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
Multidisciplinary Sciences
Juan A. Aunon, Jose M. Perez, Maria J. Martin, Fernando Aunon, Daniel Nunez
Summary: This study develops a tool that allows for the analysis of various thermodynamic models used in the study and development of Stirling engines. The tool not only allows for a comparative study of these models, but also calculates operating parameters, thermodynamic parameters, power output, and efficiency. Additionally, the tool can evaluate different mechanical configurations and regenerator models, providing a versatile and comprehensive analysis of Stirling engines.
Article
Acoustics
M. Ito, P. Murti, S. Tsuboi, E. Shoji, T. Biwa
Summary: This study analyzes the linear oscillation dynamics of the Fluidyne engine from a thermoacoustic point of view and focuses on the specific acoustic impedance of the working gas. Experimental verification of the theoretical model was achieved, and key parameters affecting the specific acoustic impedance were determined.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Engineering, Multidisciplinary
Erkan Ozturk
Summary: Stirling engines are important in renewable energy and waste heat recovery. This study optimized the ideal piston trajectories of a beta type Stirling engine, resulting in an increase in cyclic work.
ENGINEERING SCIENCE AND TECHNOLOGY-AN INTERNATIONAL JOURNAL-JESTECH
(2023)
Article
Thermodynamics
H. Yousefzadeh, A. R. Tavakolpour-Saleh
Summary: This paper presents a novel method to calculate and predict the damping coefficient and overall performance of a kinematic Stirling engine. Through a comprehensive model and experimental validation, the effectiveness of the model was confirmed.
Article
Thermodynamics
A. R. Tavakolpour-Saleh, Shahryar Zare
Summary: This paper presents a novel lumped mechanical model incorporating modern control theory to investigate performance and startup condition of thermo-acoustic Stirling engines (TASEs). The study reveals that TASEs can be considered as physical regulators from the viewpoint of modern control theory. Design parameters and quality index are analyzed to evaluate resonance phenomenon in the TASEs, and the proposed mathematical model incorporating the control-based design technique is validated using practical data of three prototype engines.
Article
Green & Sustainable Science & Technology
Moh'd Al-Nimr, Saud A. Khashan, Hashem Al-Oqla
Summary: This paper presents three novel techniques to enhance Stirling engines (SE). The use of Phase-Change Material (PCM) regenerators instead of conventional regenerators improves the performance of both the regenerator and the engine. Replacing the plate receiver of a Solar-Dish Stirling engine (SDSE) with a glass receiver increases direct radiation absorption and reduces energy losses. Coupling an SDSE system with a PCM Thermal Storage Reservoir (PCMTSR) allows for the storage and extraction of rejected heat energy during the day and night, utilizing either ambient air or geothermal water for night-time engine cooling. Theoretical models evaluate the impact of these modifications on SE performance.
Article
Energy & Fuels
Ruijie Li, Lavinia Grosu, Nadia Martaj
Summary: The study focuses on the impact of physical and geometrical parameters on the operating characteristics of two LTD Stirling engines, showing that different phase shifts affect their performance. Friction loss increases with rotation speed for both engines, and thermal efficiency first increases and then decreases with heating power.
JOURNAL OF ENERGY ENGINEERING
(2021)
Editorial Material
Chemistry, Physical
Alberto Boretti
Summary: Current alpha-Stirling engine designs have not reached Carnot cycle efficiency, but by using hydrogen as working fluid and adopting specific structures, higher energy conversion efficiencies can be achieved. Compared to current air microturbines, the efficiency is significantly higher.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Chin-Hsiang Cheng, Duc-Thuan Phung
Summary: A method of exchanging data between CFD and thermodynamic models is proposed in this study to improve simulation efficiency. Through an iterative process of prediction and correction, detailed solutions for the stable oscillatory regime in CFD model are achieved.
