Journal of Non-Equilibrium Thermodynamics最新文献_第2页

Thermodynamic characterization of transient valve temperatures in diesel engines using probabilistic methods 用概率方法对柴油机瞬态气门温度进行热力学表征

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-27 DOI: 10.1515/jnet-2024-0052

Pardeep Kumar, Anikate Gupta, Dinesh Kumar, Vipin Kumar Sharma, Santosh Kumar Rai

{"title":"Thermodynamic characterization of transient valve temperatures in diesel engines using probabilistic methods","authors":"Pardeep Kumar, Anikate Gupta, Dinesh Kumar, Vipin Kumar Sharma, Santosh Kumar Rai","doi":"10.1515/jnet-2024-0052","DOIUrl":"https://doi.org/10.1515/jnet-2024-0052","url":null,"abstract":"This investigation aimed to predict the temperature distribution in the inlet and exhaust valve and isotherms to the cooling media at a given load of a diesel engine. For the analysis that has been done a Tata- Mercedes diesel engine with 90 mm bore diameter and Stroke length of 120 mm was analysed using FEM through Ansys workbench 15.0. Steady as well as transient cases were considered in combination. The temperature distribution and isotherms are computed and plotted using Ansys. The results obtained by Ansys workbench 15.0 were satisfactory and were in line when compared with finite differential analysis. There is a large temperature variation along the length of the valve. It may vary from 560 °C to 110 °C from tip to valve head in the exhaust valve while this variation is less in the case of inlet valve from 540 °C to 100 °C from the face to the tip. The linear temperature difference between the nodes at the base of the stem to the node at the center of the face increases with time and acquires the maximum value of about 120 °C at about 10 s then it decreases till the valve attains a steady state value. Thus, was observed from analysis that during this time there is a maximum probability of failure of valves due to linear differences in temperature.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"85 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance comparison of water towers and combined pumped hydro and compressed gas system and proposing a novel hybrid system to energy storage with a case study of a 50 MW wind farm 水塔与抽水蓄能和压缩气体联合系统的性能比较，并以50mw风电场为例，提出一种新型的混合系统用于储能

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-27 DOI: 10.1515/jnet-2024-0102

Amin Hadidi

{"title":"Performance comparison of water towers and combined pumped hydro and compressed gas system and proposing a novel hybrid system to energy storage with a case study of a 50 MW wind farm","authors":"Amin Hadidi","doi":"10.1515/jnet-2024-0102","DOIUrl":"https://doi.org/10.1515/jnet-2024-0102","url":null,"abstract":"In general, the most important method of energy storage at the power plant scale is the pumped hydro method, which has been developed in two main models to improve its performance, which is pumped hydro combined with compressed gas (PHCCG) and pumped hydro in closed towers (PHWT). In this research, to answer which of these methods is more suitable, in the form of a case study, both systems were designed to store the generated energy in the Aghkand wind farm with a nominal power of 50 (MW), and the performance of both was completely compared with each other. The findings indicated that the efficiency of the PHWT method was higher, but on the other hand, the water requirement of the PHCCG method was much lower than the PHWT method. Also, in an innovative way, the PHWT system was presented with a combination of towers of different classes and the performance of each was investigated. Finally, by combining both PHWT and PHCCG systems, a new hybrid system (HPHWTCG) was proposed. By using this hybrid system, the advantages of both methods can be used at the same time and the disadvantages of each method can be eliminated to a great extent. The efficiency of PHWT and PHCCG is 65 % and 45 % respectively. The efficiency of HPHWTCG is between these two values based on its structure.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"23 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143517943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Existence of the Chapman–Enskog solution and its relation with first-order dissipative fluid theories Chapman-Enskog解的存在性及其与一阶耗散流体理论的关系

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-27 DOI: 10.1515/jnet-2024-0086

Ana Laura García-Perciante, Alma Rosa Méndez, Olivier Sarbach

引用次数: 0

Is there a need for an extended phase definition for systems far from equilibrium? 对于远离平衡的系统是否需要一个扩展的相定义？

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-13 DOI: 10.1515/jnet-2024-0063

