- Singh, P.K.; Anoop, K.B.; Sundararajan, T.; Das, S.K. Entropy generation due to flow and heat transfer in nanofluids. Int. J. Heat Mass Transf. 2010, 53, 4757–4767. [Google Scholar] [CrossRef]
- Shah, R.K.; London, A.L. Laminar Flow Forced Convection in Ducts; Academic Press: New York, NY, USA, 1978. [Google Scholar]
- Huminic, G.; Huminic, A. Heat transfer and entropy generation analyses of nanofluids in helically coiled tube-in-tube heat exchangers. Int. Commun. Heat Mass Transf. 2016, 71, 118–125. [Google Scholar] [CrossRef]
Substances | Dp/nm | k/W·m−1·K−1 | Cp/J·kg−1·K−1 | ρ/kg·m−3 | µ/Pa·s |
---|---|---|---|---|---|
Al2O3 | 30 | 36.00 | 773.00 | 3880.00 | - |
Base fluid | - | 0.60 | 4182.00 | 998.20 | 9.93e−4 |
φ/% | k/W·m−1·K−1 | Cp/J·kg−1·K−1 | ρ/kg·m−3 | µ/Pa·s |
---|---|---|---|---|
0.0 | 0.60 | 4182.00 | 998.20 | 9.93e−4 |
1.0 | 0.62 | 4053.21 | 1027.02 | 1.08e−3 |
2.0 | 0.63 | 3931.45 | 1055.84 | 1.19e−3 |
3.0 | 0.65 | 3816.16 | 1084.65 | 1.32e−3 |
Nodes | Nu | Difference % | f × 10 | Difference % | |
---|---|---|---|---|---|
1 | 498,920 | 5.775 | 12.68 | 1.370 | 5.71 |
2 | 1,163,056 | 5.125 | 5.87 | 1.296 | 3.52 |
3 | 2,452,800 | 4.841 | 0.10 | 1.252 | 0.89 |
4 | 5,689,802 | 4.836 | - | 1.241 | - |
Re | fRe | Nu | ||||
---|---|---|---|---|---|---|
Referenced Result | Proposed Model | Difference% | Referenced Result | Proposed Model | Difference% | |
50 | 18.233 | 18.136 | −0.53 | 2.94 | 2.930 | −0.35 |
100 | 18.233 | 18.300 | −0.37 | 2.94 | 2.914 | 0.87 |
200 | 18.233 | 18.344 | 0.61 | 2.94 | 2.954 | 0.46 |
300 | 18.233 | 18.401 | −0.92 | 2.94 | 2.957 | −0.59 |
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Li, P.; Xie, Y.; Zhang, D.; Xie, G. Heat Transfer Enhancement and Entropy Generation of Nanofluids Laminar Convection in Microchannels with Flow Control Devices. Entropy 2016, 18, 134. https://doi.org/10.3390/e18040134
Li P, Xie Y, Zhang D, Xie G. Heat Transfer Enhancement and Entropy Generation of Nanofluids Laminar Convection in Microchannels with Flow Control Devices. Entropy. 2016; 18(4):134. https://doi.org/10.3390/e18040134
Chicago/Turabian StyleLi, Ping, Yonghui Xie, Di Zhang, and Gongnan Xie. 2016. "Heat Transfer Enhancement and Entropy Generation of Nanofluids Laminar Convection in Microchannels with Flow Control Devices" Entropy 18, no. 4: 134. https://doi.org/10.3390/e18040134