Article
Thermodynamics
G. V. Kuznetsov, D. Yu Malyshev, S. V. Syrodoy, N. Yu Gutareva, Zh. A. Kostoreva
Summary: This study presents experimental results on the ignition process of bio-coal water fuel particles. The introduction of additives from forest combustible materials is found to accelerate the ignition process. The chemical reaction between gaseous pyrolysis products and high-temperature oxidizer is shown to be of short duration. The use of composite fuels and the introduction of biomass can reduce the ignition delay time in the coal energy sector.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Energy & Fuels
Tianfeng Liang, Hongwei Zang, Wei Zhang, Liansheng Zheng, Danwen Yao, Helong Li, Huailiang Xu, Ruxin Li
Summary: This study utilizes femtosecond filamentating laser to ignite a premixed methane-air mixture over long distance and with ultra-low energy. The technique is insensitive to the position of the ablator and can operate sustainably with minimal sample removal.
Article
Engineering, Chemical
Tianning Zhang, Youjun Lu
Summary: This paper investigates the heat transfer characteristics between the wall and bed in SCWFB, comparing the accuracy of different methods in predicting heat transfer coefficients, and studying the influence of factors such as temperature, pressure, and velocity on heat transfer characteristics.
Article
Chemistry, Analytical
Dimeng Lai, Junhui Gong, Xiaodong Zhou, Xiaoyu Ju, Yuan Zheng, Lizhong Yang, Fei Peng
Summary: The impact of cross forced airflow on pyrolysis and piloted ignition of PMMA under constant heat flux was studied through experiments, analysis, and numerical simulations. Critical airflow velocity dominates ignition, with both critical temperature and ignition time increasing with airflow velocity. Enhanced radiation reducing was observed by increasing airflow velocity, with in-depth absorption of thermal radiation showing better agreement with experimental measurements.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2021)
Article
Engineering, Civil
Jose Rivera, Daniel San Martin, Michael Gollner, Claudio E. Torres, Carlos Fernandez-Pello
Summary: This study proposes the use of machine learning algorithms to predict the critical heat flux for ignition based on known material properties and environmental variables. The algorithms are trained using existing ignition data and validated against experimental results. The results show that the ML approach can accurately predict the critical heat flux under various conditions, making it a useful tool for evaluating new materials or configuration changes.
FIRE SAFETY JOURNAL
(2023)
Article
Engineering, Environmental
Tianning Zhang, Youjun Lu
Summary: The method proposed in this study provides a solution to the constant wall flux boundary condition in a fluidized bed by CFD-DEM, and is more accurate than the previous method when tested in a gas-solid fluidized bed.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Olga Gaidukova, Pavel Strizhak
Summary: A model was developed to study the critical conditions and time characteristics of gel fuel ignition, using numerical modeling and theoretical derivation to analyze the impact of key parameters on ignition time. The accuracy and effectiveness of the model were validated by comparing theoretical results with experimental data.
Article
Agronomy
Jamie E. Burton, Trent D. Penman, Alex I. Filkov, Jane G. Cawson
Summary: Fuel moisture and flammability thresholds vary between vegetation communities. Factors influencing moisture thresholds for flammability at two spatial scales were examined. Leaf cover and size influenced point-scale moisture thresholds, while vapour pressure deficit (VPD) and aridity influenced plot-scale ignitability. Higher VPD thresholds for ignition were observed in wetter parts of the landscape. Canopy cover and aridity-induced changes in litter moisture drove variations in ignitability between vegetation communities. Ignitability models based on VPD and aridity could be used for future predictions.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Chemistry, Multidisciplinary
Gao Min
Summary: A new theoretical formulation is reported in this paper to address the operation of thermoelectric generators under constant heat flux, allowing calculation of maximum power output and conversion efficiency. This theory opens up new pathways for studying thermoelectric properties and may lead to the development of new technologies.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Thermodynamics
Junhui Gong, Chunjie Zhai
Summary: This contribution presents an alternative methodology to predict solid ignition under increasing-steady heat flux, using an approximate analytical solution based on an ignition temperature criterion. Two typical heating conditions are emphasized, and a linear dependency of ignition time on the squared critical energy is found valid. The effect of critical temperature on ignition time predictions is quantitatively examined through parametric study.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Engineering, Civil
Alexander L. Brown, Jeffrey D. Engerer, Allen J. Ricks, Joshua Christian, Julius Yellowhair
Summary: Research on material response under high heat flux conditions is often limited by experimental conditions and constraints. However, new data obtained using concentrated solar energy has allowed for a focus on data repeatability, uncertainty reduction, and environment characterization to validate predictive codes. The presented data, covering a novel flux range and materials, signifies progress in the characterization of fires resulting from high flux events.
