Krishan Kumar, Prathvi Raj Chauhan, Rajan Kumar, Rabinder Singh Bharj

DOI Number
First page
Last page


The present numerical work deals with the optimization of the micro-channel heat sink using irreversibility analysis. The nanofluid of Al2O3-water with the different nanoparticles concentration and the temperature-dependent property is chosen as a coolant. The flow is considered as fully developed, steady, and laminar in the constant cross-section of circular channels. Navier-Stokes and energy equations are solved for a single-phase flow with total mass flow rate and heat flow rate as constant. The objective functions related to the frictional and heat transfer irreversibilities are framed to assess the performance of the micro-channel heat sink. The optimum channel diameter corresponding to the optimum number of channels is determined at the lowest total irreversibility for both constant property solution and variable property solution. Designed optimum diameter is observed maximum for 2.5% Al2O3-water nanofluid with μ(T) variation followed by 1% Al2O3-water nanofluid with μ(T) variation, 2.5% Al2O3-water nanofluid with constant property solution, and 1% Al2O3-water nanofluid with constant property solution.


Micro-channel, Entropy Generation, Nanofluid, Property Variation

Full Text:



Xie, J., Amano, R.S., 2004, Numerical simulation of two-phase flow in microchannel, IEEE Ninth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (IEEE Cat. No. 04CH37543), 2, pp. 679-686.

Han, S., Gongnan, X., Chi-Chuan, W., 2020, Thermal performance and entropy generation of novel X-structured double layered microchannel heat sinks, Journal of the Taiwan Institute of Chemical Engineers., 111, pp. 90-104.

Oztop, H.F., Abu-Nada, E., 2008, Numerical study of natural convection in partially heated rectangular enclosures filled with nanofluids, International Journal of Heat and Fluid Flow, 29(5), pp. 1326-36.

Tayebi, T., Öztop, H.F., 2020, Entropy production during natural convection of hybrid nanofluid in an annular passage between horizontal confocal elliptic cylinders, International Journal of Mechanical Sciences, 171, 105378.

Zúñiga-Cerroblanco, J.L., Gonzalez-Valle, C.U., Lorenzini-Gutierrez, D., Hernandez-Guerrero, A., Cervantes de Gortari, J., 2016, Heat sink performance improvement by way of nanofluids, Proceedings of the ASME 2016 Heat Transfer Summer Conference collocated with the ASME 2016 Fluids Engineering Division Summer Meeting and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels, Washington, DC, USA, 2.

Kumar, K., Kumar, R., Bharj, R.S., Mondal, P.K., 2021, Irreversibility analysis of the convective flow through corrugated channels: a comprehensive review, The European Physical Journal Plus, 136(4), pp. 1-40.

Bejan, A., 1980, Second law analysis in heat transfer, Energy, 5(8-9), pp. 720-732.

Kumar, K., Kumar, R, Bharj, R.S., 2020, Entropy generation analysis due to heat transfer and nanofluid flow through microchannels: a review, International Journal of Exergy, 31(1), pp. 49-86.

Chen, K., 2004, Second‐law analysis and optimization of microchannel flows subjected to different thermal boundary conditions, International Journal of Energy Research, 29(3), pp.249-263.

Bejan, A., 1995, Entropy Generation Minimization: The Method of Thermodynamic Optimization of Finite-Size Systems and Finite-Time Processes, CRC Press, Boca Raton.

Bejan, A., 2002, Fundamentals of exergy analysis, entropy generation minimization, and the generation of flow architecture, International Journal of Energy Research, 26(7), pp. 545-565.

Kumar, R., Mahulikar, S.P., 2015, Effect of temperature-dependent viscosity variation on fully developed laminar microconvective flow, International Journal of Thermal Sciences, 98, pp. 179-191.

Rastogi, P., Mahulikar, S.P., 2018, Entropy generation in laminar forced convective water flow due to overloading toward the microscale, ASME Journal of Energy Resources Technology, 140(8), 082002.

Rastogi, P., Mahulikar, S.P., 2018, Optimization of micro-heat sink based on theory of entropy generation in laminar forced convection, International Journal of Thermal Sciences, 126, pp. 96-104.

