Lubrication Approach Research Articles

Electroosmotically assisted peristaltic propulsion of blood-based hybrid nanofluid through an endoscope with activation energy

The main aim of this research work is to analyze the peristaltic pumping of hybrid nanofluid through an endoscope. Here, blood is considered as base fluid and iron-oxide and gold are considered as nanoparticles. The non-Newtonian behavior of blood is studied through the Casson fluid model. The effect of nanoparticles is included in the mathematical formulation by using the modified version of Buongiorno model. Moreover, the effects of motion due to electroosmosis, activation energy, and Joule heating are also considered in fluid flow. The obtained non-linear system of equations after imposing lubrication approach is solved using Mathematica. The flow properties subject to variation in different involved parameters is analyzed through graphical results. It is assessed from graphical results that for larger Casson fluid parameters, fluid flow is more accelerated. It is also observed that presence of hybrid nanoparticles improves the velocity profile as well as cooling tendency of the working fluid when compared with the case of mono nanofluid. The electroosmotic phenomenon works a key parameter that can control the fluid flow by either assisting and opposing the flow. It has observed that a larger Debye length parameter, assisting electric field, and larger activation energy parameter reduce the nanoparticle concentration.

Role of silver nanoparticle in thermal energy process regulated by peristalsis

Electroosmosis regulated model of peristalsis with nanoparticles is significant for heat transfer efficiency regarding optimization of thermal energy process. Such investigation is useful for processes in nano-drug delivery systems, pharmacology, renewable energy, energy saving, drying, biochip fabrication, Sensing and imagining, hyperthermia, cryosurgery, oil mobility improvement, filtration and purification, drilling, cell separation and microelectro-mechanical Systems (MEMS). Therefore, mixed convective peristaltic flow of nanomaterial filling porous medium is addressed. Asymmetric flow configuration is taken. Nanomaterial comprising silver and water is considered. Thermal radiation and dissipation are invoked. Peristaltic pumping is studied under the process of electroosmosis. Electroosmosis process is modeled by Nernst-Planck and Poisson equations. Debye-Huckel assumption is used for electric potential distribution along electron double layer. Velocity slip and convective boundary constraints are considered in this analysis. Dimensionless equations are presented employing lubrication approach. Related problems have been computed numerically. Behaviors of temperature, velocity, pressure gradient and streamlines are examined graphically. Heat transfer coefficient is also studied. Result shows that temperature decreases by volume fraction of nanoparticle. Pressure gradient decays for larger porosity. Temperature reduces for larger radiation. Rate of heat transfer enhances by Grashof number whereas it reduces by volume fraction of nanoparticles.

Collision of liquid drops: bounce or merge?

Whether colliding drops will merge with or bounce off each other is critical to numerous processes, and the physics involved is notoriously complex. In particular, experiments show that both sufficiently slow and fast head-on drop collisions lead to merging, but that there is often an intermediate regime in which bouncing is observed; these transitions in behaviour were recently discovered to be surprisingly sensitive to the radius of the drops and the ambient gas pressure. We show here that these transitions between bouncing and merging are governed by nanoscale phenomena; namely, gas-kinetic and disjoining pressure effects. To capture these crucial effects, a novel, open-source computational model is developed for the simulation of colliding drops. The model uses a hybrid approach, based on solving the Navier–Stokes equations in the drop with a lubrication approach for the unconventional physics of the gas film. Our simulations show remarkably good agreement with experiments of head-on collisions and also provide new experimentally verifiable predictions.

Nanofluid minimum quantity lubrication assisted grinding force model considering anisotropy of SiCf/SiC ceramic matrix composites

SiCf/SiC ceramic matrix composites with excellent thermal stability, light weight and oxidation resistance have become key components in advanced aircraft engines. Nanofluid minimal quantity lubrication (NMQL) exhibits significant potential in enhancing heat transfer and lubrication efficiency during the grinding process. The technological challenge lies in thoroughly investigating the theoretical variation rule of grinding force, assisted by nanofluid minimal quantity lubrication, and subsequently achieving low-damage machining of SiCf/SiC composites. In this study, a prediction model for the grinding force during NMQL-assisted grinding was established, integrating diverse lubrication methods, grinding wheel geometric parameters, wear degree, process parameters, the anisotropy and damage degree of SiCf/SiC composites. The model was subsequently experimentally validated through grinding tests conducted on SiCf/SiC composites under various conditions, including dry grinding (DG), flood grinding (FG), minimum quantity lubrication (MQL), and carbon nanotube nanofluids (NMQL-CNTs), across multiple grinding depths. The present investigation’s grinding force forecasting model is evidenced to possess high accuracy of precision, showcasing mean deviations of 6.64 % and 11.97 % in the perpendicular (Fn) and tangential (Ft) grinding force components, respectively. Additionally, employing NMQL-CNTs facilitates the achievement of minimal grinding force and surface finish quality. At depths of 0.4 mm and 0.6 mm during grinding, the mean Fn magnitudes under the NMQL-CNTs lubrication approach underwent a decrease of 66.7 % and 74.5 %, respectively, in contrast, the mean Ft magnitudes experienced a reduction of 55 % and 67.2 %, correspondingly, in comparison to the DG lubrication technique. Notwithstanding the consistency in the material’s brittle removal mechanism across varying lubrication strategies, the NMQL-CNTs approach effectively alleviates fiber abrasion. Concisely, the research presented herein provides foundational theoretical insights and practical technological assistance for the achievement of low damage SiCf/SiC composite processing.

