Pub Date : 2024-10-02DOI: 10.1016/j.csite.2024.105239
A new type of disk groove mechanism was developed and manufactured. The effects of the structural and operating factors of the disk groove on the air film loading performance were examined using single factor and orthogonal experimental methods. The results of numerical simulation and experimental studies showed that the air film loading performance correlated positively with the orifice diameter and inlet pressure, with the orifice spacing and diameter having the most significant effects, and that the belt speed boosted the air film uniformity. Meanwhile, a comparative analysis of the corresponding level values showed that an air film thickness of 0.8 mm, orifice diameter of 5 mm, orifice spacing of 30 mm, inlet pressure of 8000 Pa, and conveyor speed of 5 m/s were the optimal parameter combinations for the maximum loading capacity. To verify the accuracy of the model, a field experiment was conducted at Jiangmen Southern Conveying Machinery Engineering Co., Ltd. The air film pressure at the experimental position matched the numerical simulation results. In addition, when the number of rows was one and the air volume was 10 m3/h, the smallest value of traction resistance was obtained under minimum power consumption.
{"title":"Numerical simulation and experimental study of the influence of disk groove structure optimization on the air film flow field signature of an air-cushion sandwich belt conveyor","authors":"","doi":"10.1016/j.csite.2024.105239","DOIUrl":"10.1016/j.csite.2024.105239","url":null,"abstract":"<div><div>A new type of disk groove mechanism was developed and manufactured. The effects of the structural and operating factors of the disk groove on the air film loading performance were examined using single factor and orthogonal experimental methods. The results of numerical simulation and experimental studies showed that the air film loading performance correlated positively with the orifice diameter and inlet pressure, with the orifice spacing and diameter having the most significant effects, and that the belt speed boosted the air film uniformity. Meanwhile, a comparative analysis of the corresponding level values showed that an air film thickness of 0.8 mm, orifice diameter of 5 mm, orifice spacing of 30 mm, inlet pressure of 8000 Pa, and conveyor speed of 5 m/s were the optimal parameter combinations for the maximum loading capacity. To verify the accuracy of the model, a field experiment was conducted at Jiangmen Southern Conveying Machinery Engineering Co., Ltd. The air film pressure at the experimental position matched the numerical simulation results. In addition, when the number of rows was one and the air volume was 10 m<sup>3</sup>/h, the smallest value of traction resistance was obtained under minimum power consumption.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.csite.2024.105241
The study investigates the drying characteristics of carrots under different coupling forms of airflow and high-voltage electric fields (parallel flow, PF, and cross flow, CF) using heat pump-electrohydrodynamics (EHD) combined drying. The results show that, compared to single heat pump drying, the combined drying under PF mode reduces carrot drying time by 13.33 %–31.58 %, increases effective moisture diffusivity (Deff) by 17.80 %–32.32 %, increases specific moisture extraction rate (SMER) by 12.25 %–34.26 %. While the combined drying under CF mode reduces carrot drying time by 12.5 %–18.18 %, increases Deff by 7.27 %–13.14 %, increases SMER by 4.64 %–12.58 %. The improvements in parameters under the CF mode are weaker than those under the PF mode. Additionally, the β-carotene content under PF mode is consistently higher than under CF mode. Based on the experimental results, the Modified Page model was improved, yielding an updated model MR = aexp(-(kt)^n), with an R2 value of up to 0.9999–1, which provides theoretical guidance for optimizing the heat pump-EHD combined drying process.
