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Exploration of the Arrhenius activation energy in unsteady ternary hybrid nanofluid flow past a slendering stretching sheet: RSM analysis 非定常三元杂化纳米流体通过细长拉伸片的阿伦尼乌斯活化能探索:RSM分析
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-07-14 DOI: 10.1016/j.padiff.2025.101255
N. Nithya , B. Vennila , K. Loganathan , R. Shobika , K. Senthilvadivu , S. Eswaramoorthi
This paper examines how a ternary hybrid nanofluid made by combining TiO2, SiO2, and Al2O3 in water behaves when flowing across a stretching sheet with varying thickness. The motivation comes from real world needs in systems like solar collectors, biomedical devices, and industrial cooling, where better heat transfer with minimal drag is essential. Using a blend of the Differential Transformation Method (DTM) and statistical optimization techniques like Response Surface Methodology (RSM) and Central Composite Design (CCD), we study how magnetic field, radiation, nanoparticle volume fraction, and activation energy affects the system. The hybrid nanofluid’s improved thermal behavior is a key focus. It is found that the increasing sheet thickness leads to higher temperatures, while velocity and concentration drop. Greater thermal radiation and more silicon dioxide particles enhance the heat transfer, improving efficiency by 12% and reducing drag (skin friction) by 15% under optimized conditions. Thermal conductivity improves with more nanoparticles, raising the Nusselt number. Meanwhile, mass diffusion behavior captured by the Sherwood number is influenced by activation energy and the Schmidt number. Magnetic field and nanoparticle volume fraction effects together help lower surface drag.
本文研究了在水中结合TiO2, SiO2和Al2O3制成的三元杂化纳米流体在流过具有不同厚度的拉伸片时的行为。动力来自现实世界的需求,如太阳能集热器、生物医学设备和工业冷却系统,在这些系统中,以最小的阻力进行更好的传热是必不可少的。利用微分变换方法(DTM)和响应面法(RSM)、中心复合设计(CCD)等统计优化技术,研究了磁场、辐射、纳米粒子体积分数和活化能对系统的影响。混合纳米流体的热性能的改善是一个关键的焦点。结果表明,随着板料厚度的增加,温度升高,速度和浓度下降。更大的热辐射和更多的二氧化硅颗粒增强了传热,在优化条件下,效率提高了12%,阻力(表面摩擦)减少了15%。热导率随着纳米颗粒的增加而提高,从而提高了努塞尔数。同时,由Sherwood数捕获的质量扩散行为受活化能和Schmidt数的影响。磁场和纳米颗粒体积分数效应共同有助于降低表面阻力。
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引用次数: 0
Machine learning analysis of tangent hyperbolic nanofluid with radiation and Arrhenius activation energy over falling cone under gravity 重力作用下落锥上具有辐射和Arrhenius活化能的正切双曲纳米流体的机器学习分析
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-08-22 DOI: 10.1016/j.padiff.2025.101280
Muhammad Zubair , Hamid Qureshi , Usman Khaliq , Taoufik Saidani , Waqar Azeem Khan
This study is a machine learning investigation of the advance level nanofluidic coolant through a cone in a two-dimensional transitory boundary layer. The model accounts for both radiation absorption and the Arrhenius activation energy. Synthetic datasets from governing mathematical model are used in Artificial Intelligence (AI) based Levenberg Marquardt Back Propagation algorithm (LM-BP). Multiple scenarios of Tangent Hyperbolic Nanofluidic (THNF) coolant are framed with variation of influencing characteristics like Magnetic field M, power law index n, permeability k, Radiation absorption Q, Prandtl ratio Pr, Brownian motion Nb, Lewis number Le and Chemical reaction parameter γ. Convergence parameters of AI-based feed routing Neural Network computing is presented through graphs and numerical tables. Results indicate that flow slows when the Lorentz force and surface permeability grow, but it gets stronger when thermal absorption and momentum to thermal diffusivity ratio Pr increase. Meanwhile, the temperature increases when thermal absorption rises and drops when thermal to mass diffusivity ratio Le increases so that temperature falls for greater chemical reaction influence.
