Asymmetric Channel Research Articles

Combined effects of Hall and ion-slip currents and heat transfer on peristaltic transport of a copper–water nanofluid

This work has looked at theoretically the peristaltic transport of copper–water nanofluid across an asymmetric horizontal channel with a constant applied magnetic field. Heat transfer and Hall and ion-slip currents are also taken into account. Long wave length and low Reynolds number are presumptions used in mathematical modeling. Exact analytic solutions for the present model are obtained. The expressions for the velocity field, stream function, pressure gradient, pressure rise, temperature distribution, and nanoparticle concentration are computed. The trapping phenomena have been also discussed. Graphics were used in the research to demonstrate how various factors impact the flow quantities of interest. According to the results, raising the Hall parameter or adding copper nanoparticles causes the base fluid velocity to increase at the channel’s center while decreasing toward the channel’s walls. Furthermore, it was found that, by increasing the magnitude of nanoparticle volume fraction or by adding copper nanoparticles, the Hall parameter has a diminishing influence on the pressure gradient, as well as on the temperature of the base fluid. In addition, the number of trapped boluses increases in the upper half of the channel as the Hall parameter, the volume fraction of nanoparticles, or the Grashof number increases. Exploring the combined effects of heat transfer, Hall and ion-slip currents, and peristaltic transport of a copper–water nanofluid is important for expanding our knowledge of basic science concepts related to fluid dynamics and heat transfer, as well as for real-world engineering and technological applications.

Magnetized peristaltic flow of Sisko nanofluid under thermal radiation and double-diffusive convection with viscous dissipation and slip effects in an asymmetric channel

The phenomenon of peristalsis has gathered significant attention from researchers due to its wide-ranging applications in fields such as biological sciences, industries, and biomechanics. Its practical relevance can be observed in various processes, including blending food in the digestive tract, flow in small blood vessels and the movement of cilia. Inspired by such useful applications, this theoretical study applies an analytical model that examines the movement of magnetically induced Sisko nanofluid in an asymmetric channel considering the factors like viscous dissipation, multiple slip, thermal radiation, and double diffusive convection. The fluid flow was administered using partial differential equations (PDE’s), transformed into a set of interconnected ordinary differential equations. These non-linear equations were further numerically solved by the NDSolve function in Mathematica. According to our outcomes, the temperature profile increases as the thermal slip factor rises. Moreover, the concentration and nanoparticle profile decrease with increasing values of the concentration slip and nanoparticle slip parameters. It can also determine that when the impact of thermal radiation increases, the temperature profile drops. Such a model has practical applications in simulating the small vessel transportation of particle in hemodynamics as well as in the field of biomedical and medical engineering for nanofluid peristaltic pumps.

Quasi-vertically asymmetric channels of graphene oxide membrane for ultrafast ion sieving

The high performance of two-dimensional (2D) channel membranes is generally achieved by preparing ultrathin or forming short channels with less tortuous transport through self-assembly of small flakes, demonstrating potential for highly efficient water desalination and purification, gas and ion separation, and organic solvent waste treatment. Here, we report the construction of vertical channels in graphene oxide (GO) membrane based on a substrate template with asymmetric pores. The membranes achieved water permeance of 2647 L m−2 h−1 bar−1 while still maintaining an ultrahigh rejection rate of 99.9% for heavy metal ions, which is superior to the state-of-the-art 2D membranes reported. Furthermore, the membranes exhibited excellent stability during long-term filtration experiments for at least 48 h, as well as resistance to ultrasonic treatment for over 100 minutes. The vertical channels possess very short pathway for almost direct water transport and a highly effective channel area, meanwhile the asymmetric porous template enhances the packing of the inserted GO nanosheets to avoid the swelling effect of membrane. Our work provides a simple way to fabricate vertical channels of 2D nanofiltration membranes with high water purification performance.