Fernando Bautista, Juan Paulo García-Sandoval, Octavio Manero

{"title":"Is there a need for an extended phase definition for systems far from equilibrium?","authors":"Fernando Bautista, Juan Paulo García-Sandoval, Octavio Manero","doi":"10.1515/jnet-2024-0063","DOIUrl":"https://doi.org/10.1515/jnet-2024-0063","url":null,"abstract":"Phase diagrams out of equilibrium have been the subject of intense research. An essential concept in these diagrams is the phase definition. Currently, that definition is well established for systems at classic thermodynamic equilibrium conditions. However, such phase definition is inadequate for systems that are not at equilibrium in the classic thermodynamic sense, like fluid systems under flowing conditions. Complex fluids may exhibit instabilities like shear-banding flow and a non-equilibrium critical point where banding flow ends. At this point, the fluid undergoes a phase transition from heterogeneous to homogeneous states. An extended thermodynamic space of variables is considered to adequately address this situation, which includes non-conservative variables such as stress and shear rate. Hence, the current phase definition based on conservative variables does not apply to non-equilibrium phase diagrams. On this basis, a broader definition of phase is required. We propose that this broader definition considers the thermodynamic variables space of Extended Irreversible Thermodynamics and the mathematical conditions that ensure compatibility between equilibrium and non-equilibrium conditions for systems where phases are well described by thermodynamic potentials even out of equilibrium.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"67 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation of binary convection within the Soret regime in a tilted cylinder 倾斜圆柱体Soret区二元对流的数值模拟

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-10 DOI: 10.1515/jnet-2024-0064

Arantxa Alonso, Isabel Mercader, Oriol Batiste, Alvaro Meseguer

{"title":"Numerical simulation of binary convection within the Soret regime in a tilted cylinder","authors":"Arantxa Alonso, Isabel Mercader, Oriol Batiste, Alvaro Meseguer","doi":"10.1515/jnet-2024-0064","DOIUrl":"https://doi.org/10.1515/jnet-2024-0064","url":null,"abstract":"This study computationally investigates the time-dependent patterns emerging in the Soret regime for binary fluid convection in slightly inclined cylinders heated from below, with a particular focus on positive Soret coefficient thermophobic mixtures (S T > 0) and aspect ratios Γ = 5.2, Γ = 5.3, and Γ = 5.4. By varying the Rayleigh number (Ra) and smoothly adjusting its increments, we capture a range of spatio-temporal behaviours, revealing the coexistence of large-scale shear flows (LSF) and superhighway convection (SHC) patterns. SHC-like structures, characterised by a high base frequency, involve oscillating plumes arranged in adjacent lanes, moving in opposite directions along the inclination. Remarkably, this frequency remains nearly constant across different Ra values. Some of the observed coherent structures, such as periodic and modulated solutions, exhibit equivariance with respect to some elements of the <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <m:msub> <m:mrow> <m:mi mathvariant=\"double-struck\">D</m:mi> </m:mrow> <m:mrow> <m:mn>2</m:mn> </m:mrow> </m:msub> </m:math> ${mathbb{D}}_{2}$ symmetry group inherent to the physical system. In the case of Γ = 5.4, we identify three-frequency orbits, with modulations up to two orders of magnitude smaller than the base frequency. The observed dynamics is highly sensitive to small variations of Γ, with different patterns being stabilized depending on the aspect ratio of the cell. The bifurcation scenarios are complex and case-specific, and their precise determination is computationally demanding.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"44 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143385205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Entropy as Noether charge for quasistatic gradient flow 准静态梯度流的诺特电荷熵

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-02-06 DOI: 10.1515/jnet-2024-0054

Aaron Beyen, Christian Maes

引用次数: 0

Efficient ecological function optimization for endoreversible Carnot heat pumps 内可逆卡诺热泵高效生态功能优化

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-01-03 DOI: 10.1515/jnet-2024-0061

Yiwen Su, Lingen Chen, Yanlin Ge, Huijun Feng

引用次数: 0

Study on heat and mass transfer mechanism of unsaturated porous media under CW laser irradiation: with and without carrier gas 不饱和多孔介质在连续激光照射下的传热传质机理研究：带和不带载气

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2025-01-02 DOI: 10.1515/jnet-2024-0025

