Open Access

ARTICLE

P. Madhu Sravanthi^a,b, M. Radha Madhavi^a,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-9, 2022, DOI:10.5098/hmt.19.40
Abstract In this paper, reaction of magnetic field and activation energy is applied on nanoparticles and swimming gyrotactic microorganisms under the viscous dissipation is inspecting. The effect of thermophoresis and Brownian motion is also considered. The PDEs are naturalized into ODEs by using similarity transformations. To solving the PDEs by using RK-Fehlberg with shooting approach by MATLAB software. The effect of magnetic parameter, Schmidt number, Prandtl number, Brownian motion, thermophoresis, Peclet number, porosity parameter, on velocity, temperature, concentration, motile microorganism density portrait is in detailed it is discussed and the eventualities are demonstrated in graphs. The More >

View

700

Download

396

Open Access

ARTICLE

Mousa Aqeel Ali^*, Saad Najeeb Sheha^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-10, 2022, DOI:10.5098/hmt.19.39
Abstract In this study, the hydrothermal water flow characteristics using a dimpled inner tube heat exchanger are investigated experimentally and numerically. A numerical analysis has performed on two types of dimpled tubes (In-lined and staggered distributions) for two distribution angles 60o and 90o , and two dimple diameters(4 mm and 6 mm) with constant pitch ratio (X/d=8). In experimental part, a staggered arrangement dimpled inner tube distribution with angle 60o , dimple diameter of 6 mm and constant pitch ratio (X/d=8)is used as well as plain tube. The results illustrate that the heat transfer as Nusselt More >

View

633

Download

331

Open Access

ARTICLE

Olanrewaju M. Oyewola^a,b,*, Samuel I. Afolabi^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.38
Abstract Numerical analysis of heat transfer by convection in a square with a rectangular shape heated block located at the top, center and bottommost has been numerically investigated by applying the principal partial differential equations governing mass, momentum and energy using discontinuous Galerkin weighted procedure for residual finite element with the view of examining the significance of position of rectangular shaped heated block encapsulated within the square cavity. The right wall being adiabatic while the other three walls are maintained at low constant temperature. The heated block is maintained constantly hot. The developed code of COMSOL More >

View

538

Download

366

Open Access

ARTICLE

Kamyar Mohammadpour^*, Ali Chitsazan, Eckehard Specht
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.37
Abstract The length of flame and behavior of the flame and homogenization in temperature distribution play the main roles to obtain a better quality of lime. Performing experiments in a real lime shaft kiln plant are quite complicated. A lime shaft kiln normally has a large geometry, including a height of 15 meters and a diameter of 3 meters, and is filled with large stones moving in a vertical direction. In most cases, the measuring instruments are damaged. Due to these difficulties, modeling of physical and chemical processes is required for having a better understanding of… More >

View

541

Download

377

Open Access

ARTICLE

K.V. Chandra Sekhar^*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.36
Abstract The current study explores heat and mass transfer analysis of unstable MHD boundary layer flow of electrically conducting Casson fluid near an infinite Perpendicular porous plate, moving with variable velocity. Mass diffusion equation was described by the homogenous first order chemical reaction. The equations controlling the flow converted into dimensionless form and solved by applying Laplace transform method and the expressions for velocity, temperature and concentration of the flow are acquired in exact form. To understand the physical insight of the problem a detailed study of involved parameters of the flow was done and explained More >

View

573

Download

364

Open Access

ARTICLE

Ali Chitsazan^a,*, Georg Klepp^a, Birgit Glasmacher^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.35
Abstract The objective of the present research is the prediction of large arrays of impingement jets using a computational model. The heat transfer and the force coefficient from single and multiple jet rows (1, 2, 4, 8, and infinity rows) for two different nozzle shapes as either orifice or straight pipe on a fixed flat surface were numerically investigated for drying applications to understand the physical mechanisms which affect the uniformity of the local heat transfer and pressure force coefficient as well as average heat transfer coefficient. The pipe has always a higher averaged Nu and More >