Entropy generation in Johnson–Segalman peristaltic flow with magnetic field and activation energy

AbstractThis study examines entropy generation in the peristaltic flow of Johnson–Segalman fluid through a curved channel, considering the effects of Hall and ion slip due to an externally applied magnetic field and activation energy. The fluid dynamics are modeled using a highly nonlinear mathematical framework, which is non‐dimensionalized and simplified with a lubrication approach. Numerical solutions are obtained using the shooting technique to analyze fluid flow properties. The results, presented graphically, provide a comprehensive understanding of the interactions between the non‐Newtonian characteristics of the Johnson–Segalman fluid, entropy generation, and activation energy effects. The study finds that increasing the Hall parameter enhances entropy generation. Higher activation energy increases the rate of chemical reactions and by‐products, raising system randomness. Additionally, reducing the channel curvature or increasing the curvature parameter elevates the system's entropy. These insights are valuable for biomedical and industrial applications.

A peristaltic motion for pressure driven flow of Casson nanoliquid along with gyrotactic microorganisms in an entropic porous channel: A numerical study

Pump designs can be optimized for maximum energy efficiency, reduced waste, and enhanced overall performance by taking entropy factors into account. In this regard, the current investigation concentrates on examination of thermodynamic analysis for bio-convection peristaltic phenomenon of a non-Newtonian Casson nanofluid in an asymmetrical elastic channel by considering the generation of entropy. The pressure driven flow is managed by using lubrication approach and converting the system in to laboratory (wave) frame. The resulting findings of physical expressions together with the surface conditions are tackled by shooting numerical algorithm on conventional software Mathematica with the help of built-in tool (NDSolve). Graphical attitude of numerous physical quantities (entropy generation, Bejan number, and velocity profile, density of gyrotactic motile microorganisms and nanoparticles volume fraction) is also added and the results are equated with the existing literature. After detailed discussion on graphical display, it is concluded that with porosity of the medium helps to get the entropy generation reduced while, with the increase in bio-convection Peclet value, the micro-organisms’ density declines. The results of the study can be of great significance in the fields of nanotechnology, bio-microsystems and Bio-nano cooling phenomenon.

Advancing Machinability of Ti-6Al-4V Alloy: A Sustainable Integrated Approach

Abstract Titanium alloys are indispensable materials in numerous industries, including aerospace, medical, and dental fields. This prevalence is due to their unique properties, such as their high strength-to-weight ratio, corrosion resistance, low thermal expansion, and biocompatibility. On the other hand, the machinability of these materials faces a dual challenge: their low thermal conductivity, which confines heat within the cutting zone, and their chemical reactivity with the tool material. This work aims to explore and comprehensively evaluate the advancement in cooling and lubrication approaches that have been introduced to enhance the machinability of Ti-6Al-V alloys. Despite the numerous positive outcomes observed with recently employed techniques such as reduced friction, lowered temperatures, and prolonged tool life. These methods and techniques are either not accepted yet or limitedly accepted within the industry due to the inherent weaknesses and limitations of each technique. This work introduces a new integrated and sustainable concept that can surmount the challenges associated with previous approaches, aiming for more sustainable machining of Ti-6Al-4V alloys. The suggested integrated concept may overcome the lubrication, cooling, cost, and environmental problems of the recently used approaches.