本研究采用机器学习的方法研究了先进的纳米流控冷却剂在二维过渡边界层中的锥形流动。该模型同时考虑了辐射吸收和阿伦尼乌斯活化能。基于人工智能(AI)的Levenberg Marquardt反向传播算法(LM-BP)采用控制数学模型合成的数据集。研究了正切双曲型纳米流体(THNF)冷却剂的磁场M、幂律指数n、磁导率k、辐射吸收Q、普朗特比Pr、布朗运动Nb、路易斯数Le和化学反应参数γ等影响特性的变化。以图形和数值表的形式给出了基于人工智能的馈电路由神经网络计算的收敛参数。结果表明,随着洛伦兹力和表面渗透率的增大,流动速度减慢,但随着热吸收和动量与热扩散比Pr的增大,流动速度加快。同时,随着热吸收率的升高,温度升高;随着热质扩散比Le的增大,温度降低,化学反应影响更大。
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引用次数: 0
Non-uniqueness of the solution of the Cauchy problem for one higher-order equation with a fractional derivative 具有分数阶导数的高阶方程Cauchy问题解的非唯一性
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-07-04 DOI: 10.1016/j.padiff.2025.101252
B. Yu. Irgashev , H.H. Pulatova
In the article a non-trivial solution of the homogeneous Cauchy problem for a homogeneous high-order equation with a fractional Caputo derivative is constructed.
本文构造了具有分数阶Caputo导数的齐次高阶方程的齐次Cauchy问题的非平凡解。
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引用次数: 0
A study on intuitionistic fuzzy neutral functional integro-differential PDEs with impulses 带有脉冲的直觉模糊中立泛函积分微分偏微分方程的研究
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-08-25 DOI: 10.1016/j.padiff.2025.101296
T. Gunasekar , K. Nithyanandhan , Hanumagowda B. N , Jagadish V. Tawade , Nashwan Adnan Othman , Barno Abdullaeva , Nadia Batool , Khayrilla Kurbonov
This paper investigates the existence and uniqueness of solutions for a nonlocal intuitionistic fuzzy impulsive integro-differential equation, employing intuitionistic fuzzy semigroups and the contraction mapping principle. Through a systematic theoretical framework, it establishes that, under certain conditions, a distinct solution is ensured. Additionally, the study expands its analysis to explore the existence results for intuitionistic fuzzy impulsive neutral integro-differential equations, broadening its research focus. This approach introduces a new perspective on understanding intuitionistic fuzzy integro-differential equations, introducing innovative methodologies and significant discoveries that advance theoretical exploration in this field. The findings underscore that, subject to specific assumptions, a singular fuzzy solution emerges for these problems marked by nonlocal conditions, effectively addressing crucial challenges in the analysis of fuzzy systems.
利用直觉模糊半群和压缩映射原理,研究了一类非局部直觉模糊脉冲积分微分方程解的存在唯一性。通过系统的理论框架,确立了在一定条件下,保证有一个独特的解。此外,本研究将其分析扩展到探索直觉模糊脉冲中立型积分微分方程的存在性结果,拓宽了研究的重点。这种方法引入了理解直觉模糊积分微分方程的新视角,引入了创新的方法和重大发现,推动了该领域的理论探索。研究结果强调,在特定的假设下,对于这些以非局部条件为特征的问题,一个单一的模糊解决方案出现了,有效地解决了模糊系统分析中的关键挑战。
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引用次数: 0
An immersed interface method for nonlinear convection–diffusion equations with interfaces 具有界面的非线性对流扩散方程的浸入界面法
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-07-11 DOI: 10.1016/j.padiff.2025.101250
Miguel Uh Zapata , Reymundo Itza Balam , Silvia Jerez
This paper provides an initial framework for developing high-order numerical methods to solve interface problems for nonlinear elliptic partial differential equations. The proposed formulation is based on the immersed interface method dealing with a discontinuous coefficient problem. The algorithm introduces new schemes for points near the interface, whereas standard central finite difference schemes are used in smooth regions. As a consequence, a global second-order accurate solution is guaranteed. First, theoretical results on the truncation error are given for one-dimensional linear problems. Next, the algorithm is generalized to deal with nonlinear convection and diffusion cases using the using Levenberg–Marquardt algorithm. Numerical simulations for several benchmark problems show the robustness and efficiency of the proposed scheme.
本文为发展求解非线性椭圆型偏微分方程界面问题的高阶数值方法提供了一个初步框架。该公式基于处理不连续系数问题的浸入界面法。该算法对界面附近的点引入了新的格式,而在光滑区域则采用标准的中心有限差分格式。因此,保证了全局二阶精确解。首先,对一维线性问题给出了截断误差的理论结果。然后,利用Levenberg-Marquardt算法将该算法推广到处理非线性对流和扩散情况。若干基准问题的数值仿真结果表明了该方法的鲁棒性和有效性。
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引用次数: 0
An enhanced Artificial Neural Network approach for solving nonlinear fractional-order differential equations 求解非线性分数阶微分方程的增强人工神经网络方法
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-06-18 DOI: 10.1016/j.padiff.2025.101230
Nikhil Sharma , Sunil Joshi , Pranay Goswami
This paper introduces a hybrid Chebyshev Collocation Method (CCM) and Artificial Neural Network (ANN) approach to address the computational challenges of nonlinear Caputo fractional differential equations. The purpose is to improve accuracy for static solutions by approximating the fractional derivative spatially. The methodology leverages CCM for spatial discretization and ANN for residual minimization, achieving low MSEs (e.g., 105) in three examples. The findings confirm improved convergence with increasing node count, with implications for efficient fractional PDE solvers. The novelty lies in the static CCM+ANN integration, offering a practical alternative to dynamic methods.
