Slip Effects Research Articles

Entropy generation analysis of dusty fluid with peristalsis in asymmetric channel with slip effects

Entropy generation analysis of dusty fluid with peristalsis in asymmetric channel with slip effects

Prediction of Cattaneo–Christov heat flux with thermal slip effects over a lubricated surface using artificial neural network

Prediction of Cattaneo–Christov heat flux with thermal slip effects over a lubricated surface using artificial neural network

Prabhakar fractional simulation for thermal analysis of magnetohydrodynamics flow of Oldroyd-B fluid using slip and Newtonian heating effects

Prabhakar fractional simulation for thermal analysis of magnetohydrodynamics flow of Oldroyd-B fluid using slip and Newtonian heating effects

Analytical model of curvic coupling and application in nonlinear vibration analysis of a squeeze film damper - rolling bearing - rotor system

The curvic coupling has been extensively employed in the rotor system of aero-engine. Effects of the radical slip of the teeth and damping are usually neglected in the traditional models of the curvic coupling. Additionally, there are only a few researches on the vibration characteristics of the rotor system with curvic coupling, squeeze film damper (SFD) and rolling bearing. In this paper, an analytical model of the curvic coupling is proposed. The nonlinear vibration analysis of a SFD - rolling bearing - rotor system with curvic coupling is furtherly carried out. The Jenkins element is adopted to simulate the dynamic behaviors of the curvic coupling in the model. The hysteresis curves of the analytical model show good agreement with the results of the three-dimensional (3D) finite element (FE) simulation. After that, the dynamic equation of a SFD - rolling bearing - rotor system with curvic coupling is formulated. Subsequently, detailed parametric analyses, including preload, number of teeth and pressure angle, are conducted to investigate the vibration characteristics of the rotor system. Results show that the curvic coupling mainly produces stiffness loss and damping at the interface of the curvic coupling. The motion stability of the rotor system can be enhanced by increasing the preload, number of teeth at multiple curvic couplings and pressure angle. Moreover, the vibration level of the rotor system initially decreases and then increases as the number of the teeth and pressure angle increase. Finally, the numerical results are validated to be reasonable by an experimental study.

Thermal and velocity slip conditions together with thermal radiative effects on Joule heating mixed convection MHD hybrid nanofluid flow induced by an exponentially shrinking or stretching sheet

ABSTRACT The present study analyzes the mixed convection with magnetohydrodynamic (MHD) flow, Joule heating, and heat transfer in hybrid nanofluids on exponentially stretching or shrinking sheets. The study aims to optimize heat transfer and fluid dynamics properties in engineering and industrial applications. The governing partial differential equations are converted into ordinary differential equations by employing appropriate similarity transformations and then solved using the BVP4C MATLAB tool. In this study, the effects of silver volume fraction, velocity slip, thermal slip, magnetic field, heat generation, Eckert number, and thermal radiation on the skin friction coefficient, Nusselt number, velocity profile, and temperature profile are examined and graphically discussed. The base fluid water contained 2% silver (Ag) and 0.1% titanium oxide (TiO2) nano-particles in this hybrid model. The dual solution was present for a shrinking sheet ( λ < 0 ) when λ ≥ λ c . The skin friction coefficient values decreased by approximately 37%, while the local Nusselt number increased by approximately 3.1% when the velocity slip increased in the first solution. The Nusselt number increased by approximately 0.28% and 12% when the Eckert number and radiative parameter increased, respectively, but decreased by approximately 7.5% and 0.20% when the thermal slip and heat generation increased, respectively.

High-Order Models for Gas Transport in Multiscale Coal Rock.

