Open Access

ARTICLE

Shankar Durgam
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-10, 2022, DOI:10.5098/hmt.18.49
Abstract This article explores experimentally and numerically the effect of conductance on cooling of electronic chips by forced air flow in a vertical channel for thermal control. Experiments are conducted using substrates of FR4, bakelite, copper clad board (single layer) equipped with aluminum heat sources at uniform heat fluxes of 1000, 2000, and 3000 W/m² at 500 ≤ Re ≤ 1500. Computer simulations are performed to validate experimental results using a finite element method based COMSOL Multiphysics 4.3b software and the results are in agreements of below 10%. The temperatures obtained showed high thermal conductance copper clad More >

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369

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ARTICLE

Wei Lin^a, Yongbin Zhang^b,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-4, 2022, DOI:10.5098/hmt.18.48
Abstract The cellular membrane of animal has the thickness normally between 5nm and 10nm and has the filtration nanopores with the diameters normally between 0.4nm and 1.2nm. The pressure drop and the critical power loss on the single nanopore for starting the wall slippage have been obtained. The wall slippage is sensitively raised with the pore radius reduction and has a linear dependence on the power loss on the pore. Without wall slippage, the water flow in the pore is much slower than the classical theory calculation; However it is far faster than the classical theory More >

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564

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354

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ARTICLE

Y. L. Zhang^a , H. B. Lin^b, S. P. Li^b,*, J. J. Xiao^a, L. Zhang^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.47
Abstract Centrifugal pumps need to be stopped in the case of closing valve sometimes due to some specific application requirements. This paper presents a numerical simulation of the unsteady flow inside a low specific speed centrifugal pump during closed-valve forward and reverse stopping process. The study results show that the average internal pressure gradually decreases during stopping periods. At the same blade radius, the pressure on working surface is significantly higher than the suction surface. The pressure gradually increases from the impeller inlet to the outlet. The simulation fully shows the transient flow characteristics inside the More >

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600

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385

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ARTICLE

Nazia Afrin^a,*, Jonathan Lopez, Juan Ocampo
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-7, 2022, DOI:10.5098/hmt.18.46
Abstract Large number of numerical computer simulations in engineering places is a serious burden on associated optimization problems nowadays. Kriging Surrogate based optimization (KSBO) becomes standard practice in analyzing expensive and time-consuming simulation. This paper aims to investigate the surrogate based analyze and optimization of thermal damage in living biological tissue by laser irradiation using a generalized duel phase model. The relationships of maximum temperature and thermal damage in living biological tissues of the response with two variables at a time are studied. The result shows that the surrogate model predicted response variables i.e, temperature and More >

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602

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412

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ARTICLE

Husam Abdulrasool Hasan^a,*, Jenan S. Sherza^a, Lammiaa Abdulrudah Abd^a, Kayser Aziz Ameen^a, Azher M. Abed^b, Ali Arif hatem^a, Kamaruzzaman Sopian^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.45
Abstract In a Fresnel-based Concentrated Photovoltaic system, multi junction solar cells suffer from increased PV temperature, resulting in a decrease its electrical efficiency. This study design to investigate the influence of using Water/Al₂O₃ Nanofluid as cooling fluid on heat transfer enhancement and top surface temperature for multi-junction solar cell in the Fresnel-based Concentrated Photovoltaic thermal CPVt System. The CFD simulation was conducted on mini-channel under the concentrated multi-junction solar cell with using water/Al₂O₃ Nanofluid and pure water as coolant fluids. The Reynolds number is in the range of 15000-30000 were examined. The average Nusselt numbers augmented through… More >

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410

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ARTICLE

Le Anh Duc^a , Nguyen Hay^a, Pham Van Kien^b,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-7, 2022, DOI:10.5098/hmt.18.44
Abstract This study determined the most appropriate thin layer drying model, the effective moisture diffusivity and the activation energy of moisture within Ganoderma lucidum in radio frequency (RF) assisted heat pump drying method. The thin layer drying experiments were conducted with input drying parameters such as: drying temperature of 40, 45 and 50°C and RF power of 0.65, 1.3 and 1.95 kW. In order to select a suitable form of drying curve, seven different thin layer drying models (Lewis, Page, Modified Page, Henderson and Pabis, Verma, Midilli, and Wang and Singh) were fitted to the experimental More >

