Values Of Friction Coefficient Research Articles

Effect of Surface Roughness of Pistia Leaves Inspired Surfaces on Oil Contact Angle and Coefficient of Friction under Lubricated Condition

Biomimetics field is getting more interest in engineering purposes. The plant surface roughness existing in nature such as in leaves can be mimicked into artificial technologies. Basically, the surface structures have micro and nano scales in nature and possess properties of interest. Pistia leaves for example have intrinsic of tribology application which have rarely explored. In this study, a preliminary work on 3 types of Pistia leaves inspired surface-based polymer have been conducted to look at effect of surface roughness towards contact angle (CA) measurements and coefficient of friction (COF) under lubricated condition. The surface characteristics were also examined using Variable Pressure Scanning Electron Microscope (VP-SEM). Two different oils namely palm oil and palm oil + TiO2 were tested on the Pistia leaves inspired surface to measure the CA and COF. It was found that both types of palm oils had distinct CA values and COF towards surface roughness of the Pistia inspired surfaces. A maximum difference of CA and COF were recorded in CA and COF values. The different nanocomposite of Pistia leaves inspired surface were found to affect for both parameters CA and COF under lubricated condition.

Investigation of drag reduction by slurry-like drag-reducing agent in microtube flow using response surface methodology (RSM)

In this study, we investigated the drag reduction property of a premixed slurry drag reducer in a millimeter-scale pipe. The aim of this study is to establish the correlation between Darcy friction factor and drag reducer concentration (C) and volume flow (Q). First, the experimental plan was designed by using the response surface method (RSM), and then the experimental data were processed to establish the quadratic correlation between the response variable and the description variable. After that, ANOVA analysis of variance was used to verify the accuracy of the experimental data and the correlation. Finally, the prediction model is extended to a larger concentration and volume flow range, and it is found that the accuracy between the predicted value of friction coefficient and the experimental value is ± 30%, thus verifying that the correlation is suitable for the small-scale fully turbulent region. Compared with traditional experimental design and correlation methods, the implementation of Response Surface Methodology (RSM) in this study not only reduces the experimental time but also yields a more robust correlation for predicting the friction coefficient.

Investigation of dissipation phenomenon of non-Newtonian nanofluid due to a horizontal stretching rough sheet through a Darcy porous medium

Recent advancements in thermal engineering have led to the development of stable thermal properties and practical applications for nanofluid flow. Consequently, this study aims to explore the heat and mass transfer characteristics of a non-Newtonian Maxwell nanofluid when it comes into contact with a stretched surface containing porous features that allow for fluid suction velocity. Additionally, the research takes into account how the Soret and Dufour effects impact the processes of heat and mass transfer. A less-explored aspect of research in this field relates to the velocity slip boundary conditions when nanofluids with changing viscosity are involved. Additionally, the model employed in this study illustrates the influence of both viscous dissipation and variable thermal conductivity on the processes of heat and mass transfer. The mathematical flow model is described by nonlinear partial differential equations, which are subsequently transformed into non-dimensional ordinary differential equations. The resulting system is then solved numerically using the shooting method. This study visually examines the impact of physical variables on temperature, flow characteristics, and concentration patterns. Furthermore, it provides graphical representations of estimated values for the skin friction coefficient, Sherwood numbers, and local Nusselt numbers, which are also organized in tables for analysis. In conclusion, by comparing our data with previous results, we confirm the accuracy and reliability of the proposed method. A significant discovery is that the nanofluid velocity decreases as the Maxwell, porous, and slip velocity parameters are increased. Furthermore, the nanofluid concentration rises when the thermophoresis and viscosity parameters increase.