A novel cooling and lubrication approach: Device development and machining performance evaluation of ultrasonic vibration–assisted MQL

A novel cooling and lubrication approach: Device development and machining performance evaluation of ultrasonic vibration–assisted MQL

Viscous dissipation and Joule heating in case of variable electrical conductivity Carreau–Yasuda nanofluid flow in a complex wavy asymmetric channel through porous media

This paper focuses on flow structures and thermal fields of the Carreau–Yasuda (CY) nanofluid model through a two-dimensional, wavy, complicated vertical asymmetrical conduit filled with porous elements. Formulations of the viscous dissipation in the case of CY nanofluids are derived and nonlinear radiation flux as well as joule heating are examined. Buongiorno’s nanofluid approach, which involves Brownian motion and thermophoresis aspects is considered. The electrical conductivity of the suspension is considered as a variable where it depends upon the ambient temperature and concentration distributions and the Joule heating impacts are not neglected. The approach of solving the problem is contingent upon converting the system to dimensionless form then the lubrication approach with low magnetic Reynold numbers is applied. Numerical solutions are found for the resultant system, and wide ranges are considered for Weissenberg number We, non-Newtonian parameter n and Darcy number [Formula: see text], namely, [Formula: see text], [Formula: see text] and [Formula: see text], respectively. The major results indicated that gradients of the pressure are higher in case of shear thickening [Formula: see text] comparing to in the instance of shear thinning [Formula: see text]. Also, the velocity is enhanced, close to the channel’s lowest portion, as the Weissenberg number is growing. The variable electrical conductivity gives a higher mass transfer rate compared to the constant property.

Entropy generation analysis for hybrid nanofluid mobilized by peristalsis with an inclined magnetic field

The purpose of the present study is to analyse the entropy generation for the hybrid nanofluid mobilised by peristalsis. The hybrid nanoliquid is suspension of copper [Formula: see text] and iron-oxide [Formula: see text] nanoparticles in water. Impacts of magnetic field, Joule heating, mixed convection, heat source/sink and viscous dissipation are reckoned. Governing set of equations are simplified by using lubrication approach. Obtained system of differential equations are solved numerically. Special attention is paid to analyse the effects of hybrid nanomaterial, Hartman and Grashoff numbers on entropy generation, Bejan number, axial velocity, temperature, heat transmission rate at walls, pressure gradient, skin friction, Nusselt number. Flow behaviour is visualised through streamlines. The study reveals that velocity and temperature decrease on increasing the volume fraction of solid nanomaterials. Higher Grashoff and Hartman numbers augment both velocity and temperature. Better heat transfer performance is recorded for strong Hartman number. [Formula: see text] and [Formula: see text] improve Entropy generation and Bejan number. Higher Hartman number causes decrement in pressure gradient. Addition of nanoparticles concentration reduces skin friction. High flow rate increases trapping phenomenon.

Ultra-low friction system using special wetting interfaces: Bridging across various wetting regimes

Friction was the main way of energy loss in society, and reducing friction has become a focal point in current research. Inspired by special wetting phenomena, an asymmetric multiphase composite (AMPC) friction system was constructed. Tribological behavior of the friction system was evaluated using hydrogel on anodized aluminum as friction pair and superhydrophobic alumina with micro/nano-composite as substrate. Ultra-low friction coefficients (∼10−3) were measured under both Cassie and Wenzel regimes. Especially in Wenzel state, increased contact stress or extended shear rate promoted the formation of transfer lubricant film, thus enabling the ultra-low friction coefficient. Moreover, the system showed mechanical stability during prolonged water lubrication. This novel lubrication approach may provide valuable scientific solutions for specific tribology applications.

Complex cilia-generated flow of hybrid nanofluid with electroosmosis, viscous dissipation and slippage

In this study, we investigated how electroosmsis, viscous dissipation, and slippage affect the peristaltic flow of complex cilia-generated flow of hybrid nanofluid in a ciliated tube. The complex cilia-generated flow is characterized by a complex sinusoidal wave that transmits along the wall of the tube with a uniform speed having distinct amplitudes. The main objective of this work is to examine how this complex cilia on the wall drives the hybrid nanofluid flow under electroosmosis. The Helmholtz–Smoluchowski equation is used to model the electroosmosis, and the Poisson equation is solved analytically using the Debye-Huckel approximation. The lubrication approach is utilized to simplify the governing equations. The governing non-dimensional equations for hybrid nanofluid are solved exactly using the DSolve command of Mathematica. The results are presented graphically to accomplish the theoretical results from the complex-cilia wave evolution from the necessary flow parameters in an asymmetric tube. The study shows that increasing the electroosmotic parameter leads to an increase in the velocity profile at the boundary and a decrease in the middle of the tube. Conversely, the Helmholtz–Smoluchowski velocity parameter has the opposite effect. The Brinkman parameter increases the temperature of the hybrid nanofluid. The study also presents a graphical analysis of pressure rise and pressure gradient for various values of the parameters. The pressure rise against volumetric flow is rate and pressure gradient increases by increasing the electroosmotic parameter and Helmholtz-Smoluchowski parameter, while it decreases for increasing the velocity slip parameter. The streamlines are drawn to study the trapping phenomena of blood in the hybrid nanofluid flow in an asymmetric tube by the formation of bolus and the division of streamlines. It is observed that the size and number of bolus close to the artery walls increases for electroosmotic parameter while reverse behavior is observed for Helmholtz-Smoluchowski parameter. The tabular presentation of the heat transfer coefficient at the wall is presented. The current results can be used in bio mathematical models to control fluid flow through micro-channels and to investigate ways to cure artery blockages and cancer tumors in biomedicine. The study can also be used to design and optimize microfluidic devices for drug delivery, lab-on-a-chip devices, and other biomedical applications.