View

499

Download

364

Open Access

ARTICLE

Kamyar Mohammadpour, Ali Chitsazan, Eckehard Specht
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-5, 2022, DOI:10.5098/hmt.19.34
Abstract Understanding the flow pattern of the gas jets in packed beds can have considerable significance in improving reactor design and process optimization. This study researches the fuel diffusion in the radial direction and the flame length in a packed bed of a Parallel Flow Regenerative (PFR) Shaft kiln. This kiln is characterized that the fuel being injected vertically into the packed bed using a lot of lances in the cross-section while the combustion air is distributed continuously. The packed bed approximated as a porous media and the measured values match approximately with those calculated with More >

View

515

Download

355

Open Access

ARTICLE

Andrés Zapata^a , Carlos Amaris^b,*, Alexis Sagastume^a, Andrés Rodríguez^a
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-9, 2022, DOI:10.5098/hmt.19.33
Abstract The present study aims to assess the vapour bubble absorption into the ammonia/lithium nitrate (NH₃/LiNO₃) solution by using an optimized CFD model. A detailed methodology to build up the CFD model is presented, as well as its validation using experimental data. The operating conditions set corresponds to an absorption chiller driven by low-temperature heat sources such as solar energy in warm environments. Results evidenced that the Volume of Fluid and Mixture models are adequate to be used in the CFD model to predict the absorption process in the bubble absorber assessed depending on the mesh density More >

View

638

Download

398

Open Access

ARTICLE

L. Cheng^a , Y. L. Zhang^a,† , J. F. Li^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.32
Abstract The internal characteristics during rotational speed fluctuation have an important influence on centrifugal pump to avoid or utilize its transient performance. In this paper, a circulation piping system that includes a low-specific-speed centrifugal pump is established to study the energy distribution characteristics in a centrifugal pump during speed fluctuation. The unsteady flow in the entire system is numerically calculated with a user-defined function, the sliding grid method, and the RNG k-ε turbulence model. Then, the energy distribution of the transient flow field in the centrifugal pump model during speed fluctuation is diagnosed with vortex dynamics More >

View

650

Download

367

Open Access

ARTICLE

Sarawut Sirikasemsuk^a , Songkran Wiriyasart^a, Nittaya Naphon^b, Paisarn Naphon^a,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.31
Abstract This paper investigates the working fluid with different flow directions on the battery management cooling system with de-ionized water and ferrofluid (0.015%by volume). The pack of batteries with two different coolant directions (Models I, II) used in the present study with sixty Li-ion cylindrical cells (25.2V and 30A) are tested under the trickle method for charged process and constant ampere for the discharged process to consider the battery module temperature distribution and cooling performance. The uniform temperatures of the battery pack significantly affect the long lifecycle and thermal performance. It is found that average temperatures… More >

View

554

Download

348

Open Access

ARTICLE

Rodrigo Vidonscky Pinto^a , Flávio Augusto Sanzovo Fiorelli^b,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-10, 2022, DOI:10.5098/hmt.19.30
Abstract The present paper provides a discussion about the use of constraints in step-by-step optimization algorithms used for the solution of a twodimensional inverse heat transfer problem containing a modeling error. It is observed that the unrestricted algorithms provided better estimates to the power map and the introduction of constraints is harmful to the solution of the inverse heat transfer problem, reducing the area in which this solution approaches the actual heat sources distribution, due to the solution of the unrestricted problem adopting negative values in restricted areas, which compensate the high sensitivity of this problem More >

View

494

Download

324

Open Access

ARTICLE

Nagham Yass Khudair^a,*, Ahmed Kadhim Hussein^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.29
Abstract There has been a shift in our concern for energy towards renewable energy sources as a result of the increasing demand for energy and the decreasing supply of fossil fuels. Solar energy is, without a shadow of a doubt, the most environmentally friendly and beneficial alternative among all of the other sources that are now available. In today's world, many people harvest energy from the sun using a variety of various kinds of solar collectors. It has been discovered that the efficiency of the solar collector is reliant on the properties of the working fluid,… More >

