Interfacial Slip Research Articles

Investigation of Tribological Behavior and Lubrication Mechanisms of Zinc Oxide under Poly α-olefin Lubrication Enhanced by the Electric Field.

The electric field induces complex effects on the tribological properties of zinc oxide (ZnO) under lubricated conditions, particularly at the nanoscale, where the friction process and mechanism remain unclear. In this paper, the tribological behaviors of ZnO under the lubrication of poly α-olefins (PAO) were investigated by molecular dynamics (MD) simulations with reactive force field (ReaxFF). The results reveal a significant enhancement in the tribological performances of ZnO with the application of the electric field, resulting in a 58.6% reduction in the coefficient of friction (COF) from 0.193 at 0 V/Å to 0.080 at 0.1 V/Å. This improvement can be attributed to the weakening of interfacial interaction, evidenced by a reduction in the number of C-O covalent bonds under the influence of the electric field, along with the formation of an adsorption film due to applied load and shear effects. Notably, the effect of the electric field and applied load extends the impact of interface slip on the tribological performance of ZnO. Overall, this study provides a comprehensive understanding of the impact of the electric field on reducing the friction of ZnO-based structured models, shedding light on explaining their tribological properties and lubrication mechanisms.

Grouped rubber-sleeved studs–UHPC pocket connections in prefabricated steel–UHPC composite beams: Shear performance under monotonic and cyclic loadings

Prefabricated steel–ultra-high-performance concrete (UHPC) composite beams (PSUCBs) with grouped stud–UHPC pocket connections (GSUPCs) are a successful attempt of UHPC in bridge engineering, which offers significant advantages in accelerating on-site construction, enhancing structural performance, and improving environmental benefits. However, the uneven steel–concrete interfacial shear stresses distribution caused by the insufficient deformability of ordinary studs (OSs) in UHPC may result in the premature stud failure in large interfacial slippage regions. To address this issue, rubber-sleeved studs (RSSs) that wrapped rubber-sleeves around the stud roots were introduced to improve ductility and reduce the stiffness of connectors. However, the shear performance of grouped RSSs embedded in UHPC remains unclear, which hinders their application in practices. Against this background, systematic experimental and numerical studies were conducted to investigate the monotonic and cyclic shear performance of grouped RSSs–UHPC pocket connections. The results indicated that wrapping rubber-sleeve could increase the ultimate slip capacity and remained sufficient shear resistance, demonstrating great potentials of grouped RSSs–UHPC pocket connections in PSUCBs. Increasing the rubber-sleeve thicknesses and height effectively improved the ultimate slip capacity and deformation recovery, but led to the significant plastic deformation accumulation and cyclic stiffness degradation. Finally, design recommendation on rubber-sleeve configuration rationalization, ultimate shear resistance and load–slip relationship predictive models were provided.

Role of Substrate Roughness in Soil Desiccation Cracking

Soil desiccation crack is ubiquitous in nature, yet the physics of its initiation and propagation remain under debate, as it involves complex interactions across multiple fields of mechanics, hydraulics, and thermals. Here, an experimental attempt is made to uncover the role of substrate roughness on the soil desiccation process. The substrate roughness is deliberately fabricated by 3D printing, whereas the thickness of sample and environmental humidity are controlled to eliminate the effect of large hydraulic gradient. Four types of soils with varying expansibilities were desiccated on substrates with varying roughness. It reveals that: (1) soil desiccation crack evolution can be conceived as a competing process between the shear failure of soil-substrate interface, i.e., slippage of interface, and the tensile failure of soil, i.e., crack initiation, in minimizing the total energy of drying soil; (2) substrate roughness alters the failure mode and shear strength of soil-substrate interface and its sensitivity to moisture, thereby it regulates the pattern of how soil crack propagates upon drying; (3) soil expansibility is recognized as a key factor governing the crack-initiation point in addition to the widely recognized air-entry, and flaws in soil are the sources for the 120° crack angle and bimodal crack angle distribution.