ENERGY SCIENCE & ENGINEERING
(2021)
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
Han Jiang, Zhongli Xi, Xiaoqing Zhang
Summary: This research focuses on the modeling of free piston Stirling engines (FPSEs) using network theory and emphasizes the active attribute of Stirling regenerator and differences from thermoacoustic devices. A general heat-dynamics active network model in distributed form is developed, considering the intrinsic attribute and treating nonlinear network parameters. The model is verified and compared with experiments and existing network models, showing improved accuracy and practicality.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Mohammad Hassan Khanjanpour, Mohammad Rahnama, Akbar A. Javadi, Mohammad Akrami, Ali Reza Tavakolpour-Saleh, Masoud Iranmanesh
Summary: In this study, a gamma-type MDT Stirling engine prototype is manufactured, evaluated, and structurally optimized. An inexpensive mathematical evaluation based on FDT approach led to the determination of the optimal swept volume ratio under 450K temperature difference. Experimental results showed good agreement with the theoretical approach, validating its effectiveness in optimizing MTD Stirling engines.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Ammar S. Easa, Wael M. El-Maghlany, Mohamed M. Hassan, Mohamed T. Tolan
Summary: By integrating twin wavy plate heat exchangers with gamma-type Stirling water dispensers, the performance of the water cooler can be improved, resulting in less energy consumption and providing an eco-friendly alternative.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
George-Rafael Domenikos, Irene Koronaki, Theodoros Papingiotis, Panagiotis Bitsikas
Summary: This paper presents a parametric analysis on a beta-type Stirling engine, focusing on the impact of various rotational speeds. By utilizing a three-dimensional computational fluid analysis model, the study monitors and understands the temperature variations across the engine's primary components, and provides insights into the optimal working conditions based on the analysis results.
Article
Thermodynamics
Emel Celik, Nezaket Parlak, Yusuf Cay
Summary: A laboratory scale test prototype of tower type grain dryer was installed to determine the most suitable model for the control system through experimental corn drying tests and curve fitting analysis. Midilli model was found to be the most suitable for control of industrial dryers based on the experimental data and comparisons with literature results.
HEAT AND MASS TRANSFER
(2021)
Article
Environmental Sciences
Nezaket Parlak, Saim Ozdemir, Kaan Yetilmezsoy, Majid Bahramian
Summary: The study investigated the drying of poultry abattoir sludge (PAS) in thin-layer procedure with solar drying during summer conditions. The results showed that open surface solar drying assisted with solar heated air could be an effective method for drying PAS under high intensity solar radiation.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH
(2021)
Article
Thermodynamics
Zekeriya Parlak, Nezaket Parlak, Yasar Islamoglu
Summary: The optimization operation with ANSYS Response Surface Optimization Tool was used to find the best geometry for converging-diverging channels. The study focused on the effects of channel width, wavelength, and amplitude on thermal-hydraulic performance, with thermal performance factors calculated. Results showed that the optimized channel outperformed the straight channel, with TPF values ranging from 1.4 to 1.7 across different Reynolds numbers.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Energy & Fuels
Mansour Al Qubeissi, Nawar Al-Esawi, Hakan Serhad Soyhan
Summary: The previously developed approaches for fuel droplet heating and evaporation processes have been improved and generalized for a broad range of bio-fossil fuel blends. The Complex Fuel Surrogate Model (CFSM) aims to reduce the full composition of fuel to a much smaller number of components based on their mass fractions, which has been implemented into a commercial CFD code ANSYS Fluent to improve simulation accuracy.
Article
Energy & Fuels
Cemil Koyunoglu, Huseyin Karaca, Hakan Serhad Soyhan
Summary: The study utilized Computational Fluid Dynamics for reactor modeling of DME production from syngas in a fluid bed model, with a focus on physical optimization simulation to determine conditions for maximum gas-solid contact.