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581

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402

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ARTICLE

Hamzeh T. Alkasasbeh^*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.43
Abstract The purpose of this study is mathematical simulation the combined free convection of hybrid micropolar ferrofluids about a solid sphere with magnetic force. We studied the magnetic oxide (Fe₃O₄) and Cobalt Iron Oxide (CoFe₂O₄) nanoparticles and suspended them into water–ethylene glycol (EG) (H₂O+(CH₂OH)₂ (50-50%) mixture. Numerical results for correlated physical quantities were gained through the Keller Box method along with the assistance of MATLAB software. The influence of relevant contributing parameters on physical quantities are inspected through tables and graphical illustrations. According to the current findings, the mono ferrofluid has the highest local skin friction, heat transmission More >

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340

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ARTICLE

Abderraouf Dahmani^a,∗ , José Muñoz-Cámara^b, Juan Pedro Solano^b, Samir Laouedj^a
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.42
Abstract In this paper, a steady and laminar flow of ferrofluid (Fe₃O₄/Water) in a uniformly heated tube under the effect of non-uniform magnetic field arranged periodically along the tube is numerically analyzed using the finite volume method. The analysis sheds light on the flow pattern, Nusselt number, friction factor and the Performance Evaluation Criterion, at laminar flow regime (10² ≤ Re ≤ 10³ ) and for various magnetic numbers (Mn = 0, 2.83 · 10⁴ , 6.37 · 10⁴ and 1.13 · 10⁵ ). The obtained results show that the magnetic field generated by periodic arrangement of the wire pitches, More >

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381

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ARTICLE

Harinakshi Karkera^a , Nagaraj N. Katagi^a,† , Ramesh B. Kudenatti^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-10, 2022, DOI:10.5098/hmt.18.41
Abstract In this paper, we study the characteristics of laminar boundary-layer flow of a viscous incompressible fluid over a moving wedge. The transformed boundary-layer equation given by the Falkner-Skan equation is solved by an efficient easy-to-use approximate method based on uniform Haar wavelets in conjunction with quasilinearization and collocation approach. The residual and error estimates are computed to confirm the validity of the obtained results. A meaningful comparison between the present solutions with existing numerical results in the literature is carried out to highlight the benefits and efficiency of proposed method. Furthermore, the influence of variable More >

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REVIEW

Vikas Gulia, Anirban Sur^*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-10, 2022, DOI:10.5098/hmt.18.40
Abstract Over the past few decades, the world is moving towards miniature products owing to the technological developments in variegated industrial domains such as aerospace, biomedical, electronics, etc. This has led to the exponential growth of efficient micro cooling systems which are light in weight and have effective thermal performance. Microchannel Heat Sinks and Microchannel Heat Exchangers are the widely adopted solutions for such efficient micro cooling systems. This paper comprehensively reviews the recent developments in the field of Microchannel Heat Sinks and Microchannel Heat Exchangers. Initially, the concept of microchannel cooling is discussed. Further, a More >

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E. Flilihi^a,† , E. H. Sebbar^a, D. Achemlal^a, T. EL Rhafiki^a, M. Sriti^b, E. Chaabelasri^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.39
Abstract In this paper, we made a numerical simulation of convective heat transfer in a rectangular section pipe of a air flat plate solar collector using three forms of the absorber plate namely, simple shape, rectangular-shape, and half circle-shape. The flow is considered laminar and stationary, where the heat exchange between the absorber plate and the fluid takes place in useful area. The computer code in fluid dynamics, the fluent, is applied to integrate the governing equations on each control volume. A detailed description of the fluid flow and heat transfer in the rectangular channel was More >

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387

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Yu-Liang Zhang^a , Liang-Huai Tong^b, Jun-Jian Xiao^a,† , Kai-Yuan Zhang^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.38
Abstract Nozzle flowmeter has simple structure and wide application. In order to study the influence of temperature change on the inner wall of nozzle flowmeter on the thermal effect of flowmeter, the thermal effect of nozzle flowmeter was numerically simulated at five different inner wall temperatures in this paper. It is found that with the increase of the inner wall temperature, obvious stress concentration occurs in the upstream and downstream pressure inlets and the inlet and outlet areas of the flowmeter, and the thermal stress increases with the increase of the wall temperature. There are large More >

