Article
Thermodynamics
Ramesh Kumar, Francisco J. Montero, Ravita Lamba, Manish Vashishtha, Sushant Upadhyaya
Summary: This study proposes a novel hybrid system combining photovoltaics, heat pipes, thermoelectric generators, and radiative cooling, which effectively reduces the temperature of the photovoltaic module and improves conversion efficiency and energy production.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Ryszard Buchalik, Grzegorz Nowak, Iwona Nowak
Summary: The paper focuses on simulating the transient states of thermoelectrically equipped systems. An analytical description of the system is provided considering thermal resistance and thermal capacity. The developed software is validated through experimental tests, and the results show how the performance of thermoelectric processes can be influenced by parameters like supply current and leg height.
APPLIED THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Simiao Tang, Chenglong Wang, Dalin Zhang, Wenxi Tian, Guanghui Su, Suizheng Qiu
Summary: The heat pipe cooled reactor is designed to meet future energy demands with advantages such as modularity, solid state, high reliability, and passive safety. In this study, a finite element model is established to investigate the thermoelectric performance of the TEG coupled with heat pipes, and experimental validation is conducted to verify the numerical model accuracy, with a maximum simulation error within 5%. The research provides insights into the application potential of TEGs in static heat pipe cooled reactors and lays foundations for multiphysics coupling analysis of micro heat pipe cooled reactors.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Energy & Fuels
Yanzhe Li, Shixue Wang, Yulong Zhao, Like Yue
Summary: In this study, a thermoelectric power generation system was established to recover and utilize high temperature waste heat by inserting porous foam copper to enhance the performance and heat transfer efficiency of the thermoelectric generator. The results showed that thermoelectric modules with specific properties can greatly improve the output power and heat exchange capabilities of the system, making it a promising technology for waste heat recovery and utilization.
Review
Thermodynamics
Farzad Tohidi, Shahriyar Ghazanfari Holagh, Ata Chitsaz
Summary: Thermoelectric generators are advanced devices that could potentially address energy crisis and environmental issues, offering advantages including environmental friendliness, scalability, reliability, and long lifespan. However, their low conversion efficiency has hindered widespread application, currently primarily confined to academic research.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Yuriy Lobunets
Summary: The article discusses the importance of utilizing low-potential energy sources and the potential of thermoelectric power generation technology, highlighting the key to optimizing thermoelectric generator efficiency lies in the research of material and device parameter optimization. The researchers also emphasized the importance of mathematical modeling and the possibility of tuning thermoelectric material properties for specific tasks in external conditions.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Thermodynamics
Tianjun Liao, Qidong Xu, Yawen Dai, Chun Cheng, Qijiao He, Meng Ni
Summary: By combining RC and TER, the temperature span can be significantly improved, leading to better thermal management and power generation performance.
Article
Thermodynamics
Thong Duc Hong, Minh Quang Pham, Khai Quoc Huynh, Khoi Quang Tran
Summary: This article investigates the influences of three structural parameters of the hot-side heat exchanger (HHE) on its base mean temperature. The study shows that increasing the fin quantity and height, or reducing the fin thickness, leads to an increase in the heat transfer surface area of the HHE. On the other hand, increasing the fin thickness and quantity, or decreasing the fin height, increases the convection coefficient and improves the electricity power of the thermoelectric generator unit (TGU). The findings have significant implications for improving TGU performance and reducing the size of the HHE configuration.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Thong Duc Hong, Minh Quang Pham, Phat Tan Truong
Summary: This study investigates the application of thermoelectric generator systems on internal combustion engines and explores the effects of heat exchanger structural parameters on system performance. The results show that increasing the fin quantity, height, and thickness improves the output power, but the output power decreases when the fin height reaches a certain value. Pressure loss increases with fin quantity and thickness, but decreases with fin height. The optimal parameters are found to be 28 fins, a fin height of 40 mm, and a fin thickness of 1 mm for the heat exchanger.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Thermodynamics