Tribological glazing evolution of fixed abrasive pad under different polishing solution conditions

PurposeThis study aims to clarify the influence mechanism of polishing solution type on the glazing evolution of fixed abrasive pad under different interfacial pressure conditions.Design/methodology/approachThe tribological experiments were carried out on the friction and wear machinery with W3-5 diamond fixed abrasive pad and quartz glass workpiece under three polishing solution types of five pressure conditions. The changes of surface morphology, porosity and hardness of fixed abrasive pad were detected by white light interferometer, optical microscope and shore hardness tester.FindingsThe results showed that the glazed phenomenon of fixed abrasive pad is occurred after a certain time, which is more obvious with the increasing of interfacial pressures. The polishing solution type has a significant effect on the glazing time, although the glazed phenomenon is inevitable. The mechanism of it is that the micro-convex peaks on the surface of the fixed abrasive pad are easily wear, and the pores are blocked by the accumulation of waste debris generated during the experiment process. Thus, a smooth and high-density hard layer is formed on the surface of the fixed abrasive pad which induces the decreasing of the friction coefficient and surface roughness value. For selected polishing solution types, the wear rate of micro-convex peaks is different due to the corrosion action difference with polishing pad surface.Originality/valueThe main contribution of this work is to provide a new investigating method for further understanding the glazing evolution mechanism of fixed abrasive pad.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0257/

Insights on the 2023 Kahramanmaraş Earthquake, Turkey, from InSAR: fault locations, rupture styles and induced deformation

SUMMARY We successfully detected widely distributed ground displacements for the 2023 Kahramanmaraş, Turkey, earthquakes by conducting interferometric synthetic aperture radar (InSAR) analyses using a ScanSAR observation mode. Major deformation extended approximately 350 and 150 km along the southern and northern strands bifurcating in the west of the East Anatolian Fault, produced by the main shock and the largest aftershock. The deformation map reveals that the ruptures propagated on the Erkenek, Pazarcık and Amanos segments on the southern strand and the Çardak segment on the northern strand. The fault plane of the northern strand bends approximately 45° at both edges with Z-shaped crank geometry. The bending fault at the western edge runs just along the Çardak segment but does not reach the Savrun segment, while at the eastern edge it deviates from known active faults such as Sürgü, Malatya faults and Doğansehır fault zone. A 3-D displacement map demonstrates that almost pure left-lateral fault motions were distributed along the two strands, with little vertical deformation. The moment magnitudes estimated from the slip distribution model were 7.82 and 7.66 for the southern and northern strands, respectively, with the Erkenek and Çardak segments having the largest released seismic moments on each strand, corresponding to approximately 31 and 57 per cent of the total, respectively. The Coulomb Failure Function change values indicate that the main shock can promote the largest aftershock with a standard value of the effective friction coefficient. Additionally, the unclamping effect controlled by the frictional property of the rock was a key factor in pulling the trigger of the seismic event on the northern strand. The historically accumulated and released seismic energies were imbalanced for the Pazarcık and Erkenek segments, suggesting that the 2023 event does not support a simple characteristic earthquake model; rather, it may be consistent with a supercycle model, in which the slip remnants from the characteristic earthquakes have been historically accumulated as coupling on a fault and released as huge earthquakes at longer intervals.

Microstructure-induced anisotropic tribological properties of Sc-Zr modified Al–Mg alloy (Scalmalloy®) produced via laser powder bed fusion process

AbstractIn this study, the correlation between the microstructure and tribological performance of Sc and Zr-modified Al–Mg alloy (Scalmalloy®) samples produced via laser powder bed fusion process was evaluated via a dry sliding Pin-on-Disc wear test under different planes, directions, and various normal applied loads. The results revealed a remarkable dependency of wear properties on the as-built microstructure so that different behaviors were observed along the scanning and building planes. The microstructural examination indicated the presence of bi-modal grains and finely shaped equiaxed grains observed in the building and scanning planes, respectively. Increasing the applied loads from 20 to 40 N led to a significant increase in the coefficient of friction (COF) while increasing the load from 40 to 60 N, slightly decreasing the COF for the studied samples. No dependency was found between the COF and the corresponding microstructure at the highest applied load. The anisotropic wear resistance and COF values were predominant at the lowest applied load. Due to tailored as-built microstructural features and different microhardness values, lower wear rates were noticed along the scanning plane for all applied loads. Under the 20 N applied load, however, the worn surface of the scanning plane showed a clearer and smoother surface compared to the building plane surfaces. Ultra-fine equiaxed grains along the scanning plane and columnar grains along the building plane were determined as the main factors creating anisotropic tribological behavior. The outcomes of this study can pave the way toward producing more wear-resistant surfaces and developing components for critical wear applications in as-built conditions with no need for expensive and time-consuming surface treatments.