{"title":"Analysis of the interaction between airflow and high-voltage electric fields on drying characteristics of carrots using heat pump-electrohydrodynamics combined drying","authors":"","doi":"10.1016/j.csite.2024.105241","DOIUrl":"10.1016/j.csite.2024.105241","url":null,"abstract":"<div><div>The study investigates the drying characteristics of carrots under different coupling forms of airflow and high-voltage electric fields (parallel flow, PF, and cross flow, CF) using heat pump-electrohydrodynamics (EHD) combined drying. The results show that, compared to single heat pump drying, the combined drying under PF mode reduces carrot drying time by 13.33 %–31.58 %, increases effective moisture diffusivity (<em>D</em><sub>eff</sub>) by 17.80 %–32.32 %, increases specific moisture extraction rate (<em>SMER</em>) by 12.25 %–34.26 %. While the combined drying under CF mode reduces carrot drying time by 12.5 %–18.18 %, increases <em>D</em><sub>eff</sub> by 7.27 %–13.14 %, increases <em>SMER</em> by 4.64 %–12.58 %. The improvements in parameters under the CF mode are weaker than those under the PF mode. Additionally, the β-carotene content under PF mode is consistently higher than under CF mode. Based on the experimental results, the Modified Page model was improved, yielding an updated model <em>MR = aexp(-(kt)^n)</em>, with an <em>R</em><sup>2</sup> value of up to 0.9999–1, which provides theoretical guidance for optimizing the heat pump-EHD combined drying process.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105192
This study explores flame structures and combustion dynamics in high-pressure n-dodecane fuel sprays, focusing on the formation and consumption of formaldehyde (CH2O) during autoignition and the development of poly-aromatic hydrocarbons (PAH) as soot precursors. These processes are crucial for optimizing combustion efficiency and reducing emissions. However, traditional approaches, which rely on single-shot measurements or ensemble-averaged visualizations, often overlook critical early-stage processes during low-temperature ignition. To overcome these challenges, we employed an innovative high-speed planar laser-induced fluorescence (PLIF) technique at 50 kHz using a pulse-burst Nd:YAG laser system with an excitation wavelength of 355 nm. This approach, applied for the first time to Engine Combustion Network (ECN) Spray D flames, provides unprecedented insights into the combustion processes at varying ambient temperatures and oxygen concentrations. Additionally, simultaneous high-speed schlieren imaging at 100 kHz was used to visualize spray penetration, first-stage ignition, and thermal expansion zones. Our findings reveal that, similar to Spray A flames, CH2O forms in cold, fuel-rich zones well upstream of the combustion zone. However, in Spray D flames, the schlieren signal softening observed in the jet's head does not lead to complete disappearance, and the CH2O signal is absent from the full head of the spray. During the second-stage ignition, CH2O consumption accelerates due to high-temperature reactions, leading to a significant reduction in its signal. Unlike the mushroom-shaped structure seen in Spray A flames, Spray D flames exhibit a quasi-steady PAH phase structure, with lean peripheral mixtures insufficient for soot precursor formation. Notably, reducing ambient oxygen concentration to 13 % while maintaining or increasing temperature prolongs the presence of CH2O, highlighting its influence on ignition dynamics and oxidation processes in dodecane spray flames. This study provides new insights into the combustion mechanisms of high-pressure sprays and offers valuable data for developing next-generation combustion technologies, including models, aimed at improving efficiency and reducing emissions.
本研究探讨了高压正十二烷燃料喷雾中的火焰结构和燃烧动力学，重点是自燃过程中甲醛（CH2O）的形成和消耗，以及作为烟尘前体的多芳烃（PAH）的发展。这些过程对于优化燃烧效率和减少排放至关重要。然而，依靠单次测量或集合平均可视化的传统方法往往会忽略低温点火过程中关键的早期阶段过程。为了克服这些挑战，我们采用了一种创新的高速平面激光诱导荧光（PLIF）技术，使用波长为 355 nm 的脉冲串 Nd:YAG 激光系统，频率为 50 kHz。这种方法首次应用于发动机燃烧网络（ECN）喷射 D 型火焰，为了解不同环境温度和氧气浓度下的燃烧过程提供了前所未有的见解。此外，我们还使用 100 kHz 的同步高速裂片成像技术来观察喷雾穿透、第一阶段点火和热膨胀区。我们的研究结果表明，与喷雾 A 火焰类似，CH2O 在燃烧区上游富含燃料的冷区形成。然而，在喷射 D 型火焰中，在喷射头部观察到的裂片信号软化现象并没有完全消失，整个喷射头部都没有 CH2O 信号。在第二阶段点火过程中，由于高温反应，CH2O 消耗加快，导致其信号显著减弱。与喷射火焰 A 中的蘑菇状结构不同，喷射火焰 D 显示出准稳定的多环芳烃相结构，其贫化的外围混合物不足以形成烟尘前体。值得注意的是，在保持或提高温度的同时将环境氧气浓度降低到 13% 会延长 CH2O 的存在时间，从而突出其对十二烷喷射火焰的点火动力学和氧化过程的影响。这项研究为高压喷雾的燃烧机理提供了新的见解，并为开发下一代燃烧技术（包括模型）提供了宝贵的数据，这些技术旨在提高效率和减少排放。