Kartik Srivastava, Rashmi Rekha Sahoo
Summary: This study examines a new vortex generator installed on the hot side of a thermoelectric generator's exhaust heat exchanger and analyzes its performance using numerical methods. The experiment identifies the best design configuration for the vortex generator to optimize power output in a waste heat recovery system. The results show that the configuration with a pitch/channel height ratio of 3 and a tilt angle of 60 degrees achieves the highest power output. Additionally, the study finds that the vortex generator can improve the fuel consumption efficiency of the engine.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Liang Jun Zheng, Hyun Wook Kang
Summary: This study utilized a novel PECHS to enhance the waste heat recovery capacity of a TEG, establishing a theoretical model to analyze the effects of key parameters on the TEG output capacity. The results indicated that the output capacity is positively correlated with T-H and L-f, while inversely correlated with RH, T-amb, and t(f). Additionally, the impact of increasing L-f on the cooling capability of the PECHS and the influence of RH on the TEG output capacity were discussed.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Thermodynamics
David Astrain, Juliana Jaramillo-Fernandez, Miguel Araiz, Achille Francone, Leyre Catalan, Alejandra Jacobo-Martin, Patricia Alegria, Clivia M. Sotomayor-Torres
Summary: Heat exchangers play a crucial role in optimizing the efficiency of Thermoelectric Generators (TEGs). Heat pipes without fans are preferred due to their robustness, low maintenance, and lack of moving parts. However, these heat exchangers tend to become less efficient under natural convection conditions, leading to a decrease in heat transfer capacity and thermoelectric power production. This study introduces a novel heat exchanger that combines phase change and radiative cooling in a thermoelectric generator, resulting in improved efficiency and increased electrical energy production, especially under natural convection conditions.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Miftah Y. Fauzan, S. M. Muyeen, Syed Islam
Summary: This paper presents a technique to enhance the performance of a thermoelectric generator under non-uniform heat distribution, validated through experimentation. A method for maximizing power to overcome the effects of non-uniform heat distribution is proposed.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Thermodynamics
B. Bijukumar, A. G. Kaushik Raam, V. Sukanya, C. M. Nirmal Mukundan, Ahmed Al-Durra
Summary: This work presents a new method for arranging TEMs in TEG arrays to reduce power loss associated with temperature mismatch. The physical placement of the modules is organized based on the exhaust gas flow direction to distribute the temperature gradient consistently. The superior performance of the proposed CWA structure has been validated through simulations and testing.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Alireza Hassanzadeh, Sajjad Baghestani
Summary: This article introduces a new self-powered temperature sensor based on thermoelectric generators (TEGs). The sensor utilizes two types of TEGs to measure temperature and supply the interface circuit, and employs a three-terminal TEG to account for the temperature difference between the cold and hot surfaces. By using a machine-learning algorithm and Seebeck curve fitting, the sensor achieves an error of less than +/- 1 degrees C for cold surface temperatures ranging from 0 degrees C to 70 degrees C.
IEEE SENSORS JOURNAL
(2022)
Review
Chemistry, Multidisciplinary
Dennis Valbjorn Christensen
Summary: This perspective article explores the key findings of the heterostructure formed by depositing nanoscale thin films of spinel γ-Al2O3 on perovskite SrTiO3 and proposes five directions for future research. These directions include exploring novel phenomena emerging from relaxing the epitaxial constraint, dynamic switching of polarization through electromigration, enhancement of electron mobility via oxygen vacancy diffusion, writing and erasing of nanolines using ferroelastic domain walls, and the formation of a multiferroic state. These research directions have the potential to advance both fundamental understanding and practical application in green energy devices and nanoelectronics.
