Article
Green & Sustainable Science & Technology
Rahul Kumar, Sujit Kumar Verma
Summary: This paper investigates the effects of absorber surface roughness on the performance of a triangular solar air heater. By comparing smooth and rough absorber surfaces with V ribs, the study shows that rough surfaces lead to higher thermal and exergy efficiency. Experimental and numerical analysis also reveal that the roughness significantly impacts friction factor and heat transfer characteristics.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Thermodynamics
Amit Kumar, Apurba Layek
Summary: This experimental study evaluates the thermo-hydraulic performance of a solar air heater with roughness elements in the form of a winglet type vortex generator. The results show that the roughness elements significantly enhance the Nusselt number and friction factor, with the optimum values found at a relative roughness pitch of 8, an angle of attack of 60 degrees, and a relative roughness width of 5. The maximum value of the thermo-hydraulic performance parameter is observed to be 2.95.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Energy & Fuels
Tabish Alam, Chandan Swaroop Meena, Nagesh Babu Balam, Ashok Kumar, Raffaello Cozzolino
Summary: The use of protrusion ribs with appropriate roughness in solar air heaters can significantly enhance thermo-hydraulic performance, leading to maximum net effective efficiency. Optimization of the rib parameters allows for achieving optimal performance within different ranges of temperature increase parameters.
Article
Energy & Fuels
Shreyas P. Shetty, N. Madhwesh, K. Vasudeva Karanth
Summary: Numerical analysis of a solar air heater with perforated circular absorber plate shows that increasing the vent diameter and quantity significantly improves thermohydraulic efficiency by causing vortex formation and increasing turbulence induced heat transfer.
Article
Thermodynamics
A. Saravanan, M. Murugan, M. Sreenivasa Reddy, P. S. Ranjit, P. Elumalai, Pramod Kumar, S. Rama Sree
Summary: The experimental investigation focused on the thermo-hydraulic performance of a solar air heater with staggered multiple C-shape perforated and non-perforated finned absorber plate. Results indicated that the perforated finned absorber plate outperformed the smooth plate absorber plate, especially with relative pitch to gap ratio 3.8 and relative height ratio 0.6.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Environmental Sciences
Nitesh Dutt, Ankush Jageshwar Hedau, Ashwani Kumar, Mukesh Kumar Awasthi, Varun Pratap Singh, Gaurav Dwivedi
Summary: This paper numerically investigates the thermo-hydraulic performance of a solar air heater duct roughened with discrete D-shaped ribs using ANSYS Fluent 2020 R-2. The numerical investigation is conducted at different ratios of rib radius to transverse pitch and longitudinal pitch to rib radius under various operating conditions. The results show that the values of Nusselt number and friction factor decrease with increasing longitudinal pitch to rib radius ratio, while the rib radius to transverse pitch ratio is kept constant. The optimum thermo-hydraulic performance parameters are obtained at a rib radius to transverse pitch ratio of 0.25 and longitudinal pitch to rib radius ratio of 4.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Thermodynamics
Vahid Madadi Avargani, Sohrab Zendehboudi, Amir Rahimi, Sara Soltani
Summary: The study shows that applying vertical cylindrical obstacles to solar air heaters can significantly improve the system's thermal and exergy efficiency, as well as greatly help reduce the CO2 emissions.
APPLIED THERMAL ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Kottayat Nidhul, Ajay Kumar Yadav, S. Anish, U. C. Arunachala
Summary: An experimental and computational study was conducted to investigate the effect of secondary flow on the thermo-hydraulic performance of inclined baffles in a flat plate solar air heater with semi-cylindrical sidewalls. The results show that the presence of a gap at the trailing apex enhances the thermal performance.
Article
Green & Sustainable Science & Technology
Ankush Hedau, R. P. Saini
Summary: Solar air heaters can improve their thermo-hydraulic performance by using different geometries of artificial roughness. This study investigates the heat transfer and friction characteristics of a double pass solar air heater with transverse semi-circular tubes and rectangular perforated blocks as artificial roughness. The results show that the maximum thermo-hydraulic performance parameter is achieved at Re of 3000, a/H of 0.3, e/H of 0.4, and beta of 30%.