Peristalsis of Carreau–Yasuda nanofluid possessing variable thermal conductivity regulated by electroosmosis via an expanding asymmetric channel

Peristalsis of non-Newtonian nanofluid via a non-uniform conduit has several applications in physiology and industry. This study proposes a mathematical model as well as exploration of the impacts of entropy generation for peristalsis of magneto nanofluid with temperature-dependent thermal conductivity via an expanding asymmetric channel. Buongiorno’s model for study of nanofluid flow has been adopted. Rheological aspects are accounted using the Carreau–Yasuda model due to its experimentally validated significance. Impacts of applied electric and magnetic fields have been taken into account. Thermophoresis, ohmic heating, viscous heating and Brownian motion effects are incorporated in the model. Numerical method is used via NDSolve in Mathematica after implementing the lubrication approach and Debye–Huckel linearization. The effects of embedded parameters on the flow, heat transfer, entropy generation and Bejan number are studied using graphical depictions. Outcomes indicate that a rise in electroosmotic parameter enhances heat transfer rate, whereas it reduces entropy generation and mass transfer rate at the boundary. Therefore, this study can provide basics to study nanofluidic systems which has applications in drug delivery. Increasing trends for temperature, heat transfer rate and entropy generation, while declining trends in the concentration of the particles are noted for higher joule heating.

Bayesian inference-based wear prediction method for plain bearings under stationary mixed-friction conditions

This study introduces a method to predict the remaining useful life (RUL) of plain bearings operating under stationary, wear-critical conditions. In this method, the transient wear data of a coupled elastohydrodynamic lubrication (mixed-EHL) and wear simulation approach is used to parametrize a statistical, linear degradation model. The method incorporates Bayesian inference to update the linear degradation model throughout the runtime and thereby consider the transient, system-dependent wear progression within the RUL prediction. A case study is used to show the suitability of the proposed method. The results show that the method can be applied to three distinct types of post-wearing-in behavior: wearing-in with subsequent hydrodynamic, stationary wear, and progressive wear operation. While hydrodynamic operation leads to an infinite lifetime, the method is successfully applied to predict RUL in cases with stationary and progressive wear.

Numerical study for bioconvection peristaltic flow of Sisko nanofluid with Joule heating and thermal radiation

Present work describes the peristaltic flow of Sisko nanomaterial with bioconvection and gyrotactic microorganisms. Slip conditions are incorporated through elastic channel walls. Additionally, we considered the aspects of thermal radiation and viscous dissipation. Further ohmic heating features are also present in the thermal field. Buongiorno's nanofluid model comprising thermophoresis and Brownian movement is taken. The lubrication approach is utilized for the simplification of the problem. Being highly coupled and nonlinear, the resulting system of equations must be solved numerically using the NDSolve technique and bvp4c via Matlab. Velocity, concentration, thermal field and motile microorganisms. are addressed graphically.

Contribution of electromagnetism in lowering entropy in microchannel

The study examined how entropy can be reduced in an asymmetric microchannel with sinusoidal walls by analyzing the flow of an incompressible micropolar fluid that is electrokinetically driven. The study takes into account the effects of Ohmic and viscous dissipation of energy in a magnetohydrodynamic environment. To model electroosmotic phenomena, the Poisson equation and Nernst–Planck equation were used, which were simplified using Debye–Huckel linearization and a small ionic Peclet number. The energy, rotational momentum, mass, and momentum equations for the micropolar fluid were constructed and linearized using a lubrication approach before being solved analytically. The resulting expressions for velocity microrotation and temperature were then used to compute the Bejan number and the formation of entropy number The study also examined the effects of various thermophysical parameters and discussed their potential applications in fields such as biomedical engineering, pharmaceuticals, energy conservation, cancer treatment, and manufacturing. The findings suggest that entropy generation can be reduced by increasing the micropolar coupling number and temperature difference parameter This study provides a theoretical guide for the operation and thermal control of flow actuation systems with asymmetric geometry.