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389

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ARTICLE

Layth M. Jaleel^a , Hayder M. Jaffal^b,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.37
Abstract The phase change material (PCM)-based low-grade heat harnessing exchanger is used to study the recovering wasted energy from grey water. This experimental study investigated the effect of fin shape on improving the thermal performance of a PCM-based low-grade heat harnessing exchanger. Three heat exchangers of equal dimensions, namely, finless, inclined finned and V-shaped finned heat exchangers, were manufactured and tested in a container containing the PCM. A finless heat exchanger was adopted as a base case to demonstrate the improvement of heat transfer by using fins. The finless heat exchanger consists of two serpentine tubes… More >

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650

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406

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ARTICLE

M. Y. Dhange^a,*, G. C. Sankad^a, Ishwar Maharudrappa^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.36
Abstract The present paper investigates the impacts of heat transfer and magnetic field on the boundary layer flow of Casson fluid over a linearly stretching sheet. The researchers have introduced analytical and numerical solutions for the momentum and energy equations by transforming the equations into the system of ordinary differential equations with the aid of the similarity transformations technique. The velocity and temperature profiles for pertinent constraints like Casson fluid constraint, Chandrasekhar number, Prandtl number, and thermal conductivity are presented through graphs. The influence of the wall shear stress and the Prandtl number increases while the… More >

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ARTICLE

Scott Wahlquist^a, Amir Ali^a,b,*, Su-Jong Yoon^c, Piyush Sabharwall^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.35
Abstract The heat transfer performance of a novel tube configuration that combines the swirling velocity induced by oval-twisting and secondary flow generated by a helical geometrical flow path is presented. The Nusselt number (Nu) and friction factor (f) are compared for the laminar flow regime (Re = 250- 2000) under isothermal wall conditions. Under the same flow and boundary conditions, the oval-twisted helical tube increased the Nu and slightly increased the f over the circular helical tube. The best performance with the highest Nuand lowest f occurs at the coil curvature ratio (d_h/D) of 0.17. The quantified enhancement performance factor More >

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372

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REVIEW

Priyanka Chauhan^a , Himani Pathania^a, Shriya^a, Neetika^a, Nidhi^a, Sakshi^a, Sheetal Choudhary^a, Rajesh Kumar^b,*, Mamta Sharma^a,c,*, Sameer Rahatekar^d, Anil Kumar^e,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-20, 2022, DOI:10.5098/hmt.18.34
Abstract Solar dryers have proven to be one of the best environmentally friendly approaches for drying purpose of medicinal plants and agricultural crops. Use of solar radiations in drying purpose of plant parts has proven economically as well as environmentally responsible and sensible application. Plants are the treasure of nature with hidden medicinal properties to treat diseases. Plant material should be processed properly for extraction of medicinal molecules in terms drying to decrease the manufacturing loss and to increase the standard of product. Cognizances of ethnobotanical knowledge on plant wealth are extremely beneficial in utilization and… More >

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386

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ARTICLE

Lei Zhang^a , Fuyong Su^a,*, Zhi Wen^a, Shuming Tao^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.33
Abstract To study the electric furnace melting process of different process parameters (e.g., current frequency, electric current intensity, the insertion depth of the electrode column, and water wall temperature) for each field quantity change and the impact of electric furnace slag conditioning, the mathematical model of the electromagnetic and temperature fields of the slag tempering process in electric furnace was established, and the numerical simulation was analyzed by the ANSYS finite element software. Research results show that current skin effect appears with the increase in current frequency, while the difference between the two ends and the More >