Cracking performance in the hogging moment region of HSS-UHPC continuous composite girder bridges

To elucidate the cracking performance of concrete slabs at the negative bending moment region of high strength steel (HSS)-ultra high performance concrete (UHPC) continuous composite girder bridges, eight scale-reduced steel-concrete composite beams, constructed using HSS and UHPC that varying parameters of UHPC slab thickness and width and shear connection degree at the steel-concrete interface were prepared and tested. The composite beams' cracking pattern, bending stiffness, load-deflection curve, steel-concrete interfacial slippage, and strain history were presented and discussed. The test results show that the HSS-UHPC composite beams subjected to negative bending moments exhibited favorable cracking performance. With the UHPC slab width increasing from 450 mm to 550 mm, the composite beams' initial cracking moment, bending stiffness, and flexural ductility increased by 33.4%, 20.5%, and 39.8%, respectively. The utilization of a thick UHPC slab benefited the performance of the composite beams under negative bending moments. Replacing the 80 mm-thick slab with a 110 mm-thick slab improved the structure’s cracking moment and bending stiffness by 15.0% and 21.4%, respectively. Additionally, as the shear connection degree increases from 0.64 to 1.02, the initial cracking and ultimate failure moments of the composite beam were improved by 7.2% and 1.6%, respectively. In contrast, the bending stiffness of the beams with a shear connection degree of 1.02 was 12.4% smaller than those of 0.64. A comprehensive comparison between the formula-predicted cracking performance and current experimental results was performed to examine the capability of existing design approaches in calculating the HSS-UHPC composite beams. The flexural resistance algorithm proffered by Xu exhibits favorable alignment with test results, thereby providing a compelling methodology for designing HSS-UHPC continuous composite girder bridges.

Experimental study on the effect of partial shear studs layout on flexural behavior of steel-concrete composite beams

In steel-concrete composite beams, partial shear connection offers advantages including greater ductility and lower cost. However, partial shear connection constraints on composite beam structural performance, such as reduced beam stiffness, increased steel-concrete interface slip, etc., should not be neglected. Several researches have revealed that shear connector layout is one of the main approaches to limit partially composite beam vulnerability. Shear connector layout optimization has not been completely investigated experimentally, and its effect on composite beam structural performance is still unknown. This paper focusses on the experimental study of the effect of shear connectors layout on the flexural performance of composite beams. It reports the optimization of the layout of shear connectors based on blocked distribution of shear connectors laid in a single row, while concentrating the highest number of shear studs towards the supports of a simply supported composite beam. A fully composite beam with normal layout of shear studs was tested as control specimen, while the rest of the beams used partial shear connection (η = 0.5). Beams with partial shear connection had 3 different layouts of shear studs. The first had uniformly distributed shear studs, and the rest had shear studs laid out in 2 and 3 blocks each of uniform spacing respectively. The results showed that the beam with 3 blocks layout each of equal spacing of shear studs had the closest best structural performance to the fully composite beam and had better ductility than the latter.

Characterization of Bonding Defects in Fiber-Reinforced Polymer-Bonded Structures Based on Ultrasonic Transmission Coefficient.

This research delves into the characterization of the ultrasonic transmission coefficient pertaining to various types of bonding defects in Fiber-Reinforced Polymer (FRP)-bonded structures. Initially, an ultrasonic transmission coefficient calculation model for FRP-bonded structures in a water immersion environment is established. This model is used to analyze the variation in the ultrasonic transmission coefficient under different defect types, namely intact bonding, interfacial slip, and debonding defects. Subsequently, a frequency domain finite element analysis model of FRP-bonded structures with different defect types is constructed. The simulation validates the accuracy of the theoretical analysis results and concurrently analyzes the variation in the transmission signal when the defects alter. Lastly, an experimental platform for water immersion ultrasonic transmission measurement is set up. The transmission signals under different defect types are extracted through experiments and evaluated in conjunction with theoretical calculations to assess the types of bonding defects.

Push-out test behavior and damage detection of steel-UHPC composite using PZT sensing

This present study investigates the failure mechanisms and damage evolution at the steel-UHPC interface through static push-out tests and active sensing monitoring on 15 steel-UHPC specimens. To address the ductility issue of embedded studs in UHPC as specified by Eurocode 4 to be at least 6 mm, the selected parameters particularly include large-diameter studs (≥25 mm), high-strength studs, and bolted connectors, which less frequently involved in current research. The test results indicate that large-diameter studs and bolted connectors can enhance the ductility of the steel-UHPC specimens. However, the use of high-strength studs further reduced the ductility of the specimens due to welding quality issues. Furthermore, to explore the evolution of damage at the steel-UHPC interface, the Piezoelectric Transducer (PZT)-based active sensing system was employed to continuously monitor the development of slip damage at the steel-UHPC interface during the static push-out tests and then evaluate the specimen's damage under different loading conditions. By analyzing the wave response of the piezoelectric sensor, the results reveal a strong correlation between the damage index, obtained through wavelet packet analysis, and the progression of interface slip. This correlation enables precise identification of critical damage, such as interface debonding and connector fracture, during the loading process. Utilizing the test outcomes, a quantitative relationship between the damage index and slip for the purpose of structural damage assessment has been built. Finally, based on the test data, this study assessed the applicability of current shear resistance design equations, proposed a refined load-slip relationship for studs, and offered well-founded design recommendations.