The coal reservoirs exhibit great heterogeneity and strong anisotropy in multiscale pore/fracture structures. Developing highly accurate multiscale models for real-time prediction of microgaseous flow in complicated porous media with pronounced contrast in transport coefficients is crucial but not yet available, which is time-consuming, expensive, and even computationally impossible. In this study, a multiscale approximate solution of the gas flow and pressure field is derived in this paper for predicting coalbed methane (CBM) transport in macro-microscopic two-scale porous media of typical coal rocks in Guizhou Province, China, and the detailed finite element algorithm is established. The multiscale approximate solutions are constructed from the first- and second-order auxiliary cell functions and low- or high-order derivatives of the homogenized pressure field, which can accurately approximate the solution of the original problem to a certain extent. The numerical accuracy and validity of the multiscale approximate solutions under various working conditions are analyzed in detail by comparing and verifying the results with the direct numerical simulation results of fine-mesh high-precision finite elements. The results show that the homogenized approximate solution can only roughly capture the characteristics of the macroscopic pressure evolution, the first-order approximate solution can partially reproduce the macro-microscopic pressure oscillation phenomenon, and the second-order approximate solution can accurately predict the pressure profile and its evolution law with time in porous media with macro-micro configuration under various complex conditions. The second- and high-order two-scale approximate solutions constructed in this paper exhibit high numerical accuracy and excellent computational efficiency. We also develop multiscale approximate solutions for predicting microgaseous flow at a low reservoir pressure where the slippage effects are very pronounced. Potential applications of our high-order models to the coal reservoirs with a hierarchical matrix and fractures are discussed. The developed multiscale models exhibit excellent applicability to investigating the crossflow effects and coupling mechanisms between the matrix and cleats or fractures with multiple configurations in the CBM and shale gas reservoirs, which is crucial for the effective implementation of hydraulic fracturing technology. This study provides a fundamental understanding of gas transport in multiscale matrix-fracture networks, which helps to improve the optimization design of hydraulic fracturing in tight reservoirs.

Lie symmetry neural networking for heat transfer in magnetized williamson fluid (MWF) with heat source (HS) and thermal slip (TS)

In the analysis, design, and optimization of a wide range of engineering applications involving stretching surfaces and fluid flow, the skin friction coefficient (SFC) at a stretching surface with heat transfer is an important parameter that reflects the fluid dynamics, heat transfer characteristics, and surface interactions. Owing such importance, the purpose of present article is offer artificial neural networking remedy for evaluation of SFC for Williamson flow field with thermal slip and heat source effects. The Williamson fluid flow is realized by considering surface stretching with an externally supplied magnetic field. The energy equation is used to address the heat transmission. The constructed differential system for flow field is solved by conjecturing artificial neural networking with Lie symmetry and shooting methods. Artificial Neural Networking (ANN) model is developed to predict the surface quantity namely SFC at thermally magnetized surface. The major findings includes the variation in SFC for pertinent flow parameters and we found that in the presence of heat transfer aspects, the SFC admits declining nature towards Weissenberg number while opposite is the case for magnetic field parameter.

Improving diffusion kinetics of zinc ions/stabilizing zinc anode by molecular slip mechanism and anchoring effect in supramolecular zwitterionic hydrogels

The severe hydrogen evolution reaction and parasitic side reaction on Zn anode are the key issues which hinder the development of aqueous Zn-based energy storage devices. Herein, a polyacrylamide/carboxylated cellulose nanofibers/betaine citrate supramolecular zwitterionic hydrogels with molecular slip effects are proposed for enhancing Zn2+ diffusion and protecting Zn anodes. Non-covalent interactions within supramolecular hydrogels forms the skeleton for molecular slip and the strong coordination of carboxyl and amino groups with Zn2+ further facilitates the rapid Zn2+ transfer. Additionally, anchoring carboxyl and amino groups at the anode promotes the uniform deposition of Zn2+and protects Zn anode. On the basis of molecular slip mechanism and anchoring effect in the supramolecular zwitterionic hydrogels, Zn||Zn symmetric batteries undergo 800 h of stable electroplating stripping at a depth of discharge of 80 %. Zn||Cu asymmetric batteries exhibit an impressive average coulombic efficiency of 99.4 % over a remarkable span of 900 cycles at a current density of 15 mA cm−2. Furthermore, Zn||NH4V4O10 batteries successfully undergo over 1,000 cycles at a current density of 0.5 A g−1. Intrinsic ion diffusion mechanism of supramolecular hydrogel electrolytes provides an original strategy for the application of high-performance Zn-based energy storage devices.

Effect of slip on MHD flow of fluid with heat and mass transfer through a plate

Fractional order derivatives are recognized as advanced mathematical tools with broad applications in physics and engineering for deriving real-world solutions. This study examines a fractional order model of a non-linear Casson fluid, highlighting the widespread utility of fractional derivatives. Additionally, the problem incorporates the Dufour and slip effects. Specifically, the constant proportional Caputo fractional model is formulated using generalized Fick's and Fourier's laws. Initially, the governing equations are transformed into a non-dimensional form and subsequently solved using the Laplace transform. Analysis of the figures indicates that the Casson parameter reduces fluid motion, while the diffusion thermo effect enhances it. Furthermore, the study includes a comparison between fractionalized and ordinary velocity fields. Highlight: Introduction of novel CPC fractional derivative model of Casson fluid flow. Semi-analytically solutions using Laplace transform method for accurate fluid behavior representation. comprehensive parametric analysis linking theoretical findings. Temperature contour affected by significant values of Du?

