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Boundary layer interaction of immiscible non-Newtonian nanofluids in distinct shear flows with motile microorganisms 不同剪切流动中非牛顿纳米流体的边界层相互作用
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-12-03 DOI: 10.1016/j.dynatmoce.2025.101629
Z. Abbas, S. Goher, M.Y. Rafiq
This study presents a comprehensive numerical investigation of two-phase boundary layer shear flows involving immiscible non-Newtonian Carreau and Tangent hyperbolic nanofluids incorporating motile microorganisms. The analysis explores the coupled effects of thermophoresis, Brownian motion, and thermal radiation on velocity, temperature, concentration, and microorganism density profiles across distinct shear regions. Incorporating microorganisms within nanofluids enhances thermal conductivity and stabilizes the flow structure, contributing to improved transport phenomena relevant to biomedical, energy, and environmental systems. The governing nonlinear differential equations are transformed into dimensionless form using similarity transformations and solved via the MATLAB bvp4c collocation method to ensure high numerical accuracy. A grid independence test confirms the convergence and stability of the scheme for all parametric variations. The results demonstrate that the Carreau fluid parameter promotes fluid velocity, while an increase in the viscosity ratio and shear strength ratio reduces it. Brownian motion and thermophoresis parameters suppress temperature near the interface, whereas thermal radiation enhances it. The density of motile microorganisms rises with higher bioconvection and Péclet numbers but decreases with increasing microorganism Schmidt number. Quantitative results for skin friction, Nusselt number, Sherwood number, and microorganism density validate the influence of these parameters in both regions. The findings provide valuable insights for optimizing microfluidic transport, bioconvective systems, and nanofluid-based heat exchangers where multi-phase shear interactions and microorganism activity are significant.
这项研究提出了一个全面的数值研究两相边界层剪切流动涉及非混相非牛顿卡罗和切线双曲纳米流体包含运动微生物。分析探讨了热泳、布朗运动和热辐射对不同剪切区域的速度、温度、浓度和微生物密度分布的耦合效应。在纳米流体中加入微生物可以增强导热性,稳定流动结构,有助于改善与生物医学、能源和环境系统相关的传输现象。采用相似变换将控制非线性微分方程转化为无因次形式,并采用MATLAB bvp4c配置法求解,保证了较高的数值精度。网格无关性测试证实了该方案对所有参数变化的收敛性和稳定性。结果表明:carcarau流体参数对流体速度有促进作用,而黏度比和抗剪强度比的增大对流体速度有抑制作用;布朗运动和热泳参数抑制界面附近的温度,而热辐射则增强界面附近的温度。流动微生物密度随生物对流和psamclet数的增加而升高,随微生物施密特数的增加而降低。皮肤摩擦、努塞尔数、舍伍德数和微生物密度的定量结果验证了这些参数在两个区域的影响。这些发现为优化微流体传输、生物对流系统和基于纳米流体的热交换器提供了有价值的见解,其中多相剪切相互作用和微生物活性是重要的。
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引用次数: 0
Multiple analytic solutions for irreversible mechanism and Joule heating impact on dissipative micropolar fluid flow driven by stretching/shrinking surface with PST and PHF boundary conditions PST和PHF边界条件下拉伸/收缩表面驱动耗散微极流体流动的不可逆机理和焦耳加热影响的多重解析解
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-12-01 DOI: 10.1016/j.dynatmoce.2025.101616
S.M. Sachhin , M.S. Bharath , G.M. Sachin , U.S. Mahabaleshwar , D. Laroze , H.F. Oztop
The current research aims to examine the Joule heating and magnetic field influence on micropolar fluid flow across expanding surface, which is is significant in enhancing the efficiency in biomedical and engineering fields, In this analysis, examined the influence of entropy generation, magnetic field, porous medium, and prescribed boundary restrictions. To the best of authors knowledge, no prior research has studied all these effects simultaneously, which emphasizes the originality of the current analysis. The considered governing partial differential equations are transformed to ordinary differential equations by using similarity expressions and then formulated analytically using hypergeometric series solutions. The dual solutions have been extracted from the current analysis which offers deeper insights into the micropolar fluid behaviour under considered physical effects. The outcomes of the present analysis reveal that enhancing the porous media and magnetic field reduces the momentum by 15 %. With enhancing the internal heat source enhances the temperature by 20 %, and thermal radiation enhances temperature by 29 %, enhancing the viscosity ration reduces the velocity by 23 %. These results help in analysing the blood movement modelling, advanced medical therapies, and magnetic drug delivery among others.