本文介绍了一种混合Chebyshev配置法(CCM)和人工神经网络(ANN)方法来解决非线性Caputo分数阶微分方程的计算难题。目的是通过在空间上近似分数阶导数来提高静态解的精度。该方法利用CCM进行空间离散化,利用ANN进行残差最小化,在三个示例中实现了低mse(例如10−5)。研究结果证实,随着节点数的增加,收敛性得到改善,这对有效的分数阶PDE求解器具有重要意义。新颖之处在于静态CCM+ANN集成,为动态方法提供了一种实用的替代方案。
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引用次数: 0
Stochastic reynolds equation for magnetohydrodynamics micropolar fluid and surface roughness in squeeze-film lubrication characteristics of rough parallel rectangular plates 粗糙平行矩形板挤压膜润滑特性中微极流体和表面粗糙度的随机reynolds方程
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-08-05 DOI: 10.1016/j.padiff.2025.101269
B.S. Asha , H.M. Shivakumar , B.N. Hanumagowda , Jagadish V. Tawade , Barno Abdullaeva , Manish Gupta , Murali Gundagani , Taoufik Saidani , Nadia Batool
This study presents a comprehensive theoretical investigation into the influence of surface roughness, magnetohydrodynamics (MHD), and micropolar fluid dynamics on the squeeze film behavior between two wide, parallel rectangular plates. A modified Reynolds equation is derived by incorporating Eringen’s microcontinuum theory, Christensen’s stochastic surface roughness model, and classical hydrodynamic principles. The model accounts for the effects of a perpendicular magnetic field and longitudinal surface irregularities. Key performance parameters—namely pressure distribution, load-carrying capacity, and squeeze film duration—are obtained analytically and evaluated using dimensionless groups such as the Hartmann number, coupling number, fluid gap interaction number, and surface roughness parameter. The results demonstrate that incorporating micropolar fluid properties and MHD effects significantly enhances squeeze film performance compared to the Newtonian fluid case. Surface roughness is also found to play a beneficial role in improving load support and film retention. The findings offer valuable insights for designing advanced lubrication systems in engineering applications where microstructural effects and magnetic fields are present.
本研究对表面粗糙度、磁流体动力学(MHD)和微极流体动力学对两个宽平行矩形板之间挤压膜行为的影响进行了全面的理论研究。结合Eringen的微连续统理论、Christensen的随机表面粗糙度模型和经典流体力学原理,导出了一个修正的Reynolds方程。该模型考虑了垂直磁场和纵向表面不规则性的影响。关键性能参数,即压力分布、承载能力和挤压膜持续时间,是通过分析得到的,并使用无量纲群,如哈特曼数、耦合数、流体间隙相互作用数和表面粗糙度参数进行评估。结果表明,与牛顿流体情况相比,结合微极流体特性和MHD效应显著提高了挤压膜的性能。表面粗糙度也被发现在改善负载支撑和膜保持方面起着有益的作用。这一发现为在存在微观结构效应和磁场的工程应用中设计先进的润滑系统提供了有价值的见解。
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引用次数: 0
Local dynamics of second-order differential equation with delayed derivative 二阶时滞微分方程的局部动力学
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-09-02 DOI: 10.1016/j.padiff.2025.101281
Ilia Kashchenko, Igor Maslenikov
We study the nonlinear dynamics of second-order differential equation with delayed feedback depending on the derivative. The problem in question contains a small multiplier at the highest derivative, so it is singularly perturbed. We determine the stability of equilibrium depending on the parameters and find critical (bifurcation) cases. In each critical case, asymptotic approximations for the spectrum points (roots of the characteristic equation) are determined. The main feature of the problem under consideration is that in critical cases the spectrum consists of two parts: an infinite chain of points that tend to the imaginary axis and one or two more points located near the imaginary axis.
Using methods of asymptotic analysis to study bifurcations, in the critical cases we construct special equations – quasinormal forms. Quasinormal form is an analog of normal form. It does not depends on small parameter and its solutions provide the main part of the asymptotic approximation of the solutions of the original problem. Each quasinormal form is a partial differential equation with an antiderivative operator and integral term in nonlinearity. For the constructed forms stable periodic solutions are determined, asymptotic approximations on stable periodic solutions of original problem is obtained and the bifurcations that occur are described.
Also, the situation where two successive bifurcations occur in the system was described.
