Polymer gears are increasingly implemented in lightweight, noise-critical transmission systems; however, their performance remains highly sensitive to geometric imperfections, particularly under dry-running conditions. This study delivers a systematic experimental evaluation of the influence of angular misalignment-specifically yaw and pitch-on the wear progression and thermal response of PA66 spur gears using a controlled back-to-back test rig. Continuous wear measurements were obtained through a calibrated Linear Variable Differential Transformer (LVDT) system, while thermographic and contact-temperature data provided a high-fidelity characterization of thermal evolution throughout operation. Even minor angular deviations produced notable degradation: yaw misalignments of 0.4-1.2 deg increased the steady-state wear-rate by 38-250%, whereas pitch misalignments of 0.2-0.6 deg caused more abrupt increases of 176-1500%. Misalignment also elevated peak surface temperatures by 25-45 degrees C relative to aligned conditions, with pitch misalignment consistently inducing the highest thermal load due to concentrated edge contact and reduced conjugacy. Coupled analysis of temperature and wear progression revealed clear thermomechanical acceleration effects once surface temperatures approached the nylon glass-transition range. These findings provide an experimentally grounded quantification of misalignment severity and offer practical alignment limits for the reliable use of dry-running polymer gears.

This study presents comprehensive findings on the tribological and thermal behavior of polymer gears under varying loads and operating conditions. Gear tooth wear-rates and thermal contact behavior were investigated for nylon (PA) and acetal (POM) materials, fabricated using machining (MC). Experimental investigations were performed under loads of 6.5 N m, 8.5 N m, and 9.0 N m, while maintaining a consistent rotational velocity of 1500 rpm. The wear-rates and surface temperatures were systematically monitored utilizing a linear variable differential transformer (LVDT) with a precision of 0.1 mu m and a high-resolution thermal imaging apparatus. Results revealed that at 9.0 N m, thermal stabilization reduced wear-rates by 15% compared to 8.5 N m, due to the softened material layer acting as an internal lubricant. Conversely, higher wear-rates at 8.5 N m were attributed to localized debris formation and limited thermal softening. Key findings include the identification of the glass transition temperature of PA at approximately 75 degrees C and its effect on wear behavior. These insights provide a deeper understanding of polymer gear performance, offering guidance for material selection and operational optimization in high-performance applications.

Hybrid nanofluids have unique characteristics that make them more useful than common heat transfer fluids. The potential applications can be found in applied thermal engineering, chemical engineering, hybrid powered engines, biomedical and mechanical engineering. Therefore, the analysis of SWCNTs–MWCNTs/C2H6O2–H2O with integrated effects of thermal radiations and perpendicular magnetic field is organized in this research. Thermal conductivity of C2H6O2–H2O is improved via Xue, Ota and Yamada thermal conductivity correlations. The mathematical problem is designed for two sheets and both the hybrid nanoliquid and the plates rotate in counter clockwise pattern. Mathematical treatment of the model is performed and the results were analyzed through graphical way. Keen observations of the results reveal that the fluid motion controlled by intensifying the magnetic field and higher density of SWCNTs–MWCNTs leads to optimum decrement. Further, the fluid movement is investigated optimum and slow for outward and inward plate movement, respectively. The temperature results for the parameters, especially the thermal radiations, showed that hybrid nanoliquid has the ability to store high thermal energy than common mono-nanoliquid, hence it would be suitable for future industrial applications. The parametric ranges are selected as [Formula: see text]–1.7, [Formula: see text]–0.9, [Formula: see text]–9.0 and [Formula: see text]–20.0 for the study.

This research deals with heat and mass transport in 2D, steady laminar unidirectional flow of second-grade fluid inside converging/diverging stretchable channel with no slip effects. The similarity equations were engaged for the model development and acquired a model in the form of a joint system of ODEs comprising the innovative effects of thermal radiations, magnetic field and dissipation function. Then, mathematical treatment of the model was done via HAM Package and the results were furnished under the inspiration of physical constraints. It is pointed out that the fluid moves quite slowly in diverging cases than that of converging ones under multiple Re values, whereas magnetic field effects are almost negligible for the velocity profile. The temperature of the fluid can be enlarged by increasing Ec and Pr and Rd is not proven good in this study. Further, as far as the mass transport is concerned, the dominant contribution of Sc is observed for both stretching/shrinking walls.