本研究旨在研究焦耳加热和磁场对微极流体在膨胀表面上流动的影响,这对提高生物医学和工程领域的效率具有重要意义。在本分析中,研究了熵生,磁场,多孔介质和规定边界限制的影响。据作者所知,之前没有研究同时研究所有这些影响,这强调了当前分析的独创性。利用相似表达式将所考虑的控制偏微分方程转化为常微分方程,然后用超几何级数解解析表示。从当前的分析中提取了双溶液,这为考虑物理效应下的微极流体行为提供了更深入的见解。本分析的结果表明,增强多孔介质和磁场可使动量降低15% %。增加内部热源使温度提高20 %,热辐射使温度提高29 %,增加粘度比使速度降低23 %。这些结果有助于分析血液运动模型、先进的医疗疗法和磁性药物输送等。
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引用次数: 0
Energy transport in ternary hybrid nanofluid with variable thermal conductivity under the combined effects of electroviscous, electric potential, and heat generation 电粘性、电势和产热共同作用下变导热三元杂化纳米流体中的能量输运
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-12-01 DOI: 10.1016/j.dynatmoce.2025.101619
Shafiq Ahmad , Aamir Abbas Khan , Muhammad Naveed Khan , Salah Knani , N. Ameer Ahammad , Ibrahim E. Elseesy
This article uses squeezing plates containing ternary hybrid nanofluid to scrutinize the behavior of transient electroviscous fluid flow with an induced magnetic field. By dissolving the constituents, such as silicon carbide, aluminum oxide, and multiwall carbon nanotubes, in a base fluid of water, a ternary hybrid nanofluid MWCNT+Al2O3+SiC/H2O was created. The current work aims to increase the energy transfer rate for technical and industrial applications. In the presence of heat generation, thermal radiation, and varying thermal conductivity, fluid flow exhibits its thermal behavior. Through the use of similarity substitution, an ordinary differential equation (ODE) set is obtained from a system of partial differential equations (PDEs) representing the ternary hybrid nanofluid flow. After that, using the bvp4c approach, the dimensionless ordinary differential equations in the nonlinear set are solved. On ternary hybrid nanofluid (MWCNT+Al2O3+SiC/H2O) and unary nanofluid (Al2O3/H2O), the graphical and numerical results are found against the many parameters. The findings show that, in comparing to unary nanofluids, ternary hybrid nanofluids have a greater impact on heat transfer rate owing to the fact that the inclusion of nanofluids to the base fluid intensifies heat transport rate.
本文利用含三元杂化纳米流体的挤压板研究了瞬态电粘性流体在感应磁场作用下的流动行为。通过将碳化硅、氧化铝和多壁碳纳米管等成分溶解在水的基液中,形成了MWCNT+Al2O3+SiC/H2O三元混合纳米流体。目前的工作旨在提高技术和工业应用的能量转移速度。在热产生、热辐射和热导率变化的情况下,流体流动表现出其热行为。利用相似代入的方法,从三元混合纳米流体流动的偏微分方程组中得到一个常微分方程集。在此基础上,利用bvp4c方法对非线性集合中的无量纲常微分方程进行求解。对三元杂化纳米流体(MWCNT+Al2O3+SiC/H2O)和一元纳米流体(Al2O3/H2O),在多种参数下得到了图形和数值结果。研究结果表明,与一元纳米流体相比,三元混合纳米流体对传热速率的影响更大,这是由于纳米流体与基流体的包裹体增强了传热速率。
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引用次数: 0
Risk mapping of dynamic dust storms and multi-hazard maritime navigation in the red sea using machine learning and MODIS Data 利用机器学习和MODIS数据绘制红海动态沙尘暴和多灾种海上航行风险图
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-12-01 DOI: 10.1016/j.dynatmoce.2025.101621
Yazeed Alsubhi , Bassam M. Aljahdali , Ayman F. Alghanmi , Hussain T. Sulaimani , Ahmad E. Samman
Dust storms represent a significant hazard to maritime navigation, particularly in regions such as Saudi Arabia, where frequent dust events, driven by vast desert landscapes and oceanic wind patterns, reduce visibility and disrupt maritime operations. This paper proposes a comprehensive framework for evaluating visibility risks posed by dust storms in Saudi Arabian maritime zones, specifically focusing on the Red Sea. The methodology considers MODIS AOD (Aerosol Optical Depth) data, wind speed, and cloud cover to develop a dynamic risk assessment model using random forest (RF) for dust storm detection and visibility risk prediction. The model integrates spatial data layers for environmental factors (wind, waves, and depth), creating seasonal risk maps that dynamically adjust based on changing environmental conditions. GIS technology was used to visualize risk zones, and the RF model provided data-driven weighting of risk factors. The model’s performance was validated using metrics such as probability of detection (POD) (0.92), probability of false detection (PFD) (0.05), and equitable threat score (ETS) (0.85), demonstrating superior accuracy over traditional methods like analytic hierarchy process (AHP) and CRiteria importance through intercriteria correlation (CRITIC). The findings indicate that Autumn represents the most hazardous season for maritime navigation due to frequent dust storms, with the central Red Sea being the most impacted area. The results demonstrate the potential of this approach for improving navigation safety and early warning tools in the Red Sea and similar arid coastal regions.