Article
Engineering, Electrical & Electronic
Carlos Imbaquingo, Christian Bahl, Andrea R. Insinga, Rasmus Bjork
Summary: This article presents an elliptically shaped electromagnetic vibration energy harvester that can tune the resonance frequency easily. The harvester consists of a free-to-move ring-shaped permanent magnet, elliptically distributed cube magnets in a fixed holder, and two coil windings above and below the harvester. When subjected to vibrations, the ring magnet moves until it is pushed back by the magnetic force from the fixed cube magnets, inducing an electromagnetic force on the fixed coils. Experimental results show that the harvester has two resonant frequencies at 4.5 Hz and 7 Hz, generating around 1.5 mW of power.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
Article
Chemistry, Multidisciplinary
Hang Li, Walber H. Brito, Eduardo B. Guedes, Alla Chikina, Rasmus T. Dahm, Dennis V. Christensen, Shinhee Yun, Francesco M. Chiabrera, Nicholas C. Plumb, Ming Shi, Nini Pryds, Milan Radovic
Summary: Relatively simple surface preparation can reconstruct the 2D electron gas (2DEG) at the SrTiO3 surface, leading to a Lifshitz-like transition. Experimental methods combined with ab initio calculations reveal that the modulation of the surface band structures can be achieved via transforming the chemical composition at the atomic scale. Additionally, ARPES experiments demonstrate that vacuum ultraviolet light can effectively alter the band renormalization of the 2DEG system and control the electron-phonon interaction.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Stefan Pollok, Nataniel Olden-Jorgensen, Peter Stanley Jorgensen, Rasmus Bjork
Summary: To retrieve valuable magnetic field information in high resolution, a generative adversarial network (GAN) structure is used to predict magnetic field values at a random point from a few point measurements. The trained generator can achieve a mean reconstruction test error of 6.45% when a large single coherent region of field points is missing, and 10.04% when only a few point measurements in space are available. Compared to conventional methods, such as linear interpolation, splines, and biharmonic equations, this approach performs better by a factor of two. Results are verified on an experimentally validated magnetic field.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Rasmus Bjork, Andrea Roberto Insinga
Summary: We investigate the effects of magnetic and geometric microscopic properties on the coercivity and maximum energy product of NdFeB permanent magnets. Our findings indicate that the easy axis orientation and grain boundary width have the largest influence on both coercivity and maximum energy product. In addition, we observe that the exchange constant only weakly affects the maximum energy product. This analysis helps to clarify the factors contributing to the reduction of coercivity and maximum energy product, known as Brown's paradox.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Acoustics
P. Holm, C. Imbaquingo, B. P. Mann, R. Bjork
Summary: This paper discusses an electromagnetic energy harvester composed of a tube with fixed magnets and coils, and a floating dumbbell structure with magnets. The experimental characterization shows that the harvester can produce maximum power within a certain frequency range, and exhibits a softening resonator response and two resonance peaks.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Multidisciplinary Sciences
Tristan Steegemans, Shinhee Yun, Carlos N. Lobato, Eric Brand, Yunzhong Chen, Felix Trier, Dennis V. Christensen
Summary: The electrical, optical, and magnetic properties of oxide materials can be controlled by adjusting the oxygen content. This paper outlines two methods for varying the oxygen content and provides specific examples of tuning the electrical properties of SrTiO3-based heterostructures. The first method involves adjusting the deposition parameters during pulsed laser deposition, while the second method involves annealing the samples in oxygen at high temperatures after film growth. These methods can be applied to a wide range of oxides and nonoxide materials that are sensitive to changes in oxidation state. Unlike electrostatic gating, these methods allow for control of carrier density in nonconfined electronic systems and properties that are not dependent on the density of itinerant electrons.
JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
(2023)
Review
Energy & Fuels
Arindom Chatterjee, Carlos Nunez Lobato, Haiwu Zhang, Achilles Bergne, Vincenzo Esposito, Shinhee Yun, Andrea Roberto Insinga, Dennis Valbjorn Christensen, Carlos Imbaquingo, Rasmus Bjork, Hamsa Ahmed, Mariam Ahmad, Chun Yuen Ho, Morten Madsen, Jixi Chen, Poul Norby, Francesco Maria Chiabrera, Felix Gunkel, Ziwei Ouyang, Nini Pryds
Summary: Internet-of-thing (IoT) refers to a network of devices that collect and share data with each other through the internet, enabling access to raw information and facilitating intelligent decision making. With billions of IoT devices deployed, the challenge lies in creating self-powered units that can generate sufficient energy from ambient sources. This review paper discusses the recent progress in materials and device development for power and energy management in IoT applications, providing a comprehensive overview for new researchers and addressing challenges for those already in the field.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Physics, Applied
Thierry Desire Pomar, Adrianna Elzbieta Frackowiak, Ricci Erlandsen, Dennis Valbjorn Christensen, Rasmus Bjork
Summary: This article studies the effect of manipulating the shape of the outer boundary of a magnetometer on its performance. The results show that adding a constriction between voltage or current probes increases the maximum sensitivity of the device by 70%, and shifting the boundary shape from circular to elliptical increases it by 300%. Additionally, breaking the horizontal symmetry of the device can lead to finite zero-field sensitivity. These findings highlight the significant impact of the outer boundary on device performance, paving the way for shape optimization in designing sensitive magnetometers.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ricci Erlandsen, Thierry Desire Pomar, Lior Kornblum, Nini Pryds, Rasmus Bjork, Dennis Christensen
Summary: This study systematically investigates the interplay between material geometry and magnetoresistance effects in EMR devices. The sensitivity of EMR devices is inversely proportional to carrier density, and the magnetoresistance saturates at low carrier densities. High mobilities and low interface resistances are crucial for achieving high magnetoresistance. Encapsulated graphene and InSb are promising candidates for achieving high magnetoresistance in EMR devices at room temperature.