View

511

Download

382

Open Access

ARTICLE

M. O. Petinrin^a , B. A. Sikirullahi^a, T. T. Olugasa^a, O. M. Oyewola^a,b,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.28
Abstract Tubes are commonly employed in heat exchangers for their ease of production and capacity to sustain high pressure. In this study, the heat and flow transfer behaviour of cam-shaped tube bank in staggered configuration at varying angles of attack 0°to 180° was numerically investigated. The study was carried out by solving the continuity, momentum, energy and realizable k-ε transport equations using the finite volume-based ANSYS Fluent solver. This was performed to acquire the friction factor and heat transfer characteristics in the air inlet velocity range of 9 to 15 m/s. The results showed that the… More >

View

497

Download

345

Open Access

ARTICLE

P. Chandra Reddy^a, B. Hari Babu^b,*, K. Sreenivasulu^c
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-5, 2022, DOI:10.5098/hmt.19.27
Abstract This examination carried out on thermophoresis impact on a micropolar fluid under heat flux which is not changeable in conducting field. The flow past a vertical porous plate is taken with the influence of thermal radiation and diffusion simultaneously. The flow governed non linear partial differential equations in this model are distorted to a structure of non-linear ordinary ones through fitting corresponding transformations and later solved by Runge–Kutta Fourth order with shooting technique method. The effects of selected corporal parameters on the dimensionless velocity, microrotation and temperature profiles are examined and handled graphically. Lastly, numerical More >

View

488

Download

347

Open Access

ARTICLE

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-13, 2022, DOI:10.5098/hmt.19.26
Abstract CFD analyses of flow characteristics and heat transfer topology in a heat exchanger duct (HXD) placed with three various configurations of the double V-baffles (DVB) are reported. Parameters of interest are DVB height ratios (b/H = 0.05 – 0.25), gap spacing ratios (g = 0.05 – 0.40), flow directions (+x, -x), and DVB configurations (Type I, II and III). Laminar flow with Reynolds numbers (based on the inlet conditions) between 100 – 2000 is measured. The present problem is solved with the finite volume method (a commercial program). Fluid flow and heat transfer characteristics in More >

View

580

Download

334

Open Access

ARTICLE

Ida Bagus Alit, I Gede Bawa Susana^* , I Made Mara
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.25
Abstract The study compared solar dryers with hot air from a heat exchanger double furnace during the drying of white turmeric. Solar drying is the process of drying the product in the sun. The hot air dryer consists of two furnaces with heat exchanger pipes and a drying chamber with six vertical shelves. During the test, the use of rice husk energy in a constant amount of 35 kg. Temperature and drying rate are higher in hot air dryers. Tests carried out for 420 minutes resulted in a change in moisture content from 88% to 35.88%… More >

View

583

Download

347

Like

1

Open Access

ARTICLE

Namphon Pipatpaiboon^a , Teerapat Chompookham^b, Sampan Rittidech^b, Yulong Ding^c, Thanya Parametthanuwat^d, Surachet Sichamnan^a,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-9, 2022, DOI:10.5098/hmt.19.24
Abstract When nanofluid (NF) is used as the working fluid in a rectangular two-phase closed thermosyphon (RTPCT), the formations and heat performance of two-phase flow patterns are explored qualitatively. Silver nanoparticles were mixed with deionized water at a concentration of 0.5 wt% in the NF. Nanoparticles improved the thermal contact surface area within the base flow, allowing the base fluid to boil quickly and easily. When the working fluid was boiled, NF also demonstrated high thermal conductivity capabilities, which diffused and moved along with the dual flow patterns. As a result, these qualities improved the RTPCT's More >

View

667

Download

397

Open Access

ARTICLE

Rabha Khatyr^*, Jaafar Khalid Naciri
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.23
Abstract The aim is to study the asymptotic behavior of the temperature field for the laminar forced convection of a Herschel-Bulkley fluid flowing in a circular duct considering both viscous dissipation and axial heat conduction. The asymptotic bulk and mixing Nusselt numbers and the asymptotic bulk and mixing temperature distribution are evaluated analytically in the cases of uniform wall temperature and convection with an external isothermal fluid. In particular, it has been proved that the fully developed value of Nusselt number for convective boundary conditions is independent of the Biot number and is equal to the More >