研究了二阶时滞反馈微分方程的非线性动力学问题。所讨论的问题在最高导数处包含一个小乘数,因此它是奇异摄动的。我们根据参数确定平衡的稳定性,并找到临界(分岔)情况。在每个临界情况下,确定谱点(特征方程的根)的渐近逼近。所考虑的问题的主要特征是,在临界情况下,频谱由两部分组成:一个趋向于虚轴的无限点链和位于虚轴附近的一个或两个以上的点。利用渐近分析的方法研究分岔问题,在临界情况下构造了特殊方程——拟正规形式。拟正规是正规的一种类似形式。它不依赖于小参数,它的解提供了原问题解的渐近逼近的主要部分。每一个拟正规形式都是一个具有不定积分算子和非线性积分项的偏微分方程。对于所构造的形式,确定了稳定周期解,得到了原问题稳定周期解的渐近逼近,并描述了出现的分岔。此外,还描述了系统中连续出现两个分岔的情况。
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引用次数: 0
Asymptotic behavior of dark multi-solitons to the intermediate nonlinear Schrödinger equation 暗多孤子对中间非线性Schrödinger方程的渐近行为
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-08-29 DOI: 10.1016/j.padiff.2025.101273
Takafumi Akahori
The intermediate nonlinear Schrödinger equation (abbreviated to (INS)) is a model equation for envelope waves in a deep stratified fluid and can be thought of as a generalization of the defocusing nonlinear Schrödinger equation. Furthermore, it possesses dark multi-solitons as well as the defocusing nonlinear Schrödinger equation. In this paper, we reveal the asymptotic behavior of dark multi-solitons to (INS). We also give the asymptotic behavior of bright multi-solitons to the intermediate long wave equation. Our analysis relies only on the explicit forms of multi-solitons obtained by Hirota’s bilinear method.
中间非线性Schrödinger方程(缩写为INS)是深层分层流体中包络波的模型方程,可以认为是散焦非线性Schrödinger方程的推广。此外,它还具有暗多孤子和离焦非线性Schrödinger方程。在本文中,我们揭示了暗多孤子对(INS)的渐近行为。给出了亮多孤子对中长波方程的渐近性质。我们的分析只依赖于Hirota双线性方法得到的多孤子的显式形式。
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引用次数: 0
The impact of carbon nanotubes (CNT) on heat generation and absorption, the behaviour of water and blood suspensions in an inclined channel with a porous matrix 碳纳米管(CNT)对热产生和吸收的影响,水和血液悬浮液在多孔基质倾斜通道中的行为
Q1 Mathematics Pub Date : 2025-09-01 Epub Date: 2025-06-26 DOI: 10.1016/j.padiff.2025.101241
Mangala Kandagal , Ramesh Kempepatil , Jagadish V. Tawade , Nodira Nazarova , Manish Gupta , M. Khan
The study investigates the heat generation and absorption of engine oil, human blood and single wall carbon Nano tube (SWCNT) in an inclined channel filled with a porous matrix. Two regions are considered, both regions are of porous medium. Due to their enhanced thermal conductivity, are utilized to improve heat transfer efficiency in various applications. Formulation of the problem is framed using conservation of mass, energy and momentum in both regions. The flow of oil, human blood through a porous medium is analysed, considering the effects of both heat generation and absorption within the system. Key parameters such as the inclination angle of the channel, the porosity and the type of fluids are examined to understand their impact on the overall heat transfer process and velocity. To solve the problem regular perturbation method is applied for non-dimensional quantities; The presence of CNTs significantly improves the thermal conductivity of both engine oil and blood suspensions, leading to improved heat dissipation or absorption capabilities, which are influenced by the inclination and the porous structure. This study offers valuable insights into fluid flow processes in the human body using Nanotubes. Influence of CNTs on the fluid flow of human body and heat generation/absorption with porous matrix in both regions is unsolved problem.
研究了发动机机油、人体血液和单壁碳纳米管(SWCNT)在多孔基质填充的倾斜通道中的产热和吸热特性。考虑两个区域,两个区域均为多孔介质。由于其增强的导热性,在各种应用中被用来提高传热效率。问题的表述是利用两个区域的质量、能量和动量守恒来构建的。考虑到系统内热的产生和吸收的影响,分析了油、人的血液在多孔介质中的流动。研究了通道倾角、孔隙度和流体类型等关键参数,以了解它们对整体传热过程和速度的影响。为解决这一问题,对无量纲量采用正则摄动法;CNTs的存在显著提高了机油悬浮液和血液悬浮液的导热性,从而提高了其散热或吸收能力,而这些能力受倾斜和多孔结构的影响。这项研究为利用纳米管研究人体流体流动过程提供了有价值的见解。CNTs对人体流体流动以及多孔基质在这两个区域产生/吸收热量的影响是尚未解决的问题。
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引用次数: 0
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Partial Differential Equations in Applied Mathematics
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