FIRE SAFETY JOURNAL
(2021)
Article
Thermodynamics
J. Cespiva, J. Skrinsky, J. Veres, M. Wnukowski, J. Serencisova, T. Ochodek
Summary: This study investigates a solid recovered fuel gasification process as a regional, clean energy supply from an affordable source. A unique cross/updraft gasification reactor is utilized, and various equivalence ratios and load regimes are examined. The parameters studied include producer gas quality, conversion efficiency, and char material yield. The findings suggest that low material load improves gas purity and conversion efficiency, and the process shows low tar content and potential for material valorization.
Article
Engineering, Aerospace
M. A. Kotov, P. V. Kozlov, G. Ya Gerasimov, V. Yu Levashov, A. N. Shemyakin, N. G. Solovyov, M. Yu Yakimov, V. N. Glebov, G. A. Dubrova, A. M. Malyutin
Summary: The problem of flight safety of high-speed aircrafts is primarily related to the reliability of engines, which depends on the understanding of fuel ignition and combustion processes. This study proposes a new method using a thermoelectric detector to register the ignition of shock heated gaseous fuels. The detector demonstrated high efficiency in measuring ignition delay time and showed desirable properties such as high heat flux values, low inertia, high signal-to-noise ratio, and high temporal resolution.
Article
Engineering, Civil
Mohamad L. Ramadhan, Sergio Zarate, Jeronimo Carrascal, Andres F. Osorio, Juan P. Hidalgo
Summary: The study investigated the effect of fuel bed size and moisture content on the flammability of Eucalyptus saligna leaves using Cone Calorimeter. Results showed a noticeable influence of sample diameter and fuel moisture content on flammability.
FIRE SAFETY JOURNAL
(2021)
Article
Energy & Fuels
David A. Castaneda, Benveniste Natan
Summary: An experimental investigation was conducted to determine the hypergolic ignition delay time and behavior of various solid fuels containing sodium borohydride with high-grade hydrogen peroxide. The results showed that the hypergolic reaction between sodium borohydride and hydrogen peroxide provides the heat necessary for ignition and combustion of the fuels. Tests at elevated pressures demonstrated shorter ignition delay times.
Article
Thermodynamics
Mustafa Turkyilmazoglu
Summary: This paper extends the classical models for fluid flow, heat transfer, and impulsive acceleration by introducing fractional derivatives. The solutions are represented as steady and transient parts, and alternative solution methods are provided. The findings demonstrate the impact of fractional derivative in different time regimes, contributing to the understanding of diffusion phenomena.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Mathematics, Interdisciplinary Applications
Mustafa Turkyilmazoglu, Mohamed Altanji
Summary: Distinct fractional models of falling object with linear and quadratic air resistive forces are investigated using Caputo fractional derivative. Analytical solutions are obtained for each model, providing a vivid understanding of the object's motion. The contribution of nonlinearity to the fractional models is carefully examined. These fractional models exhibit rich phenomena not found in traditional integer derivative models, but still converge to the traditional model. Short time perturbation and large time asymptotic formulae are derived. The solutions for some fractional models suggest either an increased speed surpassing gravity or asymptotic deceleration to a stop, in contrast to reaching a terminal speed. In the case of quadratic air resistance, power series and asymptotic series solutions are derived under Caputo fractional derivative and infinite base fractional differentiation, respectively. The analysis of ideal falling object motion emphasizes the impact of fractional models and fractional derivative definitions on physical motion, necessitating proper justification.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Thermodynamics
Mustafa Turkyilmazoglu
Summary: The purpose of this work is to study the fluid flow and heat transfer between a rotating cone above a stretching disk. By using suitable similarity transformations, it is found that the physical phenomenon can be represented by a system of similarity equations, which is consistent with the literature in the absence of wall expansion. Numerical simulations are used to study the effects of surface expansion on momentum, thermal layers, swirling angles, and heat transports.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Physics, Applied
Muhammad Rahman, Humma Waheed, Mustafa Turkyilmazoglu, M. Salman Siddiqui
Summary: This paper explores the significance of slip situations in porous media and frictional heating on unsteady fluid flow through porous media. Numerical solutions of the differential equation for fluid flow through porous material, including slip effects, are presented. Using a similarity transformation, a nonlinear ordinary differential equation is obtained. The resulting set of nonlinear problems is numerically solved using Maple packages under velocity and thermal slip conditions. Both velocity and temperature increase with an increase in the Brinkman viscosity ratio parameter ?. The effects of the nondimensional parameters on flow velocity and temperature are examined using graphical profiles. The implications of relevant parameters on dimensionless temperature, velocity, local Nusselt number, and skin friction coefficient are shown and explained. The fluctuation of parameters for various flow quantities of interest is investigated and the results are presented in graphs and tables.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Thermodynamics