View

617

Download

384

Open Access

ARTICLE

Rajen Kumar Nayak^a,* , Ravi Shankar Prasad^a,† , Ujjwal Kumar Nayak^a, Amit Kumar Gupta^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-12, 2022, DOI:10.5098/hmt.19.22
Abstract The present experimental work has been carried out for a solar air heater under cross flow condition having inline hole jet plate between bottom plate and absorber plate with longitudinal fins underside the absorber surface. The performance of this inline hole jet plate solar air heater is compared with the performance of jet plate solar air heaters without longitudinal fins under cross and non-cross flow conditions for similar geometrical and operational parameters. Results are presented for mass flow rates of air, ṁ₁ = 0.020 - 0.070 kg/sec, ṁ₂ = 0.018 - 0.041 kg/sec, flow Reynolds number, Re_ja2… More >

View

473

Download

339

Open Access

ARTICLE

Farhan Lafta Rashid^a , Abbas Fadhil Khalaf^a, Ahmed Kadhim Hussein^b, Mohamed Bechir Ben Hamida ^c,d,e, Bagh Ali^f, Obai Younis^g,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.21
Abstract Convection and conduction in a fluid flow and a rigid body in contact with each other often occur in engineering situations, resulting in unsteady conjugate heat transfer (CHT). Although the analytical solutions to the separate conduction and convection issues are surprisingly straightforward, the combined conjugate heat transfer problem is substantially more complex to solve. This study investigates the CHT of a fluid (air) passing through an unbounded hemisphere. The hemisphere produces heat at a predictable and regular pace. The governing equations are solved using a finite volume system (FVS) using ANSYS Fluent V.16.0, with axisymmetric, More >

View

554

Download

320

Open Access

ARTICLE

Olanrewaju M. Oyewola^a,b,*, Samuel I. Afolabi^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.20
Abstract This paper investigates numerically the problem of convective heat transfer and entropy generation by two adiabatic obstacles positioned inside a square cavity heated at the left wall and cooled on the right wall while horizontal walls are adiabatic. The inclination angle of the cavity orientation investigated are 30, 60 and 90 degrees. Rayleigh numbers ranging from 103 to 106 were calculated for two vertical obstacles. The method of Galerkin finite element was employed to solve the conservation equations of mass, momentum and energy. The cavity is assumed to be filled with air with Prandtl number More >

View

524

Download

378

Open Access

ARTICLE

Qi Zhuang^a,* , Zhuo Chen^b, Dong Liu^c, Yangyang Tian^d
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.19
Abstract In order to improve the accuracy and efficiency of wax deposition rate prediction of waxy crude oil in pipeline transportation, A GRA-IPSO-ELM model was established to predict wax deposition rate. Using Grey Relational Analysis (GRA) to calculate the correlation degree between various factors and wax deposition rate, determine the input variables of the prediction model, and establish the Extreme Learning Machine (ELM) prediction model, improved particle swarm optimization (IPSO) is used to optimize the parameters of ELM model. Taking the experimental data of wax deposition in Huachi operation area as an example, the prediction performance More >

View

587

Download

392

Open Access

ARTICLE

Yulin Tian^a , Chengyi Long^b, Linghong Tang^a,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.18
Abstract In this study, the thermal-hydraulic performance of eight different printed circuit heat exchanger (PCHE) configurations with supercritical liquefied natural gas as the working fluid are studied by a numerical method. Firstly, the thermal-hydraulic performance of the PCHE with different airfoil fins are investigated at different operating pressures, which indicate that the PCHE with airfoil fins has better thermal performance but worse hydraulic performance when it operates at higher pressure condition. Furthermore, the effects of different airfoil configurations on the thermal-hydraulic performance are analyzed in detail. The results show that asymmetric airfoils can provide better heat More >