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630

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368

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ARTICLE

Bamdeb Dey^a,† , Bhrigu Kumar Kalita^b, Rita Choudhury^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.32
Abstract In this paper, we attempt to analyze the effects of radiation and chemical reactions on laminar boundary layer flow of an electrically conducting unsteady viscoelastic incompressible fluid flow along a vertical semi-infinite plate passing through porous channel. The coupled nonlinear partial differential equations for energy, momentum, and mass diffusions are solved analytically with the use of perturbation technique. Moreover, the analytical expressions for fluid velocity, temperature, and concentration distributions are obtained and interpreted using the software MATLAB. The enhancement of velocity is prominent with the growth of G_r, G_m, N_r and K_r but a reverse pattern is More >

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641

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358

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ARTICLE

O. M. Oyewola^a,b,*, S. I. Afolabi^b, O. S. Ismail^b, M.O. Olasinde^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-7, 2022, DOI:10.5098/hmt.18.31
Abstract Finite element method is adopted in analyzing a two dimensional partial differential equations of Navier Stokes that governs mass, momentum and energy for a convective heat transfer problem within a square cavity. The cavity walls kept at constant cold temperature except for the right wall being adiabatic. With an embedded circular heated block located in the cavity, simulations are performed to determine the effect of the position of the block at the top, middle and bottom of the cavity on natural convection. The experiments are carried out for different values of Rayleigh number varying from 10³… More >

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395

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ARTICLE

O. M. Oyewola^a,b,* , O. S. Ismail^b , M. O. Olasindeb , O. O. Ajide^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.30
Abstract In this work, attempt is made to investigate the effect of cylindrical arrangement on the thermal and flow fields within the mixed convective regime for different values of Reynolds number within the study zone. Constructal design was used to design the flow geometric. Two-dimensional unsteady laminar flow equations with buoyancy force were solved numerically using finite element technique implemented on ANSYS FLUENT software. The study showed an optimised arrangement of 50% difference in coefficient of drag and 10% difference in Nusselt number within the geometrical arrangement variation. The effect of geometric arrangement is pronounced at More >

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418

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ARTICLE

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… More >

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426

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Hussein Al-Gburi^*, Doaa Fadhil Kareem, Malik N. Hawas
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.28
Abstract In this article, an investigational analysis has been conducted to explore the effect of biodiesel fuel blends on characteristics of engine and releases (CO2, CO, HCl, and NOx) of single-cylinder, four strokes at the variable biodiesel concentration. The releases of gases and the engine's characteristics were measured at six blending biofuels and six-speed conditions and constant load. The blending proportions of biodiesel with diesel fuel-based by volume were at 0% pure diesel, 5%, 10%, 15%, 20%, and 25%. This investigation aims to assess the biodiesel fuel mixture's impact on the CI engine performance in terms More >

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364

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ARTICLE

Fithry Mohd Amir^*, Mohd Zamri Yusoff, Saiful Hasmady Abu Hassan
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-15, 2022, DOI:10.5098/hmt.18.27
Abstract Nanofluid film on a horizontal tube is investigated numerically on the circular and multi-faceted cylinder. The fluid flow characteristics, including film thickness, shear stress, and thermal performance, are observed and analyzed. Fluid film on the circular surface is typical in many engineering applications, but the study of nanofluid film on non-circular surface is deficient in literature. The study provides a numerical model of a multi-faceted cylinder to simulate the nanofluid film on the non-circular surfaces using a volume of fluid (VOF) method. The ratio of Brownian motion to thermophoretic diffusion, N_BT developed along the film thickness More >

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577

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ARTICLE

L. Cheng, Y. L. Zhang^†
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.26
Abstract To obtain the transient characteristics of a centrifugal pump during a rapid startup process accurately, a circulating piping system, including the pump, is established. A full three-dimensional unsteady incompressible viscous flow of a low-specific speed centrifugal pump during rapid startup is numerically simulated using the finite volume method, RNG k-ε turbulence model, sliding grid technology, dynamic grid technology, and userdefined function. Results show that the effect of dynamic and static interference becomes remarkably evident with the increase in speed in the starting process. The effect of dynamic and static interference makes the flow rate show More >