{"title":"High spatiotemporal resolution optical measurements of two-stage ignition and combustion in Engine Combustion Network Spray D flames","authors":"","doi":"10.1016/j.csite.2024.105192","DOIUrl":"10.1016/j.csite.2024.105192","url":null,"abstract":"<div><div>This study explores flame structures and combustion dynamics in high-pressure n-dodecane fuel sprays, focusing on the formation and consumption of formaldehyde (CH<sub>2</sub>O) during autoignition and the development of poly-aromatic hydrocarbons (PAH) as soot precursors. These processes are crucial for optimizing combustion efficiency and reducing emissions. However, traditional approaches, which rely on single-shot measurements or ensemble-averaged visualizations, often overlook critical early-stage processes during low-temperature ignition. To overcome these challenges, we employed an innovative high-speed planar laser-induced fluorescence (PLIF) technique at 50 kHz using a pulse-burst Nd:YAG laser system with an excitation wavelength of 355 nm. This approach, applied for the first time to Engine Combustion Network (ECN) Spray D flames, provides unprecedented insights into the combustion processes at varying ambient temperatures and oxygen concentrations. Additionally, simultaneous high-speed schlieren imaging at 100 kHz was used to visualize spray penetration, first-stage ignition, and thermal expansion zones. Our findings reveal that, similar to Spray A flames, CH<sub>2</sub>O forms in cold, fuel-rich zones well upstream of the combustion zone. However, in Spray D flames, the schlieren signal softening observed in the jet's head does not lead to complete disappearance, and the CH<sub>2</sub>O signal is absent from the full head of the spray. During the second-stage ignition, CH<sub>2</sub>O consumption accelerates due to high-temperature reactions, leading to a significant reduction in its signal. Unlike the mushroom-shaped structure seen in Spray A flames, Spray D flames exhibit a quasi-steady PAH phase structure, with lean peripheral mixtures insufficient for soot precursor formation. Notably, reducing ambient oxygen concentration to 13 % while maintaining or increasing temperature prolongs the presence of CH<sub>2</sub>O, highlighting its influence on ignition dynamics and oxidation processes in dodecane spray flames. This study provides new insights into the combustion mechanisms of high-pressure sprays and offers valuable data for developing next-generation combustion technologies, including models, aimed at improving efficiency and reducing emissions.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105208
Due to the high miniaturization of electronic devices, there is an urgent need to eliminate high heat flux in electronic devices and improve their heat transfer characteristics. This article simulated the single-phase flow to study the effects of five different arrangements of column ribs and different volume concentration (1 %–5%) of nanofluids on the convective heat transfer coefficient, pressure drop, and the irreversibility of flow heat transfer in ribbed microchannel heat sinks with multiple jets impingement (MJI) within the Re range of 200–1000. The working coolants is deionized water and water - Al2O3 nanofluid. Different important parameters, such as the characteristic of heat transfer and flow, Performance Evaluation Criterion (PEC), and entropy generation are investigated. The results indicated that MJI III can effectively improve the convective heat transfer coefficient while the increase in pressure drop is not obvious. The PEC of MJI III is 1.408 at Re = 600, which is much higher than the other MJIs. Additionally, the cooling performance and irreversibility of water-Al2O3 nanofluid are superior to those of deionized water within the research scope. With the concentration, the irreversibility of flow and heat transfer of water-Al2O3 nanofluid increasing increases. The data shows that, the overall performance is optimal when = 1 %, and its highest PEC is 1.75 at Re = 400.
