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  • Open Access

    ARTICLE

    Lubrication of Asymmetric Rollers Using Roelands Viscosity–Pressure-Temperature Relationship

    Swetha Lanka1, Venkata Subrahmanyam Sajja1,*, Dhaneshwar Prasad2
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.042544
    Abstract An attempt is made to analyse some lubrication characteristics of rigid cylindrical asymmetric rollers under adiabatic and isothermal boundaries with rolling and sliding motion lubricated by a non-Newtonian incompressible Bingham plastic fluid under the behaviour of line contact. Here the lower surface is considered to move quicker than that of the upper surface; and the Roelands viscosity model is considered and assumed to depend upon the fluid pressure and the mean film temperature. The governing equations for fluid flow such as equations of motion with continuity and the momentum energy equation are solved using Runge-Kutta forth order and MATLAB is… More >

  • Open Access

    ARTICLE

    Numerical Investigations of Laminar Air Flow and Heat Transfer Characteristics in a Square Channel Inserted with Discrete X-V Baffles (XVB)

    Amnart Boonloi1, Withada Jedsadaratanachai2,*
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.044929
    Abstract Thermal performance enhancement in a square channel heat exchanger (HX) using a passive technique is presented. Vortex turbulator insertion in a square channel HX as a passive technique is selected for thermal improvement. The vortex turbulator of interest is discrete X-V baffles (XVB). The discrete XVBs are inserted in the square channel with the main aim to generate vortex flow. The vortex flow generated can support to enhance convective heat transfer coefficient and also enhance HX performance. Effects of baffle configuration (type A and B), baffle size (w/H = 0.05, 0.10, 0.15 and 0.20), baffle distance (e/H = 1, 1.5… More >

  • Open Access

    ARTICLE

    The Numerical Simulation of Nanofluid Flow in Complex Channels with Flexible Wall

    Amal A. Harbood*, Hameed K. Hamzah, Hatem H. Obeid
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.01518
    Abstract The current work seeks to examine numerical heat transfer by using a complicated channel with a trapezoid shape hanging in the channel. This channel demonstrates two-dimensional laminar flow, forced convective flow, and incompressible flow. To explore the behavior of heat transfer in complex channels, several parameters, such as the constant Prandtl number (Pr = 6.9), volume fraction (ϕ) equal to (0.02 to 0.04), Cauchy number (Ca) equal to (10−4 to 10−8), and Reynolds number equal to (60 to 160) were utilized. At the complex channel, different elastic walls are used in different locations, with case A being devoid of an… More >

  • Open Access

    ARTICLE

    Numerical Simulation of Heat Transfer of High-Temperature Slag Flow Inside the Blast Furnace Slag Trench

    Guangyan Fan, Fuyong Su*, Cunwang Li, Bin Li
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.043221
    (This article belongs to this Special Issue: Advances in Heat and Mass Transfer for Process Industry)
    Abstract To investigate the flow and heat transfer process of blast furnace slag through the slag trench after the slag is discharged, a three-dimensional physical model is established and simulated according to the actual size of the slag trench and the physical properties of the high-temperature slag. The temperature fied and flow field distribution of the high-temperature slag liquid inside the slag trench is obtained by numerical simulation under different working conditions, and the effects of operating conditions such as slag trench inclination, high-temperature slag inlet flow rate, and inlet temperature are investigated. The results show that the flow rate of… More >

  • Open Access

    REVIEW

    Use of Statistical Tools for Comparison between Different Analytical and Semi-Empirical Models of the Bleve Fireball

    Abderraouf Guelzim1,2,*, Baraka Achraf Chakir3, Aziz Ettahir1, Anas Mbarki1,*
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041832
    Abstract The Bleve is an explosion involving both the rapid vaporization of liquid and the rapid expansion of vapor in a vessel. The loss of containment results in a large fireball if the stored chemical is flammable. In order to predict the damage generated by a Bleve, several authors propose analytical or semi-empirical correlations, which consist in predicting the diameter and the lifetime of the fireballs according to the quantity of fuel. These models are based on previous experience, which makes their validity arbitrary in relation to the initial conditions and the nature of the product concerned. The article delves into… More >

  • Open Access

    ARTICLE

    Numerical Comparison of Stagnation Point Casson Fluid Stream over Flat and Cylindrical Surfaces with Joule Heating and Chemical Reaction Impacts

    Shaik Jaffrullah1, Sridhar Wuriti1,*, Raghavendra Ganesh Ganugapati2, Srinivasa Rao Talagadadevi1
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.043305
    Abstract In this particular study, we have considered the flow of Casson fluid over inclined flat and cylindrical surfaces, and have conducted a numerical analysis taking into account various physical factors such as mixed convection, stagnation point flow, MHD, thermal radiation, viscous dissipation, heat generation, Joule heating effect, variable thermal conductivity and chemical reaction. Flow over flat plate phenomena is observed aerospace industry, and airflow over solar panels, etc. Cylindrical surfaces are commonly used in several applications interacting with fluids, such as bridges, cables, and buildings, so the study of fluid flow over cylindrical surfaces is more important. Due to the… More >