The role of variable viscosity and variable thermal conductivity in nanofluid flows is significant, as they can strongly influence the flow behavior and heat transfer performance of nanofluids. Keeping in mind the importance of these effects of variable characteristics, our motivation in this study is to investigate the role of nonlinear radiative heat flux on unsteady Casson nanofluid flow across two concentric stretched cylinders in the presence of temperature-dependent viscosity and thermal conductivity. A convective condition on the inner cylinder wall is also considered. In addition, the nanofluid is immersed with microorganisms that can swim and move independently. The addition of microorganisms has a significant role in the stability of the nanofluid flow. The influence of thermophoresis and Brownian motion on the flow, heat, mass, and microorganisms are scrutinized by employing the Buongiorno model. The governing flow equations are converted into a system of differential equations engaging similarity transformations, and the bvp4c method is employed to solve it numerically. Engineering parameters are computed and tabulated numerically. The findings demonstrate that as the unsteadiness parameter upsurges, the radial profile intensifies while the axial profile diminishes near the outer cylinder surface. It is also comprehended that both Lewis and bioconvective Lewis numbers reduce the motile density profiles. The accuracy of the presented model is also given in a graphical illustration by comparing it with a published result in a limiting case.

A hybrid nanofluid is an amalgamation of two or more types of nanoparticles in a customary and possesses a variety of industrial applications. This exploration examines the blend of copper (Cu) and gold (Au), and engine oil as a hybrid nanofluid. The model considers the Hall current, Cattaneo-Christov (C-C) heat flux, thermal stratification, nonuniform heat source, and nonlinear thermal radiative effects for heat analysis. Ordinary differential equations (ODEs) are obtained through a similarity transformation scheme, and the model is visualized using a MATLAB function bvp4c. Graphs are presented to demonstrate the impact of various parameters on velocities and temperatures, and the wall drag coefficient and wall heat transfer rate are calculated and tabulated for both disks. The results show that a stronger Hall effect leads to a decrease in tangential velocity, while nonuniform heat sources increase fluid temperature. Thermal radiation and stratification have opposite effects on liquid temperature. It is interesting to note that for the radiation parameter at Rd=0.5, a higher heat transfer rate occurred at the lower disk, i.e., (Nu(1)=-3.63314) as compared to the upper disk (Nu(2)=-3.63324). Moreover, for the stratification parameter at S=0.2, it is observed that the heat transfer rate is lesser at the upper disk (Nu(2)=-3.64374) than at the lower disk (Nu(1)=-3.64274). Verification of the truthfulness of the proposed model is also included in the article.

An induced magnetic field is produced owing to an electric current flowing through the conductor. The induced magnetic field and the length of the conductor are in direct proportion. The current study examines the comparison of Yamada-Ota and Xue thermal conductivity models for a mixed convective hybrid nanoliquid flow through the permeable vertical channel influenced by an induced magnetic field. The projected model is supported by the combination of thermal radiation and heat generation and multiple slip conditions imposed on the walls. The Tiwari and Das model is adopted considering engine oil as a working liquid with immersed multiwalled and single-walled carbon nanotubes (CNTs) nanoparticles. The unique combination of strength, conductivity, and other properties make CNTs a promising material for an extensive variety of applications. These governing partial differential equations undergo conversion to ordinary differential equations via the similarity transformation and are then numerically processed with the bvp4c technique of the MATLAB program. The outcomes are deliberated logically via illustrations and tables. It is perceived that fluid velocity is compromised by strengthening the induced magnetic field. Nevertheless, an opposing trend is witnessed for the enhanced values of the Prandtl number.

Hybrid nanofluids generally exhibit better thermal efficiency than traditional nanofluids due to the synergistic effects of different types of nanoparticles. The combination of these nanoparticles can improve stability, thermal conductivity, and heat transfer performance. This study aims to investigate the effects of Hall current and ion slip on a three-dimensional, steady flow of hybrid nanofluid induced by a bidirectional extending surface while considering the presence of Zinc oxide (ZnO) and Gold (Au) nanoparticles dispersed in Kerosene oil and water to establish two different hybrid nanofluids. Additionally, a heat transfer analysis is conducted in the presence of Cattaneo-Christov (C-C) heat flux and variable heat source/sink. The characteristics of fluid flow are elaborated using the Tiwari and Das model, and a comparison between the two hybrid nanofluid models is presented in detail. The novelty of the envisioned model lies in the heat transfer comparison of two assumed hybrid nanofluid flows in the presence of Hall current and the ion slip over a bidirectional extended surface. The other assumed factors also boost the uniqueness of the model under consideration. To convert the flow model of partial differential equations into ordinary differential equations, relevant transformations are implemented, which are then numerically handled using the bvp4c scheme. The consequences of dimensionless quantities on flow and temperature distributions are highlighted using graphs, and the surface drag coefficients and surface heat transfer rates are also assessed and summarized. The study shows that ZnO-Au/water combination leads to higher heat transfer rates compared to ZnO-Au/Kerosene Oil. Additionally, the proposed model is validated in this research work.