Flexural performance of T-shape light-weight concrete filled steel tubular girder

This paper proposes an optimization study for both structure and materials to obtain an affordable, long-span, light-weight, and fast-constructing T-shape lightweight concrete-filled steel tubular (LWCFST) girder in order to be used in bridge construction. This research was performed on a hollow steel tube of Steel-52 (yield limit 360 MPa), which was filled with LWC. A set of parameters had been investigated to illustrate its effect on T-shape LWCFST girder stiffness, toughness, resilience, and ultimate carrying load capacity in order to obtain an equivalent stiffness to that of the typically used precast concrete girder. Based on design codes (EN 1994-1-1/Euro code 4 and ANSI/AISC 360-10) that permit the use of LWC as a filler material, the parameters considered were: the thickness of the steel tube, compressive strength of the filler concrete, and the bond condition between the steel tube and filler lightweight concrete. The yielding and ultimate bending capacity were determined based on the interpreted failure criteria of T-shape LWCFST girder, considering non-linear analysis for both material and loads using ANSYSWORKBENCH software. The results showed that T-shape LWCFST girder can be employed as a significant relative economic alternative to a typical precast girder in the bridge construction field, thanks to its high stiffness/weight ratio. The lightweight concrete inside was effectively employed to delay the local web buckling of the steel tube to increase its bending capacity. In addition, it reduced the total self-weight of the bridge’s superstructure by 20% compared with a typical precast concrete girder. The dominant failure of T-shape LWCFST girders was found in the upper concrete slab due to the compression stress, even though the tensile cracks in the filler concrete occurred after reaching tensile yield stress in the steel tube. Additionally, increasing the value of friction coefficient between steel tube and lightweight concrete up to 0.8 was found to significantly affect the girder stiffness and has a slight effect after, no matter how high it is.

Active and Passive Control of Nanoparticles Under the Influence of Magnetized Nanofluid Flow Over a Convectively Heated Slippery Wedge

This research investigate the upshots of actively and passively controlled nanofluid flow over a wedge. Comparison is done for various wedge angle parameter. Magnetic field is employed in normal to the flow direction. Velocity slip effect and external heat source is incorporate to the system. Leading partial differential equations are converted nonlinear ordinary differential equations with the help of suitable similarity transformation. Runge Kutta-4 method with shooting technique is used to solve the system. MAPLE-2019 software is applied to simulate the whole system. The results are described by graphs and corresponding values of engineering interest are tabulated properly. For magnetic parameter reduced skin friction coefficient value is increased by 7.31% but for injection situation and 9.32% or suction effect. Biot number also gives us escalated velocity profile. We get 10.56% increment in skin friction for suction effect and 7.25% for injection effect. Heat lines and mass lines also show excellent result for different parameter under the comparison of active and passive controlled of nanofluid flow.