Analysis of an unsteady mucus flow through an isothermal channel with thermal conduction: An analytical solution

The human body regularly produces mucus, and its presence does not mean that something bad is going on. The boundary tissues of mammals, including the nose, throat and lungs, serve as a barrier against pollution and are produced by our respiratory system. Our work describes the flow comprehension of the components moulding the fluid elements of respiratory irresistible infections. A mathematical model is introduced to concentrate on the mucus fluid flow driven by natural convection through asymmetric channel. This study also summarized biological disorder of human lung build-up fluid. The nonlinear governing equations contain importance of heat transfer and fluid motion of mucus fluid. The analytic solutions of unsteady mucus flow through an isothermal channel with thermal conduction are accomplished adopting Laplace transform method. Significance of mucus fluid heat source thermal conductivity on momentum distribution and energy distribution is enumerated. The comparison of various dimensionless parameters is shown graphically with the help of MATLAB software. In order to provide some understanding on the behavior of mucus fluids and heat transfer mechanisms, extension of this study explores at how temperature influences mucus flow properties.

Channel-Hopping Sequence and Searching Algorithm for Rendezvous of Spectrum Sensing.

In this paper, we propose a method for applying the p-ary m-sequence as a channel-searching pattern for rendezvous in the asymmetric channel model of cognitive radio. We mathematically analyzed and calculated the ETTR when the m-sequence is applied to the conventional scheme, and our simulation results demonstrated that the ETTR performance is significantly better than that of the JS algorithm. Furthermore, we introduced a new channel-searching scheme that maximizes the benefits of the m-sequence and proposed a method to adapt the generation of the m-sequence for use in the newly proposed scheme. We also derived the ETTR mathematically for the new scheme with the m-sequence and showed through simulations that the performance of the new scheme with the m-sequence is superior to that of the conventional scheme with the m-sequence. Notably, when there is only one common channel, the new scheme with the m-sequence achieved approximately four times the improvement in the ETTR compared to the conventional scheme.

Radiation Effect on Inclined Peristaltic Couple Stress Fluid Flow in an Asymmetric Horizontal Channel

In the Present paper a theoretical investigation on the influence of radiation Impact on the couple stress fluid in an inclined horizontal channel with peristalsis is considered. The velocity, pressure gradient and frictional force are analyzed by utilizing numerical and analytical methods. The numerical outcomes are graphically represented with relevant numerical data in the scientific literature for the non-dimensional physical parameters. The observations show that the trapping fluid is removable and the magnetic field will substantially reduce central line axial velocity.

Characteristics of hydraulic jump in asymmetrical trapezoidal channel with rough beds: experimental investigations

Understanding the dynamics of hydraulic jumps is crucial for optimizing the design of stilling basins in dams, enhancing energy dissipation efficiency, and reducing corrosion risks in hydraulic structures. This work aims to investigate the effect of bed geometry and roughness on the properties of hydraulic jump in an asymmetric trapezoidal channel, including parameters such as sequential depths, roller length and energy loss. Experiments were carried out under open channel flow conditions using three different bottom roughness element heights and mm. The channel's bottom is inclined transversely with a slope of covering a wide range of inflow Froude Number . Results indicate that the increase in bottom roughness leads to a decrease in the subsequent depth ratio by 28.91% compared to a hydraulic jump in a smooth bed. It was also found that the average reduction in roller length on the shallow and deep sides is 21.62% and 20.4%, respectively. Increasing the height of the roughness element enhances the relative energy dissipation by 8.53%. Finally, empirical equations were developed to describe hydraulic jump characteristics based on the Froude number and roughness element height, aiding in the optimal design of stilling basins.

A numerical approach to study the energy dissipation effects on Couette–Hartmann flow of a nanoliquid within an asymmetrical channel

A numerical approach to study the energy dissipation effects on Couette–Hartmann flow of a nanoliquid within an asymmetrical channel

Peristaltic flow of magnetized hyperbolic tangent fluid through an asymmetric channel in the presence of homogeneous-heterogeneous reactions

The hyperbolic tangent fluid model accurately captures the shear-thinning phenomenon and is widely used in both laboratory experiments and industrial applications. The primary aim of this research is to investigate the key characteristics of the peristaltic flow of electrically conducting hyperbolic tangent fluid through an asymmetric channel, considering the effects of homogeneous and heterogeneous reactions. Slip conditions at the sinusoidal channel walls are also incorporated. The resulting nonlinear equations are solved using the lubrication theory approximation, which is particularly relevant for predicting physiological characteristics, such as blood flow dynamics. Analytical solutions for velocity, pressure gradient, streamlines, and concentration distributions are obtained using the regular perturbation technique. The influence of various parameters on these distributions is presented through graphical analysis. Additionally, the pressure rise per wavelength along the channel walls is computed numerically. The results indicate that homogeneous and heterogeneous reaction parameters exhibit opposing effects on the concentration field. Furthermore, increasing the magnetic parameter leads to a reduction in fluid velocity. This study has practical applications, including the use of peristaltic pumps in the chemical and pharmaceutical industries, particularly for drug delivery systems.