This paper examines the impacts of heat radiation and Soret effects on nanofluid flow in a micropolar magnetohydrodynamic (MHD) framework over an inclined sheet that is stretching. This issue is critical for applications in biomedical engineering, sophisticated cooling systems, and chemical reactions where accurate fluid flow and heat transfer control are required. Brownian diffusion and thermophoretic motion effects are included in the model. Similarity transformations are utilized to transform the system of partial differential equations (PDEs) into a set of ordinary differential equations (ODEs) in order to tackle this intricate challenge. These ODEs are solved using the Levenberg–Marquardt backpropagation (LMB) optimization technique. Utilizing a dataset produced by MATLAB’s “bvp4c” solver, the results are verified. To assess the LMB algorithm’s correctness, a number of statistical tools are used, such as curve fitting, performance plots, regression measures, and histograms. The best measures of performance in the form of mean square errors (MSEs) are obtained as 2.7164E - 09 , 1.0276E - 08 , 1.217E - 08 , 1.3125E - 08 , 2.9218E - 08 , 1.0184E - 09 , 2.874E - 10, and 3.6039E - 10 against 373 , 1000 , 1000 , 1000 , 134 , 660 , 133, ,and 648 iterations. The comparative analysis verifies the validity of the suggested solver, showing absolute errors ranging from E - 10 to E - 03 for all significant parameter findings. According to quantitative studies, there is a noticeable damping effect when the magnetic component is increased since it lowers the fluid velocity. On the other hand, fluid velocity is improved when the material parameter is increased. Furthermore, as the Lewis number increases, the concentration profile diminishes, emphasizing its impact on mass transfer rates. Thermal diffusion, the hallmark of the Soret effect, significantly alters concentration gradients, which are essential for industrial process optimization. These results show the originality of our methodology by offering a thorough examination of the interactions among magnetic fields, material characteristics, and diffusion effects in nanofluid flow. By mathematically describing the ways in which these parameters affect flow and heat transfer, this study goes above and beyond earlier research, providing important new information for the design and optimization of systems that depend on micropolar MHD flows.

This paper elaborates on the significance of liquid chromatography for a single-component reactive linear general rate model. The model equations consist of a set of two coupled partial differential equations, which include diffusion, interfacial mass transfer, axial dispersion, external and intraparticle pore diffusivity, and heterogeneous chemical reaction of the first order with two sets of boundary conditions. The model equations are solved by the Laplace transformation. The actual time domain solution is obtained by numerical Laplace inversion, as analytical inversion cannot be obtained. The graphical sketch of different physical parameters is presented to analyze the dynamics of the elution profiles. The result indicates that the chromatographic reactor works more efficiently on increasing the value of the heterogeneous-type first-order reaction. To check the analytical results, a second-order high-resolution finite volume scheme is used. Both results are in good agreement and indicate the correctness of the numerical scheme. The current work is also compared with the previously available numerical schemes, which shows that the proposed numerical scheme is better for elaborating the chromatographic reactor performance. A comparison table is also presented to compute error analysis and computational run time for analyzing the efficiency of the reactor. A graphical sketch of the numerical temporal moment analysis is also presented, which gives significant information about the performance and the shape of the concentration profiles.

APPLICATIONS:The dynamics of superior heat transport fluids are of much interest and dominant over traditional fluids. Applications of such fluids can be found in advanced medical sciences, to maintain the building temperature, environmental sciences, chemical engineering, food engineering, and other applied research areas where enhanced heat transfer is required. AIM AND RESEARCH METHODOLOGY:The major aim of this research is to report the thermal performance of the Glycerin-titania nanofluid using a thermal conductivity model comprising the effects of nanoparticles aggregation, and CCTF over a permeable slanted surface. The enhanced heat transport model was then analyzed numerically via RK scheme and furnished the outcomes with graphical aid under the variations of physical parameters. CORE FINDINGS:It is examined that the addition of CCTF (A1) in the model potentially contributes to thermal performance of aggregated nanofluid. The temperature β(η) enhances for injecting fluid from the surface and reduces due to strong suction. Further, the fluid particles attained maximum velocity for γ1=0.1,0.2,0.3,0.4 at the surface and it shows asymptotic behavior far from the working domain.