Influence of Glyceryl Monostearate Adsorption on the Lubrication Behavior of a Slider Bearing

Glyceryl monostearate (GMS) was used as an organic friction modifier (OFM) and added to the base oil (PAO10, polyα-olefin) in this study. The film thickness and friction coefficient of the base oil added with GMS (PAO10G) under different slider inclinations and loads were investigated experimentally by using a slider-on-disc contact lubricant film measurement system, and the effect of the adsorption of GMS on the friction behavior of lubricant was studied. Contact angle hysteresis (CAH) was used to evaluate the wettability of the solid–liquid interface, and its correlation with the coefficient of friction was analyzed. The results show that CAH is in good agreement with the wettability of the solid–liquid interface. Compared with the base oil, the wettability of POA10G is weak, which can effectively reduce the coefficient of friction. However, different from the classical lubrication theory, the film thickness of PAO10G is higher than that of PAO10; this unusual phenomenon is preliminarily explained by the interface slippage in this paper.

A cationic type long-lasting drag-reduction agent based on reduced interfacial water film thickness for enhanced injection in low-permeability reservoirs

In water injection development of low-permeability reservoirs, the elevated flow resistance between the rock surface and the injected water results in enhanced injection pressure. Reducing the thickness of interfacial water film to expand flow radius is a new thought to achieve a decrease in injection pressure. In this work, a hydroxyl-containing cationic surfactant tetradecyl methyl dihydroxy-ethyl ammonium bromide (HTTAB) was designed and synthesized. The introduction of hydroxyl groups enhances the binding to the negatively-charged rock surface. HTTAB can modify the strong hydrophilic rock surface to a hydrophobic state, with the water contact angle increasing from 20.2° to 110.3°. HTTAB shows excellent drag-reducing effect, maintaining a drag reduction rate of over 30 % even after 30 PV of flushing. Particle Image Velocimetry (PIV) experiments show that after HTTAB adsorption, the interfacial slip velocity and centerline velocity can increase by 1.67 times and 33.66 % respectively, and the flow radius expands significantly. In addition, the thickness of the interfacial water film is obtained using Atomic Force Microscope (AFM). The results show that the thickness of the interfacial water film is reduced significantly from 79.42 nm to 8.85 nm. This study provides important guidance for the design of drag-reducing agents and the understanding of interfacial drag-reduction behavior.

Digital image correlation and cracked hinge model applied to notched beams reinforced with GFRP bars

In this study, three-point bending fracture tests of notched beams reinforced with a glass fiber-reinforced polymer bar are conducted. Plain concrete beams are also tested for comparison. Two different widths are considered for the beams. Digital image correlation (DIC) is used on the lateral surface of the beam to study the fracture process zone (FPZ) and neutral axis depths at different load stages. A non-linear analytical model named cracked hinge model and cross-sectional analysis are used to obtain the force in the bar and the interfacial slip between bar and concrete, which are compared to the results from pull-out tests.

Characterization of the Time–Space Evolution of Acoustic Emissions from a Coal-like Material Composite Model and an Analysis of the Effect of the Dip Angle on the Bursting Tendency

Rock bursts pose a grievous risk to the health and lives of miners and to the industry. One factor that affects rock bursts is the dip angle of the coal seam. Because of the uniquely high gas content of the coal in a mine in Shanxi Province, China, coal specimens were obtained from this mine to produce coal–rock combination specimens and test the effects of various seam inclinations. Using a DYD-10 uniaxial compression system and a PCI-8 acoustic emission (AE) signal acquisition system, we investigated the spatial and temporal evolution characteristics of the burst tendency of specimens with different coal seam inclination angles (0°, 10°, 20°, 30°, 35°, 40°, and 45°). Uniaxial pressure was applied to the specimens, and we found that, as the inclination angle increased, the coal–rock combination specimens exhibited structural damage and destabilization, which was attributed to the generation of an interface slip phenomenon. In all tests, the coal exhibited greater damage than the rock. There was an energy convergence at the coal–rock interlayer interface, which was the main carrier for the accumulated energy. The impact energy dissipation index is defined according to the energy dissipation properties of the loading process of coal–rock composites. As the inclination angle increased, the impact energy dissipation index, energy storage limit, compressive strength, elastic modulus, and other indexes gradually decreased. This effect was strongest where the angles were 40° and 45°. The indexes used to assess the impact propensity decreased to a notable degree at these angles, revealing that the burst tendency of coal–rock is curtailed as the inclination angle increases. The results of this research are of great importance to the early evaluation of mine burst risks and the sustainable development of coal utilization.