沙尘暴对海上航行构成重大危害,特别是在沙特阿拉伯等地区,在那里,由于广阔的沙漠景观和海风模式,频繁发生沙尘暴,降低了能见度,扰乱了海上作业。本文提出了一个综合框架,用于评估沙尘暴在沙特阿拉伯海域造成的能见度风险,特别是关注红海。该方法考虑了MODIS AOD(气溶胶光学深度)数据、风速和云量,开发了一个使用随机森林(RF)进行沙尘暴探测和能见度风险预测的动态风险评估模型。该模型集成了环境因素(风、波浪和深度)的空间数据层,创建了基于不断变化的环境条件动态调整的季节性风险图。利用GIS技术可视化风险区域,RF模型提供数据驱动的风险因素加权。通过检测概率(POD)(0.92)、误检概率(PFD)(0.05)和公平威胁评分(ETS)(0.85)等指标验证了该模型的性能,显示出比传统方法(如层次分析法(AHP)和标准间相关性(CRITIC)标准重要性)更优的准确性。研究结果表明,由于沙尘暴频繁,秋季是海上航行最危险的季节,其中红海中部是受影响最严重的地区。结果表明,这种方法在改善红海和类似干旱沿海地区的航行安全和预警工具方面具有潜力。
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引用次数: 0
Behavior of magneto-viscoelastic fluid flow through a permeable medium with heat source/sink using hybrid methodology 采用混合方法研究具有热源/热源的磁粘弹性流体在可渗透介质中的流动行为
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-11-27 DOI: 10.1016/j.dynatmoce.2025.101620
P.P. Nayak , S.R. Mishra , Subhajit Panda
Viscoelastic fluids change their rheological properties in response to an applied electric or magnetic field. In particular, applications in vehicle damping systems, vibration control devices, shock absorbers, and smart materials for structural engineering the role of viscoelastic fluid is vital. Therefore, the proposed study investigates the influence of magnetized viscoelastic fluid through a permeable medium due to the interaction of a heat source/sink. The free convection with radiative heat transfer characterizes the transport properties significantly. The relevant similarity rules are adopted for the transmutation of the governing phenomena into ordinary as well as dimensionless. Further, the complexity of the flow phenomena impulses to the implementation of perturbation technique to reduce the order of the problem, and then a numerical method such as shooting combined with Runge-Kutta fourth-order contributes to solving the system. Graphs are used to illustrate the characteristics of physical parameters that contribute to the flow phenomena. However, the analysis ended with important flow behaviour described briefly in the conclusion. The study reveals that the heat transfer shows dual behavior with magnetic and radiation effects, being stronger in permeable media. Magnetization reduces shear and mass transfer, while buoyancy boosts velocity. Radiation and chemical reactions influence temperature rise and concentration drop, respectively.
