Article
Thermodynamics
Shaker Alaqel, Nader S. Saleh, Rageh Saeed, Eldwin Djajadiwinata, Muhammad Sarfraz, Abdulelah Alswaiyd, Hany Al-Ansary, Obida Zeitoun, Syed Danish, Zeyad Al-Suhaibani, Abdelrahman El-Leathy, Sheldon Jeter, Ahmad Khayyat
Summary: The paper validates two theoretical models of a direct-contact counter-flow particle-to-air heat exchanger and explores their integration with a particle-based central tower system. It found that the mixing model accurately predicted outlet temperature for 0.5 mm particles, while the simple equilibrium model (SEM) overpredicted regardless of particle size. Additionally, the use of a double dump valve and particle strainers at the exchanger outlet were identified as crucial for the practical integrated system.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Shaker Alaqel, Nader S. Saleh, Eldwin Djajadiwinata, Rageh Saeed, Abdulelah Alswaiyd, Hany Al-Ansary, Abdelrahman El-Leathy, Obida Zeitoun, Sheldon Jeter, Said Abdel-Khalik, Ahmad Khayyat, Syed Danish, Zeyad Al-Suhaibani
Summary: A novel particle-to-fluid direct-contact counter-flow heat exchanger (PFDCHX) is proposed for efficient integration with an air-breathing power cycle. The system consists of a particle handling unit and a direct-contact heat exchanger, with various enhancement features to prevent particle carryover. Results show that over 80% of the temperature rise can be achieved within a short distance from the air inlet, indicating the effectiveness of the tangential inlet's swirl flow pattern.
Article
Thermodynamics
M. Hedeshi, A. Jalali, A. Arabkoohsar, A. Amiri Delouei
Summary: This paper experimentally investigates the simultaneous impacts of using nanofluid and ultrasonic vibrations in a double-pipe heat exchanger. The effects of adding nanoparticles and applying ultrasonic vibrations are studied using water-based Al2O3 nanofluid. The results show that both nanoparticles and ultrasonic vibrations have a positive effect on the heat exchanger's performance, especially at higher inlet hot fluid temperatures and higher nanofluid concentrations. The effectiveness-NTU analysis demonstrates that using nanofluid and ultrasonic-excited nanofluid can significantly increase the thermal system's efficiency.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Acoustics
Zhonglong Wang, Yinghou Jiao, Zhaobo Chen, Xiuquan Qu, Tao Fu
Summary: The study focuses on the average sound radiation efficiency of a rotating annular plate under transverse load in a rotating coordinate system. The governing equation is solved using Galerkin's Method, and the sound radiation efficiency is derived based on Rayleigh integral. Experimental verification and boundary element method simulation are conducted to validate the results. The study shows that rotating speed, geometry parameters, material parameter, and boundary conditions all affect the sound radiation efficiency of the plate. Results indicate an increase in efficiency with higher rotating speeds and a decrease in efficiency with lower thickness in different frequency ranges.
Article
Thermodynamics
Wagd Ajeeb, Renato R. S. Thieleke da Silva, S. M. Sohel Murshed
Summary: This study investigates the performance of a compact gasketed plate heat exchanger using Al2O3 nanofluids. The experiment measured the thermophysical properties of the nanofluid samples and compared their performance with conventional heat transfer fluids. The results showed that increasing the concentration of nanoparticles improved heat transfer efficiency and energy efficiency.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Yuce Liu, Ke Li, Jian Wen, Simin Wang
Summary: The distributed parameter models of counter flow and cross flow plate fin heat exchanger (PFHE) were constructed to investigate their thermodynamic characteristics. The effect of longitudinal heat conduction (LHC) on the heat transfer performance of PFHE was found to be positive when appropriate boundary conditions were set. Considering LHC, the effectiveness of constant wall temperature boundary conditions increased by 31.7 to 35.8%, and the effectiveness of constant heat flux boundary conditions increased by 22.8%.
APPLIED THERMAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Ivan Pavlenko, Oleksandr Kulikov, Oleksandr Ratushnyi, Vitalii Ivanov, Jan Pitel, Vladyslav Kondus
Summary: The article presents a study on increasing the pressure and power characteristics of centrifugal pumps by using a counter-rotating pumping stage. The research uses CFD modeling and the Moore-Penrose pseudoinverse approach to analyze the performance of the pumps. The results show that pumps with a counter-rotating stage can significantly increase the pressure head, reaching 2.1 times higher than the standard design, while reducing weight and size indicators.