Mustafa Turkyilmazoglu
Summary: This paper investigates the mechanism of triggering Benard convection through the absolute instability mode in the presence of a uniform magnetic field perpendicular to the channel walls. The locus of wavenumbers and critical Rayleigh numbers leading to absolute instability onset is determined through a theoretical linear stability approach. The magnetic field has a stabilizing effect on convection, but it becomes ineffective against the absolute instability mechanism beyond a critical location.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Thermodynamics
Mustafa Turkyilmazoglu, Abuzar Abid Siddiqui
Summary: In this study, the scope is to extend previous work by incorporating the effective viscosity term within the transitional flow in the frame of Brinkman-Darcy-Benard convection. Numerical simulations were performed to investigate the onset of instability within the linear stability analysis, considering the Darcy number, Rayleigh number, and horizontal temperature parameter as essential physical parameters. The results showed that comparatively larger Rayleigh numbers were obtained within the Brinkman's model than the published Darcy model.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Engineering, Chemical
Mustafa Turkyilmazoglu
Summary: This study investigates the onset and formation of Darcy-Bernard convection in a channel filled with fluid-saturated porous medium of finite depth. The Darcy model of porosity is used to identify a new family of solutions controlled by two parameters. These solutions cover most basic states associated with the Darcy law equations. The results reveal the relaxed impermeable wall constraints and provide insight into the triggering/delaying of Darcy-Bernard cells.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Chemistry, Analytical
Mustafa Turkyilmazoglu, Faisal Z. Duraihem
Summary: The paper introduces new tubular shapes resulting from the imposition of Navier's velocity slip at the surface. A family of pipes induced by the slip mechanism is discovered, which modifies traditional pipes with elliptical cross-sections and resembles collapsible tubes. The velocity and temperature fields of the new pipes are analytically determined, and physical features such as wall shear stress and convective heat transfer are studied in detail. The new pipes are considered to have engineering and practical value in the micromachining industry.
Article
Mechanics
Mustafa Turkyilmazoglu
Summary: This paper presents full solutions of the energy and Navier-Stokes equations in the approximate form of Boussinesq. The study focuses on the advective fluid layer flowing within parallel horizontal infinite walls with hydro-thermal slip conditions and the control of momentum/thermal motion by a vertically applied magnetic field. The results show that hydro-thermal slip enhances both velocity and temperature fields, while magnetic field has a weaker suppression effect.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Physics, Multidisciplinary
Mustafa Turkyilmazoglu
Summary: Forecasting the epidemic peak time is crucial for making decisions on isolation, social distance, and lockdown measures. This research introduces two formulas for accurately predicting the peak time of an infectious disease based on the SIR epidemic model. These formulas can be easily computed using a regular calculator and do not require advanced mathematical functions. The accuracy of the formulas is confirmed through a comparison with COVID-19 data and the formulas can also accurately capture the past peak time of an endemic illness. Additionally, simple approximations are provided for easy use without sophisticated laboratory equipment.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Mathematics, Applied
Mustafa Turkyilmazoglu
Summary: In this article, the onset of convection in porous media with through flow is studied based on Darcy formulation. The effects of uniform vertical flow on the thermal instability of convective cells are investigated using three different thermal boundary constraints. The influence of the Peclet number on the stability response of the porous layer is analyzed, and the critical Darcy-Rayleigh numbers and Benard cell wavenumbers are determined numerically. The results show that opposing and assisting through flows have different effects on the stability of convection depending on the thermal conditions of the walls.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Biology
Mustafa Turkyilmazoglu
Summary: This study models the heat transfer in a bi-layer spherical composite region representing a cancerous tumor embedded in homogeneous muscle tissue using fractional energy equations with additional interface boundary constrictions. The authors obtained exact analytical solutions to the fractional hyperthermia problem by determining the order of fractional derivative through an inverse solution scheme. The distribution of temperature within the tumor-tissue medium is studied and anomalous heat diffusion process is detected. The presented analytical expressions are beneficial for optimizing the operational thermal parameters during hyperthermia treatment of different tumors.
