Article
Thermodynamics
Hang-Suin Yang, Chin-Hsiang Cheng, Muhammad Aon Ali
Summary: This study proposes a theoretical model for analyzing the performance and operating modes of a thermal-lag Stirling engine. The model is solved by the method of multiple scales, and it predicts the performance, operating regions, and transitions between different modes. The performance of the engine under stable operating state and the dependence of the indicated power on engine speed are evaluated. An optimal loading and a minimum operating speed are also predicted.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Moh'd Al-Nimr, Saud Khashan, Hashem Al-Oqla
Summary: This paper demonstrates the technical feasibility of a novel hybrid Stirling Engine, coupled with inserted pyroelectric generators in its thermal regenerator, to produce extra power through the pyroelectric effect and increase engine performance.
Article
Energy & Fuels
Haojie Sun, Guoyao Yu, Wei Dai, Limin Zhang, Ercang Luo
Summary: This paper proposes a novel resonance tube-coupled free-piston Stirling engine-based combined cooling and power system. It employs a resonance tube to couple an engine and a cryocooler, and introduces a linear alternator for startup and multiple demands, achieving flexible adjustments and higher exergy efficiency.
Article
Energy & Fuels
Haojie Sun, Guoyao Yu, Wei Dai, Limin Zhang, Ercang Luo
Summary: This paper proposes a novel resonance tube-coupled free-piston Stirling engine-based combined cooling and power system for efficient energy utilization and flexible adjustments, leading to higher exergy efficiency. A time-domain unsteady model was developed to investigate the onset behavior of the system and successfully predict the onset temperature and frequency. Results showed that a resonance tube with larger diameter or shorter length can lead to a lower onset temperature.
Article
Thermodynamics
Jiqiang Li, Fuping Wang
Summary: With the development of social economy, countries around the world have been paying close attention to the development of new energy sources. The Stirling engine, as a new power engine, has many advantages and can utilize waste heat in various fields. The study shows that changing the dynamic configuration and thermodynamic ratio of the Stirling engine affects its power and efficiency. Additionally, installing a regenerator can also affect the output and efficiency.
ADVANCES IN MECHANICAL ENGINEERING
(2022)
Article
Thermodynamics
Duc-Thuan Phung, Chin-Hsiang Cheng
Summary: In this study, a novel CFDMD model is used to analyze and investigate the behavior of thermal-lag engines (TLE). The study shows that the CFDMD model effectively captures the thermodynamic behavior of the working gas and the dynamic behavior of the engine mechanism. Additionally, the study explores the temporal evolution of engine speed and the influence of various parameters on shaft power and brake thermal efficiency. The research also reveals the existence of a thermal-lag phenomenon in TLE.
APPLIED THERMAL ENGINEERING
(2024)
Review
Energy & Fuels
Shunmin Zhu, Guoyao Yu, Kun Liang, Wei Dai, Ercang Luo
Summary: Small- and micro-scale combined heat and power (CHP) technologies have great potential for reducing energy costs and CO2 emissions in residential and small commercial buildings, with Stirling engines showing particular promise. However, current challenges facing Stirling-engine CHP systems include low on-site operational efficiencies and high investment costs, which need to be addressed for future development and successful commercial dissemination.
Article
Thermodynamics
Ermerson F. de Moura, Izabela B. Henriques, Guilherme B. Ribeiro
Summary: With the advancement of the new space era, there is an increasing need for long-term missions beyond Earth's orbit, such as Mars and Moon exploration. These missions are more complex in terms of duration and energy demand. In this study, a thermodynamic model of a nuclear-powered Stirling cycle coupled with a dynamic engine model was developed to provide insights into the system performance. The results showed that the regenerator efficiency and compression ratio have significant effects on the engine efficiency. The best parameters yielded a system with a power output of 260.5 kW and a power density of 35.38 kg.kW(-1). This study serves as a theoretical guideline for the future design of nuclear-powered Stirling engines for space applications.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Thermodynamics
G. V. Vorotnikov, E. A. Zinovyev, S. O. Nekrasova
Summary: This paper presents a new numerical solution for the thermodynamic cycle of a thermoacoustic engine and develops a mathematical solution for calculating the gas averaged velocity. The results of power output and thermal efficiency for a tested traveling-wave engine are obtained through experiments and the numerical solution.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Shunmin Zhu, Kai Wang, Iker Gonzalez-Pino, Jian Song, Guoyao Yu, Ercang Luo, Christos N. Markides
Summary: This paper presents a comprehensive analysis of a micro-combined heat and power (CHP) system, including hybrid photovoltaic-thermal (PVT) collectors, a Stirling engine (SE), and energy storage. The results show that the system can achieve a high degree of self-sufficiency and energy savings, but the initial investment is currently high.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Mohammad Amin Babazadeh, Mojtaba Babaelahi, Mahdi Saadatfar
Summary: This study focuses on using heat transfer fins to enhance energy absorption in the heater section of a solar Stirling engine, and proposes modifications and introduces unique heat transfer fins to increase the heat received by the working fluid. Thermal analysis shows that using these new fins significantly increases the power and efficiency of the system.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
John Dyreby, Justin Shumaker, Kristin E. Schaefer, John Corey, James J. Carroll, Christopher J. Chiara, Gregory Nellis
Summary: Currently, power systems are limited by the source and energy density of chemical fuels, leading to the development of nuclear energy sources. Nuclear isomers have a significantly higher energy density than chemical fuels and can be transformed to release energy. Switched nuclear isomer (SNI) materials provide abundant energy, but pose challenges in power conversion. This study explores the coupling of an SNI heat source to a kinematic Stirling engine and demonstrates its potential in achieving high conversion efficiency, high power density, and inherent modulation capability.