  • Open Access

    ARTICLE

    Comparison and Analysis of Heat Transfer and Inflow Rate for Supercritical Carbon Dioxide Based on Different Tubes

    Huda Adel Hassan Ali, Ameer Abed Jaddoa*, Jafaar Mohamme Daif
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.042288
    Abstract This paper is twofold. First, the effect of non-linear thermophysical property variation was presented using supercritical carbon dioxide (SCO2) around the thermodynamic pivotal point. The second part exhibits an experimental examination of the heat transfer (HT) behaviour of SCO2 in a helical tube with a hydraulic diameter of 2 mm at different mass fluxes (MF), heat fluxes (HF), and pressures (P). The experiments were carried out based on various pressures, mass fluxes, and heat fluxes for both scenarios. CO2 was cooled in a 2 mm diameter serpentine tube made of copper material. The experimental results showed that HT degradation could… More >

  • Open Access

    ARTICLE

    Effect of the Wick Deflection Angles on Heat Transfer Characteristics for the Flat LHP

    Zhuohuan Hu1, Sixian Sun1, Chengwei Yuan1, Yan Cao2, Jiayin Xu1,*
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041837
    Abstract Loop Heat Pipe (LHP) is an efficient two-phase heat transfer device, which can be used in waste heat recovery, electronics cooling, aerospace and other fields. The wick, the core component of LHP, plays an important role in its start-up and operation. In this paper, the wick fabricated by 3D printing technology had uniform and interconnected pores. In the experiment, the position of the parallel vapor removal grooves was always fixed towards the vapor outlet. When the cylindrical wick was placed in the evaporator, the rotation angle relative to its central axis could be changed, thus changing the number and shape… More >

  • Open Access

    ARTICLE

    Evaporation Heat Transfer Characteristics from a Sintered Powder Wick Structure Sandwiched between Two Solid Walls

    Yasushi Koito1,*, Shoma Hitotsuya2, Takamitsu Takayama2, Kenta Hashimoto2
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041829
    Abstract An ultra-thin flattened heat pipe has been developed with a centered wick structure. This structure is essential to make the heat pipe thinner. However, the centered wick structure reduces the evaporation and condensation surface areas of the wick structure because it is sandwiched between heat pipe walls. In this study, because detailed discussion has not been made, heat transfer experiments were conducted for the wick structure sandwiched between two solid walls. This study focused on the evaporation heat transfer characteristics from the sandwiched wick structure. The experiments were conducted with three wick structures, that is, strip-shaped sintered copper powders with… More >

  • Open Access

    ARTICLE

    Analysis of Profile and Unsteady Flow Performance of Variable Base Circle Radius Scroll Expander

    Junying Wei*, Gang Li, Chenrui Zhang, Wenwen Chang, Jidai Wang
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041793
    Abstract To study the complex internal flow field variation and output characteristics of a variable base radius scroll expander, this paper uses dynamic mesh techniques and computational fluid dynamics (CFD) methods to perform transient numerical simulations of a variable base radius scroll expander. Analysis of the flow field in the working cavity of a variable base radius scroll expander at different spindle angles and the effect of different profiles, speeds and pressures on the output characteristics of the scroll expander. The results of the study show that due to the periodic blocking of the inlet by the orbiting scroll, the fluid… More >

  • Open Access

    ARTICLE

    MHD (SWCNTS + MWCNTS)/H2O-Based Williamson Hybrid Nanouids Flow Past Exponential Shrinking Sheet in Porous Medium

    Hamzeh Taha Alkasasbeh1,*, Muhammad Khairul Anuar Mohamed2
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041539
    Abstract The present study numerically investigates the ow and heat transfer of porous Williamson hybrid nanouid on an exponentially shrinking sheet with magnetohydrodynamic (MHD) eects. The nonlinear partial dierential equations which governed the model are first reduced to a set of an ordinary differential equations by using the similarity transformation. Next, the BVP4C solver is applied to solving the equations by considering the pertinent fluid parameters such as the permeability parameter, the magnetic parameter, the Williamson parameter, the nanoparticle volume fractions and the wall mass transfer parameter. The single (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) nanoparticles are taken as the hybrid… More >

  • Open Access

    ARTICLE

    Heat Transfer Characteristics for Solar Energy Aspect on the Flow of Tangent Hyperbolic Hybrid Nanofluid over a Sensor Wedge and Stagnation Point Surface

    Asmaa Habib Alanzi, N. Ameer Ahammad*
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.042009
    Abstract The conversion of solar radiation to thermal energy has recently attracted a lot of interest as the requirement for renewable heat and power grows. Due to their enhanced ability to promote heat transmission, nanofluids can significantly contribute to enhancing the efficiency of solar-thermal systems. This article focus solar energy aspect on the effects of the thermal radiation in the flow of a hyperbolic tangent nanofluid containing magnesium oxide (MgO) and silver (Ag) are the nanoparticle with the base fluid as kerosene through a wedge and stagnation. The system of hybrid nanofluid transport equations are transformed into ordinary differential systems using… More >