Flow and irreversible mechanism of pure and hybridized non-Newtonian nanofluids through elastic surfaces with melting effects

Abstract The significance of nanofluid research in nanotechnology, pharmaceutical, drug delivery, food preparation, and chemotherapy employing single- and two-phase nanofluid models has drawn the attention of researchers. The Tiwari–Das model does not capture the diffusion and random movement of nanoparticles (NPs) when they are injected into complex functional fluids. In order to fix the peculiar behavior of NPs, more complex models like the Buongiorno model are coupled with the single-phase model. To examine the heat-mass transfer attributes of nanofluids, a single- and two-phase mixture model is coupled for the first time. The effect of hybrid NPs on the hemodynamic properties of the blood flow through a stretched surface with interface slip in the neighborhood of the stagnation point is examined. Due to their significance in medicinal uses and nominal toxicity, blood is loaded with zinc–iron ( ZnO − F e 2 O 3 ) {\rm{ZnO}}\left-{\rm{F}}{{\rm{e}}}_{2}{{\rm{O}}}_{3}) NPs. However, blood is speculated to have the hematocrit viscosity of the Powell–Eyring fluid. The single-phase model predicts an improvement in heat transport due to an increased volumetric friction of NPs, while the two-phase models provide closer estimates of heat-mass transfer due to Brownian and thermophoretic phenomena. Entropy evaluation predicts the details of irreversibility. The mathematical structures are effectively solved with a Runge–Kutta fourth-order algorithm along with a shooting mechanism. The Eyring–Powell parameters decrease the drag coefficient and mass/thermal transport rate. A higher estimation of the slip, material, and magnetic parameters decreases the flow behavior. The Bejan number increases with the diffusion parameter and decreases as the magnetic and Brinkman numbers increase. The effect of iron oxide ( F e 2 O 3 ) \left({\rm{F}}{{\rm{e}}}_{2}{{\rm{O}}}_{3}) is observed to be dominant.

Wettability-modulated behavior of polymers under varying degrees of nano-confinement

Extreme confinement in nanochannels results in unconventional equilibrium and flow behavior of polymers. The underlying flow physics dictating such paradigms remains far from being understood and more so if the confining substrate is composed of two-dimensional materials, such as graphene. In this study, we conducted systematic molecular dynamics simulations to explore the effect of wettability, confinement, and chain length on polymer flow through graphene-like nanochannels. Altering the wetting properties of these membranes that structurally represent graphene results in substantial changes in the behavior of polymers of disparate chain lengths. Longer hydrocarbon chains (n-dodecane) exhibit negligible wettability-dependent structuring in narrower nanochannels compared to shorter chains (n-hexane) culminating in higher average velocities and interfacial slippage of n-dodecane under less wettable conditions. We demonstrate that the wettability compensation comes from chain entanglement attributed to entropic factors. This study reveals a delicate balance between wettability-dependent enthalpy and chain-length-dependent entropy, resulting in a unique nanoscale flow paradigm, thus not only having far-reaching implications in the superior discernment of polymeric flow in sub-micrometer regimes but also potentially revolutionizing various applications in the oil industry, including innovative oil transport, oil extraction, ion transport polymers, and separation membranes.

Experimental Study on the Mechanical Performance of Column Underpinning Joints with Prestressed U-Shaped Steel Bars

To meet the requirements of highly efficient force transmission, easy operation and low damage in RC column underpinning engineering, a new underpinning joint with prestressed U-shaped steel bars was proposed. Static testing of seven specimens was carried out, and the number of the U-shaped steel bars, their arrangement and the pre-pressure acting on the joint were considered as the main parameters. The results demonstrated that the U-shaped steel bars might greatly increase the load-bearing capacity of the underpinning joint, and the more the number, the higher the capacity; the arrangement of the U-shaped steel bars also had a significant effect on the load-bearing capacity. Two pairs of the U-shaped steel bars arranged on the opposite sides of the column was better than that arranged on four sides. And the horizontal part of the UsSBs embedded in the column grooves was better than in the underpinning beams; the pre-pressure could effectively improve the sliding stiffness of the underpinning joint, while the effects on the load-bearing capacity was not obvious. Based on the curve of load-displacement, force process of the underpinning joint was divided into four phases: no slip, initial slip, interfacial slip expansion and punch slip, consequently a constitutive force-slip model was constructed. As a result, a simple mechanical model of the underpinning joint was established, and the calculation formula for the load-bearing capacity of the new joint was proposed. Finally, the engineering design expression was prepared according to the characteristics of the real underpinning project.