Article
Energy & Fuels
Mostafa Esmaeili Shayan, Farzaneh Ghasemzadeh, Seyed Hossein Rouhani
Summary: This study investigates the impact of roughness parameter on heat transfer and pressure drop in solar air heaters. The results show that using an artificial roughness staggered arrangement can significantly enhance heat transfer in the system.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Green & Sustainable Science & Technology
Rajneesh Kumar, Varun Goel
Summary: The study investigates the influence of various roughness elements on the performance of solar air heater, with experiments conducted in a triangular passage solar air heater. Results show that among different geometries, the forward-chamfered rectangular rib has the best thermohydraulic performance parameter.
Article
Thermodynamics
Rahul Kumar, Sujit Kumar Verma, Naveen Kumar Gupta, Andres Z. Mendiburu, Abhishek Sharma, Tabish Alam, Sayed M. Eldin
Summary: This research compares the efficiency of solar air heaters with and without rib roughness on absorber plates. Results show that smooth plates are more efficient in heat conversion than rough ones. Experimental and numerical analysis confirm that the roughness of V-shaped ribs improves heat transfer in triangular duct absorber surfaces.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Tabish Alam, Md Irfanul Haque Siddiqui, Hassan Alshehri, Masood Ashraf Ali, Paolo Blecich, Kushagra Saurabh
Summary: This paper presents the thermo-hydraulic performance of small conical ribs on the absorber plate of a solar energy air heater. By optimizing the rib design, the thermal performance of the air heater can be enhanced.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Mechanical
Nanjundappa Madhukeshwara, A. Alhadhrami, Hassan A. H. Alzahrani, B. H. Prasanna
Summary: This study focuses on evaluating heat transmission and friction in a solar air heater with V-shaped wire rib roughness, and generating prediction equations for key metrics. By varying parameters, the optimal configuration for maximizing heat transfer while minimizing friction losses is identified.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Pu Zhang, Peng Xia, Xueyan Guo, Shaozhang Xie, Wensheng Ma
Summary: In this study, an intelligent design method was developed to enhance SAH heat efficiency using artificial ribs. By calculating the shape sensitivity of the rib profile, a reverse design was conducted to improve thermo-hydraulic performance. The results showed significant improvement in flow and heat transfer characteristics with the reversely designed ribs.
Article
Engineering, Manufacturing
Md Absar Alam, Rajan Kumar, Deepen Banoriya, Anil Singh Yadav, Geetesh Goga, Kuldeep K. Saxena, Dharam Buddhi, Ravindra Mohan
Summary: This study analyzes the thermal comfort of passengers in a train cabin and identifies the optimal design arrangement that provides the best temperature distribution and thermal comfort.
INTERNATIONAL JOURNAL OF INTERACTIVE DESIGN AND MANUFACTURING - IJIDEM
(2023)
Article
Automation & Control Systems
Abhisek Omkar Prasad, Pradumn Mishra, Urja Jain, Anish Pandey, Anushka Sinha, Anil Singh Yadav, Rajan Kumar, Abhishek Sharma, Gaurav Kumar, Karrar Hazim Salem, Avdhesh Sharma, Anil Kumar Dixit
Summary: Autonomous vehicles and self-driving technology have attracted a lot of attention in recent research. This paper discusses various aspects of autonomous driving, including the software architecture and hardware components. The software architecture mainly covers ROS, ML, DL, and OpenCV frameworks, as well as sensor and camera calibration. The paper also discusses SLAM-based path tracking, computer vision-based controller, and intelligent object avoidance. Furthermore, filters such as point cloud, ground, radius, and raycast are implemented for real-time object detection. The paper highlights the overall hardware modules responsible for car control.