Numerical Analysis to Investigate the Impact of Skirt Geometric Parameters on Secondary Piston Movement in a Single-cylinder Diesel Engine

Currently, modern internal combustion engines are receiving great attention due to their efficiency, particularly in response to the increasing limits imposed by environmental and emission legislation. Sound emissions of internal combustion engines are mainly caused by three sources of noise: combustion, mechanical and aerodynamic flow. The secondary motion of the piston plays a crucial role in the analysis of performance, noise, vibration and reliability of internal combustion engine (ICE). In the presented article, a mathematical simulation model has been developed by using of the GT-Suite software to study the rotational and lateral motion of the piston (called secondary motion) as well as the piston slap in ICE. This model takes into account the effect of variation in the major geometric parameters of the skirt design, such as the piston pin offset (P.P.O) and the length of the skirt. Furthermore, a combined model that accounts for the interplay between the secondary dynamics of the piston and the dynamic fluid lubrication has been developed. This model utilizes a mixed lubrication approach for the purpose of simulation. The results of this simulation have demonstrated that the variations in length of the skirt and the P.P.O have a considerable effect on piston secondary motion and tribological performances, and that the lateral motion of the piston is significantly influenced by the piston side force, which plays a crucial role in this behavior.

A multiphase ciliary flow of Casson fluid in a porous channel under the effects of electroosmosis and MHD: Exact solutions

The electro-osmosis effects on ciliary multiphase flow have broad applications in diverse fields, including microfluidics, biotechnology, chemical engineering, and environmental sciences. In the current analysis, the authors have elaborated the electro-osmosis effects on a ciliary two-phase channel flow of Casson fluid in the presence of solid particles and magnetic effects. The governing equations have been considered for the physical problem by applying the wave frame and dimensionless transformations. A lubrication approach has also been followed by the equations. Systems of differential equations have been solved on well-known software Mathematica by a built-in DSolve tool to acquire the exact solutions. From graphical evidences, it is observed that Helmholtz Smoluchowski velocity factor and solid particles contribution affects the electro-kinetic energy and reduces the flow speed.

Hall impact on peristaltic stream of Prandtl hybrid nano-blood via a tapered endoscopic annular vessel with blood clotting

This research article is proposed to frame and simulate the peristaltic transport mechanism with heat and mass transfer behavior of bloodstream infused with hybridized nanoparticles (Cu and CuO) via a tapered endoscopic annular vessel under the act of highly strengthened magnetic and buoyancy forces. The consequences of Brownian motion, thermophoresis, heat source, viscous and Joule heating are presumed for heat and mass transport examination. Darcy law is postulated to describe the porous medium's attribute to the blood flow dynamics. Prandtl fluid model is invoked to emulate the non-Newtonian behavior of the blood with the suspension of hybridized nanoparticles. The modeled equations are condensed by employing the lubrication approach. The homotopy perturbation technique is implemented to determine the optimal series solution of the coupled nonlinear subsequent equations. The physical aspects of diverse emerging parameters on the underlying hemodynamical features are delineated and pondered via plotting graphs. The trapping event is elucidated in the form of contour designs. Outcomes extract that a higher Hartmann number depreciates the blood motion adjacent to the peristaltic wall, while the opposing manner attends for augmenting Hall parameter. It is also testified that more trapped boluses are generated for hybrid nano-blood (Cu-CuO/blood) contrasted with other cases.

Impacts of entropy generation for nonlinear radiative peristaltic transport of Powell-Eyring nanofluid: A numerical study

The importance of mathematical simulation in studying biological fluids extends to various medical disciplines. The peristaltic process is crucial for comprehending different biological flows. Additionally, nanoparticles serve essential functions in a range of engineering and industrial applications, such as heat exchangers, boilers, cooling systems, and chemical engineering. This current study addresses the numerical investigation of entropy optimization for (magnetohydrodynamic) MHD peristaltic activity of Eyring-Powel nanoliquid. Here channel boundaries are flexible in nature. Effects of mixed convection and hall current were also considered. Slip conditions are imposed on channel walls. Viscous dissipation and nonlinear thermal radiation are also present in thermal transport. Brownian movement and thermophoresis aspects are considered in the nanoliquid model. Chemical reaction of order first is also present the mass transport. Simplification of transport expressions is done by operating lubrication approach. The resulting system of nonlinear equations is numerically tackled. Both numerical techniques for heat transfer rate are validated by comparing them to numerical results computed by MATLAB using bvp4c and NDSolve. Graphical analysis is carried out for different flow parameters by plotting velocity, temperature, concentration, and entropy.