Analysis of entropy generation of ferrofluid flow in the microchannel with twisted porous ribs: The

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Powder Technology 380 (2021) 349–357

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Powder Technology journal homepage: www.elsevier.com/locate/powtec

Analysis of entropy generation of ferrofluid flow in the microchannel with twisted porous ribs: The two-phase investigation with various porous layers Amirhosein Mosavi a,b, Shahab Naghdi Sedeh c, Davood Toghraie c, Aliakbar Karimipour d,⁎ a

Environmental Quality, Atmospheric Science and Climate Change Research Group, Ton Duc Thang University, Ho Chi Minh City, Vietnam Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam c Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Khomeinishahr, Iran d Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam b

a r t i c l e

i n f o

Article history: Received 10 July 2020 Received in revised form 8 September 2020 Accepted 26 November 2020 Available online 3 December 2020 Keywords: Entropy generation Twisted porous rib Microchannel Nanofluid flow Two-phase flow

a b s t r a c t Heat sinks are always in the center of electronic cooling researchers' attention. Microchannels, due to their increased surface and better thermal performance than that of normal heat sinks were used in electronic cooling devices. In this numerical investigation, the first and second laws of the thermodynamic impact of twisted porous ribs on the microchannel were studied. The effects of the Reynolds number and volume fraction of nanoparticles were investigated. The range of Reynolds number was 250 to 1000. All types of the microchannel in this study consisted of a clear microchannel, a twisted porous ribbed microchannel with two and three layers of twisted porous ribs. The results show that by inserting porous ribs, the local cross-section decreases, and the local Reynolds number increases. Also, twisted porous ribs are the cause of nanofluid flow circulation and make the heat transfer coefficient greater. Increasing the porous layer from one layer to three layers has an increasing effect on the heat transfer coefficient, and the friction factor and increasing the φ is the reason for increasing the friction factor. Finally, the microchannel with triple layers of twisted porous ribs has better performance in total entropy generation, and by inserting twisted porous ribs, the entropy generation decreases. © 2020 Elsevier B.V. All rights reserved.

1. Introduction In almost all cooling electronic devices, the generated magnetic field due to electricity exists. Electronic cooling devices generate heat, and it is necessary to remove the heat from the devices. At first, the normal heat sink did this task, but in recent years, normal heat sinks have been replaced with microchannels owing to their far better thermal performance. Several approaches, such as the use of nanoparticles and porous medium, contribute to the better thermal performance of microchannels than that heat sinks. Malvandi et al. [1] studied the impact of nanoparticle immigration on the vertical microchannel considering the thermophysical properties of nanofluid dependent on the temperature. They showed that their results of properties with temperature dependency were almost equal to those of properties with temperature independency. Khodabandeh and Abbassi [2] optimized the thermal and hydrodynamic performance of microchannel coolant contain nanofluid using the Eulerian-Lagrangian method. They indicated that the trapezoidal microchannel with the ⁎ Corresponding authors. E-mail addresses: amirhosein.mosavi@tdtu.edu.vn (A. Mosavi), aliakbarkarimipour@duytan.edu.vn (A. Karimipour).

https://doi.org/10.1016/j.powtec.2020.11.078 0032-5910/© 2020 Elsevier B.V. All rights reserved.

side angle of 70 degrees had the maximum thermal conductivity. Hosseini and Sheikholeslami [3] investigated the impact of the magnetic field on the nanofluid and entropy generation in the microchannel. They demonstrated that by increasing the φ, the friction factor and entropy generation was increased. Hosseini et al. [4] numerically analyzed the magnetohydrodynamic and entropy generation effect on the microchannel contain a porous medium. They illustrated that the optimal value was equal to 6.5 following the Reynolds number and the constant Hartman number for total entropy generation. Yang et al. [5] numerically studied the entropy generation and heat transfer of the microchannel to control flow. Their results indicated that the microchannel with the v groove shape had the minimum entropy generation. Toghraie et al. [6] numerically investigated the performance of the microchannel with L-shaped porous ribs and nanofluid. They inserted porous ribs in the microchannel, which increased thermal performance from 25 to 42% at different Reynolds numbers. For more information about nanoparticles, nanosheets, nanocomposites and membrane, please see Refs. [7–17]. In this study, the thermal performance of twisted porous ribs compared to the clear microchannel was analyzed. The effects of porosity percentage, the φ, and dimensionless numbers, including Reynolds and Hartman numbers on nanofluid flow and entropy generation,


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