View

483

Download

347

Open Access

ARTICLE

P.S.S. Nagalakshmi, N. Vijaya^*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-18, 2022, DOI:10.5098/hmt.19.17
Abstract The main emphasis of this study is to examine the entropy generation of the spatial-temporal state of Bingham visco-plastic nanofluid flow between parallel plates are solved numerically using adequate similarity solutions. Python with BVP solver is used to interpret the results of the adopted model. Heat and mass transfer rate with respect to yield stress was investigated. The results report that the entopy generation of nanofluids exploring single and multiwalled carbon nanotubes dims with the increasing local thermal Peclet number nearer the lower and upper plates. Researchers have established that entropy generation can be reduced More >

View

541

Download

410

Open Access

ARTICLE

Ravi Shankar Prasad^a,*, S.N. Singh^b, Amit Kumar Gupta^c
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.16
Abstract The results of numerical analysis of coupled laminar natural convection and surface radiation in a two-dimensional closed square cavity with the uniformly heated bottom wall, linearly heated vertical side wall(s) and the adiabatic top wall is discussed. The cavity is filled with natural air (Pr = 0.70) as the fluid medium. In the present study, the governing equations i.e., the Navier-Stokes Equation in the stream function – vorticity form and the Energy Equation are solved for a constant property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. More >

View

476

Download

314

Open Access

ARTICLE

Vijay W. Bhatkar^a,*, Anirban Sur^b,*, Anindita Roy^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.15
Abstract Versatile vapor compression refrigeration system is designed, developed and fabricated such that desired condensing and evaporating temperatures can be obtained by providing different electronic controls for superheating, subcooling, fan speed, air heaters and water heatersto use alternative refrigerants to R134a such as R1234ze, R152a, R600a, R290 and R290/R600a (50/50%) with conventional and minichannel condenser. All the refrigerant are tested for condensing temperature ranging from 40 °C to 55 °C while evaporating temperature changes from -10 °C to 15 °C for both condensers. The total exergy loss for main system components such as compressor, condenser, expansion… More >

View

532

Download

356

Open Access

ARTICLE

Roshan Devidas Bhagat^a,* , Samir J. Deshmukhsup>b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.14
Abstract Numerical analysis of liquid vapor slug flow in a vertically placed U-shaped closed capillary tube is carried out with family of hydrocarbon fluid like Acetone, Ethanol, Methanol and Pentane. A 3D computational domain has been developed for vertically placed U-shaped capillary tube sealed at both end with three small turns in evaporator section, two small and one large turn in condenser section. The diameter of vertically placed U-shaped capillary tube is taken as 2mm. The volume of fluid (VOF) approach, suitable model of K-epsilon is used to predict the behavior of liquid vapor slug flow… More >

View

661

Download

363

Open Access

ARTICLE

Mingjie Zhang^a , Kai Yang^a, Le Qin^b, Xiaole Yao^b, Qian Liu^b, Xing Ju^b,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-10, 2022, DOI:10.5098/hmt.19.13
Abstract Lithium-ion batteries used for energy storage systems will release amount of heat during operation. It will cause serious consequences of thermal runaway if not dissipate in time. In this study, a self-forming air-cooled battery rack of the energy storage system is established based on the normal battery rack for energy storage and the shape of the energy storage battery itself. The frames of the battery rack acts as air ducts, which greatly reduce the system complexity. In this paper, the heat generation model is established based on the experiment, and the four battery rack forms… More >

View

557

Download

338

Open Access

ARTICLE

Muhammad Ramzan^a,*, Zaib Un Nisa^b , Mudassar Nazar^a,c,†
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-9, 2022, DOI:10.5098/hmt.19.12
Abstract A magnetohydrodynamics (MHD) flow of fractional Maxwell fluid past an exponentially accelerated vertical plate is considered. In addition, other factors such as heat generation and chemical reaction are used in the problem. The flow model is solved using Caputo fractional derivative. Initially, the governing equations are made non-dimensional and then solved by Laplace transform. The influence of different parameters like diffusion thermo, fractional parameter, Magnetic field, chemical reaction, Prandtl number and Maxwell parameter are discussed through numerous graphs. From figures, it is observed that fluid motion decreases with increasing values of Schmidt number and chemical More >