由于电子设备的高度微型化，迫切需要消除电子设备中的高热通量并改善其传热特性。本文模拟了单相流，研究了五种不同的柱肋布置方式和不同体积浓度（1%-5%）的纳米流体对多射流撞击（MJI）肋式微通道散热器中对流传热系数、压降和流体传热不可逆性在 Re 200-1000 范围内的影响。工作冷却剂为去离子水和水-Al2O3 纳米流体。研究了不同的重要参数，如传热和流动特性、性能评估标准（PEC）和熵生成。结果表明，MJI III 能有效提高对流传热系数，而压降的增加并不明显。在 Re = 600 时，MJI III 的 PEC 为 1.408，远高于其他 MJI。此外，在研究范围内，水-Al2O3 纳米流体的冷却性能和不可逆性均优于去离子水。随着浓度的增加，水-Al2O3 纳米流体的流动和传热不可逆性也随之增加。数据显示，当 φ = 1 % 时，整体性能最佳，当 Re = 400 时，最高 PEC 为 1.75。
{"title":"Numerical study of heat transfer and entropy generation in ribbed microchannel with nanofluid and multiple jet impingement","authors":"","doi":"10.1016/j.csite.2024.105208","DOIUrl":"10.1016/j.csite.2024.105208","url":null,"abstract":"<div><div>Due to the high miniaturization of electronic devices, there is an urgent need to eliminate high heat flux in electronic devices and improve their heat transfer characteristics. This article simulated the single-phase flow to study the effects of five different arrangements of column ribs and different volume concentration (1 %–5%) of nanofluids on the convective heat transfer coefficient, pressure drop, and the irreversibility of flow heat transfer in ribbed microchannel heat sinks with multiple jets impingement (MJI) within the Re range of 200–1000. The working coolants is deionized water and water - Al<sub>2</sub>O<sub>3</sub> nanofluid. Different important parameters, such as the characteristic of heat transfer and flow, Performance Evaluation Criterion (<em>PEC</em>), and entropy generation are investigated. The results indicated that MJI III can effectively improve the convective heat transfer coefficient while the increase in pressure drop is not obvious. The <em>PEC</em> of MJI III is 1.408 at Re = 600, which is much higher than the other MJIs. Additionally, the cooling performance and irreversibility of water-Al<sub>2</sub>O<sub>3</sub> nanofluid are superior to those of deionized water within the research scope. With the concentration, the irreversibility of flow and heat transfer of water-Al<sub>2</sub>O<sub>3</sub> nanofluid increasing increases. The data shows that, the overall performance is optimal when <span><math><mrow><mi>φ</mi></mrow></math></span> = 1 %, and its highest <em>PEC</em> is 1.75 at Re = 400.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105203
To strengthen the rationality of the design of CO2 injection volume in goaf, a framework is proposed to study goaf inerting characteristics with hidden fire sources under CO2 injection volume of adsorption compensation. The zone of hidden fire source is determined by similar simulation experiment of coal spontaneous combustion on a working face of coal mine. The range of injection volume without adsorption is calculated theoretically. A three-dimensional initial flow field model of coal spontaneous combustion is established combined with field measurement. The error of oxidation zone width is 3.64 %, which verifies the reliability of model. The influence of injection volume on the inerting effect in goaf is studied, and optimal injection volume without adsorption is 1000 m3/h. Based on the relationship between adsorption capacity and temperature, a quantization model of injection volume with adsorption compensation is established. The maximum dissipation ratio is then proposed. The optimal injection volume after adsorption compensation is calculated. The results show that intermittent injection of gaseous CO2 is recommended under simulated conditions. The maximum dissipation ratio is 1/4, and the CO2 injection volume compensated by adsorption is 1333 m3/h. The research results can provide theoretical guidance for the optimization of CO2 inerting parameters in goaf.
{"title":"New exploration on the goaf inerting with hidden fire source under CO2 injection volume of adsorption compensation","authors":"","doi":"10.1016/j.csite.2024.105203","DOIUrl":"10.1016/j.csite.2024.105203","url":null,"abstract":"<div><div>To strengthen the rationality of the design of CO<sub>2</sub> injection volume in goaf, a framework is proposed to study goaf inerting characteristics with hidden fire sources under CO<sub>2</sub> injection volume of adsorption compensation. The zone of hidden fire source is determined by similar simulation experiment of coal spontaneous combustion on a working face of coal mine. The range of injection volume without adsorption is calculated theoretically. A three-dimensional initial flow field model of coal spontaneous combustion is established combined with field measurement. The error of oxidation zone width is 3.64 %, which verifies the reliability of model. The influence of injection volume on the inerting effect in goaf is studied, and optimal injection volume without adsorption is 1000 m<sup>3</sup>/h. Based on the relationship between adsorption capacity and temperature, a quantization model of injection volume with adsorption compensation is established. The maximum dissipation ratio is then proposed. The optimal injection volume after adsorption compensation is calculated. The results show that intermittent injection of gaseous CO<sub>2</sub> is recommended under simulated conditions. The maximum dissipation ratio is 1/4, and the CO<sub>2</sub> injection volume compensated by adsorption is 1333 m<sup>3</sup>/h. The research results can provide theoretical guidance for the optimization of CO<sub>2</sub> inerting parameters in goaf.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105187
