Article
Physics, Multidisciplinary
Farhan Ahmed
Summary: The present study investigates the influence of constant pressure gradient on flow and heat transfer rate of Jeffrey fluid through concentric pipes annular sector duct. Simulation results show that increasing the ratio of relaxation to retardation times, lambda, can improve the friction factor under certain conditions, while the forced convective heat transfer rate remains almost constant in the absence of viscous dissipation. Additionally, the effect of viscous dissipation becomes favorable with the increase in Brinkman number, Br, on heat transfer rate for higher value of lambda at specific radius ratio and apex angle of the concentric pipes annular sector duct.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Nuclear Science & Technology
M. Farnam, M. Khoshvaght-Aliabadi, M. J. Asadollahzadeh
Summary: The study proposes a twisting structure to enhance the thermal performance of a coil heat exchanger equipped with a helical tube. Experiments and simulations show improvements in Nusselt number and friction factor, with parametrization analysis revealing that the helical-diameter has the most significant impact on the thermal-hydraulic characteristics of the helical-twisted tube. Decreasing the helical-diameter and twist-pitch leads to an overall improvement in hydrothermal performance.
ANNALS OF NUCLEAR ENERGY
(2021)
Article
Thermodynamics
Gloria Biswal, Subhasisa Rath, Sukanta Kumar Dash
Summary: This study numerically investigated the natural convection and surface radiation heat transfer from a vertically oriented isothermal helical coil. The effects of Rayleigh number, surface emissivity, and geometrical parameters of the helical coil on heat transfer characteristics were studied. The results showed that an increase in coil diameter and pitch led to an increase in the mass flow rate induced through the coil. The contribution of convection heat transfer was found to be higher for lower emissivity and higher Rayleigh number, while radiative heat transfer played a larger role for higher emissivity and lower Rayleigh number. A correlation for the average Nusselt number was developed based on the parameters considered in this study.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Roohollah Hosseini Monfared, Mohammadreza Niknejadi, Davood Toghraie, Pouya Barnoon
Summary: In this research, fluid flow and heat transfer of a water/Al2O3 nanofluid in a tube with helical ribs were investigated. The results indicated that as Reynolds number increases, heat transfer increases, and friction factor decreases, with helical ribs enhancing heat transfer efficiency. Using nanofluid can lead to improved heat transfer and reduced friction factor.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Thermodynamics
Zhiliang Lei, Zewei Bao
Summary: This study experimentally investigated the laminar heat transfer characteristics of RP-3 in the liquid phase and supercritical phase in helical coiled tubes under 5 MPa pressure. The influences of secondary flow and buoyancy on heat transfer were analyzed, and correlations were established.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Wagd Ajeeb, Monica S. A. Oliveira, Nelson Martins, S. M. Sohel Murshed
Summary: This study investigates the laminar flow of non-Newtonian MWCNTs nanofluids in a circular tube under a constant wall heat flux condition. The results show an enhancement in heat transfer performance by adding nanoparticles to the base fluid, with a slight increase in pressure drop and improvement in overall energy efficiency. The methodology developed in this study provides important insights for future heat transfer studies and applications.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Thermodynamics
Cody M. Cummings, Hailei Wang, Mark Thomas Smith
Summary: Bioprocessing utilizes cells to produce high-value lifesaving products, and precise environmental control is crucial for maintaining the integrity of the production process. A transient thermal model has been developed to predict the temperature profiles, and experimental validation shows good agreement between the predicted and measured heat transfer coefficients.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mathematics, Applied
Adel Karimbakhshi Rostami, Davood Domiri Ganji
Summary: This study investigates the heat transfer in a shell and helically coiled finned tube heat exchanger with stepped annular fins for the first time. Using response surface methodology, correlations are proposed to predict the Nusselt number based on geometric and operating parameters. The results show that the parameters Re and Pr have the most impact on the Nusselt number.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Thermodynamics
Kim Leong Liaw, Jundika C. Kurnia, Agus P. Sasmito
Summary: This study investigates the convective heat transfer performance of Newtonian fluid in a helical twisted multilobe tube using computational fluid dynamics (CFD) simulations. The results show that the combination of number of lobes and tube twisting has a significant effect on the heat transfer coefficient, while increasing the number of lobes alone has a minimal impact. The helical coiled tube outperforms the straight tube within a certain range of Reynolds numbers, while twisting is recommended primarily for straight tubes.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Prabhakar Zainith, Niraj Kumar Mishra
Summary: Nowadays, there is a growing interest in the cooling and heating of micro-thermal devices, and researchers are making various efforts to improve their thermal management. This study investigates the heat transfer rate and friction factor of non-Newtonian nanofluids using conically shaped micro helical tubes, and the numerical analysis shows good agreement with earlier experimental results.
JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS
(2022)
Article
Mechanics
Oswald Jason Lobo, Dhiman Chatterjee
Summary: In the case of a long, straight rectangular channel, the hydrodynamic development of flows is influenced by the growth of the boundary layer along the walls. However, in reality, channels often have plenums on each end and this aspect is not extensively studied. This study addresses this gap and proposes an alternate method of defining entrance length.
Article
Thermodynamics
Arvind Kumar, Hardik B. Kothadia, R. Arun Kumar, S. V. Prabhu
Summary: The flow boiling process in helical coils is experimentally investigated. The orientation of the helical coil affects the heat transfer distribution, pressure drop, and critical heat flux. Little information is available on the influence of the orientation on these parameters. Experiments are conducted on horizontal and vertical helical coils, and the results show that the heat transfer coefficient and heat flux are higher in vertical coils compared to horizontal coils. The orientation does not significantly affect the pressure drop.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Engineering, Aerospace
David Leiser, Fabian Hufgard, Christian Duernhofer, Stefan Loehle, Stefanos Fasoulas
Summary: This paper proposes a methodology to scale the stagnation point plasma conditions of an axially symmetric body to a two-dimensional planar body, providing a theoretical basis for the testing of material samples under thermochemical loads combined with aeromechanical loads, and the experimental verification has been conducted.
Article
Geochemistry & Geophysics
Maolin Liao, Yuxi Wang, Jiaze Ma, Zhipeng Liu, Caiyin Ji
Summary: This study investigates the flow of cement slurry in narrow or varied radial sizes well annuli for precise calculation of equivalent circulating density (ECD) in petroleum industry. The Metzner-Reed (MR) method and direct numerical simulation (DNS) are used to calculate the ECD for different types of cement slurries, considering Bingham and Power-Law rheological models. The theoretical MR method is verified to be in agreement with the DNS results. The accuracy of commercial software (DRILL BENCH (DB), LANDMARK (LM), and PVI) in calculating ECD is compared based on the DNS results, with LM showing the highest accuracy for Power-Law fluid and PVI being optimal for Bingham fluid, while DB exhibits sharp fluctuations in calculation errors.
Article
Computer Science, Interdisciplinary Applications
Mohamed Abdi, Abdelfettah Menouer, Khaled Chaib, Slimane Benferhat, Nordeddine Sad Chemloul, Ahmed Kadari
Summary: This study conducted a numerical analysis to evaluate the flow and heat transfer characteristics of a heated corrugated cylinder. The findings suggest that increasing the number of grooves can significantly reduce the total drag coefficient of the cylinder, with a more noticeable effect at higher Reynolds numbers. The groove number has limited impact on the pressure coefficient, but significantly affects the average Nusselt number, with a gradual reduction as the groove number increases.
INTERNATIONAL JOURNAL OF MODERN PHYSICS C
(2022)
Review
Chemistry, Analytical
Ana T. S. Cerdeira, Joao B. L. M. Campos, Joao M. Miranda, Jose D. P. Araujo
Article
Engineering, Chemical
Ana I. Moreira, Luis A. M. Rocha, Joao Carneiro, Jose D. P. Araujo, Joao B. L. M. Campos, Joao M. Miranda
Article
Thermodynamics
A. Fonseca, S. F. Neves, J. B. L. M. Campos
Summary: This study investigates the use of phase change materials (PCMs) in firefighting garments during fire exposure, post fire exposure, and resting phases. The data shows that these materials can reduce heat hazards in these scenarios.
APPLIED THERMAL ENGINEERING
(2021)
Review
Nanoscience & Nanotechnology
A. Moreira, J. Carneiro, J. B. L. M. Campos, J. M. Miranda
Summary: Hydrogels are biocompatible materials widely used in biological applications, and using them in the form of microparticles offers numerous advantages. Microfluidic devices show great potential in producing hydrogel microparticles with precise properties.