JOURNAL OF PHYSICS-MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Jixi Chen, Alessandro Palliotto, Shinhee Yun, Dennis Valbjorn Christensen, Vincenzo Esposito, Nini Pryds
Summary: In this study, a method that combines synthesis optimization with a post-lithiation process is introduced to enhance the ionic conductivity of LLZO electrolyte. By compensating lithium loss and stabilizing the LLZO phase, the ionic conductivity is amplified by more than three orders of magnitude. The research also determines the optimal process conditions for the highest conductivity.
MATERIALS ADVANCES
(2023)
Article
Thermodynamics
Yunxia Ma, Fei Liu, Honggang Pan, Hongjian Zhang, Shuxia Yan, Ailing Zhang
Summary: This paper proposes a dynamically tunable and switchable perfect infrared absorber that exhibits excellent electrical regulation performance and high absorptance. The absorption mechanism is explained using a multiple interference model, and it is proven to be polarization insensitive.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
F. J. dos Santos, G. S. M. Martins, M. Strobel, L. Beckedorff, K. V. de Paiva, J. L. G. Oliveira
Summary: This study investigates the effects of inlet conditions and plate's features on the thermal-flow performance of a gasket plate heat exchanger (GPHE) and assesses the impact of a modified tightening distance on its performance. No systematic study on the combined effects of inlet conditions and assembly accuracy on GPHE performance has been conducted before.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Alok K. Ray, Dibakar Rakshit, K. Ravi Kumar, Hal Gurgenci
Summary: The low thermal conductivity of phase change materials limits the heat transfer rate and application of latent heat storage systems. This numerical study examines the impact of two passive heat transfer enhancement techniques on the thermal performance of a latent heat storage system. The results show that the orientation and position of the heat transfer fluid tube have significant effects on the charging duration, while the discharging duration remains unchanged. The combined effect of orientation and eccentricity reduces the charging duration, but increases the discharging duration compared to the concentric domain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Yalu Han, Yanlong Wang, Chenyang Liu, Xinmin Hu, Yin An, Zhengcai Li, Jiaxun Jiang, Lizhi Du
Summary: This paper investigates the calculation method of thermal conductivity in NAPLs-contaminated soils. By establishing NAPLs-contaminated soil models and using the Lattice Boltzmann Method (LBM) for calculation, an optimized three-dimensional model with high computational accuracy and efficiency is obtained. The study also finds that saturation and Nz parameters have a significant impact on calculation time, while the thermal conductivity of the two-dimensional model is more sensitive to anisotropy. The influence of porosity and NAPLs content on thermal conductivity should be considered during in-situ thermal desorption.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Mostafa Taha, Song Zhao, Aymeric Lamorlette, Jean-Louis Consalvi, Pierre Boivin
Summary: For the first time, large-eddy simulations (LES) of the near-field region of large-scale fire plumes were performed using a pressure-based Lattice Boltzmann method (LBM) with low-Mach number approximation. The simulations showed quantitative agreement with experimental data and were consistent with previously-published numerical studies. The study demonstrated the computational efficiency of the proposed LBM solver in tackling fire-induced flows, suggesting LBMs as a good alternative candidate for modeling fire-related problems.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weixin Zhang, Yehang Xie, Yuqiang Ding, Zhao Liu, Zhenping Feng
Summary: This study investigated the impact of upstream slot leakage on the endwall film cooling characteristics of turbine blades. Pressure Sensitive Paint (PSP) technology was used to measure the film cooling characteristics, and numerical analysis was conducted to evaluate the aerodynamic performance. It was found that increasing the mass flow ratio of the upstream slot enhanced film cooling, decreased aerodynamic losses, and reduced the strength of passage vortex. However, reducing the distance between the slot and the blade leading edge only enhanced film cooling without affecting the leakage coverage area.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Rui Zhang, Zhen-lei Li, Yan-sheng Zhang, Dong Chen, Guo Yuan
Summary: This study discusses the heat transfer behavior of different jet forms on steel tubes. The results show that the annular jet performs better in terms of cooling intensity and uniformity. The cooling performances of the two jet forms are similar when the steel tube size is small. Therefore, the planar jet can be considered for smaller diameters due to its simplicity, low cost, and convenience in application.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