Chauhan, P.R., Kumar, R., Bharj, R.S., 2019, Optimization of the circular microchannel heat sink under viscous heating effect using entropy generation minimization method, Thermal Science and Engineering Progress, 13, 100365.

Kumar, K., Kumar, R. Bharj, R.S., 2020, Circular microchannel heat sink optimization using entropy generation minimization method, Journal of Non-Equilibrium Thermodynamics, 45(4), pp. 333-342.

Heshmatian, S., Bahiraei, M., 2017, Numerical investigation of entropy generation to predict irreversibilities in nanofluid flow within a microchannel: effects of Brownian diffusion, shear rate and viscosity gradient, Chemical Engineering Science, 172, pp. 52-65.

Bianco, V., Scarpa, F., Tagliafico, L.A., 2018, Numerical analysis of the Al2O3-water nanofluid forced laminar convection in an asymmetric heated channel for application in flat plate PV/T collector, Renewable Energy, 116, pp. 9-21.

Manay, E., Akyürek, E.F., Sahin, B., 2018, Entropy generation of nanofluid flow in a microchannel heat sink, Results in Physics, 9, pp. 615-624.

Bianco, V., Marchitto, A., Scarpa, F., Tagliafico, L.A., 2019,Numerical investigation on the forced laminar convection heat transfer of Al2O3-water nanofluid within a three-dimensional asymmetric heated channel, International Journal of Numerical Methods for Heat & Fluid Flow, 29(3), pp. 1132-1152.

Alfaryjat, A.A., Dobrovicescu, A., Stanciu, D., 2019, Influence of heat flux and Reynolds number on the entropy generation for different types of nanofluids in a hexagon microchannel heat sink, Chinese Journal of Chemical Engineering, 27(3), pp. 501-513.

Shashikumar, N.S., Gireesha, B.J., Mahanthesh, B., Prasannakumara, B.C., Chamkha, A.J., 2019, Entropy generation analysis of magneto-nanoliquids embedded with aluminium and titanium alloy nanoparticles in microchannel with partial slips and convective conditions, International Journal of Numerical Methods for Heat & Fluid Flow, 20(10), pp. 3638-3658.

Kumar, R., Mahulikar, S.P., 2018, Physical effects of variable thermophysical fluid properties on flow and thermal development in micro-channel, Heat Transfer Engineering, 39(4), pp. 374-390.

Kumar, R., Mahulikar, S.P., 2020, Heat transfer characteristics of water flowing through micro-tube heat exchanger with variable fluid properties, Journal of Thermal Analysis and Calorimetry, 140, pp. 1919–1934.

Chauhan, P.R., Kumar, K., Kumar, R., Rahimi-Gorji, M., Bharj, R.S., 2020, Effect of thermophysical property variation on entropy generation towards micro-scale, Journal of Non-Equilibrium Thermodynamics, 45(1), pp. 1-7.

Wen, D., Ding, Y., 2004, Experimental investigation into convective heat transfer of nanofluids at the entrance region under laminar flow conditions, International Journal of Heat and Mass Transfer, 47(24), pp. 5181-5188.

Hussein, A.M., Bakar, R.A., Kadirgama, K., Sharma, K.V., 2013, Experimental measurement of nanofluids thermal properties,International Journal of Automotive and Mechanical Engineering, 7, pp. 850-863.

Kumar, R., Mahulikar, S.P., 2017, Numerical re-examination of Chilton–Colburn analogy for variable thermophysical fluid properties, ASME Journal of Heat Transfer, 139(7), 071701.

Bejan, A., 1982, Entropy Generation through Heat and Fluid Flow, New York: Wiley.

Genić, S., Jaćimović, B., Petrovic, A., 2018, A novel method for combined entropy generation and economic optimization of counter-current and co-current heat exchangers, Applied Thermal Engineering, 136, pp. 327-334.

Milovančević, U.M., Jaćimović, B.M., Genić, S.B., El-Sagier, F., Otović, M.M., Stevanović, S.M., 2019, Thermoeconomic analysis of spiral heat exchanger with constant wall temperature, Thermal Science, 23(1), pp. 401-410.


  • There are currently no refbacks.

ISSN: 0354-2025 (Print)

ISSN: 2335-0164 (Online)

COBISS.SR-ID 98732551

ZDB-ID: 2766459-4