Based on the finite volume method (FVM), a numerical scheme is constructed to simulate the unsteady convection–diffusion transport problem. New expressions are obtained for interface approximation of the field variable, subsequently, these newly obtained interface expressions are used to develop the numerical scheme. Convection-dominant and diffusion-dominant phenomena are simulated by taking different values of convective velocity [Formula: see text] and diffusion coefficient [Formula: see text]. This newly proposed numerical scheme gives second order of convergence along space and time. Experiments are carried out to test the new proposed upwind approach. Numerical results produced by the proposed approach are compared with the conventional finite volume method, step-wise approach FVM and quadratic upwind interpolation finite volume approach. This comparative study indicates that for different cases for convection-dominant and diffusion-dominant problems, our proposed approach gives highly accurate and stable solution. The conventional finite volume method and other approaches result solution with non-physical oscillations. Our obtained numerical results are consistent and support our theoretical approach.

Purpose: and Methodology: The heat transport investigation in non-Newtonian fluids suspended by distinct sort of nanoparticles is a rich motive in the present time. Therefore, inspired by the physical characteristics of base fluid and ternary nanoparticles (Al2O3-CuO-Cu), a comprehensive analysis conducted over a cylinder with wavy radius with special emphasis in Saddle and Nodal points. The key effects of dissipation, the first order thermal slip, surface convection and stretching/shrinking added in the model. The acquired model is then examined via RK-scheme and portrayed the results against the physical ranges of the parameters.Key findings: A comprehensive discussion of the results provided that the nanofluid velocity increased for higher Casson number (& alpha; = 0.5, 1.0, 1.5, 2.0) and is examined optimum for stretched cylinder surface. The higher viscous dissipation which results the effects of Eckert number (Ec = 0.01, 0.02, 0.03, 0.04), surface convection due to Biot number (B1 = 0.1, 0.2, 0.3, 0.4) and the first order thermal slip (& alpha;1 = 0.1, 0.3, 0.5, 0.7) are the key physical factors to acquire the favorable heat transfer amount for the practical interest. Further, the particles concentration in the range of 1%-6% is observed good to increase the heat transmission in ternary nanoliquid and the values of effective characteristics (dynamics viscosity and thermal conductivity) upsurges against the concentration factor up to 6%.

Background: Rheological fluids enduring bio convection are gaining great attention in modern day industrial, technological and several manufacturing industries. Such flows are evident in chemical and mining industry, biomedical flows, and many other fields of science and engineering. Among the many other rheolgical liquids, Sutterby fluid model is significant due to its characteristics of Pseudoplastic and dilatant fluids. It portrays dilute polymer solutions, which has numerous applications in industrial practice.Methods: In this theoretical research two-dimensional hydromagnetic stagnation point flow of Sutterby bio convective fluid through an elastic surface has been discussed. The mathematical model of governed problem is transformed into a set of ordinary differential equations using similarity transformation. These nonlinear coupled ordinary differential equations are handled by using shooting scheme (numerical technique).Significant findings: Influence of all physical constraints for temperature, concentration of gyrotactic microor-ganism and velocity profiles are presented graphically. Local heat & mass flux and density of microorganisms (Physical quantities of interest) are presented numerically through bar charts.

The hydrothermal characteristics of (Ag+TiO2+H2O) hybrid nanofluid three dimensional flow between two vertical plates, in which the right permeable plate stretches as well as rotates, are investigated by employing varying magnetic, heat and radiation fluxes. The motion is governed by coupled PDEs (nonlinear) obeying suitable boundary conditions. The PDEs coupled system is transformed to a coupled set of nonlinear ODEs employing appropriate similarity transformation relations. The resultant equations are numerically solved through the bv4c solver. The impact of the changing strength of associated parameters on the flow is investigated graphically and through tables. It has been found that the velocity gradient and velocity initially increase and then decrease with increasing Grashof number values in both the suction and injection cases. The enhancing magnetic field first augments and then lowers the velocity gradient in the presence of radiation source of maximum strength. The increasing strength of injection parameter drops the velocity. The temperature distribution in the fluid increases with the increasing Eckert number, radiation flux and heat strength and nanomaterial concentration, and depreciates with the enhancing injection parameter values and Prandtl number. The Cfx increases with a higher magnetic field magnitude and nanomaterial concentration, and declines with an increasing Grashof number. The results obtained are compared with the available literature in the form of tables.