A. R. Khoei, A. M. Orvati Movaffagh, A. Rezaei Sameti
Summary: This paper presents a comprehensive study on the thermo-mechanical characteristics of oxide-coated aluminum nano-powder. It is found that the thermal conductivity of oxide-coated aluminum nano-powder is significantly lower than that of the bulk aluminum, and it is affected by the density and temperature.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Yanjin Wang, Jintao Xiong, Lingyu Chen, Zhihai Lv, Qian Wang
Summary: A solar radiation transfer model for spray cooling double skin facade (SC-DSF) is proposed in this study. The model is validated by experimental results and various influence factors are analyzed. The effectiveness of adjusting droplet coverage rate and size is also evaluated.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Bostjan Zajec, Blaz Mikuz, Anil Kumar Basavaraj, Marko Matkovic, Matej Tekavcic, Martin Draksler, Leon Cizelj, Bostjan Koncar
Summary: We have developed an advanced experimental setup to investigate flow and heat transfer in an annular channel. The setup allows heat transfer measurements and flow visualization using a temperature-controlled inner tube. Measurements can be conducted in both single-phase and two-phase flow regimes. The setup ensures a uniform velocity field in the annular channel using specially designed inlet and outlet headers. The inner copper tube is heated by water and contains turbulators for enhanced heat transfer and thermocouples for temperature measurement. A three-dimensional conjugate heat transfer CFD model has been developed and validated to accurately estimate heat losses in the setup. This study demonstrates the importance of numerical simulations in improving the interpretation of complex experimental results.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weijie Chen, Ke Wang, Yongqing Wang, Shantung Tu, Zunchao Liu, Huijuan Su
Summary: In this study, a novel gradient porosity transpiration cooling plate structure (GP-TCPS) is proposed to alleviate heat transfer deterioration caused by non-uniform temperature distribution in transpiration cooling plate structure (TCPS). Computational fluid dynamics (CFD) and response surface method (RSM) were used for qualitative and quantitative analysis of the flow and heat transfer of GP-TCPS. The optimized structure of GP-TCPS significantly improves temperature uniformity, injection pressure, and average cooling efficiency compared to traditional TCPS.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
R. Essam, A. Elsaid, W. K. Zahra
Summary: This study presents a novel bioheat model for simulating heat transfer in skin tissue. The model offers an improved representation of thermal dynamics in the skin and has been validated using numerical solutions and experimental measurements. The study highlights the importance of incorporating vascular inlet parameters and thermal relaxation effects in the thermal profile, and suggests potential applications in thermal therapy and wound healing.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Dongbo Shi, Tao Xu, Zifeng Chen, Di Zhang, Yonghui Xie
Summary: The cooling structure design of turbine blades is crucial for the safety and reliability of the gas turbine set. This research investigates different arrangement schemes, including dimple/protrusion arrangements, to enhance the cooling performance. The results show that the arrangement scheme with both passes arranged by dimples has the best comprehensive thermal performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Emrehan Guersoy, Hayati Kadir Pazarlioglu, Mehmet Guerdal, Engin Gedik, Kamil Arslan
Summary: The thermo-hydraulic performance of Al2O3/H2O nanofluid with different nanoparticle shapes flowing in a sudden expansion tube with variable sudden expansion inclination angles and elliptical dimpled fins with different diameters were numerically investigated. The results showed that the nanoparticle shapes, sudden expansion inclination angles, and elliptical dimpled fin have significant impact on the thermo-hydraulic performance. This study reveals the novelty and importance of these factors in the research.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Rukun Hu, Xinyu Huang, Xinyu Gao, Liu Lu, Xiaohu Yang, Bengt Sund
Summary: This study examines the impact of applying bottom cross-cut on PCM's spatial distribution in a horizontal LHTES unit using numerical simulation. The findings show that bottom cross-cut can improve the heat storage rate and natural convection heat transfer gain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)