Shintaro Hayakawa^a , Takashi Fukue^a,*,† , Yasuhiro Sugimoto^a , Wakana Hiratsuka^b , Hidemi Shirakawa^c , Yasushi Koito^d

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.29

Abstract This paper describes the effects of a combination of rib and pulsating flow on heat transfer enhancement in an mm-scale model that simulates the narrow flow passages in cooling devices of downsized electronic equipment. This research aims to develop a novel water cooling device that increases heat transfer performance while inhibiting pumping power. Our recent study has reported that a combination of pulsating flow and rib could enhance heat transfer performance relative to the simple duct. In the present study, to verify the optimal rib height for improving heat transfer by pulsating flow, we evaluated the relationship between heat transfer… More >

Ameer Abed Jaddoa^* , Karema Assi Hamad, Arshad Abdul Jaleil Hameed

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-9, 2023, DOI:10.5098/hmt.20.18

Abstract In the Heat Transfer process, many innovations were introduced aiming to obtain the most optimum behavior of the cooling process using nanofluids as coolant liquids. These nanofluids have gained much attention in cooling systems due to their special rheological and thermal performance. In this work, an experimental evaluation is conducted for nanofluids Al₂O₃, SiO₂, CuO, ZnO, and TiO₂ nanoparticles applied to a mini-channel. The nanofluid particles were entirely spread out in purified water (size of 15 nm) before being passed to the heat sink through a confined inflow channel. The obtained results showed that the achieved improvement rates are 25%,20%,… More >

Hussein Al-Gburi^*, Akeel Abbas Mohammed, Audai Hussein Al-Abbas

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-7, 2023, DOI:10.5098/hmt.20.17

Abstract Transferring thermal energy efficiently necessitates utilizing a heat exchanger capable of producing the full thermal power of the energy supply at lowest possible cost and time. Therefore, in the present investigation, the impact of corrugated helical coil concentric tube-in-tube heat exchanger on the thermal performance is investigated experimentally. As a continuous in our issue of heat exchanger, the corrugated helical tube-in-tube is carried out and compared with smooth helical tube-in-tube for free convection heat transfer. The set-up of the experimental apparatus are designed and utilized to be appropriate for the cooling and heating systems of working fluid. The impacts of… More >

O. M. Oyewola^a,b,* , M. O. Petinrin^a , and H. O. Sanusi^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-8, 2023, DOI:10.5098/hmt.20.16

Abstract The flow and heat transfer behaviour of channels with dimples and protrusions of spherical and piriform shapes was numerically explored by solving the Navier-Stokes and energy equations with a CFD software, the ANSYS Fluent 19.3, in the range of Reynolds numbers from 8,500 to 59,000. The values of the Nusselt number and friction factors were estimated and the non-dimensional Performance Evaluation Criterion (PEC) was determined to measure the thermal-hydraulic performance. The results reveal that the piriform protruded channel demonstrated a higher thermal performance with Nusselt number values of 36%, 15%, 23%, and 9% than the smooth, spherical dimpled, piriform dimpled,… More >

Sheikh Hassan¹, Didarul Ahasan Redwan¹, Md. Mamun Molla^1,2,*, Sharaban Thohura³, M. Abu Taher⁴, Sadia Siddiqa⁵

Energy Engineering, Vol.118, No.6, pp. 1659-1679, 2021, DOI:10.32604/EE.2021.017657

Abstract A two-dimensional (2D) laminar flow of nanofluids confined within a square cavity having localized heat source at the bottom wall has been investigated. The governing Navier–Stokes and energy equations have been non dimensionalized using the appropriate non dimensional variables and then numerically solved using finite volume method. The flow was controlled by a range of parameters such as Rayleigh number, length of heat source and nanoparticle volume fraction. The numerical results are represented in terms of isotherms, streamlines, velocity and temperature distribution as well as the local and average rate of heat transfer. A comparative study has been conducted for… More >