OneTip: A Soft Tactile Interface for 6-D Fingertip Pose Acquisition in Human-Computer Interaction

Advances in display technology have created the need for more efficient and natural multi-degree-of-freedom interaction devices. The movement of a single fingertip has six degrees of freedom (DOFs), but traditional rigid touchscreens usually sense only 2-D information. This article proposes a new deformable tactile interface, OneTip, for single-fingertip human-computer interaction with 6 DOFs. It is manufactured based on the principle of vision-based tactile sensing using virtual stereoscopic cameras, and its size is about twice that of a thumb. The contact surface of OneTip has a specially designed structure and material to mimic the sensitivity and softness of human skin. Also, OneTip employs a new sensing method to address the problem of soft fingertip pose estimation (measuring relative change only) with incipient slip effects. Experiments show that OneTip has good 6-D pose estimation accuracy, with root mean square errors (RMSE) of translation and rotation not exceeding 0.1mm and 2.6°, respectively, within the linear interval (x and y: −1.2 to 1.2mm; z: 0 to 3mm; yaw: −15 to 15deg; pitch and roll: −40 to 40deg). Experiments were also conducted to explore the application of OneTip in typical virtual manipulation tasks and the possibility of combining it with other interaction devices.

Slip effects on the receptivity of supersonic flat-plate boundary layer to freestream acoustic waves

The receptivity phase located upstream from the neutral point might be significantly affected by local rarefaction effects (especially surface slip effects) in terms of the boundary-layer transition of near-space hypersonic vehicles. In this paper, the receptivity of a supersonic flat-plate boundary layer to freestream acoustic waves in no-slip and slip flows is analyzed using direct numerical simulations and linear stability theory. The Maxwell–Smoluchowski velocity-slip and temperature-jump boundary conditions are adopted at the wall to account for surface slip effects. A Mach 4.5 flow at different wall-cooling degrees is mainly analyzed, and another Mach-6 case is presented, both with freestream unit Reynolds number on the order of 1×106/m. The main goal is to clarify the qualitative and quantitative influence of surface slip effects on the receptivity phase under different conditions. The results show that the receptivity mechanism in the slip flow is similar to that in the no-slip flow. That is, the mode S or F is excited near the leading edge due to synchronization with slow or fast acoustic waves, and the Mack second mode is excited further downstream after synchronization between modes S and F. However, the slip effects lead to distinctly quantitative differences in receptivity. The slip effects have little influence on the excitation of mode S or F near the leading edge but largely affect the evolution (intermodal exchange) of modes S and F as propagating downstream. Consequently, as for the receptivity to slow acoustic waves, the slip effects play a stabilizing role in receptivity when mode S is stable while a destabilizing role when mode S converts to the first mode in the upstream. As for receptivity to fast acoustic waves, as slip degree increases, the slip effects initially stabilize and then destabilize the receptivity, where the receptivity coefficient of the tested slip case can increase by 25% compared with the no-slip case.

Thermal conductivity impact on MHD convective heat transfer over moving wedge with surface heat flux and high magnetic Prandtl number

The present evaluation focused on heat transfer and magnetic flux along the moving non-conducting wedge shape with thermal conductivity and surface heat flux effects. A suitable and well-known similarity transformation for integration is used for the coupled non-linear partial differential equations with stream formulations. The Keller Box technique is utilized to integrate the final non-similar equations numerically. The discretized algebraic equations are displayed graphically and numerically using the MATLAB software. The physical characteristics like temperature, magnetic field, velocity profiles, skin friction, heat transfer and magnetic intensity are investigated with various factors. The influence of relevant characteristics like thermal conductivity ξ, Prandtl number Pr, wedge parameter β, variable viscosity ε, and Biot number Bi is interpreted graphically and numerically. It is noted that velocity graph effects are declined at lower value of Biot number and enhanced value is obtained at the higher value of Biot number. The fluid temperature with highest thermal slip effects is displayed with minimum value of thermal conductivity but minimum value is obtained at large value of thermal conductivity. The maximum heat flux value is obtained at large value of moving parameter.