Article
Energy & Fuels
Usame Demir, Gokhan Coskun, Hakan S. Soyhan, Ali Turkcan, Ertan Alptekin, Mustafa Canakci
Summary: This study experimentally and numerically analyzed the effects of using conventional camshafts and electromechanical valve mechanisms (EMV) in a single-cylinder spark-ignition engine. Results showed that the use of EMV system significantly influences volumetric efficiency and parameters such as in-cylinder air flow.
Article
Energy & Fuels
Omer Boyukdipi, Gokhan Tuccar, Hakan Serhad Soyhan
Summary: The experimental study investigated the effects of NH3 as a fuel additive on engine vibration parameters, revealing that increasing levels of NH3 additive led to increased engine vibration and had a negative impact on engine vibration when blended with sunflower biodiesel. High accuracy rates were achieved in predicting vibration data through artificial neural networks models.
Article
Engineering, Multidisciplinary
Emel Celik, Nezaket Parlak, Yusuf Cay
Summary: This study developed a laboratory scale dryer integrated with a capacitive sensor for real-time measurement of seed moisture content. The electrical properties of grains were found to be influenced by moisture content, density, temperature, material structure, and electric field frequency. The dielectric properties of shelled corn with different moisture content were measured to determine the optimal working frequency. A model was built based on the relationship between corn moisture content and electrical properties, using curve fitting techniques to characterize the dielectric properties. Experimental drying tests were conducted to verify the accuracy of the model.
SADHANA-ACADEMY PROCEEDINGS IN ENGINEERING SCIENCES
(2022)
Article
Thermodynamics
Zekeriya Parlak, Nezaket Parlak, Yasar Islamoglu, Ufuk Durmaz
Summary: In this study, a parametric numerical investigation is conducted for a converging-diverging channel under pulsatile flow conditions. The findings reveal a limited potential for heat transfer improvement in turbulent pulsatile airflow within a specific range.
HEAT TRANSFER ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Zekeriya Parlak, Ismail Sahin, Nezaket Parlak
Summary: This study developed a numerical model to characterize the hysteresis behavior of a magnetorheological shock absorber, and achieved good agreement when comparing the model data with experimental data. Additionally, the model was able to observe all effects and changes in the flow domain over time.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2022)
Article
Energy & Fuels
Mansour Al Qubeissi, Ayob Mahmoud, Moustafa Al-Damook, Ali Almshahy, Zinedine Khatir, Hakan Serhad Soyhan, Raja Mazuir Raja Ahsan Shah
Summary: Liquid fuel has traditionally been the primary energy source for internal combustion engines (ICE), but lithium-ion batteries (LIB) have replaced ICE for eco-friendly vehicles and reduced reliance on fossil fuels. This study compares different battery thermal management systems (BTMS) to maintain a temperature range of 15-35 degrees Celsius, prevent thermal runaway and temperature gradients, and improve LIB lifespan and performance. The proposed approach uses biodiesel as both the engine feed and coolant. Simulation results show that biodiesel fuels, such as palm, karanja, jatropha, and mahua oils, can effectively maintain LIB temperature within the optimum working range and outperform conventional coolants like air and 3M Novec.
Article
Energy & Fuels
Mustafa Metin Cam, Hakan Serhad Soyhan, Mansour Al Qubeissi, Cenk Celik
Summary: The design of energy efficient engineering systems is crucial for sustainable operation. This study focuses on optimizing the bell-type primary air nozzle used in CFB boilers through CFD simulations. By changing the nozzle geometry, pressure drop can be decreased and flow uniformity can be improved, resulting in energy savings and improved boiler operation.
Article
Engineering, Chemical
Emel Celik, Mehmet Akif Koc, Nezaket Parlak, Yusuf Cay
Summary: In this study, an innovative intelligent software based on Adaptive Neuro-Fuzzy Inference System (ANFIS) was developed to effectively estimate corn drying process parameters. The system showed high performance in improving the operation and efficiency of corn dryers, resulting in higher-quality dried corn.