View

734

Download

403

Open Access

ARTICLE

Aparna Kottapallia , Ramakrishna Konijeti^b,*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.11
Abstract Scroll technology is widely used in refrigerators as compressors. This research paper presents the performance of a scroll-type expander derived from a scroll compressor. The research is carried out at low pressures. The effect of mechanical load on performance has been evaluated using compressed air as a working fluid. Two stages of the evaluation process are carried out in this research. In the first stage, the scroll expander model is numerically simulated using the CFD approach to predict the factors influencing the scroll expander performance. In the later stage, an experiment is carried out on… More >

View

634

Download

391

Open Access

ARTICLE

Nitesh Kumar, Shiva Kumar^*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 10-11, 2022, DOI:10.5098/hmt.19.10
Abstract In the present study, the use of wavy fin turbulators on the annulus body of a double pipe air heater has been numerically investigated. The inner pipe consists of hot water whereas the annular section consists of cold air whose Reynolds Number (Re) ranged from 3000-15,000. Rectangular crosssectioned wavy fin turbulators with various curvature ratios of 2, 3, 5, and 7.5 is numerically simulated to investigate the influence of curvature effects on turbulence. Results have been compared with the bare pipe and with rectangular straight fins. It is seen that wavy fin turbulators perform better More >

View

522

Download

359

Open Access

ARTICLE

A.C. Budiman^a,*, S. M. Hasheminejad^b, Sudirja^a, A. Mitayani^c, S. H. Winoto^d
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.9
Abstract Streamwise development of counter-rotating vortices induced by three different types of chevron Vortex Generators (VGs) placed upstream an Electric Vehicles (EV) dummy battery module is experimentally visualized using a smoke-wire method. From the single chevron reference case, the mushroom-like vortices do not collapse until passing the module. When more chevrons are used in line, the vortices become more prominent. It can also be observed that the vortex sizes and shapes are significantly influenced by the spanwise base length of the chevron. The induced vortices from all three VGs suggest a potential heat transfer augmentation for More >

View

613

Download

392

Open Access

ARTICLE

Wadhah Hussein Al doori^*
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-9, 2022, DOI:10.5098/hmt.19.8
Abstract Perforated fin forced convection heat transfer is the primary focus of this investigation. The purpose of this research is to see if perforated pin fins can help with heat transmission in the devices. Each pin's perforation diameter and number of holes are rigorously examined. The Nusselt numbers for perforated pins are 47 percent higher than those for solid pins, according to the study, and this number raises as the number of holes increases. The pressure drop is reduced by 19% when perforated pins are used instead of solid pins. Heat transmission in a round-holed pin More >

View

549

Download

370

Open Access

ARTICLE

Rajen Kumar Nayak^a,* , Ravi Shankar Prasad^a,† , Ujjwal Kumar Nayak^a, Amit Kumar Gupta^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-12, 2022, DOI:10.5098/hmt.19.7
Abstract This analytical study has been carried out on inline and staggered hole jet plate solar air heater with longitudinal fins attached underside the absorber surface under the cross flow and non-cross flow conditions of air through the channels for varying mass flow rate of air, ṁ₁ (50-300 kg/hm² ), jet hole diameter, D (6 mm-10 mm) and distance between the absorber and jet plate, Z₂ (5 cm-10 cm) with fixed number of jet holes, N (480 and 1008 for inline and staggered hole respectively) and pitch of the fins, p (3 mm). The result shows the performance… More >