Damping and mechanical properties of SiC particles reinforced aluminium matrix composites prepared by colloidal dispersion and suction filtration method

In order to uniformly distribute SiCp in the aluminium matrix and prepare SiCp/Al composites with high mechanical and damping properties, a preparation method of colloidal dispersion and suction filtration was developed. It was observed from the microstructure of the composites that the SiCp/Al composites prepared by colloidal dispersion and suction filtration method had good interfacial structures, and the interfacial reaction between SiCp and aluminium matrix was effectively inhibited. Tensile mechanical properties at room temperature and damping properties in the temperature range of 25 °C to 300 °C were tested for the SiCp/Al composites with volume fractions of 5% to 10%. The results showed that SiCp/Al composites have excellent mechanical and damping properties when the volume fraction of SiCp was 7%. This is because SiCp were uniformly distributed in the aluminium matrix, and formed a good interfacial bond with the aluminium matrix, which benefitted both the interfacial slip loss and the strengthening effect of SiCp.

Research on Micro Gap Flow Field Characteristics of Cylindrical Gas Film Seals Based on Experimental and Numerical Simulation

Flexible support cylindrical gas film seals (CGFSs) adapt well to rotor whirling and have a good gas lubrication effect during thermal deformation. However, when a CGFS operates under the “three high” (high interface slip speed, high-pressure differential, and high ambient temperature) operating conditions, the complex deformation of the support structure is a crucial factor affecting the stability of the CGFS. A thorough and systematic analysis of the micro gap flow field characteristics of flexible support CGFSs is a fundamental problem when we study the deformation of the support structure under multiple physical field conditions. This study uses a cylindrical gas film high-speed rotor test rig to study and compare the sealing characteristics of experiments and numerical simulations and then optimizes and verifies the accuracy and effectiveness of the simulation model. A cross-scale gas film grid model is used to analyze the flow field characteristics and seal ability of different groove models and compare the mechanical characteristics and sealing performance. We also analyze the gas film pressure distribution in micro gaps and explore the impact of dynamic pressure groove microstructure on flow field characteristics. Results show that micro gaps are the primary conditions for generating hydrodynamic effects, and high rotational speed, high-pressure differential, and large eccentricity have a significant effect on improving hydrodynamic effects and enhancing gas film stability. However, an increase in these parameters can cause an increase in leakage rate. A single flow channel makes it easier to improve the hydrodynamic effect, gas film load-bearing ability, and gas film stability while reducing leakage rate. The analyses in this study supplement and improve the theory of the flow field characteristics of cylindrical annular micro gaps and provide a theoretical basis for exploring the relation between the support structural parameters of the CGFS and the mechanical characteristics of the micro gap flow field. This study provides important guidance to the establishment of a quantitative design theory of supporting structures.

Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine

The force and deformation characteristics of the rock layer on the top and bottom of the coal seam change significantly when the dip angle changes. The mechanical properties and damage characteristics of differently inclined coal–rock assemblages were investigated, and the results were combined with acoustic emission information, including acoustic emission ringdown counts, to quantify the damage of inclined coal–rocks under compression. The experimental results showed that the stress‒strain curves of the inclined coal–rock assemblages had four main stages, with approximately similar curves in the early stage and deformation in the later stage. The damage gradually changed from shear damage to interfacial slip damage, and the damage area gradually transitioned to the structural surface from coal body components. The cumulative acoustic emission energy tended to decrease with increasing inclination angle, and the peak acoustic emission energy gradually decreased. When the inclination angle was less than 30°, the cumulative energy of acoustic emissions increased slowly, then decreased, and it finally decreased significantly between 30° and 45°; from 0° → 15° → 30° → 45°, the energy change rates were +3.0%, −25.1%, and −78.2%, respectively. For coal–rock assemblages with different interfacial angles, the sliding damage instability caused by the coal–rock interface increased with increasing interfacial angle within the assemblage. The results of this study provide a deeper understanding of the mechanical properties of coal–rock assemblages with different inclinations and the characteristics of fissure extension. The fractal dimension based on particle number decreased with increasing loading rate, and the larger the loading rate was, the smaller the fractal dimension. In addition, the current findings provide a reliable foundation for further understanding the mechanisms of disasters caused by coal–rock disturbances, such as excavation of inclined roadways and extraction of gas, as well as supporting the development of methods for monitoring, early warning, and prevention and control of these types of disasters.