APPLIED THERMAL ENGINEERING
(2024)
Article
Materials Science, Multidisciplinary
Wei Wang, Lijun Wu, Junjie Li, Niraj Aryal, Xilian Jin, Yu Liu, Mikhail Fedurin, Marcus Babzien, Rotem Kupfer, Mark Palmer, Cedomir Petrovic, Weiguo Yin, Mark P. M. Dean, Ian K. Robinson, Jing Tao, Yimei Zhu
Summary: Combining quantitative MeV ultrafast electron diffraction analysis with Monte Carlo simulation and first-principles calculations, this study directly reveals the soft, anharmonic lattice distortions of SnSe thermoelectric material. The identified interlayer shear strain character induced by c-axis atomic displacements provides a promising route to optimizing thermoelectric devices by reducing thermal conductivity.
NPJ QUANTUM MATERIALS
(2021)
Article
Energy & Fuels
Fatih Aksoy, Hamit Solmaz, Muhammed Arslan, Emre Yilmaz, Duygu Ipci, Alper Calam
Summary: This study examined the effects of a regenerator on the engine performance of a beta type Stirling engine. Stainless steel wire was used as the regenerator material in experiments, leading to a 5.97% increase in engine power and a 4% increase in engine torque when the regenerator was used.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2021)
Article
Thermodynamics
Pengchao Zang, Yanlin Ge, Lingen Chen, Qirui Gong
Summary: Based on the irreversible Porous Medium cycle model established in previous literature, this study investigates the optimal performance of the cycle by using finite time thermodynamics and taking cycle power density as the optimization objective. It is found that the Porous Medium cycle engine achieves higher thermal efficiency and smaller size under the condition of maximum power density, compared to the condition of maximum power output.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Chin-Hsiang Cheng, Duc-Thuan Phung
Summary: The study presents a three-dimensional CFD model for simulating a compact 100-W beta-type Stirling engine, and explores the influence of various parameters on engine performance in terms of power and thermal efficiency. Results show that heating temperature, cooling temperature, and piston length have significant effects on both power output and thermal efficiency of the engine.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Thermodynamics
Chin-Hsiang Cheng, Hang-Suin Yang, Yi-Han Tan
Summary: This paper proposes an energy method to solve the relationship between the crank angle of the main shaft and the work generated by the working fluid in a double-acting Stirling engine with a wobble yoke mechanism. The study also employs a modified non-ideal adiabatic model to predict the transient variation in thermal properties of the working fluid. The simulation results demonstrate the potential of the proposed engine in terms of maximum shaft power and performance prediction.
Article
Thermodynamics
Hang-Suin Yang, Chin-Hsiang Cheng, Muhammad Aon Ali
Summary: This study proposes a theoretical model for analyzing the performance and operating modes of a thermal-lag Stirling engine. The model is solved by the method of multiple scales, and it predicts the performance, operating regions, and transitions between different modes. The performance of the engine under stable operating state and the dependence of the indicated power on engine speed are evaluated. An optimal loading and a minimum operating speed are also predicted.
APPLIED THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Chin-Hsiang Cheng, Yu-Ting Lin
Summary: This study aimed to develop an algorithm for the computational optimization of free-piston Stirling engines. The algorithm includes an optimization method and compatible strategies, which can handle multiple-parameter optimization and provide faster convergence.
Article
Engineering, Manufacturing
Chin-Hsiang Cheng, Cherng-Chyi Loh, Yi-Jie Zhang
Summary: This study uses a composite material with copper powder added in Polylactide (PLA) to manufacture metallic parts via 3D printing, and sintering process is applied for PLA removal and mechanical strengthening. Numerical simulation is conducted to investigate the heat transfer characteristics of the system during heating process.