ROBOTICS AND AUTONOMOUS SYSTEMS
(2023)
Article
Chemistry, Physical
Ranjeet Kumar Arya, Rajan Kumar, Amit Telang, Anil Singh Yadav
Summary: This research focuses on the development of aluminum alloy hybrid composite using Al6061 as matrix and silicon nitride (Si3N4) and silicon carbide (SiC) as hybrid reinforcement particles. The microstructures of the composites exhibited a uniform distribution of hybrid reinforcements with no significant porosity. XRD and EDX analysis confirmed the stability of the reinforcement particles and the presence of desired elements. The hybrid composites showed increased hardness and ultimate tensile strength, and heat treatment further improved these properties.
Article
Materials Science, Multidisciplinary
Rajan Kumar, Ravi Kumar Dwivedi, Ranjeet Kumar Arya, Pankaj Sonia, Anil Singh Yadav, Kuldeep K. Saxena, M. Ijaz Khan, Sana Ben Moussa
Summary: A pragmatic shift in metal development has been ongoing for industrialization in recent decades. There is a high demand for materials with high tensile strength and ductility in various engineering and industrial applications. Carbide-free bainitic in high silicon steel can meet this demand and be fabricated cost-effectively. This research thoroughly evaluates the wear rate of the proposed material in numerous applications, highlighting the influence of carbide-free bainitic and retained austenite on wear resistance in high silicon steel and the working parameters.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Engineering, Chemical
Injamamul Haque, Tabish Alam, Jagmohan Yadav, Naveen Kumar Gupta, Md Irfanul Haque Siddiqui, Tauseef Uddin Siddiqui, Naushad Ali, Shivam Srivastava, Anil Singh Yadav, Abhishek Sharma, Rohit Khargotra, Amit Kumar Thakur
Summary: Higher density heat flux causes damage to electronic components, so cooling them is crucial for safe operation and longer lifespan. In this study, lozenge-shaped pin-fins were designed and used in microchannel heat sinks to achieve better cooling performance. The results showed that introducing lozenge-shaped pin-fins greatly improved heat transmission, with the best performance observed at an aspect ratio of 1.00.
INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING
(2023)
Article
Engineering, Mechanical
Rahul Kumar, Anil Singh Yadav, Abhishek Sharma, Upendra Rajak, Tikendra Nath Verma, Tabish Alam, Nishant Tiwari, C. P. Jawahar
Summary: Due to urbanisation, the energy reuse of scrap tyres through pyrolysis has gained attention. In a prior study, a blend of jatropha methyl ester (JME) and tyre pyrolysis oil (TPO) was used as a diesel engine fuel, but it performed inferior to diesel due to higher viscosity. This study attempts to utilize the JME-TPO blend at different preheating temperatures and compares the results with diesel in a single-cylinder diesel engine.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2023)
Article
Thermodynamics
Anil Kumar, Rajesh Maithani, Masood Ashraf Ali, Naveen Kumar Gupta, Sachin Sharma, Tabish Alam, Hasan Sh Majdi, T. M. Yunus Khan, Anil Singh Yadav, Sayed M. Eldin
Summary: This article introduces the use of twisted tape inserts on the absorber plate of a flat plate solar heat collector to increase its efficiency. The thermal and hydraulic performance of the absorber plate is analyzed by varying the twist pitch and twist height. Computational fluid dynamics is used to perform the analysis, and a maximum thermal-hydraulic performance value of 2.41 is observed for specific twisted tape parameters.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Ramakrishna Konijeti, Abhishek Dasore, Upendra Rajak, Rajan Kumar, Abhishek Sharma, Anil Singh Yadav
Summary: This study investigates heat transfer through free convection mode across circular fins on a vertical cylinder. The analysis includes both laminar and turbulent regimes, exploring the influence of various factors on convective heat transfer characteristics. The findings provide valuable insights for the design and optimization of heat transfer systems in diverse engineering and scientific domains.