Sodium acetate trihydrate (SAT) is a promising candidate for thermal energy storage due to its high latent enthalpy and economic viability. However, limitations like supercooling and low thermal conductivity hinder its practical application. Herein, these challenges are addressed by developing a novel SAT-based composite phase change material (PCM) through incorporation of binary nanoadditives—graphene oxide (GO) and graphene nanoplatelets (GNP) to mitigate supercooling and enhance thermal conductivity, respectively. Notably, the optimal composite, SAT/0.25GO/0.75GNP, identified through systematic formulation optimization, retains a high latent enthalpy (281.09 J/g), comparable to pure SAT (290.47 J/g), with improved thermal conductivity and substantially reduced supercooling and phase separation issues. The combined effects of GO and GNP, likely due to noncovalent interactions, enhanced heat transfer in the composite, which was further tested in a vacuum mug. The SAT/0.25GO/0.75GNP composite achieved ideal drinking temperatures (60–50 °C) for hot water in just 4 minutes–18 times faster than the PCM-free control mug and 6 times faster than the Mug containing pure SAT. While the PCM-free mug maintains hot water within this interval for only 49 min, MugPCM, encapsulating pure SAT, retains heat for 76 min, and that with SAT/0.25GO/0.75GNP keeps remarkably hot for as long as 100 min.
{"title":"Optimizing thermal performance of sodium acetate trihydrate phase-change-materials through synergistic effects of binary graphene nanoadditives for prolonged hot beverage maintenance","authors":"","doi":"10.1016/j.csite.2024.105187","DOIUrl":"10.1016/j.csite.2024.105187","url":null,"abstract":"<div><div>Sodium acetate trihydrate (SAT) is a promising candidate for thermal energy storage due to its high latent enthalpy and economic viability. However, limitations like supercooling and low thermal conductivity hinder its practical application. Herein, these challenges are addressed by developing a novel SAT-based composite phase change material (PCM) through incorporation of binary nanoadditives—graphene oxide (GO) and graphene nanoplatelets (GNP) to mitigate supercooling and enhance thermal conductivity, respectively. Notably, the optimal composite, SAT/0.25GO/0.75GNP, identified through systematic formulation optimization, retains a high latent enthalpy (281.09 J/g), comparable to pure SAT (290.47 J/g), with improved thermal conductivity and substantially reduced supercooling and phase separation issues. The combined effects of GO and GNP, likely due to noncovalent interactions, enhanced heat transfer in the composite, which was further tested in a vacuum mug. The SAT/0.25GO/0.75GNP composite achieved ideal drinking temperatures (60–50 °C) for hot water in just 4 minutes–18 times faster than the PCM-free control mug and 6 times faster than the Mug containing pure SAT. While the PCM-free mug maintains hot water within this interval for only 49 min, MugPCM, encapsulating pure SAT, retains heat for 76 min, and that with SAT/0.25GO/0.75GNP keeps remarkably hot for as long as 100 min.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105182
The innovation of nanofluid has contributed significantly towards a decrease in friction and an increase in heat transmission rates. So, the purpose of this research is to investigate magnetohydrodynamics nanofluid flow in a rotating system for heat, mass, and microorganism transfer. The rotating system has lower and upper plates positioned at and . Different solid nanoparticles i.e. copper, graphene, and oxide nanoparticles i.e. titanium oxide, aluminum oxide, and water as base fluid are used to prepare different hybrid nanofluids. Such fluids have applications in medical technologies, aerospace, cooling systems, hyperthermia treatment, and energy systems like nuclear reactors and solar systems. Additionally, it improves environmental engineering by improving pollutant movement and removal during water treatment. These different applications highlight the importance of present research. Heat, mass, and microorganism transmission incorporating inclined magnetic force and thermal radiation effects are discussed in detail. Through a similarity function, the governing equations are transformed into interconnected ordinary differential equations (ODEs). Using MATLAB's bvp4c ODE solver, numerical and graphical solutions are derived. Detailed exploration is conducted on the impacts of various parameters such as thermophoresis, Peclet number, Schmidt number, inclination angle, magnetic field, and rotation on velocity, temperature, volumetric concentration, and motile concentration. Notably, the maximum heat transfer rate occurs when the radiation parameter varies from 0 to 15, highlighting maximum heat transfer in the absence of radiation. The Peclet number is between 5 and 20, and the motile microorganism transmission rate changes from 7.3 to 20 for Cu/Graphene nanoparticles and 6.4 to 21 for nanoparticles fluid. This shows the efficiency of both types of hybrid nanofluids.