Thermophoretic particle deposition on double-diffusive Ree-Eyring fluid flow across two deformable rotating disks with Hall current and Ion slip

This work emphasizes the characteristics of thermophoretic particle deposition on Ree-Eyring fluid flow with Hall current and Ion slip effects between two deformable spinning disks. The novelty of the envisioned model is strengthened by considering generalized Fourier and Fick laws with thermal source/sink. The proposed model is optimized by taking multiple slip boundary constraints at the surface. The equations that govern the flow are simplified with the use of the proper transformations. The numerical solution is obtained using the boundary value problem of fourth order (bvp4c) method. Graphical representations of the emerging parameters are presented. Numerical values of skin friction coefficient, local Nusselt, and Stanton number are highlighted in tabular form. The velocity field depicts a deteriorating behavior on incrementing the Reynold number. For augmented values of Hall and ion slip parameters fluid velocity elevates. An upsurge is noticed in the axial and radial velocities on amplifying the rotation parameter. On augmenting the thermophoretic parameter the particle deposition at the interface of the upper disk diminishes. Growing values of rotation parameter, Weissenberg, and Reynold numbers imply an additional resistance to the fluid flow that ultimately reinforced the surface drag force causing a decline in the fluid velocity. The rate of heat transmission accelerates on enhancing the Reynold number, however, heat flux exhibits a decay on augmenting the thermal slip parameter. On augmenting the thermophoretic parameter particle deposition deteriorates at the interface of the upper disk. An excellent concordance is noticed when the outcomes are contrasted with the previous literature. For the value of the rotation parameter β=-1 and β=-8 the percentage error of the present analysis with Imtiaz et al. [68] are 0.00001 and 0.00002.

Effect of Varying the Volume Fractions of Ledeburitic Cementite and Graphite on the Tribological Properties of Commercially Used Cast Irons

The types and volume fractions of the carbonaceous phases present in the microstructures of cast irons strongly influence their properties. In the case of materials used commercially for tools, an important parameter with regard to their use is the resistance to abrasion wear. Cementite is the main reinforcing phase in cast irons and is present in significant quantities. In addition, cast irons contain graphite precipitates, which also affect wear by interacting with the matrix of the alloys. In this study, abrasive wear tests were carried out on a group of cast irons with different chemical compositions and, consequently, different microstructural morphologies. Due to the wide scatter of the results and the commercial rather than laboratory nature of the alloys studied, it was decided to use analysis of variance (ANOVA) to determine whether there was a statistically significant difference between the volume fractions of the carbonaceous phases. The volume fractions of graphite and ledeburite were then related to the results of the tribological tests. Statistical analysis confirmed significant differences in the results obtained for the alloys tested. A continuous increase in the volume fractions of both graphite and ledeburitic cementite is unfavourable in terms of the wear resistance and friction coefficient values. Optimum results can be obtained by balancing the volume fractions of the two phases observed. In addition, the phase composition of the material matrix plays an important role in wear, as the differences in the matrix of the tested alloys modify the nature of the influence of cementite and graphite on the wear.

Samarium-modified NBT ceramics: a comprehensive exploration of cumulative effects

In the present report, ceramic specimens of sodium bismuth titanate [Na0.5(Bi1-xSmx)0.5TiO3] were prepared through solid-state reaction method with variations in the dopant concentrations specifically, x = 0.0, 0.1, 0.3, 0.5. The structural, optical, mechanical, and magnetic properties of lead-free NBT ceramics were investigated. The rhombohedral phase with space group R3c was confirmed in all prepared ceramic samples using X-ray diffraction patterns and Rietveld analysis. SEM micrographs and Energy Dispersive x-ray spectroscopy (EDAX) assess the morphology, grain size, overall structure, and stoichiometry of the developed compounds. FTIR spectroscopy was used for characterizing and identifying the functional groups. UV–vis spectroscopy revealed that band gap values decreased as dopant concentration increased, confirming the use of NBT-based perovskite as a photoactive material. PL spectra at room temperature exhibited reddish-orange emission. Colour coordinates and CCT values are in the range of 3483 K to 5912 K. At a concentration of x = 0.3, the materials displayed a high Vickers hardness of 8.20 GPa and exhibited minimal wear with low frictional coefficient values. Ferromagnetic behaviour at room temperature (RTFM) was detected in Sm-modified ceramic samples, as confirmed by the VSM study. The cumulative effect impact of the rare earth dopant cation at the Bi-site of NBT was widespread and demonstrated significant potential for use in optoelectronic devices.