粘弹性流体在外加电场或磁场的作用下改变其流变特性。特别是在车辆阻尼系统、振动控制装置、减震器和结构工程智能材料的应用中,粘弹性流体的作用至关重要。因此,本研究探讨了磁化粘弹性流体通过可渗透介质时由于热源/热源的相互作用而产生的影响。带辐射换热的自由对流对传热特性有显著的影响。将控制现象转化为普通现象和无量纲现象时,采用了相关的相似规则。进一步,由于流动现象的复杂性,需要采用微扰技术来降低问题的阶数,然后采用射击等数值方法结合龙格-库塔四阶方法对系统进行求解。图形用来说明导致流动现象的物理参数的特征。然而,分析以结论中简要描述的重要流动特性结束。研究表明,传热表现为磁效应和辐射效应的双重行为,在渗透性介质中传热更强。磁化减少剪切和质量传递,而浮力提高速度。辐射和化学反应分别影响温度上升和浓度下降。
{"title":"Behavior of magneto-viscoelastic fluid flow through a permeable medium with heat source/sink using hybrid methodology","authors":"P.P. Nayak ,&nbsp;S.R. Mishra ,&nbsp;Subhajit Panda","doi":"10.1016/j.dynatmoce.2025.101620","DOIUrl":"10.1016/j.dynatmoce.2025.101620","url":null,"abstract":"<div><div>Viscoelastic fluids change their rheological properties in response to an applied electric or magnetic field. In particular, applications in vehicle damping systems, vibration control devices, shock absorbers, and smart materials for structural engineering the role of viscoelastic fluid is vital. Therefore, the proposed study investigates the influence of magnetized viscoelastic fluid through a permeable medium due to the interaction of a heat source/sink. The free convection with radiative heat transfer characterizes the transport properties significantly. The relevant similarity rules are adopted for the transmutation of the governing phenomena into ordinary as well as dimensionless. Further, the complexity of the flow phenomena impulses to the implementation of perturbation technique to reduce the order of the problem, and then a numerical method such as shooting combined with Runge-Kutta fourth-order contributes to solving the system. Graphs are used to illustrate the characteristics of physical parameters that contribute to the flow phenomena. However, the analysis ended with important flow behaviour described briefly in the conclusion. The study reveals that the heat transfer shows dual behavior with magnetic and radiation effects, being stronger in permeable media. Magnetization reduces shear and mass transfer, while buoyancy boosts velocity. Radiation and chemical reactions influence temperature rise and concentration drop, respectively.</div></div>","PeriodicalId":50563,"journal":{"name":"Dynamics of Atmospheres and Oceans","volume":"113 ","pages":"Article 101620"},"PeriodicalIF":2.0,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145625414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Thermomagnetic unsteady convection of nanofluid flow in an inclined-field cavity 纳米流体在斜场腔内的热磁非定常对流
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-11-26 DOI: 10.1016/j.dynatmoce.2025.101617
Majdeddin Emad , Payam Jalili , Bahram Jalili , Davood Domiri Ganji
This work concisely investigates unsteady magnetohydrodynamic (MHD) convection of nanofluids within a confined enclosure subjected to an inclined magnetic field and internal heat generation or absorption. Utilizing the Buongiorno model, which incorporates thermophoresis and Brownian motion, the coupled mass, momentum, energy, and nanoparticle concentration equations are solved using the finite element method (FEM), which is an efficient procedure for solving two-dimensional thermal problems. Parametric analysis is carried out over Reynolds, Hartmann, and Schmidt numbers, magnetic field inclination angle, and heat source/sink strength. Results indicate that higher Reynolds numbers significantly enhance fluid flow and the mean Nusselt number. Increasing Hartmann numbers suppresses convection but yields modest improvements in heat transfer. A magnetic inclination of 30° maximizes heat transfer efficiency. Elevated Schmidt numbers enhance momentum transport but decrease thermal efficiency due to reduced mass diffusivity. Internal heat generation significantly enhances heat transfer performance, resulting in nearly a 300 % increase in Nusselt numbers at the base wall under conditions of heat generation. These findings offer valuable insights into the dynamic coupling of nanoparticle transport, magnetic control, and thermal regulation in unsteady MHD systems.