Modeling and predicting heat transfer performance in bioconvection flow around a circular cylinder using an artificial neural network approach

The current research aims to study the heat transfer rate in mixed convection flow of viscous fluid along a vertical cylinder containing swimming microorganisms and velocity slip effects. The thermal and solutal processes are examined using gyrotactic microorganisms, chemical reaction and slip conditions. The non-linear (PDEs) of the governing flow are transformed into set of highly nonlinear (ODEs) by employing appropriate similarity transformations, which are then resolved computationally by Runge-Kutta-Fehlberg 4th order toward with shooting approach. The predicted solution is derived using the Levenberg-Marquardt scheme combined with a backpropagation neural network (LMS-BPNN). The labelled data sheet is divided into three parts: 80% data is used for training, 10% for validation and 10% for testing. The performance of the proposed AI-based LMS-BPNN is examined in term of MSE for considered scenarios. An optimal solution is achieved at 675, 397, 727, 647, and 711, epochs, while performance in terms of MSE for these epochs is to be 1.06×E−9, 8.47×E−10, 9.20×10−9, 9.94×E−10,and 9.09×10−10. The assigned computational valuations and ANN valuations are in excellent alignment than those existing studies on numerous special cases. The predicted solution with AI-based technique LMS-BPNN is reliable, well-organized, and easy to handle the thermal and solutal transport analysis of flow across a stretchable cylinder. The validity of proposed LMS-BPNN algorithm is examined with absolute error analysis and error is found to be approximately 10−4.

Influence of radiation and thermal slip on electrically conductive dusty Walter’s B fluid moving peristaltically through an asymmetric channel

MotivationThe motivation of this recent article is to study dusty Walter’s B fluid flow due to its wide range of applications in biology and polymer industry. The fluid is traveling peristaltically through an asymmetric channel with wall slip. A discussion is also presented to examine heat transfer effects with thermal radiation and slip. MethodologyThe regular perturbation technique is employed to evaluate the mathematical model of the problem, which is first simplified by using stream functions. Mathematical results are simulated to illustrate flow characteristics of fluid and solid particles in salient quantities. Also, graphs of temperature distribution of fluid and dust particles have been discussed to study the impacts of various parameters. OutcomesWalter’s B fluid parameter reduces speed of both fluid and dust particles. By increasing thermal slip parameter, temperature transference becomes slower through the fluid, while Brinkman number significantly raises the temperature profile of both fluid and particles. This article presents a theoretical analysis of the problem. Moreover, the characteristics of liquids involved in the plastic industry and medical science can also be understood using the current analysis. Originality/ValueWalter’s B fluid with dust particle suspension has not been investigated for slip and thermal radiation effects.

A numerical study of heat and mass transfer characteristic of three-dimensional thermally radiated bi-directional slip flow over a permeable stretching surface

Within fluid mechanics, the flow of hybrid nanofluids over a stretching surface has been extensively researched due to their influence on the flow and heat transfer properties. Expanding on this concept by introducing porous media, the current study explore the flow and heat and mass transport characteristics of hybrid nanofluid. This investigation includes the effect of magnetohydrodynamic (MHD) with chemical reaction, thermal radiation, and slip effects. The nanoparticles, copper, and alumina are combined with water for the formation of a hybrid nanofluid. Using the self-similar method for the reduction of Partial differential equations (PDEs) to the system of Ordinary differential equations (ODEs). These nonlinear equation systems are solved numerically using the bvp4c (boundary value solver) technique. The effect of the different physical non-dimensional flow parameters on different flow profiles such as velocity, temperature, concentration, skin friction, Nusselt and mass transfer rate are depicted through graphs and tables. The velocity profiles diminish with the effect of magnetic and slip parameters. The temperature and concentration slip parameters reduce the temperature and concentration profile respectively. The higher values of magnetic factor lessened the skin friction coefficient for both slip and no-slip conditions. An elevation in the thermal slip parameter reduced the boundary layer thickness and the heat transfer from the surface to the fluid. The Nusselt number amplified with the climbing values of the radiation parameter. The mass transfer rate depressed with the solutal slip parameter. Comparison is made with the published work in the literature and there is excellent agreement between them.

Nonlinear Analysis of Prestressed Steel-Reinforced Concrete Beams Based on Bond–Slip Theory

In this study, a static load test of prestressed steel-reinforced concrete simply supported beams was carried out utilizing three test beams to investigate the bond–slip effect between the section steel and concrete in prestressed steel-reinforced concrete beams. Finite element models of three beams considering two different bond–slip constitutive relations and without considering bond–slip performance were developed in ABAQUS. The influence of shear bolt nails on the bond slip between the section steel and concrete was analyzed, and the load–slip curves of the three test beams were also computed. Generally, the results showed that the finite element calculations considering the bond–slip effect are more consistent with the experimental calculations, and the bond–slip constitutive relationship proposed by Yang Yong is more suitable for the numerical simulation of prestressed steel-reinforced concrete beams. When the effective prestress is increased from 222.15 KN to 279.61 KN, the ultimate bearing capacity increases by 14.8%. When the concrete strength is increased from 37.21 MPa to 47.97 MPa, the ultimate bearing capacity increases by 15.2%. When the stirrup ratio is 0.50%, compared with 0.25%, the ultimate bearing capacity increases by 7.8%. When the steel content is 5.41%, compared with 3.37%, the ultimate bearing capacity increases by 9.1%. The results of this study can provide a reference for future research and engineering applications of bond slip between section steel and concrete in prestressed steel-reinforced concrete beams in the future.