COMPUTERS IN BIOLOGY AND MEDICINE
(2023)
Article
Mechanics
Mustafa Turkyilmazoglu, Faisal Z. Duraihem
Summary: Thermally-driven natural convection in a porous layer is explored theoretically in this work based on Darcy's law. The study focuses on the non-circulating basic cellular flow between two infinitely long horizontal plates and its instability onset. The results show that a circulatory flow and temperature variation along the horizontal axis govern the motion, and the instability can be determined through linear stability analysis and numerical calculations.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Materials Science, Multidisciplinary
Mustafa Turkyilmazoglu, Faisal Z. Duraihem
Summary: This paper provides closed form solutions for fluid flow affected by a uniform magnetic field inside a triangular cross section pipe. The governing equation for pressure gradient induced flow under the magnetic field is reduced to a Helmholtz partial differential equation with Dirichlet boundary conditions. The velocity solution is derived using exponential functions involving the magnetic strength parameter or Hartmann number. The effects of Lorentz force on velocity variations, centerline velocity, volumetric flow rate, and wall shears are analyzed graphically by increasing the magnetic field strength.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Muhammad Rahman, Mustafa Turkyilmazoglu, Kiran Matloob
Summary: This research investigates the thermal performance of a hybrid nanofluid consisting of aluminum oxide and copper nanoparticles on the flow of water and ethylene glycol over a permeable cylinder. Different nanoparticle shapes are considered and the effects of different parameters are analyzed. The study reveals the impact of porosity, Hartmann numbers, inertia factors, Prandtl number, stratification parameter, Eckert number, and Hartmann's number on the velocity field and fluid temperature of the hybrid nanofluid.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Thermodynamics
Yong Cheng, Fukai Song, Lei Fu, Saishuai Dai, Zhiming Yuan, Atilla Incecik
Summary: This paper investigates the accessibility of wave energy absorption by a dual-pontoon floating breakwater integrated with hybrid-type wave energy converters (WECs) and proposes a hydraulic-pneumatic complementary energy extraction method. The performance of the system is validated through experiments and comparative analysis.
Article
Thermodynamics
Jing Gao, Chao Wang, Zhanwu Wang, Jin Lin, Runkai Zhang, Xin Wu, Guangyin Xu, Zhenfeng Wang
Summary: This study aims to establish a new integrated method for biomass cogeneration project site selection, with a focus on the application of the model in Henan Province. By integrating Geographic Information System and Multiple Criterion Decision Making methods, the study conducts site selection in two stages, providing a theoretical reference for the construction of biomass cogeneration projects.
Article
Thermodynamics
Mert Temiz, Ibrahim Dincer
Summary: The current study presents a hybrid small modular nuclear reactor and solar-based system for sustainable communities, integrating floating and bifacial photovoltaic arrays with a small modular reactor. The system efficiently generates power, hydrogen, ammonia, freshwater, and heat for residential, agricultural, and aquaculture facilities. Thermodynamic analysis shows high energy and exergy efficiencies, as well as large-scale ammonia production meeting the needs of metropolitan areas. The hybridization of nuclear and solar technologies offers advantages of reliability, environmental friendliness, and cost efficiency compared to renewable-alone and fossil-based systems.
Editorial Material
Thermodynamics
Wojciech Stanek, Wojciech Adamczyk
Article
Thermodynamics
Desheng Xu, Yanfeng Li, Tianmei Du, Hua Zhong, Youbo Huang, Lei Li, Xiangling Duanmu
Summary: This study investigates the optimization of hybrid mechanical-natural ventilation for smoke control in complex metro stations. The results show that atrium fires are more significantly impacted by outdoor temperature variations compared to concourse/platform fires. The gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for smoke prevention/mitigation.
Article
Thermodynamics
Da Guo, Heping Xie, Mingzhong Gao, Jianan Li, Zhiqiang He, Ling Chen, Cong Li, Le Zhao, Dingming Wang, Yiwei Zhang, Xin Fang, Guikang Liu, Zhongya Zhou, Lin Dai
Summary: This study proposes a new in-situ pressure-preserved coring tool and elaborates its pressure-preserving mechanism. The experimental and field test results demonstrate that this tool has a high pressure-preservation capability and can maintain a stable pressure in deep wells. This study provides a theoretical framework and design standards for the development of similar technologies.