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608

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ARTICLE

Erdiwansyah Erdiwansyah^a,d , Mahidin Mahidin^b, Husni Husin^b, Muhammad Faisal^c, Usman Usman^c, Muhtadin Muhtadin^c, Asri Gani^b,*, Rizalman Mamat^e
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.25
Abstract The modification of the perforated plate applied in this study aims to provide sufficient air access into the combustion chamber. Burning experiments were carried out with three different types of fuel (such as palm kernel shell (PKS), oil palm midrib (OPM), and empty fruit bunches (EFB). The purpose of the experiment with the modification of the perforated plate is to investigate the combustion temperature and the rate of heat transfer in the boiler. The fluidized-bed combustor (FBC) combustion chamber is used as the combustion chamber. Experimental results were obtained at four different points using a… More >

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ARTICLE

Ningxiang Lu, Jinwang Li^*, Yongkang Sun
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-15, 2022, DOI:10.5098/hmt.18.24
Abstract Heat pipe is a kind of high-efficiency heat transfer element which depends on the phase change of its internal working liquid. It has the characteristics of high heat conductivity and excellent average temperature performance. As the core component of heat pipe, capillary wicks play the role of transmitting working fluid and have a crucial impact on the heat transfer performance of heat pipe. In this paper, the research progress of capillary wicks in recent years is introduced from the aspects of structure, fabrication method, performance research, numerical analysis and so on. The current research results More >

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ARTICLE

Yu.E. Nikolaenko^a , D.V. Pekur^b,*, V.Yu. Кravets^a, V.M. Sorokin^b, D.V. Kozaka , R.S. Melnyk^a, L.V. Lipnitskyi^a, A.S. Solomakha^a
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-13, 2022, DOI:10.5098/hmt.18.23
Abstract This study compares thermal characteristics of two design versions of a new low-cost air-cooling system with a standard heat sink profile and built-in flat heat pipes of a simple design with a similar cooling system design without the heat pipes. The aim of the work is to determining the thermal characteristics and choosing the most effective option in a practical context. Using computer simulation in the Solidworks Flow Simulation standard software package allowed determining how the temperature of 8 transistors with a total power of 224 W was affected by changes in air velocity from… More >

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470

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ARTICLE

Mei Su^a , Ligai Kang^b, Kangjie Sun^b,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-5, 2022, DOI:10.5098/hmt.18.22
Abstract To study the heat transfer effect of rough surface in laminar flow, the direction splitting method is introduced by fully developed fields for solving the Navier–Stokes equations of incompressible flow in assuming two-dimension. Firstly, the algorithm of the incompressible Navier–Stokes equations with pressure correct is carried out. Secondly, the effects of pressure drop and heat transfer are investigated in different rough surface elements which are configured with triangular and rectangular elements. The Reynolds number, roughness element spacing, and roughness height are also considered as the factors which affect the heat transfer. The results indicate that More >

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ARTICLE

K.S. Balamurugan^a,*, S. Sreelatha^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.21
Abstract This study is focused on the investigation of magneto hydrodynamic mixed convection radiative heat and mass transfer flow of a steady, viscous, incompressible electrically conducting Newtonian fluid which is an optically thin gray gas over a permeable vertical infinite plate in the presence of first order chemical reaction, temperature gradient heat source, induced magnetic field and magnetic Prandtl number. The governing equations for this flow model are formulated and solved using perturbation technique. The velocity, temperature, concentration and induced magnetic field are studied through graphs, and the skin friction coefficient, Nusselt number and Sherwood number More >

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385

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ARTICLE

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-15, 2022, DOI:10.5098/hmt.18.20
Abstract Numerical analysis of fluid flow mechanism and heat transfer in a heat exchanger duct (HXD) with dual-inclined baffles (DIB) are reported. Three DIB types are examined: 1. “Type A” is located at the center of the HXD, 2. “Type B” is located on the upper-lower duct walls (as an orifice) and 3. “Type C” is a combination of the type A and B (as double orifices). The impacts of the ratio of DIB heights (b) to the square duct height (H; b/H) on increased heat transfer and friction loss are analyzed. Laminar flow (Re =… More >