Analysis of friction and wear performance of eco-friendly basalt filler reinforced polylactic acid composite using the Taguchi approach

The main goal of this research is to utilize sustainable and eco-friendly basalt materials for the fabrication of bio-based thermoplastic composites. This will help to keep up with ecologically balanced factors. There have been several studies on natural fiber reinforced with different polymer matrices during the past 10 years. As a result, the academics and experts expressed concern about the environmental imbalance. By keeping these points, an attempt was made to fabricate basalt fillers reinforced polylactic acid composites with the maximum weight ratio (30 wt %), and the tribological study is conducted for the fabricated composites. In this study, the Taguchi and analysis of variance (ANOVA) approaches have been used to analyze the coefficient of friction (COF) and specific wear rate (SWR) of polylactic acid composite reinforced with constant 30 wt% basalt fillers. The morphology, particle size, and elemental composition of the basalt fillers are examined using scanning electron microscopy, a particle size distribution analyzer, and energy-dispersive X-ray analysis, respectively. The tribology tests are conducted with Pin-on-Disk Tribometer following the ASTM G99 standard, following the L18 orthogonal array design, which was developed using the statistical program MINITAB-19. The selected parameters for the analysis are basalt (wt %), load (N), speed (rpm), and distance (m) under dry conditions. For PLA samples, the optimum parameters in response to COF is found to be 0 wt% basalt, 3 N load, 100 rpm speed, and 100 m distance; for the SWR output, the optimum parameters are 30 wt% basalt, 6 N load, 100 rpm speed, and 150 m distance. The consistent observation is that adding basalt fillers has not significantly reduced COF but has contributed more to SWR reduction with PLA composite. The best COF value for PLA samples is obtained with low sliding distance. The typical observation across all COF graphs is that the COF value first seems to be lower due to a smoothened polymer surface, rises throughout an experiment, and then stabilizes with very little variance. Regardless of the processing parameters, the depth of wear steadily increases with increasing load as observed in 2D depth profiles. The neat PLA polymer morphology that gives the illusion of deep grooves and many tracks dispersed over a single worn surface shows how the maximum parameter influence is more obvious on the surface of the sample. Overall, the results suggest that thermoplastic composites are feasible for the manufacturing of paper mill rollers.

Effect of cold spray processing parameters on the microstructure, wear, and corrosion behavior of Cu and Cu–Al2O3 coatings deposited on AZ31 alloy substrate

Cold spray coatings represent a newly emerging and recently implemented approach to enhance the poor wear and corrosion resistance of AZ31 magnesium alloy. In this study, the authors applied pure Cu and Cu-50 wt% Al2O3 composite coatings on an AZ31B substrate using the cold spray deposition method and investigated the effects of gas pressure (1, 2, and 3 MPa) and stand-off distance (1, 2, and 3 cm) on their microstructure characteristics. An increase in gas pressure from 1 MPa to 3 MPa resulted in a decrease in porosity, ranging from 33 % to 38 %, across varying stand-off distances. Increasing the stand-off distance from 1 to 3 cm resulted in a nearly four-fold rise in porosity for 2 and 3 MPa pressures and about 1.5 times for 1 MPa. The porosity increased with higher pressure due to the fragmentation of Al2O3 particles but decreased with greater spraying distance due to reduced Al2O3 retention. Additionally, the incorporation of Al2O3 particles into Cu coatings led to a significant improvement in sliding wear resistance, by up to 50 %, compared to the bare substrate. Abrasive wear and delamination were identified as the dominant wear mechanisms for the composite coatings based on friction coefficient values and micromorphology of wear tracks. Electrochemical results indicated a significant increase in the corrosion resistance of the Cu coating compared to both the bare Mg substrate and Cu–Al2O3 coating, attributed to improved resistance to galvanic corrosion.