APPLIED SCIENCES-BASEL
(2023)
Article
Thermodynamics
Emilio Navarro-Peris, Lucas Alvarez-Pineiro, Lena Schnabel, Jose M. Corberan
Summary: The study investigates the maldistribution of refrigerant mass flowrate in a brazed plate heat exchanger evaporator with distributor, finding that the water temperature drop has a strong influence on the penalty caused by refrigerant maldistribution. A data reduction methodology is proposed for quantifying the maldistribution based on simple assumptions and flow conservation equations. The study concludes that the penalty of maldistribution on evaporation performance depends on the availability of the secondary fluid in the concentrated channels of refrigerant liquid.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2021)
Article
Thermodynamics
Emilio Navarro-Peris, Lucas Alvarez-Pineiro, Paloma Albaladejo, Lena Schnabel, Jose M. Corberan
Summary: The study investigated the uneven refrigerant distribution in a brazed plate heat exchanger evaporator with distributor under different conditions, and highlighted the significant influence of water temperature drop on evaporator performance. The research also emphasized the degradation of evaporator performance due to refrigerant maldistribution and the importance of analyzing temperature data.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2021)
Article
Thermodynamics
Urban Mocnik, Simon Muhic
Summary: Compared to traditional herringbone-shaped heat plates, a microplate heat exchanger consists of smaller dimples, which determine its characteristics. However, there is limited literature on the flow characteristics in such channels. Understanding the flow specifics is crucial for developing efficient new products. The study investigated single-phase water flow and heat transfer in a microplate heat exchanger through laboratory experiments and computational fluid dynamics simulations. Novel experiments were conducted to measure flow characteristics and heat transfer, and the results were used to validate numerical simulations. The simulations showed that the heat transfer coefficient in the channel is proportional to Re^0.64, and the Reynolds stress model yielded the most reliable results.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Chemical
Nidal H. Abu-Hamdeh, Radi A. Alsulami, Abdulmalik A. Aljinaidi, Mashhour A. Alazwari, Mohamed A. Eltaher, Khalid H. Almitani, Khaled A. Alnefaie, Muhyaddin J. H. Rawa, Abdullah M. Abusorrah, Hatem F. Sindi, Elias M. Salilih, Hani A. Abulkhair
Summary: This research focuses on designing and analyzing a solar power plant in Jeddah, Saudi Arabia. The study found that the plant generates the most electricity during June and July, with the use of molten salt nanofluid improving efficiency. Additionally, the use of two pre heaters instead of one can increase cycle efficiency by up to 3%.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Thermodynamics
Mohammad Rasoul Ahmadi, Davood Toghraie
Summary: The study simulated the flow and heat transfer of nanofluids in a shell and tube heat exchanger, investigating the impact of factors like fluid velocities, volume fraction of nanofluids, and the use of twisted tape and baffles on thermal performance. Results showed that twisted tape had a greater effect on improving thermal performance compared to baffles, and the use of seawater led to decreased thermal efficiency and increased pressure drop.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Thermodynamics
Dantong Shi, Kuan-Ting Lin, Milind A. Jog, Raj M. Manglik
Summary: This study investigates the enhanced heat transfer performance of airflows in slotted sinusoidal wavy-plate-fins through experimental and computational analysis. The results show that the slotted wavy fin core reduces the pressure drop by as much as 31% compared to the equivalent or nonslotted wavy fin core, while maintaining similar heat transfer. Computational analysis reveals that the form drag induced by flow recirculation in the trough region is a significant contributor to pressure loss in plain wavy-fin channels, and can be substantially reduced by slotted fins.
ASME JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Mechanics
Huanbo Cheng, Yong Liu, Yuan Lu, Lijun Guo
Summary: The main purpose of this paper is to design a small plate heat exchanger that meets the needs of the enterprise and improve its efficiency by adding a distributor at the entrance of each layer. The study investigates the relationship between the distributor's structure and the fluid uniformity and heat transfer coefficient of the heat exchanger. The research provides theoretical basis and technical support for improving the performance of plate heat exchangers, and has good prospects for engineering application.
Article
Chemistry, Multidisciplinary
Mircea Neagoe, Radu Saulescu, Codruta Jaliu, Olimpiu Munteanu, Nadia Cretescu
Summary: Wind energy conversion systems are important in the transition to carbon-neutral power systems. This paper presents a comparative study on the energy performances of wind turbines with counter-rotating generators. The results show that increasing the number of wind rotors increases the output power, and the transmission efficiency is highest when the input torque ratio is 1.
APPLIED SCIENCES-BASEL
(2022)
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)