Shao-Hui Han, Yuan Dong, Guang-Yong Jin

{"title":"Study on heat and mass transfer mechanism of unsaturated porous media under CW laser irradiation: with and without carrier gas","authors":"Shao-Hui Han, Yuan Dong, Guang-Yong Jin","doi":"10.1515/jnet-2024-0025","DOIUrl":"https://doi.org/10.1515/jnet-2024-0025","url":null,"abstract":"The use of laser irradiation to remove contaminants from soil is an emerging soil remediation technology with broad application prospects. The mechanisms of temperature field variations, moisture transport, evaporation, and condensation under conditions with or without a carrier gas during laser soil remediation are still unclear. This paper utilizes a heat and mass transfer model under continuous wave (CW) laser irradiation, established based on local non-thermal equilibrium, to analyze the variation characteristics of the physical field within the soil, with or without introducing a carrier gas. The results show that CW laser irradiation can rapidly heat the soil to the expected remediation temperature (90 °C–560 °C). However, the gas transport speed induced solely by CW laser irradiation within the soil is very limited (on the order of 0.01 mm/s), making it ineffective at removing vapor from the soil. In contrast, using a carrier gas significantly improves gas flow (on the order of 10 mm/s), enhancing both heat and mass transfer processes and assisting in removing contaminants during laser soil remediation. This study elucidates the coupled heat and moisture transfer process in unsaturated porous media under conditions with and without a carrier gas, providing theoretical support for applying laser soil remediation.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"27 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142917066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling high-pressure viscosities of fatty acid esters and biodiesel fuels based on modified rough hard-sphere-chain model and deep learning method 基于改进的粗糙硬球链模型和深度学习方法的脂肪酸酯和生物柴油燃料高压粘度建模

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2024-11-21 DOI: 10.1515/jnet-2024-0040

Sayed Mostafa Hosseini, Mariano Pierantozzi

{"title":"Modeling high-pressure viscosities of fatty acid esters and biodiesel fuels based on modified rough hard-sphere-chain model and deep learning method","authors":"Sayed Mostafa Hosseini, Mariano Pierantozzi","doi":"10.1515/jnet-2024-0040","DOIUrl":"https://doi.org/10.1515/jnet-2024-0040","url":null,"abstract":"This work aimed to demonstrate that a simple modification to the previously developed rough hard-sphere-chain (RHSC) model would significantly improve the accuracy of that model for viscosities of fatty acid esters and biodiesel fuels at extended pressures up to 200 MPa and higher isotherms. The new finding of this work is the temperature dependence of the exponential factor of the roughness factor (RF) of the earlier RHSC model as the accuracy of the original model (with an average absolute relative deviation, AARD of 8.29 % for 715 data points examined) was significantly improved achieving the AARD of 3.77 % once a universal function of reduced temperature replaced the original exponential factor of 6.4 × 10−4 for RF. Besides, the predictive capability of the modified RHSC model has been compared with original RHSC model and several previously developed semi-empirical models based on friction theory and free volume theory in literature. Expanding AARD on the progress in deep learning, our research introduces Artificial Neural Network (ANN) model that is simpler than previous models while maintaining high viscosity correlation accuracy for fatty acid esters and biodiesel fuels. The refined ANN model, with a single hidden layer and sigmoid activation function, achieved an AARD% of 0.78 %. Additionally, we conducted a thorough comparison with other deep learning architectures, affirming the effectiveness of our simplified approach for viscosity correlations.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"71 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variational approach to chemical reactions beyond local equilibrium 超越局部平衡的化学反应变量法

IF 6.6 3区工程技术

Journal of Non-Equilibrium Thermodynamics Pub Date : 2024-11-21 DOI: 10.1515/jnet-2024-0072

Filiberto Herrera-Castro, Jesus Antonio del Río

{"title":"Variational approach to chemical reactions beyond local equilibrium","authors":"Filiberto Herrera-Castro, Jesus Antonio del Río","doi":"10.1515/jnet-2024-0072","DOIUrl":"https://doi.org/10.1515/jnet-2024-0072","url":null,"abstract":"The formal description of chemical reactions far from equilibrium is an open task. Chemical reactions are central to various phenomena in life, industry, and the environment. In this work, we use a variational principle within the framework of extended irreversible thermodynamics to obtain relaxation equations for the fast variables and close the balance equations. Our approach extends traditional local equilibrium thermodynamics by incorporating formal expressions for the unknown generalized equations of state, which we can expand in low and higher-order terms, allowing for a more comprehensive representation of non-linear and dissipative phenomena and capturing wave-like behaviours relevant to oscillatory chemical systems. The formalism aligns well with previous theoretical works and provides additional insights into the influence of diffusion fluxes on reaction rates. The resulting equations may describe velocity reactions with different relaxation times and diffusion reactions. We present a comparison of our results with experiments in the context of a particular chemical kinetics case. We emphasize the need for practical applications in areas like environmentally friendly chemical reaction systems.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"70 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0