Review
Multidisciplinary Sciences
Ridha Ennetta, Hakan Serhad Soyhan, Cemil Koyunoglu, Veli Gokhan Demir
Summary: With the increasing use of rapidly developing technology in daily life, the need for energy has become essential for human beings. This paper focuses on the application of biodiesel production technologies in the transportation industry, with a special emphasis on the importance of microwave-assisted biodiesel production technology in low-income countries.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2022)
Article
Thermodynamics
G. Coskun, U. Demir, H. S. Soyhan
Summary: This study simulated the spread of smoke and evacuation time in a University building during a possible fire. Fire dynamic simulations (FDS) were conducted for natural and forced smoke evacuation, and evacuation simulations were done for various scenarios at different exits. Fractional Effective Dose (FED) was used to evaluate the poisoning risk of occupants. The combination of forced smoke evacuation and evacuation from all exits in the basement had the lowest FED value.
JOURNAL OF APPLIED FLUID MECHANICS
(2022)
Article
Green & Sustainable Science & Technology
Cameron Bracken, Nathalie Voisin, Casey D. Burleyson, Allison M. Campbell, Z. Jason Hou, Daniel Broman
Summary: This study presents a methodology and dataset for examining compound wind and solar energy droughts, as well as the first standardized benchmark of energy droughts across the Continental United States (CONUS) for a 2020 infrastructure. The results show that compound wind and solar droughts have distinct spatial and temporal patterns across the CONUS, and the characteristics of energy droughts are regional. The study also finds that compound high load events occur more often during compound wind and solar droughts than expected.
Article
Green & Sustainable Science & Technology
Ning Zhang, Yanghao Yu, Jiawei Wu, Ershun Du, Shuming Zhang, Jinyu Xiao
Summary: This paper provides insights into the optimal configuration of CSP plants with different penetrations of wind power by proposing an unconstrained optimization model. The results suggest that large solar multiples and TES are preferred in order to maximize profit, especially when combined with high penetrations of wind and photovoltaic plants. Additionally, the study demonstrates the economy and feasibility of installing electric heaters (EH) in CSP plants, which show a linear correlation with the penetration of variable energy resources.
Article
Green & Sustainable Science & Technology
M. Szubel, K. Papis-Fraczek, S. Podlasek
Article
Green & Sustainable Science & Technology
J. Silva, J. C. Goncalves, C. Rocha, J. Vilaca, L. M. Madeira
Summary: This study investigated the methanation of CO2 in biogas and compared two different methanation reactors. The results showed that the cooled reactor without CO2 separation achieved a CO2 conversion rate of 91.8%, while the adiabatic reactors achieved conversion rates of 59.6% and 67.2%, resulting in an overall conversion rate of 93.0%. Economic analysis revealed negative net present worth values, indicating the need for government monetary incentives.
Article
Green & Sustainable Science & Technology
Yang Liu, Yonglan Xi, Xiaomei Ye, Yingpeng Zhang, Chengcheng Wang, Zhaoyan Jia, Chunhui Cao, Ting Han, Jing Du, Xiangping Kong, Zhongbing Chen
Summary: This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid anaerobic digestion and increase methane production. The results showed that adding NMCs with 15% PNPs can lower the concentrations of volatile fatty acids and ammonia nitrogen, and increase methane yield.
Article
Green & Sustainable Science & Technology
Zhong Ge, Xiaodong Wang, Jian Li, Jian Xu, Jianbin Xie, Zhiyong Xie, Ruiqu Ma
Summary: This study evaluates the thermodynamic, exergy, and economic performance of a double-stage organic flash cycle (DOFC) using ten eco-friendly hydrofluoroolefins. The influences of key parameters on performance are analyzed, and the advantages of DOFC over single-stage type are quantified.