View

511

Download

403

Open Access

ARTICLE

Farhan Lafta Rashid^a, Sarmad Kamal Fakhrulddin^b, Muhammad Asmail Eleiwi^c, Ahmed Kadhim Hussein^d,e, Tahseen Ahmad Tahseen^f , ObaiYounis^g,h,*, Mohammed Ibrahim Ahmedⁱ
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.6
Abstract The current study numerically analyzes the heat transfer enhancement and laminar fluid flow characteristics of four flat tubes with varying attack front airflow. The heat transfer characteristics of flat tubes are investigated in terms of Reynolds number, heat fluxes, and inclination angle. Four Reynolds numbers are studied (100, 200, 300, and 400), and three heat fluxes on the surface of the tubes are (1000, 2500, 3800 W/m2 ), the inclination angle of the four flat tubes are (30o , 45o , 90o). ANSYS Fluent software v.18 discretizes and solves the governing equations using the finite More >

View

599

Download

365

Open Access

ARTICLE

Kun Zhang^a,b,* , Zhiyong Li^a,b, Jia Yao^a,b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.5
Abstract Detailed numerical analysis is presented for heat transfer characteristics of charging or discharging process in phase change thermal energy storage unit with inner corrugated tube. The results indicated that the charging or discharging rate of phase change material (PCM) for the case of inner corrugated tube is obviously higher than that in unit with inner plain tube due to the increasing heat transfer surface. The heat transfer rate increase with the increasing mass flow rate. However, when the mass flow rate of heat transfer fluid (HTF) is greater than 0.0315kg/s, the charge and discharge time More >

View

614

Download

374

Open Access

ARTICLE

Ravi Shankar Prasad^a,*,†, Ujjwal Kumar Nayak^a, Rajen Kumar Nayak^a, Amit Kumar Gupta^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.4
Abstract This paper presents the results of numerical analysis of coupled laminar natural convection and surface radiation in a two-dimensional closed square cavity with the inversely linearly heated vertical opposite side walls and the adiabatic top and bottom walls. The cavity is filled with natural air (Pr = 0.70) as the fluid medium. In the present study, the governing equations i.e., Navier-Stokes Equation in the stream function - vorticity form and Energy Equation are solved for a constant property fluid under the Boussinesq approximation. For discretization of these equations, the finite volume technique is used. For More >

View

522

Download

344

Open Access

ARTICLE

V. W. Bhatkar^a, Anirban Sur^b,*, Anindita Roy^b
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.3
Abstract In heating, Wet-bulb temperature in HVAC (heating, ventilation, and air conditioning) applications is crucial for building the equipment. But radiation from the surrounding surfaces caused the errors during the thermodynamic wet-bulb temperature measurement. The wet-bulb temperature of moist air is measured in the current work utilising an aspiration psychrometer designed, developed, and built to reduce the error term caused by radiation and convection heat transfer. Wet-bulb temperature is calculated in the experiments using an aspiration psychrometer at various locations throughout the year, both with and without a shield. It has been found that the error… More >

View

582

Download

352

Open Access

ARTICLE

Yiding Cao
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-16, 2022, DOI:10.5098/hmt.19.2
Abstract This paper introduces a novel air-water thermal power plant working at low temperatures and employing hot water as a heat-supply fluid to produce utility-scale power with high second-law efficiency. The air-water power plant uses both air and water as working fluids and employs a direct-contact mass and heat transfer packing to facilitate latent heat (in terms of vapor) and sensible heat transfer from the hot water to moist air for expansion in a gas turbine to produce power. A cycle analysis indicates that with a heat source temperature of around 100o C, the power plant… More >

View

525

Download

361

Open Access

ARTICLE

Yiding Cao
Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-12, 2022, DOI:10.5098/hmt.19.1
Abstract This paper introduces utility-scale underground hot water storage (USUHWS) systems and evaluates their performance to enable renewable energy sources to produce dispatchable utility-scale power or supply heat with minimized interruption and impact by weather conditions. The USUHWS systems could retain the thermal energy content of the stored hot water for years so that renewable energy can be extracted and stored at any time year-round and be used whenever needed. Another major objective of this paper is to introduce hot-water power and heat internets to interconnect storage systems, power plants, energy sources, and various water and More >

View

495

Download

362