这项工作简明地研究了纳米流体在受倾斜磁场和内部热产生或吸收的封闭外壳内的非定常磁流体动力学(MHD)对流。利用结合热电泳和布朗运动的Buongiorno模型,采用有限元法求解了耦合的质量、动量、能量和纳米颗粒浓度方程,这是求解二维热问题的有效方法。对雷诺数、哈特曼数和施密特数、磁场倾角和热源/汇强度进行了参数分析。结果表明,雷诺数越高,流体流动能力越强,平均努塞尔数越高。增加哈特曼数抑制对流,但在传热方面产生适度的改善。30°的磁倾角最大限度地提高了传热效率。升高的施密特数增强了动量输运,但由于质量扩散率降低而降低了热效率。内部产热显著提高了传热性能,在产热条件下,基底壁上的努塞尔数增加了近300 %。这些发现为非定常MHD系统中纳米颗粒输运、磁控制和热调节的动态耦合提供了有价值的见解。
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引用次数: 0
Characteristics of low-frequency activities of Northeast China cold vortices and their impacts on the precipitation in Northeast China 东北冷涡低频活动特征及其对东北降水的影响
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-11-26 DOI: 10.1016/j.dynatmoce.2025.101618
Xiaoxuan Su , Yihe Fang , Ling Zhu , Chenghan Liu , Zhenghua Tan
Based on daily precipitation data from 87 national rain gauge stations in Northeast China from 1981 to 2023 and the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data, This study reveals the characteristics of low-frequency activities of Northeast China cold vortex (NCCV) during the warm season and their impact on precipitation in Northeast China. The results show that the low-frequency activities of NCCV are closely related to the intraseasonal oscillation of middle-high latitudes. When the low-frequency NCCV activities reach the strongest, the geopotential height field over Northeast China exhibits negative anomalies, and the high-latitudes of the Eurasian continent show an anomaly pattern of “− + −”. When the NCCV key area is controlled by high-pressure anomalies, the middle-high latitudes are dominated by the East Asian-Pacific pattern from May to June. From July to September, the East Asian-Pacific pattern is weak and the Eurasian pattern is dominant. During the active phase of NCCV, Northeast China is under the control of a strong westerly jet, which is conducive to upper-level divergence. This further promotes the maintenance and development of cold vortices. At this time, the NCCV is located between two jets, which benefits energy accumulation and moisture transport. Moreover, there is obvious ascending motion over Northeast China, providing favorable dynamic conditions for notable low-frequency precipitation. The upper level low-frequency vorticity can also reflect the propagation of low frequency oscillations in the NCCV key area, as well as its upstream and downstream regions. When the NCCV is the strongest, the rear of the key area is controlled by positive vorticity anomalies, while the front is controlled by negative vorticity anomalies. The phases of NCCV low-frequency activities have good indications for cold vortex precipitation in early summer and midsummer in Northeast China. From phases 1–4, the low-frequency precipitation in Northeast China is less. As the low-frequency NCCV forms, develops and moves eastward (phases 5–8), the low-frequency rain band generates in the Liaoning Province and gradually moves northeastward, affecting Jilin and Heilongjiang provinces. As the low-frequency NCCV weakens and moves out, the precipitation in Northeast China gradually decreases from southwest to northeast.
利用1981 ~ 2023年东北地区87个国家级雨量站逐日降水资料和国家环境预报中心/国家大气研究中心再分析资料,揭示了暖季东北冷涡低频活动特征及其对东北地区降水的影响。结果表明,NCCV的低频活动与中高纬度的季节内振荡密切相关。低频NCCV活动最强时,东北地区位势高度场呈负异常,欧亚大陆高纬度地区呈“−+ −”异常。当NCCV重点区受高压异常控制时,5 - 6月中高纬地区以东亚-太平洋型为主。7 - 9月,东亚-太平洋格局偏弱,欧亚格局为主。在NCCV活动期,东北地区受一强西风急流控制,有利于高空辐散。这进一步促进了冷涡的维持和发展。此时,NCCV位于两个射流之间,有利于能量积累和水分输送。此外,东北上空有明显的上升运动,为显著的低频降水提供了有利的动力条件。上层低频涡量也能反映低频振荡在NCCV关键区域及其上下游区域的传播。当NCCV最强时,关键区后部受正涡度异常控制,而前部受负涡度异常控制。NCCV低频活动的相位对东北初夏和仲夏冷涡降水有较好的指示作用。从1 ~ 4期来看,东北地区低频降水偏少。随着低频NCCV的形成、发展和东移(5-8相),低频雨带在辽宁省产生并逐渐向东北移动,影响吉林和黑龙江等省。随着低频NCCV的减弱和移出,东北降水由西南向东北逐渐减少。
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引用次数: 0
Non-Darcy and Joule heating in MHD convective micropolar heat transfer flow over a stretchy cooling sheet with variable heat gain 可变热增益的弹性冷却片上MHD对流微极换热流动的非达西和焦耳加热
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-11-14 DOI: 10.1016/j.dynatmoce.2025.101615
T. Venu , MD. Shamshuddin , S.O. Salawu , Subhajit Panda
The research intends to characterize the thermal performance in micropolar fluid flows on a vertically elongated porous sheet with buoyancy-induced forces. The model incorporates the distribution of a non-uniform heat source/sink, Darcy dissipation, and the fluid flows across a porous substrate. The mathematical problem is non-dimensionalized under the similarity transformation approach as a coupled set of ordinary differential equations from the principal partial differential equations. A similarity transformation is done on the model to reduce it to ordinary differential equations are subsequently solved by the Runge-Kutta 4th order method utilizing the shooting scheme to evaluate numerical findings of dependent quantities of physical importance through MATLAB. The impact of varied parameters on the fluid momentum, angular momentum, and energy was analyzed and shown graphically. The key results revealed that the Darcy porosity meaningfully affects the momentum and thermal boundary layer. This brings about a higher wall shear stress. Micropolar fluid term contributes significantly to the microrotation and shear stress distributions development. Boundary convective conditions spur a nonlinear thermal distribution response that is sensitive to the Biot number variation for an effective boundary thermal exchange.