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Tounsi Chati^a,* , Kouider Rahmani^b, Toufik Tayeb Naas^c, Abdelkader Rouibah^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-11, 2022, DOI:10.5098/hmt.18.19
Abstract Numerical results of turbulent natural convection and mass transfer in an open enclosure for different aspect ratios (AR = 0.5, 1, and 2) with a humidair are carried out. Mass fraction and local Nusselt number were proposed to investigate the heat and mass transfer. A heat flux boundary conditions were subjected to the lateral walls and the bottom one make as an adiabatic wall, while the top area was proposed as a free surface. Effect of Rayleigh numbers (10⁶ ≤ More >

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ARTICLE

Bhagawan Singh Yadav, Sushila Choudhary^†
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-10, 2022, DOI:10.5098/hmt.18.18
Abstract The present study concentrates on squeeze MHD flow of Casson fluid between parallel plates surrounded by a porous medium. The influence of melting, viscous dissipation and thermal radiation on the heat transfer process is disclosed. The characteristics of mass transport are detected with chemical reactions. Suitable similarity transforms are used to convert the partial differential equations into a system of ordinary differential equations. The transformed equations are solved using the bvp4c matlab solver with the shooting method. Our present study concluded that fluid velocity has direct relation with melting parameter while it is reciprocally related More >

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Ali Chitsazan^a , Georg Klepp^a, Mohammad Esmaeil Chitsazan^b, Birgit Glasmacher^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.17
Abstract For the optimization of the impinging round jet, the pressure force coefficient and drying energy consumption on the moving curved surface are set as the objective functions to be minimized simultaneously. SHERPA search algorithm is used to search for the optimal point from multiple objective tradeoff study (Pareto Front) method. It is found that the pressure force coefficient on the impingement surface is highly dependent on the jet to surface distance and jet angle, while the drying energy consumption is highly dependent on the jet to jet spacing. Generally, the best design study during the More >

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ARTICLE

Ali Chitsazan^a, Georg Klepp^a, Birgit Glasmacher^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.16
Abstract The effect of jet Reynolds number, jet exit angle, the nozzle to surface distance, jet to jet spacing on the heat transfer, and pressure force performance from multiple impinging round jets on a moving curved surface have been numerically evaluated. Two correlations are developed and validated for the average Nu number and the pressure force coefficient and the agreement between the CFD and correlations was reasonable. The surface motion effect becomes more pronounced on the Nu number distribution for low jet Re number, high jet to jet spacing, large jet to surface distance, and angled More >

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ARTICLE

Ali Chitsazan^a , Georg Klepp^a, Birgit Glasmacher^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-7, 2022, DOI:10.5098/hmt.18.15
Abstract The effect of surface curvature, number of jets, number of jet rows, jet arrangement, crossflow, and surface motion on the heat transfer and pressure force performance from multiple impinging round jets on the moving flat and curved surface have been numerically evaluated. The more number of jets (more than three jets) has no significant effect on the average heat transfer rate. The more number of jet rows increases the strength of wall jets interference and crossflow effects and degrade the average heat transfer rates. There is a minor difference between inline and staggered arrangements on More >

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ARTICLE

Zahra F. Hussain^a,*, Ahmed J. Hamed^b, Abdul Hadi N. Khalifa^b, Mohanad F. Hassan^b, Fawaz A.Najim^c,†
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-11, 2022, DOI:10.5098/hmt.18.14
Abstract At places far from the energy grid lines, freshwater is sometimes needed. Consequently, even countries with rich energy resources, such as the Arabian Gulf countries, have shown strong interest in desalination processes that often use renewable energy sources. In the present work, a desalination unit depending on the humidification-dehumidification principles is fabricated and tested under Baghdad, Iraq conditions. The HDH system under study consists of 6 parabolic trough solar collectors (PTSC) of a total aperture area of 8.772 m2 , the humidifier, and the dehumidifier and a tracking system. The effects of salty water flow More >

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ARTICLE

N. Poyyamozhi^a,* , A. Karthikeyan^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.13
Abstract This research focuses on the development of solar ponds for efficient storage of solar energy. The influence of phase change material in the solar storage capability of solar ponds has been studied in the present wok. A comparison in the temperature fluctuations of a typical solar pond is made with its counterpart provided with phase change material. Readings have been taken during the sunshine hours in a day, and extended to seventy-five days. The solar pond exhibited identical fluctuations in average temperature irrespective of the presence of phase change material. The results revealed that during… More >