{"title":"MHD hybrid nanofluid flow in a rotating system with an inclined magnetic field and thermal radiation","authors":"","doi":"10.1016/j.csite.2024.105182","DOIUrl":"10.1016/j.csite.2024.105182","url":null,"abstract":"<div><div>The innovation of nanofluid has contributed significantly towards a decrease in friction and an increase in heat transmission rates. So, the purpose of this research is to investigate magnetohydrodynamics nanofluid flow in a rotating system for heat, mass, and microorganism transfer. The rotating system has lower and upper plates positioned at <span><math><mrow><msub><mi>y</mi><mn>0</mn></msub></mrow></math></span> and <span><math><mrow><msub><mi>y</mi><mi>h</mi></msub></mrow></math></span>. Different solid nanoparticles i.e. copper, graphene, and oxide nanoparticles i.e. titanium oxide, aluminum oxide, and water as base fluid are used to prepare different hybrid nanofluids. Such fluids have applications in medical technologies, aerospace, cooling systems, hyperthermia treatment, and energy systems like nuclear reactors and solar systems. Additionally, it improves environmental engineering by improving pollutant movement and removal during water treatment. These different applications highlight the importance of present research. Heat, mass, and microorganism transmission incorporating inclined magnetic force and thermal radiation effects are discussed in detail. Through a similarity function, the governing equations are transformed into interconnected ordinary differential equations (ODEs). Using MATLAB's bvp4c ODE solver, numerical and graphical solutions are derived. Detailed exploration is conducted on the impacts of various parameters such as thermophoresis, Peclet number, Schmidt number, inclination angle, magnetic field, and rotation on velocity, temperature, volumetric concentration, and motile concentration. Notably, the maximum heat transfer rate occurs when the radiation parameter varies from 0 to 15, highlighting maximum heat transfer in the absence of radiation. The Peclet number is between 5 and 20, and the motile microorganism transmission rate changes from 7.3 to 20 for <em>Cu/Graphene</em> nanoparticles and 6.4 to 21 for <span><math><mrow><msub><mrow><mi>A</mi><mi>l</mi></mrow><mn>2</mn></msub><msub><mi>O</mi><mn>3</mn></msub><mo>/</mo><msub><mrow><mi>T</mi><mi>i</mi><mi>O</mi></mrow><mn>2</mn></msub></mrow></math></span> nanoparticles fluid. This shows the efficiency of both types of hybrid nanofluids.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105174
The internal flow field of snout affects the quality of hot-dip zinc products significantly. The prediction of zinc evaporation is a key issue of analyzing the atmosphere flow in the snout. In this paper, simulations of the atmosphere flow with zinc evaporation considered are carried out in the snout of a high temperature hot-dip zinc-aluminum-magnesium coating line. In order to eliminate the false diffusion in numerical calculation of zinc evaporation, a strategy of high-order scheme combined with local orthogonal grids at the zinc vaporization boundary is proposed. The simulation is validated by available experimental data. The effects of operation parameters such as the temperature of snout wall, the width and the speed of the strip on the zinc vapor flow are studied. It is found that with the increased temperature gradient between the snout wall and strip wall, the concentration of zinc vapor in the snout is also increased. Therefore, the method of heating the snout wall can reduce the temperature gradient between the snout wall and strip wall, so it is beneficial to reduce the evaporation of zinc liquid in the snout.