Composition and property correlation of Nd3+ ion doped (Na0·5Bi0.5) TiO3 Lead-free ceramics

Physicochemical, optical, magnetic, and mechanical properties of ceramic compositions of Na0·5[Bi1-xNdx]0.5TiO3 (NBNdxT) (x = 0.0, 0.1, 0.3, and 0.5) were obtained from the solid-state reaction method. X-ray diffraction (XRD) confirmed the primary rhombohedral phase of perovskite belonging to the space group R3c. SEM analysis revealed the multi-grain morphology with induced porosity. The elemental composition of the prepared NBT ceramics was obtained by EDAX. The corresponding FTIR absorption peaks in NBT shifted due to Nd3+ ion doping. The diffuse reflectance spectroscopy (DRS) showed a decrease in the band gap due to the inhomogeneous spread out of the dopant in NBT. The photoluminescence spectroscopy reflected that the Commission International del’Eclairage (CIE) hue coordinates in neodymium-modified NBT appeared in the red region. The hysteresis loop at higher fields is symbolic of the ferromagnetic nature of the material. The ceramics that were examined exhibit low values of wear and friction coefficients.

Nanotribological Characteristics of the Al Content of AlxGa1−xN Epitaxial Films

The nanotribological properties of aluminum gallium nitride (AlxGa1−xN) epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated using a nanoscratch system. It was confirmed that the Al compositions played an important role, which was directly influencing the strength of the bonding forces and the shear resistance. It was verified that the measured friction coefficient (μ) values of the AlxGa1−xN films from the Al compositions (where x = 0.065, 0.085, and 0.137) were in the range of 0.8, 0.5, and 0.3, respectively, for Fn = 2000 μN and 0.12, 0.9, and 0.7, respectively, for Fn = 4000 μN. The values of μ were found to decrease with the increases in the Al compositions. We concluded that the Al composition played an important role in the reconstruction of the crystallites, which induced the transition phenomenon of brittleness to ductility in the AlxGa1−xN system.

Impacts of Arrhenius energy and viscous dissipation on variable properties of viscoelastic nanofluid flow with slip velocity

ABSTRACT In this article, the viscoelastic nanofluid external flow using the model that considers the Brownian motion and thermophores is examined. A non-Newtonian liquid has variable properties, namely dynamic viscosity and thermal conductivity, and these depended on temperature distributions. Third order mathematical formulations include some important impacts such as Lorentz force, non-linear radiation, exponential heat generation, viscous dissipation, and Arrhenius activation energy. Also, the flow on the outer edge has slip conditions, variable nanoparticle distributions, and convective boundary conditions. The solution technique is based on reducing the fourth order derivatives of ODEs (Ordinary Differential Equations) and shooting method. From the major results, it is noted that the variable property case gives a higher rate of heat transfer compared to the constant case. The slip-velocity condition in the case of the viscoelastic nanofluids causes higher velocity features for the non-Newtonian suspension compared to the case of Newtonian nanofluids. Minimization of the viscoelastic parameter, viscosity parameter, and mixed convection parameter is the best to obtain the higher values of skin friction coefficient.

Impact of particle elongation on the behavior of round and angular granular media: Consequences of particle rotation and force chain development

We developed a 2D discrete element model to simulate shearing response of elongated round and angular particles. Model was calibrated and validated by comparing numerical results with corresponding biaxial shearing tests on circular (round) and hexagonal (angular) rods at microscopic and macroscopic scales. Then, the systematic effect of particles aspect ratio was investigated on quasi-static shearing response of round and angular granular materials. Macroscopically, we observed a nonlinear tendency wherein as the aspect ratio decreased from 1, the critical state stress ratio initially increased, reaching a maximum, followed by a decreasing trend. This effect was more prominent in round samples. Microscopically, decreasing the aspect ratio from 1 reduced particle rotations and increased the mean coordination number. Elongated particles exhibited significant contact anisotropy, forming irregular force chains, facilitating interparticle sliding, and reducing overall strength. Additionally, we explored the impact of the interparticle friction coefficient. A high value of interparticle friction coefficient led to a monotonically increasing strength with elongation, underscoring the importance of accurately calibrating microscopic friction coefficients.