本研究旨在利用浮力表征微极流体在垂直细长多孔板上的热性能。该模型结合了非均匀热源/热源的分布、达西耗散和流体流过多孔基板的情况。在相似变换方法下,将数学问题无量纲化,转化为由主偏微分方程组成的常微分方程的耦合集。对模型进行相似变换,将其简化为常微分方程,然后利用四阶龙格-库塔法求解,利用射击格式通过MATLAB对物理重要性相关量的数值结果进行评价。分析了不同参数对流体动量、角动量和能量的影响,并用图形表示。关键结果表明,达西孔隙度对动量和热边界层有重要影响。这导致了较高的壁剪应力。微极流体项对微旋转和剪应力分布的发展有重要影响。为了实现有效的边界热交换,边界对流条件激发了对Biot数变化敏感的非线性热分布响应。
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引用次数: 0
Mixed convective heat transfer enhancement in hybrid nanofluid flow through complex-finned tube cavities 混合纳米流体流过复杂翅片管腔时的混合对流换热增强
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-11-10 DOI: 10.1016/j.dynatmoce.2025.101612
Noreen Sher Akbar , Salman Akhtar , Shakil Shaiq , Muhammad Fiaz Hussain , Taseer Muhammad , M. Farooq , M. Bilal Habib
The advanced energy regulation systems demand an optimal heat balance that can be successfully accomplished through the application of hybrid nanofluids. This research work examines the numerical analysis on convective heat transfer with flow attributes of hybrid nanoparticles formed from molybdenum disulfide and graphene oxide inside a circular domain having narrow edge fins. We have integrated a novel fin configuration with convective heat transfer analysis of hybrid nanofluids. Thermal convection and magnetohydrodynamic effects are employed for this steady, incompressible, laminar flow phenomenon. The complex configuration of governing partial differential equations is numerically solved by utilizing finite element simulations. The impact of fin count on thermal efficiency is evaluated by incorporating 4 and 10 fins respectively. Streamlines, isotherms, and Nusselt number patterns are analyzed against significant dimensionless parameters. The increased fin count optimizes the heat transfer mechanism through improved fluid mixing and greater recirculation zones. The synergistic effects of hybrid nanofluid flow phenomenon efficiently improves heat absorption, flow characteristics, and overall thermal efficiency. The flow field is further stabilized through the application of external magnetic field effects that promotes a uniform distribution with efficient heat transfer. The fin count and design have pivotal role in supervising flow obstructions with better heat flux in magnetohydrodynamic flow environment. The increasing value of Reynold number from 1.1 to 1.5 results in a 20 % increase of Nusselt number from 3.0 to 3.6. A further increase of 11 % in Nusselt number is noted for Reynold equal to 1.7. Nusselt number significantly increases up to 67 %, 89 %, and 95 % with an 80 % increase in Prandtl number for Reynold equal to 1.1, 1.5, and 1.7 respectively. Thus, the higher flow rate and increased viscous effects significantly enhance convective heat transfer in finned tube cavity. The studied parameters have the following ranges 0.1Pr20.1;1M41;0.1Gr0.002;1Re31;1Ec61;1Rd6;0.01ϕ20.05.