PROGRESS IN ADDITIVE MANUFACTURING
(2022)
Article
Chemistry, Physical
Chin-Hsiang Cheng, Yi-Shen Chen, Hsin-Yu Tsai, Yu-Ling Liang, David T. W. Lin, Yitung Chen
Summary: The present study aims to develop and test a cost-effective and efficient printing method for fabricating flexible metamaterial film with high electromagnetic wave absorptivity. Numerical and experimental results show that the flexible metamaterial film fabricated using a silver nanoparticles ink jet printer has a high absorptivity.
Article
Thermodynamics
Hang-Suin Yang, Muhammad Aon Ali, Karumudi Venkata Ravi Teja, Yi-Feng Yen
Summary: The study focuses on optimizing the design of a kW-class beta-type Stirling engine with a rhombic drive mechanism for a concentrated solar power system, validating the simulation results with experimental data. The research demonstrates an increase in maximum shaft power of the prototype engine to 1503 W and improvements in thermal efficiency to 13.5% and mechanical efficiency to 94.3% can be achieved.
APPLIED THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Chin-Hsiang Cheng, Duc-Thuan Phung
Summary: Thermal-lag engines are external combustion engines with a single moving piston, resulting in lower manufacturing and maintenance costs. This study focuses on the performance of thermal-lag engines by developing a three-dimensional computational fluid dynamics model and validating it with experimental data. The study finds that the CFD model's predictions align well with the experimental data and highlights the significant impact of engine speed and temperature on engine power.
Article
Energy & Fuels
Chin-Hsiang Cheng, Surender Dhanasekaran
Summary: This research focuses on reducing the cogging force acting on the translator of a slot-spaced Permanent Magnet Linear Alternator (PMLA) by making geometrical changes to the machine structure. The aim is to align the cogging force profile with the displacement profile of the translator to minimize vibrations and prevent damage to the piston of the Free Piston Stirling Engine (FPSE). The outcome of this work is achieving a balance between reduced voltage and cogging force through minor geometrical changes and a sinusoidal cogging force profile.
Article
Thermodynamics
Hang-Suin Yang, Hao-Qiang Zhu, Xian-Zhong Xiao
Summary: This study investigates the dynamic characteristics and performance of beta-type Stirling engines (BTSEs) with five driving mechanisms. A thermodynamic model is used to predict the variations in the thermal properties of the working fluid, and friction losses are considered in the dynamic models. The results show that the trajectories of the piston and displacer significantly affect the performance of BTSEs. Among the five mechanisms, BTSEs with the bell crank mechanism achieve the highest shaft power (1533 W) at 550 rpm, with a mechanical efficiency of 80.5%.
Article
Energy & Fuels
Chin-Hsiang Cheng, Shang-Ting Huang
Summary: This study aims to model a hybrid power system that can continuously generate power by switching between solar radiation and combustion energy from synthesis gases. The system includes a hybrid energy receiver, solar dish, Stirling generator, fluidized-bed gasifier, boiler, and water tank. The modeling results indicate that switching can result in a continuous power output ranging from 600 to 1200 W.
ENERGY SCIENCE & ENGINEERING
(2023)
Article
Thermodynamics
Jhen-Syuan Huang, Chin-Hsiang Cheng
Summary: This paper presents a theoretical model for analyzing the performance of a rotary-integral Stirling cryocooler. Transient variations of thermodynamic properties are used to predict cooling temperature and capacity. A precise evaluation method for the regenerator is introduced, and temperature and pressure dependent thermophysical properties are considered. An experimental prototype is manufactured and numerical results from the model are validated. The results show good agreement between the predicted and measured values, indicating the effectiveness of the proposed model. Parametric studies are also conducted to explore performance enhancements.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Energy & Fuels
Chin-Hsiang Cheng, Surender Dhanasekaran
Summary: This research focuses on the design and development of a tubular slot-spaced Permanent Magnet Linear Alternator coupled with Free-Piston Stirling Engines. By studying parameters, the power density of the machine has been increased, and the performance variation of the machine under different conditions has been studied.
Article
Energy & Fuels
Chin-Hsiang Cheng, Hang-Suin Yang, Yi-Han Tan, Jun-Hong Li
Summary: A theoretical model combining thermodynamic and dynamic models is proposed in this article for predicting the performance and transient behavior of a double-acting Stirling engine with four cylinders. The model can simulate the shaft power and total efficiency of the engine under different operating conditions and with different design parameters.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
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)