  • Open Access

    ARTICLE

    Numerical Calculation of Transient Thermal Characteristics of Nozzle Flowmeter

    Xin Li1, Shaohan Zheng1,2, Yuliang Zhang1,*, Minfeng Lv3
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041778
    Abstract This article aims to reveal the transient thermal characteristics of the solid domain in a nozzle flowmeter when measuring fluids of varying temperatures. Based on finite element method, the transient numerical calculation of the thermal characteristics of each component of the nozzle flowmeter has been conducted. The research shows that: as the fluid passes through the flowmeter, the high heat flux area inside the nozzle flowmeter gradually transfer from the center of the nozzle to the inlet and outlet, as well as the pressure tapping points upstream and downstream; High thermal stress zones are present near the upstream and downstream… More >

  • Open Access

    ARTICLE

    Study on the Fractal Characteristics of Cavitation Shedding over a Twisted Hydrofoil

    Zilong Hu1, Weilong Guang1, Ran Tao1,2,*, Ruofu Xiao1,2, Di Zhu3
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041402
    Abstract Cavitation and cavitation erosion often occur and seriously threaten the safe and stable operation of hydraulic machinery. However, during the operation of hydraulic machinery, the cavitation flow field is often difficult to contact and measure, and the shedding and development characteristics of cavitation flow are unknown. This paper uses the Detached Eddy Simulation (DES) turbulence model and Zwart-Gerber-Belamri (ZGB) cavitation model to conduct numerical research on the cavitation flow of a twisted hydrofoil and verifies the effectiveness of numerical simulation by comparing it with experimental results. Then, based on the fractal dimension method, the number and fractal dimension of the… More >

  • Open Access

    ARTICLE

    Numerical Investigation Thermal Performance of Solar Air Heater Using Different Angle V-Grooved of Corrugated Absorber Plate

    Ayad S. Abedalh*, Sohaib Hassan Mohammed
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041777
    Abstract Solar energy, a renewable resource, can be harnessed instead of fossil fuels to generate power and heat. One effective method for converting solar energy into heat is through a solar air heating (SAH) system. The theoretical investigation focused on the thermal performance of various V-groove angles on a corrugated absorber plate. The researchers maintained the exterior dimensions and constraints of the absorber plate while increasing its surface area by using a corrugated absorber surface. For the simulation, three different V-groove angles were employed: 45°, 30°, and 15°. The temperature and air flow rate into the system had been set at… More >

  • Open Access

    ARTICLE

    Effect of Nanomaterials Addition to Phase Change Materials on Heat Transfer in Solar Panels under Iraqi Atmospheric Conditions

    Majid Ahmed Mohammed1, Abdullah Talab Derea2, Mohammed Yaseen Lafta3, Obed Majeed Ali1, Omar Rafae Alomar4,*
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041668
    Abstract It is common knowledge that phase-change materials are used for the purpose of thermal storage because of the characteristics that are exclusive to these materials and not found in others. These characteristics include a large capacity for absorbing heat and a large capacity for releasing heat when the phase changes; however, these materials have a low thermal conductivity. This paper presents the results of an experimental study that investigated the impact that nanoparticles of copper oxide had on reducing the temperature of solar panels. The phase change substance that was used was determined to be beeswax. The impact of adding… More >

  • Open Access

    ARTICLE

    Investigation the Influence of Phase Change Material Amount on a Hot-Water Stratification in Charging Mode

    Abeer H. Falih*, Basim Freegah, Adnan A. Abdulrasool
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.01525
    Abstract Among the various techniques for enhancing the storage and consumption of energy in a thermal energy storage system, the establishment of thermal stratification in a hot-water container is an effective technology. The current study aims to assess the performance of the thermal stratification for hot-water containers using (ANSYS Fluent) R.1.0, 2022, through the study of the impact of different numbers of paraffin-filled containers, namely 3, 5, and 7, that are equivalent to 5, 7, and 9 kg of paraffin, respectively. To validate the present numerical model, a comparison between the current study results and the experimental findings from the literature… More >

  • Open Access

    ARTICLE

    Numerical Assessments on Flow Topology and Heat Transfer Behavior in a Round Tube Inserted with Three Sets of V-Ribs

    Amnart Boonloi1, Withada Jedsadaratanachai2,*
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2023.041547
    Abstract Simulation of fluid-flow topology and thermal behavior in a round tube heat exchanger (RTHX) installed by three V-rib sets is reported. The expected phenomena for the rib installation are the generated vortex flow, impinging flow, greater fluid blending and thermal boundary layer disturbance (TBLD). These phenomena are key causes of the augmentation of heat transfer potentiality and thermal efficiency of the RTHX. Effects of rib height (b1 = 0.05D – 0.25D and b2 = 0.05D – 0.25D), rib pitch or rib spacing (P = D, 1.5D and 2D) and fluid directions (positive x (+x flow direction) and negative x (–x… More >