先进的能量调节系统需要一个最佳的热平衡,这可以通过混合纳米流体的应用成功地实现。本文研究了由二硫化钼和氧化石墨烯组成的杂化纳米颗粒在窄边翅片圆形区域内对流换热特性的数值分析。我们集成了一种新的翅片结构与混合纳米流体的对流传热分析。热对流和磁流体动力学效应被用于这种稳定的、不可压缩的层流现象。利用有限元模拟方法对控制偏微分方程的复杂构型进行了数值求解。通过分别纳入4片和10片翅片来评估翅片数量对热效率的影响。流线,等温线,和努塞尔数模式分析对显著无因次参数。增加的翅片数量通过改善流体混合和更大的再循环区域来优化传热机制。混合纳米流体流动现象的协同效应有效改善了吸热、流动特性和整体热效率。通过应用外磁场效应,流场进一步稳定,促进均匀分布和有效的传热。在磁流体动力流动环境中,翅片的数量和设计对监测热流密度较好的流动障碍具有关键作用。雷诺数从1.1增加到1.5,努塞尔数从3.0增加到3.6,增加20 %。雷诺的努塞尔数进一步增加了11. %,等于1.7。努塞尔数显著增加,分别为67 %、89 %和95 %,雷诺的普朗特数增加80 %,分别为1.1、1.5和1.7。因此,更高的流速和增加的粘性效应显著增强了翅片管腔内的对流换热。所研究的参数范围为0.1≤Pr≤20.1,1≤M≤41,0.1≤Gr≤0.002,1≤Re≤31,1≤Ec≤61,1≤Rd≤6,0.01≤ϕ2≤0.05。
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引用次数: 0
Double-layer stratification of Cross fluid flow with viscous dissipation and variable thermal conductivity 具有粘性耗散和变导热系数的交叉流体流动的双层分层
IF 2 4区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Pub Date : 2025-11-10 DOI: 10.1016/j.dynatmoce.2025.101614
T. Salahuddin , A. Maqsood , Muhammad Awais , Mair Khan , Anum Tanveer , Samia Elattar
In this study, we analyse the boundary layer flow and heat transport of a two-dimensional Cross fluid model flowing over a linearly stretched sheet. The variable thermal conductivity, mass diffusivity, chemical interactions, and viscous dissipation are also used to depict intricate transport processes. To simulate realistic stratified boundary layers, double stratification is included in both the temperature and concentration fields. By using the boundary layer approximation approach, the governing partial differential equations are obtained. The transformed ordinary differential equations are calculated by using the suitable transformations. The modelled problem is graphically handled using numerical techniques (BVP4c) in MATLAB software. Graphical representations of important factors on concentration, velocity and temperature fields are illustrated. The findings show that when the thermal stratification parameter is increased, then the wall temperature declines. For the same range of variance, solutal stratification also reduces surface concentration. The power law index and Weissenberg number reduce the velocity of fluid. The Eckert number, which measures viscous dissipation, greatly increases fluid heating and thickens the thermal boundary layer. The higher inputs of chemical reaction lower the concentration region. The variable thermal conductivity enhances the temperature region, and variable mass diffusion augments the concentration profile. The arrangement of the boundary layer is significantly influenced by the combined impacts of stratification, dissipation, and varied transport characteristics.
在这项研究中,我们分析了流动在线性拉伸薄片上的二维交叉流体模型的边界层流动和热传递。变热导率、质量扩散率、化学相互作用和粘性耗散也被用来描述复杂的传输过程。为了模拟真实的分层边界层,温度场和浓度场都考虑了双重分层。利用边界层近似方法,得到了控制偏微分方程。变换后的常微分方程通过适当的变换进行计算。在MATLAB软件中使用数值技术(BVP4c)对建模问题进行图形化处理。给出了浓度场、速度场和温度场等重要因素的图解。结果表明:随着热分层参数的增大,壁面温度下降;在相同的变化范围内,溶质分层也会降低地表浓度。幂律指数和Weissenberg数降低了流体的速度。测量粘性耗散的埃克特数大大增加了流体加热并使热边界层变厚。化学反应输入量越大,浓度区域越小。变热导率增大了温度区域,变质量扩散增大了浓度分布。边界层的排列受分层、消散和各种输运特征的综合影响。
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引用次数: 0
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Dynamics of Atmospheres and Oceans
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