Non-Stick Length of Polymer-Polymer Interfaces under Small-Amplitude Oscillatory Shear Measurement.

Interfaces in soft materials often exhibit deviation from non-slip/stick response and play a determining role in the rheological response of the overall system. We discuss detection techniques for the excess interface rheology using small-amplitude oscillatory shear (SAOS) measurements. A stacked bilayer of different polymers is sheared parallel to the interface and the dynamic shear response is measured. Deviation of the bilayer shear modulus from the superposition of the shear moduli of the component layers is analysed. Furthermore, we introduce a frequency-dependent non-stick length based on the bilayer SAOS response to characterize the excess interface rheology. We observe an approximate stick response in the interface in bilayers composed of the chemically same monomer as well as an apparent slip in the interface between immiscible polymers. The results suggest that the proposed non-stick length in SAOS is capable of detecting the apparent interfacial slip. The non-stick length in SAOS is readily applicable to other complex interfaces of different soft materials and offers a convenient tool to characterize the excess interface rheology.

Thermodynamics of hydromagnetic boundary layer flow of Prandtl nanofluid past a heated stretching cylindrical surface with interface slip

BackgroundThe mathematical modelling of a non-Newtonian fluid in the backdrop of applied magnetic field against an electrically conducting liquid is recognized as magnetohydrodynamics (MHD), which has important implications in chemical engineering and the biological sciences. Illustrations of such magneto-fluids include molten metals, electrolytes, blood plasma, and salty water. The applications of flowing liquids over cylindrical geometries is a fascinating due to its wide range importance in engineering. The aforementioned uses of MHD encourage scientists and analysts to establish new mathematical modelling in the area of fluid dynamics. Therefore, we considered the Prandtl fluid flow with loaded nanoparticles over a cylindrical tube with slip triggered by wall shear stress. The transport equation involving thermophoresis and Brownian diffusions are modelled using the Buongiorno model. The modelling of energy and entropy are established considering the effects of frictional dissipation, non-uniform heat source, thermal stratification, and Ohmic heating. MethodsThe formulated mathematical model leading to a complex system of partial differential equations with numerous integrated parameters. Using numerical algorithm RK-45 with a tolerance limit of 10−6, the system of resultant ordinary differential equations is simulated. The solver is used repeatedly to select the parameters that best meet the intended boundary conditions. Significant findingThe results of the current study revealed that the influence of heat source and thermal stratification on fluid temperature are conflicting. Additionally, the magnetic variable and Brinkman parameter have an escalating relationship with the rate of entropy development. The Bejan number detract with the magnetic variable. For distinct estimations of slip factors, heat and mass transport behave identically. However, the effect of slip is higher as compared to no slip scenario. The effect of Lewis number against nanoparticles concentration is opposite.

Numerical analysis on thermal control and irreversibility for 3D Casson hybrid nanofluid flow within two permeable stretching surfaces with interfacial nanolayer thickness and slip velocities

During the preparation of nanoparticles, the nanolayer thickness plays a vital role in further controlling the flow and thermal–physical features of the fluid. Features are observed to be more prominent in the presence of hybrid nanomaterials. In the present problem, the concomitant effects of the interfacial nanolayer of nanomaterials MWCNT and Fe 3 O 4 during a 3D Casson hybrid nanofluid flow between two parallel plates have been investigated. An appropriate transition is applied to rationalize the substantially paired and nonlinear governing equations. Equations after similarity transformation are processed by concerning the finite element method. Impressions of different governing parameters on the governing systems in conjunction with entropy and the Bejan number are displayed through graphs and tables. Graphs are drawn with an evaluation of general and hybrid nanofluids and different nanolayer thicknesses of nanoparticles. Three-dimensional features were observed for skin friction and the rate of heat transfer. The thermal impact is very significant in the presence of nonlinear thermal radiation and a heat source. After simulation, it is indicated that heat transfer rate disrupts with Biot number while it upgrades with heat generation. The entropy of the system is restricted with an increase in the magnetic and Brinkman numbers, while the Bejan number shows the opposite behavior with respect to those parameters. With an increase in the interfacial nanolayer thickness, the entropy of the system slows down.