Effect of Co-content on microstructure, phases, and mechanical properties of laser additive manufactured Cox(CrNi)100-x alloy

This study describes the combination of mechanical properties of the CoCrNi medium entropy alloy system by tailoring its non-equiatomic compositions. The Laser Directed Energy Deposition (LDED) based Additive Manufacturing (AM) technique is deployed to fabricate the Cox(CrNi)100-x (x=40, 50, 60) alloy system. All compositions exhibit the formation of solidification substructures, with the refinement of subgrain size correlated with an increase in Co-content. The Co40 alloy exhibited a single-phase FCC structure, while Co50 (3.1 % ε-martensite) and Co60 (53.6 % ε-martensite) exhibited dual FCC+HCP structure during deposition. The combined effect of dislocation slip, deformation twinning, and deformation-induced HCP ε-martensite transformation strengthened the Co40 alloy during deformation. However, the Transformation-Induced Plasticity effect (TRIP) resulted in greater HCP ε-martensite transformation during deformation. Due to limited slip systems in the HCP structure, the Co60 alloy showed lower strength. The TRIP effect is highly dominant in Co60 alloy due to the prevalent HCP phase fraction in the initial samples. This led to stress concentration at FCC grain boundaries and ε-martensite, resulting in early failure of the alloy. With the increase in Co-content, the deformation mechanism changed from dislocation slip to deformation twinning to HCP ε-martensitic transformation. The LDED-built Cox(CrNi)100-x alloy system showed a good combination of strength and ductility. The study suggests that additive manufacturing is an easier and more suitable technique for obtaining compositions with the desired combination of mechanical properties.

Numerical Simulation of Non-Darcy Flow in Naturally Fractured Tight Gas Reservoirs for Enhanced Gas Recovery

In this work, we analyze non-Darcy two-component single-phase isothermal flow in naturally fractured tight gas reservoirs. The model is applied in a scenario of enhanced gas recovery (EGR) with the possibility of carbon dioxide storage. The properties of the gases are obtained via the Peng–Robinson equation of state. The finite volume method is used to solve the governing partial differential equations. This process leads to two subsystems of algebraic equations, which, after linearization and use of an operator splitting method, are solved by the conjugate gradient (CG) and biconjugate gradient stabilized (BiCGSTAB) methods for determining the pressure and fraction molar, respectively. We include inertial effects using the Barree and Conway model and gas slippage via a more recent model than Klinkenberg’s, and we use a simplified model for the effects of effective stress. We also utilize a mesh refinement technique to represent the discrete fractures. Finally, several simulations show the influence of inertial, slippage and stress effects on production in fractured tight gas reservoirs.

Significance of 3D rectangular closed domain filled with charged particles and nanoparticles engaging finite element methodology

Abstract This article aims to use passive flow control to analyze the transportation of heat, mass, and charged particles toward a 3D plate. The current problem offers a novel exploration of the flexible domain of non-Newtonian materials, which are well known for their wide range of applications in the engineering and industrial domains. The current study explores the complex dynamics of heat and mass transfer in a fluid that flows over an elongating sheet. The motion of the nanofluid on the surface is caused by the stretching of the 3D plate. The suspension of mixtures of tetra-hybrid nanoparticles can enhance thermal performance and cooling mechanism. Moreover, the 3D model includes modeling of multiple important parameters, such as heat source, thermal radiation, and Hall and Ion slip effects, in Cartesian coordinates for a three-dimensional stretched plate. This comprehensive analysis of various effects offers a new perspective to the field. Partial differential equations represent the emergent phenomena in the problem formulation process. It was estimated that an enhancement of charged particles and motion regarding nanoparticles is enhanced versus an enhancement of charged particles. With the greater power law index, suction, and Weissenberg number, the acceleration of nanoparticles is enhanced.

Effect of magnetic field and hydrodynamic slippage on electro-osmotic Brinkman flow through patterned zeta potential microchannel

Effect of magnetic field and hydrodynamic slippage on electro-osmotic Brinkman flow through patterned zeta potential microchannel