Article
Green & Sustainable Science & Technology
Nicolas Kirchner-Bossi, Fernando Porte-Agel
Summary: This study investigates the optimization of power density in wind farms and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced to optimize power density and turbine layout. The results show that the PDGA-driven solutions significantly reduce the levelized cost of energy (LCOE) compared to the default layout, and exhibit a convex relationship between area and LCOE or power density.
Article
Green & Sustainable Science & Technology
Chunxiao Zhang, Dongdong Li, Lin Wang, Qingpo Yang, Yutao Guo, Wei Zhang, Chao Shen, Jihong Pu
Summary: In this study, a novel reversible liquid-filled energy-saving window that effectively regulates indoor solar radiation heat gain is proposed. Experimental results show that this window can effectively reduce indoor temperature during both summer and winter seasons, while having minimal impact on indoor illuminance.
Article
Green & Sustainable Science & Technology
Alessandro L. Aguiar, Martinho Marta-Almeida, Mauro Cirano, Janini Pereira, Leticia Cotrim da Cunha
Summary: This study analyzed the Brazilian Equatorial Shelf using a high-resolution ocean model and found significant tidal variations in the area. Several hypothetical barrages were proposed with higher annual power generation than existing barrages. The study also evaluated the installation effort of these barrages.
Article
Green & Sustainable Science & Technology
Francesco Superchi, Nathan Giovannini, Antonis Moustakis, George Pechlivanoglou, Alessandro Bianchini
Summary: This study focuses on the optimization of a hybrid power station on the Tilos island in Greece, aiming to increase energy export and revenue by optimizing energy fluxes. Different scenarios are proposed to examine the impact of different agreements with the grid operator on the optimal solution.
Article
Green & Sustainable Science & Technology
Peimaneh Shirazi, Amirmohammad Behzadi, Pouria Ahmadi, Sasan Sadrizadeh
Summary: This research presents two novel energy production/storage/usage systems to reduce energy consumption and environmental effects in buildings. A biomass-fired model and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump were designed and assessed. The results indicate that the solar-based system has an acceptable energy cost and the PVT-based system with a heat pump is environmentally superior. The biomass-fired system shows excellent efficiency.
Article
Green & Sustainable Science & Technology
Zihao Qi, Yingling Cai, Yunxiang Cui
Summary: This study aims to investigate the operational characteristics of the solar-ground source heat pump system (SGSHPS) in Shanghai under different operation modes. It concludes that tandem operation mode 1 is the optimal mode for winter operation in terms of energy efficiency.
Article
Green & Sustainable Science & Technology
L. Bartolucci, S. Cordiner, A. Di Carlo, A. Gallifuoco, P. Mele, V. Mulone
Summary: Spent coffee grounds are a valuable biogenic waste that can be used as a source of biofuels and valuable chemicals through pyrolysis and solvent extraction processes. The study found that heavy organic bio-oil derived from coffee grounds can be used as a carbon-rich biofuel, while solvent extraction can extract xantines and p-benzoquinone, which are important chemicals for various industries. The results highlight the promising potential of solvent extraction in improving the economic viability of coffee grounds pyrolysis-based biorefineries.
Article
Green & Sustainable Science & Technology
Luiza de Queiroz Correa, Diego Bagnis, Pedro Rabelo Melo Franco, Esly Ferreira da Costa Junior, Andrea Oliveira Souza da Costa
Summary: Building-integrated photovoltaics, especially organic solar technology, are important for reducing greenhouse gas emissions in the building sector. This study analyzed the performance of organic panels laminated in glass in a vertical installation in Latin America. Results showed that glass lamination and vertical orientation preserved the panels' performance and led to higher energy generation in winter.
Article
Green & Sustainable Science & Technology
Zhipei Hu, Shuo Jiang, Zhigao Sun, Jun Li
Summary: This study proposes innovative fin arrangements to enhance the thermal performance of latent heat storage units. Through optimization of fin distribution and prediction of transient melting behaviors, it is found that fin structures significantly influence heat transfer characteristics and melting behaviors.