MULTISCALE AND MULTIDISCIPLINARY MODELING EXPERIMENTS AND DESIGN
(2023)
Article
Environmental Sciences
Nibedita Nath, Subhendu Chakroborty, Durga Prasad Vishwakarma, Geetesh Goga, Anil Singh Yadav, Ravindra Mohan
Summary: The lightweight, low-density, and low-cost natural polymers such as cellulose, chitosan, and silk have unique structural and functional elements with good chemical and biodegradable properties. Among them, chitosan lacks good mechanical properties compared to cellulose and silk. The synthesis of nano natural polymer and reinforcement with suitable chemical compounds has promising multidisciplinary applications. Many studies have focused on the biomedical applications of bio-derived polymeric functional materials (Bd-PFM), especially as biosensors. This review provides an overview of the nanostructures and biosensor applications of Bd-PFM.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Nibedita Nath, Subhendu Chakroborty, Sumit Sharma, Abhishek Sharma, Anil Singh Yadav, Tabish Alam
Summary: Graphene-based materials (GMs) have gained popularity in energy storage due to their distinct two-dimensional structure, good electrical conductivity, and wide surface area. Developing effective energy storage materials is a primary focus in advancing environmentally friendly energy technology. This review covers the topic of using GMs for hydrogen storage in green energy applications.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Multidisciplinary
Manish Kumar, Arun Arora, Shanu Pandey, Anil Singh Yadav, Rajan Kumar, Abhishek Sharma, Tabish Alam
Summary: This study investigates the thermodynamics of a triple power cycle that combines Gas Turbine, Rankine cycle, and Kalina cycle with Solar and Biomass assistance. Parametric optimisation was used to determine the best efficient system operating parameters as well as the likely maximum overall performances for each of the single and multi-systems. The research found that the addition of solar and biomass assistance contributes to enhancing the power of a triple power cycle.
MULTISCALE AND MULTIDISCIPLINARY MODELING EXPERIMENTS AND DESIGN
(2023)
Proceedings Paper
Materials Science, Multidisciplinary
Anil Singh Yadav, Abhay Agrawal, Abhishek Sharma, Abhay Gupta
Summary: Solar air heating is a renewable energy heating technology that converts solar energy into air. Adding ribs to the surface of a solar air heater can enhance its effectiveness. Computational fluid dynamics (CFD) is a useful method for optimizing the design of solar air heaters.
MATERIALS TODAY-PROCEEDINGS
(2022)
Proceedings Paper
Materials Science, Multidisciplinary
Anil Singh Yadav, Shaman Gupta, Abhay Agrawal, Rajiv Saxena, Naveen Agrawal, Sachi Nashine
Summary: Despite the limitations of conventional energy sources, the use of solar energy is considered important for sustainable energy development due to its environmental friendliness and abundant resources. Solar air heaters (SAHs) convert solar energy into thermal energy using air as a working fluid. However, the low thermal efficiency of SAHs and the resulting low temperature rise can limit their effectiveness. Various efforts have been made to improve SAH performance in turbulent flow, including the use of ribs, baffles, and fins. This article provides a detailed review of the thermal performance of a ribbed SAH and explores the effects of ribs on pressure drop and heat transfer rate. The use of artificial roughness has been found to enhance the thermal performance of SAHs.
MATERIALS TODAY-PROCEEDINGS
(2022)
Proceedings Paper
Materials Science, Multidisciplinary
Anil Singh Yadav, Anupritha Mishra, Kaustubh Dwivedi, Abhay Agrawal, Ayush Galphat, Neeraj Sharma
Summary: This study investigates the influence of ribs on heat transfer and fluid flow in a solar air heater. Computational simulations show that ribs with smaller pitch achieve higher heat transfer performance at higher Reynolds numbers, but also result in higher friction factors at lower Reynolds numbers.
MATERIALS TODAY-PROCEEDINGS
(2022)
Proceedings Paper
Materials Science, Multidisciplinary
Anil Singh Yadav, Mayank Kumar Dwivedi, Abhishek Sharma, Vimal Kumar Chouksey
Summary: This article numerically analyzes the influence of adding rib roughness to a solar air heater duct on heat transfer. The study finds that the height and pitch of the ribs have a significant impact on heat transfer. A new heat transfer correlation is developed and the resulting data is analyzed and predicted using a regression algorithm.
MATERIALS TODAY-PROCEEDINGS
(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)