Article
Thermodynamics
Aolin Lai, Qunwei Wang
Summary: This study assesses the impact of China's de-capacity policy on renewable energy development efficiency (REDE) using the Global-MSBM model and the difference-in-differences method. The findings indicate that the policy significantly enhances REDE, promoting technological advancements and marketization. Moreover, regions with stricter environmental regulations experience a higher impact.
Article
Thermodynamics
Mostafa Ghasemi, Hegazy Rezk
Summary: This study utilizes fuzzy modeling and optimization to enhance the performance of microbial fuel cells (MFCs). By simulating and analyzing experimental data sets, the ideal parameter values for increasing power density, COD elimination, and coulombic efficiency were determined. The results demonstrate that the fuzzy model and optimization methods can significantly improve the performance of MFCs.
Article
Thermodynamics
Zhang Ruan, Lianzhong Huang, Kai Wang, Ranqi Ma, Zhongyi Wang, Rui Zhang, Haoyang Zhao, Cong Wang
Summary: This paper proposes a grey box model for fuel consumption prediction of wing-diesel hybrid vessels based on feature construction. By using both parallel and series grey box modeling methods and six machine learning algorithms, twelve combinations of prediction models are established. A feature construction method based on the aerodynamic performance of the wing and the energy relationship of the hybrid system is introduced. The best combination is obtained by considering the root mean square error, and it shows improved accuracy compared to the white box model. The proposed grey box model can accurately predict the daily fuel consumption of wing-diesel hybrid vessels, contributing to operational optimization and the greenization and decarbonization of the shipping industry.
Article
Thermodynamics
Huayi Chang, Nico Heerink, Junbiao Zhang, Ke He
Summary: This study examines the interaction between off-farm employment decisions between couples and household clean energy consumption in rural China, and finds that two-paycheck households are more likely to consume clean energy. The off-farm employment of women is a key factor driving household clean energy consumption to a higher level, with wage-employed wives having a stronger influence on these decisions than self-employed ones.
Article
Thermodynamics
Hanguan Wen, Xiufeng Liu, Ming Yang, Bo Lei, Xu Cheng, Zhe Chen
Summary: Demand-side management is crucial to smart energy systems. This paper proposes a data-driven approach to understand the relationship between energy consumption patterns and household characteristics for better DSM services. The proposed method uses a clustering algorithm to generate optimal customer groups for DSM and a deep learning model for training. The model can predict the possibility of DSM membership for a given household. The results demonstrate the usefulness of weekly energy consumption data and household socio-demographic information for distinguishing consumer groups and the potential for targeted DSM strategies.
Article
Thermodynamics
Xinglan Hou, Xiuping Zhong, Shuaishuai Nie, Yafei Wang, Guigang Tu, Yingrui Ma, Kunyan Liu, Chen Chen
Summary: This study explores the feasibility of utilizing a multi-level horizontal branch well heat recovery system in the Qiabuqia geothermal field. The research systematically investigates the effects of various engineering parameters on production temperature, establishes mathematical models to describe their relationships, and evaluates the economic viability of the system. The findings demonstrate the significant economic feasibility of the multi-level branch well system.
Article
Thermodynamics
Longxin Zhang, Songtao Wang, Site Hu
Summary: This investigation reveals the influence of tip leakage flow on the modern transonic rotor and finds that the increase of tip clearance size leads to a decline in rotor performance. However, an optimal tip clearance size can extend the rotor's stall margin.
Article
Thermodynamics
Kristian Gjoka, Behzad Rismanchi, Robert H. Crawford
Summary: This paper proposes a framework for assessing the performance of 5GDHC systems and demonstrates it through a case study in a university campus in Melbourne, Australia. The results show that 5GDHC systems are a cost-effective and environmentally viable solution in mild climates, and their successful implementation in Australia can create new market opportunities and potential adoption in other countries with similar climatic conditions.
Article
Thermodynamics
Jianwei Li, Guotai Wang, Panpan Yang, Yongshuang Wen, Leian Zhang, Rujun Song, Chengwei Hou
Summary: This study proposes an orientation-adaptive electromagnetic energy harvester by introducing a rotatable bluff body, which allows for self-regulation to cater for changing wind flow direction. Experimental results show that the output power of the energy harvester can be greatly enhanced with increased rotatory inertia of the rotating bluff body, providing a promising solution for harnessing wind-induced vibration energy.