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ARTICLE

Mohammed Z. Swalmeh^*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.12
Abstract Heat transfer characteristics for free convection boundary layer flow with a Ferro-hybrid nanofluid in the Casson field, over a stretching sheet, have been numerically investigated and tested. The constant wall temperature boundary condition was applied in this study. The dimensional governing equations were transformed to partial differential equations (PDEs) and then solved numerically by an implicit finite difference scheme known as Keller box method. The Numerical findings were presented by tabular and figures by using MATLAB program. These numerical findings were gained according to considering and analyzing the impacts of Ferro-hybrid nanofluids Casson parameters, on More >

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K.S. Balamurugan^a,*, N. Udaya Bhaskar Varma^b, J.L. Ramaprasad^c, J. Prakash^d
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.11
Abstract Current work reports heat and mass transfer effects on unsteady free convection flow past a linearly accelerated isothermal inclined plate with variable temperature and mass diffusion with thermal radiation. The fluid is gray and non-scattering medium. When time t>0, the plate is accelerated with velocity u0 t, the plate temperature is raised linearly with respect to time and the mass is diffused from the plate linearly with time. The Mathematical equations represent the present flow problem are solved by Laplace transform method. The influences of significant involved parameters on velocity, temperature and concentration are tested. More >

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Ayad S. Abdallah^a,b,*, Nabil Jamil Yasin^a, Hani Aziz Ameen^a
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-7, 2022, DOI:10.5098/hmt.18.10
Abstract To reduce the energy consumption in air-conditioning systems without changing the required temperature level in the air-conditioned space, Heat Pipe Heat Exchanger (HPHE) has been experimentally used and tested. The heat pipe has been filled with working fluid by about 50% of the volume of the evaporator which represents the filling ratio. In this research, three mass concentration of nanoparticle from copper oxide (CuO), 1wt%, 3wt% and 5wt% have been used and studied. Additionally, its effect on the HPHE effectiveness and the heat recovery ratio at different inlet air temperatures, 30, 35, 40, 45, 50,… More >

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422

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Marwa M. Ibrahim^a,*, Amal El Berry^a, Karim Ashour^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-11, 2022, DOI:10.5098/hmt.18.9
Abstract Conventional sources of energy are rapidly decreasing more and more. Hence, Renewable energy is presently attracting significant. Therefore, this paper aims at investigating the techno-economic feasibility of SWHS for swimming pools in tourist hotels and resorts. The proposed system presents an active direct system without auxiliary heaters to evaluate the potential for using solar thermal collectors for heating swimming pools of tourist resort; installed in El Gouna city, Egypt, and to size solar collector using TSOL simulation software package to meet the demand of hot water, to analyze the impact of collector design-parameters concerning system… More >

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403

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Rongge Xiao^a,* , Qi Zhuang^a, Shuaishuai Jin^a , Wenbo Jin^a
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-7, 2022, DOI:10.5098/hmt.18.8
Abstract A model for predicting wax deposition rate in pipeline transportation is constructed to predict wax deposition in actual pipeline, which can provide decision support for the flow guarantee of waxy crude oil in pipeline transportation. This paper analyzes the working principle of Back Propagation Neural Networks (BPNN). Aiming at the problems of BPNN model, such as over learning, long training time, low generalization ability and easy to fall into local minimum, the paper proposes an improved scheme of using Whale Optimization Algorithm (WOA) to optimize BPNN model(WOABPNN).Taking 38 groups of crude oil wax deposition experimental More >

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438

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Mian Wang¹, Yongbin Zhang^2,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-5, 2022, DOI:10.5098/hmt.18.7
Abstract Blood capillaries are the ends of blood vessel tissues in human bodies, which are importantly functioned as exchanging the nutrients between bloods and interstitial fluids. Most blood capillaries such as in skins, skeletal muscles, cardiac muscles and lungs etc. have the walls with massively distributed cylindrical nanopores with diameters around from 50nm to 60nm. These pores are the only channels for transporting water, oxygen, carbon dioxide and ions, while preventing all the substances with the diameters greater than 60nm or a little more from passing through. The present paper presents the analytical results for the More >