Xiaoyu Hu, Yi Wang, Siyuan Li, Qiang Sun, Shuzhan Bai, Guoxiang Li^*, Ke Sun^*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1049-1066, 2021, DOI:10.32604/fdmp.2021.016763

Abstract The increasing demand of cooling in internal combustion engines (ICE) due to engine downsizing may require a shift in the heat removal method from the traditional single phase liquid convection to the application of new technologies based on subcooled fluid boiling. Accordingly, in the present study, experiments based on subcooled flow boiling of 50/50 by volume mixture of ethylene glycol and water coolant (EG/W) in a rectangular channel heated by a cast iron block are presented. Different degrees of subcooling, velocity and pressure conditions are examined. Comparison of three empirical reference models shows that noticeable deviations occur especially when low… More >

Hashem Shatnawi^1,2,*, Chin Wai Lim², Firas Basim Ismail³, Abdulrahman Aldossary¹

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 1693-1711, 2021, DOI:10.32604/cmc.2021.016741

Abstract The receiver is an important element in solar energy plants. The principal receiver’s tubes in power plants are devised to work under extremely severe conditions, including excessive heat fluxes. Half of the tube’s circumference is heated whilst the other half is insulated. This study aims to improve the heat transfer process and reinforce the tubes’ structure by designing a new receiver; by including longitudinal fins of triangular, circular and square shapes. The research is conducted experimentally using Reynolds numbers ranging from 28,000 to 78,000. Triangular fins have demonstrated the best improvement for heat transfer. For Reynolds number value near 43,000… More >

Jingying Li¹, Tiejun Zhu¹, Fengming Li¹, Dong Wang¹, Xianbiao Bu², Lingbao Wang^2,*

Energy Engineering, Vol.118, No.3, pp. 517-534, 2021, DOI:10.32604/EE.2021.014464

Abstract The single well geothermal heating (SWGH) technology has attracted extensive attention. To enhance heat extraction from SWGH, a mathematical model describing heat transfer is set up, and the key influence factor and heat transfer enhancement method are discussed by thermal resistance analysis. The numerical results show that the thermal resistance of rock is far greater than that of well wall and fluid. So, reducing rock thermal resistance is the most effective method for enhancing the heat extraction power. For geothermal well planning to drill: rock thermal resistance can be reduced by increasing well diameter and rock thermal conductivity; the temperature… More >

Daoming Shen^1,*, Xia Zhang¹, Wei He¹, Jinhong Xia¹, Songtao Xue²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1259-1272, 2020, DOI:10.32604/fdmp.2020.010951

Abstract Experiments about heat transfer in the presence of a two-phase flow due to the condensation of a R1234yf refrigerant have been performed considering a smooth tube and two micro-fin tubes. The following experimental conditions have been considered: Condensation temperatures of 40°C, 43°C and 45°C, mass fluxes of 500–900 kg/(m² ·s), vapor qualities at the inlet and outlet of the heat transfer tube in the ranges 0.8–0.9 and 0.2–0.3, respectively. These tests have shown that: (1) The heat transfer coefficient increases with decreasing the condensation temperature and on increasing the mass flux; (2) The heat transfer coeffi- cient inside the micro-fin… More >

Anees Imtiaz¹, Oi-Mean Foong², Aamina Aamina¹, Nabeel Khan¹, Farhad Ali^{3, 4, *}, Ilyas Khan⁵

CMC-Computers, Materials & Continua, Vol.65, No.1, pp. 171-192, 2020, DOI:10.32604/cmc.2020.011397

Abstract Gold metallic nanoparticles are generally used within a lab as a tracer, to uncover on the presence of specific proteins or DNA in a sample, as well as for the recognition of various antibiotics. They are bio companionable and have properties to carry thermal energy to tumor cells by utilizing different clinical approaches. As the cancer cells are very smaller so for the infiltration, the properly sized nanoparticles have been injected in the blood. For this reason, gold nanoparticles are very effective. Keeping in mind the above applications, in the present work a generalized model of blood flow containing gold… More >