MICROFLUIDICS AND NANOFLUIDICS
(2021)
Article
Biophysics
S. F. Neves, J. Ponmozhi, F. J. Mergulhao, J. B. L. M. Campos, J. M. Miranda
Summary: This study evaluates the impact of WSS, convection, and Brownian diffusion on cell adhesion in microchannels, finding that these effects are significantly more pronounced in regions with high WSS. Good agreement is observed between experimental and predicted Sherwood numbers, especially at the entrance and within multiple constrictions. Further mechanisms are needed to accurately predict cell adhesion in expansion zones.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2021)
Article
Engineering, Civil
Andre Fonseca Malaquias, S. F. Neves, J. B. L. M. Campos
Summary: This study simulated heat and mass transport in thermal protective clothing (T.P.C) using numerical methods, finding that the presence of water in the outer shell increases second-degree burn times, while water in the inner layer has the opposite effect under high heat fluxes. The results also help in identifying environmental and protective clothing conditions where steam burns may become a potential hazard.
FIRE SAFETY JOURNAL
(2022)
Article
Chemistry, Physical
A. I. Moreira, J. B. L. M. Campos, J. M. Miranda
Summary: In this study, gelatin microdroplets were successfully generated using a PDMS microchannel, and the dripping and jetting regimes were studied in detail. It was found that the regime map depends significantly on the viscosity ratio, and a correlation to calculate the droplet size was obtained. The gelatin microparticles produced through this method exhibited small size and monodispersity.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Forestry
Gilda Santos, Rita Marques, Joao Ribeiro, Adriana Moreira, Patricia Fernandes, Margarida Silva, Andre Fonseca, Joao M. Miranda, Joao B. L. M. Campos, Soraia F. Neves
Summary: Continuous research and development have greatly improved firefighters' personal protective equipment (PPE) in recent decades. However, there are still a significant number of firefighters who are seriously injured or lose their lives during firefighting operations. The incorporation of smart textiles and advanced materials, such as phase change materials, in PPE can enhance the protection for firefighters. The evolution of PPE has led to the development and update of international and national standards to ensure the performance requirements of firefighters' protective clothing.
Article
Energy & Fuels
M. C. F. Silva, J. B. L. M. Campos, J. D. P. Araujo
Summary: This study fills a knowledge gap by simulating slug flow in inclined tubes using CFD tools. The results show that tube inclination significantly affects the flow and changes the position, velocity, and shape of the bubbles, as well as the flow of liquid around them.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2023)
Article
Thermodynamics
Andre Fonseca Malaquias, S. F. Neves, J. B. L. M. Campos
Summary: The presence of water in firefighting garments has been found to affect the thermal performance of PCM FPC assemblies. Moisture management is important to promote maximum PCM efficiency.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Engineering, Chemical
J. Carneiro, J. Ferreira, E. Doutel, J. M. Miranda, J. B. L. M. Campos
Summary: Optical measurement techniques such as & mu;PIV and LDV are widely used in experimental fluid dynamics research on pure fluids or suspension flows. This study presents a novel refractive-index-matched transparent suspension, using sub-10 & mu;m spherical PDMS particles suspended in a DMSO aqueous solution. The suspension rheology was characterized and optical properties were analyzed, and the results showed good agreement with analytical solutions when measuring the velocity flow in a circular-section microchannel using & mu;PIV.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Gilda Santos, Soraia F. Neves, Margarida Silva, Joao M. Miranda, Joao B. L. M. Campos, Joao Ribeiro, Adriana Moreira, Patricia Fernandes, Francisca Miranda, Rita Marques
Summary: Considering the high level of heat and flame exposure faced by firefighters, personal protective equipment (PPE) is crucial for their safety. This study developed a PCM-vest for the first time and evaluated its thermal performance. The results show that PCMs significantly affect the heating rate of the multilayer assembly, but also increase the cooling time. The PCM-vest sample met the requirements of heat and flame tests, highlighting the positive impact of using PCMs to enhance traditional PPE's heat protection.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Physical
J. Carneiro, R. Lima, J. B. L. M. Campos, J. M. Miranda
Summary: In vitro handling of blood poses challenges due to ethical, economic, and safety considerations. This study developed a blood analogue suspension using PDMS microparticles, mimicking the rheological properties of blood and capable of simulating whole blood. The high throughput production of PDMS particles and their similarity to blood rheologies make them a promising candidate for blood analogues.
Article
Thermodynamics
M. C. F. Silva, J. B. L. M. Campos, J. D. P. Araujo
Summary: This study used computational fluid dynamics to validate the impact of bubble flow on mass transfer, identifying correlations between mass transfer and hydrodynamic parameters for predicting mass transfer with deviations around 10-20%.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Chemical
Monica F. Silva, Joao B. L. M. Campos, Joao M. Miranda, Jose D. P. Araujo
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)