{"title":"Prediction of zinc evaporation in the snout of high-temperature hot-dip zinc-aluminum-magnesium coating line","authors":"","doi":"10.1016/j.csite.2024.105174","DOIUrl":"10.1016/j.csite.2024.105174","url":null,"abstract":"<div><div>The internal flow field of snout affects the quality of hot-dip zinc products significantly. The prediction of zinc evaporation is a key issue of analyzing the atmosphere flow in the snout. In this paper, simulations of the atmosphere flow with zinc evaporation considered are carried out in the snout of a high temperature hot-dip zinc-aluminum-magnesium coating line. In order to eliminate the false diffusion in numerical calculation of zinc evaporation, a strategy of high-order scheme combined with local orthogonal grids at the zinc vaporization boundary is proposed. The simulation is validated by available experimental data. The effects of operation parameters such as the temperature of snout wall, the width and the speed of the strip on the zinc vapor flow are studied. It is found that with the increased temperature gradient between the snout wall and strip wall, the concentration of zinc vapor in the snout is also increased. Therefore, the method of heating the snout wall can reduce the temperature gradient between the snout wall and strip wall, so it is beneficial to reduce the evaporation of zinc liquid in the snout.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105207
Lithium-ion batteries significantly extend the driving range for electric motorcycles. The battery thermal management system (BTMS) is critical for achieving optimal battery performance. Moreover, precise battery temperature prediction is essential for efficient thermal management. Therefore, a battery thermal management system integrating air and phase change material (PCM) cooling is proposed. Initially, the impact of PCM height, PCM thickness, and air velocity on battery temperature is analyzed. Subsequently, with cost minimization as the objective and ensuring that the maximum battery temperature remains below a threshold, the Black Kite Algorithm (BKA) is employed to optimize the BTMS structure. Finally, a BKA-Convolutional Neural Network (CNN)-Self Attention (SA) model is introduced for battery temperature prediction. The results indicate that increasing the thickness of the PCM and air velocity facilitates battery heat dissipation but with diminishing marginal effects. An increase in PCM height enhances battery cooling at low air velocities but becomes detrimental at high air velocities. The optimized PCM height is 35 mm, resulting in a cost of 0.073 USD for the BTMS per battery. Additionally, the BKA-CNN-SA model achieved a maximum error of 0.45 °C on the validation set and accurately predicted battery temperature changes before and after PCM melting.
{"title":"Structural optimization and battery temperature prediction of battery thermal management system based on machine learning","authors":"","doi":"10.1016/j.csite.2024.105207","DOIUrl":"10.1016/j.csite.2024.105207","url":null,"abstract":"<div><div>Lithium-ion batteries significantly extend the driving range for electric motorcycles. The battery thermal management system (BTMS) is critical for achieving optimal battery performance. Moreover, precise battery temperature prediction is essential for efficient thermal management. Therefore, a battery thermal management system integrating air and phase change material (PCM) cooling is proposed. Initially, the impact of PCM height, PCM thickness, and air velocity on battery temperature is analyzed. Subsequently, with cost minimization as the objective and ensuring that the maximum battery temperature remains below a threshold, the Black Kite Algorithm (BKA) is employed to optimize the BTMS structure. Finally, a BKA-Convolutional Neural Network (CNN)-Self Attention (SA) model is introduced for battery temperature prediction. The results indicate that increasing the thickness of the PCM and air velocity facilitates battery heat dissipation but with diminishing marginal effects. An increase in PCM height enhances battery cooling at low air velocities but becomes detrimental at high air velocities. The optimized PCM height is 35 mm, resulting in a cost of 0.073 USD for the BTMS per battery. Additionally, the BKA-CNN-SA model achieved a maximum error of 0.45 °C on the validation set and accurately predicted battery temperature changes before and after PCM melting.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.csite.2024.105221
The following comments address missing information, incomplete mathematical expressions, and the erroneous quantitative findings in the above-mentioned paper. This analysis, therefore, serves as a comparison and correction to the publication “Using natural convection mechanism of nanofluid for cooling an embedded hot plate in corner of a square enclosure: a numerical simulation.” [Case Studies in Thermal Engineering 33 (2022) 101926]
{"title":"Comment on “Using natural convection mechanism of nanofluid for cooling an embedded hot plate in corner of a square enclosure: A numerical simulation” [Case Stud. Therm. Eng. 33, (2022) 101926]","authors":"","doi":"10.1016/j.csite.2024.105221","DOIUrl":"10.1016/j.csite.2024.105221","url":null,"abstract":"<div><div>The following comments address missing information, incomplete mathematical expressions, and the erroneous quantitative findings in the above-mentioned paper. This analysis, therefore, serves as a comparison and correction to the publication “Using natural convection mechanism of nanofluid for cooling an embedded hot plate in corner of a square enclosure: a numerical simulation.” [Case Studies in Thermal Engineering 33 (2022) 101926]</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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