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395

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Zainab Kareem Ghoben^a,*,†, Ahmed Kadhim Hussein^b
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-11, 2022, DOI:10.5098/hmt.18.6
Abstract he numerical analysis of a V-shaped baffle effect on the natural convection inside a parallelogrammical cavity filled with two different water-based nanofluids (Al2O3 and Cu) were studied in this work. The enclosure walls were maintained at a constant hot and cold temperatures on the left and right walls sequentially. The horizontal walls were isolated, while the baffles located on the right wall and sharing the same cold temperature with it. The finite element method was used to derive and solve the governing equations. The flow and thermal fields computed for different arrangements of: the number… More >

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362

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Hawraa T. Gatea^a , Atheer S. Hasson^a, Adil A. Alwan^b, Mohammed Y. Jabbar^b, Azher M. Abed^a
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.5
Abstract The present work is an experimental study into the thermal performance of air conditioning system (split unit), bases on using renewable energy as an assisted facter. The serpentine tube flat plate solar collector (STFPSC) is combined with 1-ton capacity split air conditioning system, which is installed after the compressor to superheat the refrigerant that leaves the compressor. The conventional air conditioning (A/C) system is compared with the suggested system. The results show that the coefficient of performance (COP) of the solar assisted air conditioning system (SAAC), is affected by the enhancement of the solar collector, More >

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387

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Albio D. Gutierrez^a,*, Hayri Sezer^b, Jose L. Ramirez^c
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-12, 2022, DOI:10.5098/hmt.18.4
Abstract This paper presents a computational model along with a thermal comfort criterion aimed at assisting the design of operating rooms (ORs) from the perspective of meeting suitable flow patterns and thermal comfort conditions for the occupants. The computational model is based on the finite volume method (FVM) to describe the air inside ORs along with the human thermoregulation model implemented in virtual mannequins for thermal comfort. The air model considers turbulent fluid motion, species transport and the conservation of energy, including thermal radiation. The human thermoregulation model incorporates two interacting systems of thermoregulation. Namely, the… More >

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431

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Yun Hao^* , Shaohua Lv, Song Wu
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.3
Abstract Traditional methods of enhancing the thermal efficiency of heating furnaces in continuously producing oilfields, such as replacing existing units with more efficient units or renovating old furnaces, are highly inconvenient. This paper studied on the characteristics of nanofluids, a novel heat transfer medium with excellent heat transfer characteristics to enhance the thermal efficiency of heating furnaces. The stable nanofluids (Al₂O₃-H₂O, SiO₂- H₂O, and TiO₂-H₂O) were prepared by a two-step method and various chemical and physical treatments were carried out. Thermal conductivities of the nanofluids were measured using the transient hot-wire method. Based on the analysis, the most More >

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382

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Amnart Boonloi^a, Withada Jedsadaratanachai^b,*
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-13, 2022, DOI:10.5098/hmt.18.2
Abstract This study numerically investigates pressure loss, heat transfer and thermal efficiency in round tube heat exchangers attached with various types of Vrings. A typical type A V-ring is compared with two types of modified V-rings (type B and C). The impacts of blockage ratios, b/D = 0.05, 0.10, 0.15 and 0.20 for all V-ring types in the turbulent region are discussed (Re = 3000 – 20,000). Flow directions in the round pipe attached with the V-rings are varied. The V-apex setting downstream is referred to as “V-Downstream, while the V-apex setting upstream is referred to More >

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371

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Boonchai Lertnuwat
Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-9, 2022, DOI:10.5098/hmt.18.1
Abstract The aim of this work is to numerically investigate the effect of mounting winglet vortex generators on different positions in rectangular-duct-type air heaters. The two investigated positions were the absorber plate and the insulation plate, opposite to the absorber plate. Four shapes of winglet vortex generator, i.e. perforated rectangular winglet vortex generators (P-RWVG), rectangular winglet vortex generators (RWVG), perforated trapezoidal winglet vortex generators (P-TWVG) and trapezoidal winglet vortex generators (TWVG), were used. Results showed that heat-transfer capability would be better if the winglet vortex generators were mounted on the opposite insulation plate in the cases More >

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