Upcycling spent coffee grounds and waste PET bottles into electrospun composite nanofiber mats for oil structuring applications

Spent coffee grounds (SCG) and post-consumer PET bottles (PETbot) are major waste materials from the food industry. In this work, their use to obtain electrospun composite nanofibers is explored aiming to develop a new route for their upcycling into high added-value oil-based products. Raising the proportion of PETbot increased the average fiber diameter (from 0.36 to 0.89 μm) and enhanced the tensile properties of the mats. Young's modulus and strain-at-break increased from 5.1 to 32.8 MPa and from 13.8 to 39.4 %, respectively, as the SGC:PETbot weight ratio decreased. Dispersions of the mats in castor oil exhibited shear-thinning and gel-like viscoelastic properties which can be tuned through the SCG:PETbot ratio. Friction coefficient values of resulting oleogels tested in a tribological contact ranged from 0.165 to 0.092. SCG and PETbot can be used to obtain electrospun nanofibers with oil structuring capabilities while resulting oleogels are proposed as environmentally-friendly alternatives to semisolid lubricants.

MHD Boundary Layer Flow due to an Exponentially Stretching Surface Through Porous Medium with Radiation Effect and Chemical Reaction

In this study, the numerical solutions for an exponentially stretching sheet with radiation effects, chemical reaction and a heat sink is obtained for the problem of MHD boundary layer flow. By using similarity transformation, the PDEs ruling system is converted into an ODEs system. The resulting nonlinear equations governing the flow problem are numerically solved by a successive linearization method (SLM) using MATLAB software. The significance of this paper is to show and compare the results of solving velocity, temperature, and concentration equations in the existence of changes through SLM for presenting it as appropriate and accurate method for solving nonlinear differential equations. Tables with the numerical data are created for comparison and displayed graphically. Analysis and studies of the effects of different parameters are conducted. The numerical values for the local skin friction coefficient, local Sherwood number, and local Nusselt number are tabulated and explained. The study demonstrates that different parameters have a substantial impact on the fluid flow profiles. It was noted that the concentration patterns were impacted by the reaction rate parameter. In addition, it was found that as the magnetic and radiation parameters increase in value, the local heat transfer rate at the surface decreases.

Similarity solution of fractional viscoelastic magnetohydrodynamic fluid flow over a permeable stretching sheet with suction/injection

A novel easy‐to‐use similarity technique for spatial fractional partial differential equations is introduced to solve the flow and heat transfer of fractional viscoelastic magnetohydrodynamic (MHD) fluid over a permeable stretching sheet. The proposed method represents a new technique for deriving similarity transformations, which allows the conversion of the fractional partial differential equations to fractional ordinary differential equations. Moreover, using the Grünwald–Letnikov formula, the fourth‐order Runge–Kutta method is adopted here to solve the obtained similarity equations, using the shooting method. The transformed governing equations were found to be dependent on six physical parameters, namely, fractional parameter, magnetic field parameter, generalized local Reynolds number, generalized Prandtl number, the wall suction/injection parameter, and the wall stretching exponential. The results reveal that maximums of the skin friction coefficient and local Nusselt number are obtained for fractional‐order derivative of about 0.5. Moreover, application of a magnetic field on electrically conducting fractional fluid thins the velocity boundary layer and thickens the thermal boundary layer; therefore, the skin friction coefficient increases whereas the local Nusselt number decreases. Furthermore, an increase in any parameters of the local Reynolds number, suction parameter, or the wall stretching exponential leads to thinner boundary layers and higher values of skin friction coefficient and local Nusselt number, whereas imposing injection has opposite effects. Finally, increasing the generalized Prandtl number leads to a thinner thermal boundary layer and higher local Nusselt number for the fractional viscoelastic fluid. It would be of interest to extend the proposed method to other practical problems in the same field.