Applications: Newly developed fluids termed as “Nanofluids” and their study in dilating/squeezing channel cannot be disregarded. Such flows under various physical constraints are important for purification purposes and other industrial applications. Purpose: and Methodology: This work comprises the modeling and heat transmission ability of TiO2/G inside a dilating/squeezing channel. The conventional model upgraded including the aggregation effects of nanoparticles and directed nonlinear thermal radiations. The resultant model examined through numerical scheme for actual understanding the heat transport phenomena inside the channel. Major findings: The results reveal that high viscosity parameter (R1=0.5,1.0,1.5,2.0), porous absorber walls and strong surface-surface interaction due to aggregation of nanoparticles significantly control the fluid movement. The pores at the surface (A1=0.1,0.3,0.5,0.7) attract the fluid particles and strong frictional forces between them resists the motion and is rapid for aggregated nanofluid. Further, thermal radiations (Rd=1.0,1.5,2.0,2.5) produce considerable heat which can be used to breakdown the aggregation between the nanoparticles.

Numerical and physical simulations of the magnetohydrodynamic mixed convective flow of electrically conducting fluid along avertical magnetized and symmetrically heated plate with slip velocity and thermal slip effects have been performed. The novelty of the present work is to evaluate heat transfer and magnetic flux along the symmetrically magnetized plate with thermal and velocity slip effects. For a smooth algorithm and integration, the linked partial differential equations of the existing fluid flow system are converted into coupled nonlinear ordinary differential equations with specified streaming features and similarity components. By employing the Keller Box strategy, the modified ordinary differential equations (ODEs) are again translated in a suitable format for numerical results. The MATLAB software is used to compute the numerical results, which are then displayed in graphical and tabular form. The influence of several governing parameters on velocity, temperature distribution and magnetic fields in addition to the friction quantity, magnetic flux and heat transfer quantity has been explored. Computational evaluation is performed along the symmetrically heated plate to evaluate the velocity, magnetic field, and temperature together with their gradients. The selection of the magnetic force element, the buoyancy factor 0<ξ<∞ , and the Prandtl parameter range 0.1≤Pr≤7.0 were used to set the impacts of magnetic energy and diffusion, respectively. In the domains of magnetic resonance imaging (MRI), artificial heart wolves, interior heart cavities, and nanoburning systems, the present thermodynamic and magnetohydrodynamic issuesare significant.

In this research, a new heat transfer model for ternary nanofluid (Al2O3-CuO-Fe3O4)/C2H6O2 inside slippery converging/diverging channel is reported with innovative effects of dissipation function. This flow situation described by a coupled set of PDEs which reduced to ODEs via similarity and effective ternary nanofluid properties. Then, LSM is successfully coded for the model and achieved the desired results influenced by \begin{document}$ \alpha ,Re,{\gamma }_{1} $\end{document} and \begin{document}$ Ec $\end{document}. It is examined that the fluid movement increases for \begin{document}$ Re $\end{document} in the physical range of 30–180 and it drops for diverging channel (\begin{document}$ \alpha > 0 $\end{document}) when the slippery wall approaches to \begin{document}$ \alpha = {60}^{o} $\end{document}. The fluid movement is very slow for increasing concentration factor \begin{document}$ {\varphi }_{i} $\end{document} for \begin{document}$ i = \mathrm{1,2},3 $\end{document} up to 10%. Further, ternary nanofluid temperature boosts rapidly due to inclusion of trinanoparticles thermal conductivity and dissipation factor (\begin{document}$ Ec = \mathrm{0.1,0.2,0.3,0.4,0.6} $\end{document}) also contributes significantly. Moreover, the temperature is maximum about the center of the channel (\begin{document}$ \eta = 0 $\end{document}) and slip effects (\begin{document}$ {\gamma }_{1} = \mathrm{0.1,0.2,0.3,0.4,0.5,0.6} $\end{document}) on the channel walls lead to decrement in the temperature \begin{document}$ \beta \left(\eta \right) $\end{document}.