Exploring alpha emissions in neutron induced reactions via QMFT based dynamical cluster-decay approach

Abstract This study theoretically investigates alpha emission from compound nuclei formed in neutron-induced reactions, inspired by the experiments of Yu M. Gledenov et al. at Peking University, China. The research focuses on the decay dynamics of even-mass compound nuclei 144Nd* and 148Sm*, formed with neutron beam energies of 4 to 6 MeV. Employing the Dynamical Cluster-decay Model (DCM) based on Quantum Mechanical Fragmentation Theory (QMFT), high Q-value alpha emission channels 144Nd*→ 140Ce+α and 148Sm*→ 144Nd+α are explored. Cross-sections for alpha emissions are calculated by optimizing the neck-length parameter “∆R”, showing agreement with experimental data. Given the highly asymmetric incoming channel, the beam energy approximates the centre of mass energy (E beam≈E c.m. ). The study evaluates the impact of deformations, considering spherical and quadrupole-deformed configurations of the decaying fragments, and examines the alterations in potential energy surfaces. For deformed fragmentation, orientations are optimized for hot configurations. A comparative analysis of fragmentation structures, preformation profiles, and barrier characteristics is conducted between spherical and quadrupole-deformed fragmentation. The DCM’s collective clusterization approach treats all exit channels equally, emphasizing the formation of the preferred decay channel over competing channels such as fission. Observed changes in fragmentation profiles underscore the influence of nuclear parameters like angular momentum and deformations, providing insights into the dynamics of compound nucleus decay and the pivotal role of these parameters in shaping reaction outcomes.

Inertial aftermaths on peristaltic drive of MHD micropolar fluid in a two-dimensional asymmetric inclined porous soaked channel independent of wavelength: Galerkin finite element simulation

This manuscript presents a detailed investigation of the peristaltic propulsion of a micropolar fluid in an inclined asymmetric channel, which is also subjected to a magnetic field applied in the normal direction. The medium is considered to be a porous, saturated environment. Unlike traditional lubrication theory, which often assumes long wavelengths and negligible Reynolds numbers, our analysis does not adhere to these constraints. This approach introduces nonlinearity into the modeled equations and allows for significant Reynolds numbers, thereby enhancing our understanding of the peristaltic phenomenon. Numerical solution of coupled partial differential equations is gained by employing a novel Galerkin built finite element method and is presented through graphs of velocity and pressure distributions in accordance with variation in several flow parameters. Streamlines’ gyration, microrotation, and vorticity for different configurations that emerged with varying phase transitions are displayed in this regard as well. It is confessed that peristaltic mixing diminishes for all values of phase differences as the permeability parameter increases, while a rising Hartmann number significantly exacerbates this effect. In addition, the microrotation of micropolar particles is observed to become increasingly distorted with higher Reynolds numbers. Furthermore, the pressure rise throughout both pumping and co-pumping regions is enhanced when the inclined channel is subjected to a greater angle of inclination.

Manufacturer’s agency channel encroachment on an online retail platform

Channel encroachment intensifies competition among channels and changes the relationships within the supply chain. This study examines the manufacturer’s agency channel encroachment decision and its impact when it has already operated a platform reselling channel and a retailer channel on the platform. Equilibrium results reveal that the manufacturer’s agency channel encroachment triggers a competition effect, leading to a reduction in market demand for both the platform’s reselling channel and the retailer’s channel, as a larger share of the market shifts toward the manufacturer’s agency channel. To compensate for the losses in sales experienced by the platform and retailer, the manufacturer lowers the wholesale price. The manufacturer consistently benefits from channel encroachment and a Pareto improvement region exists, allowing all supply chain participants to improve their profits. The model is extended to consider sequential decision-making and asymmetric substitution. In comparison, under sequential decision-making, the manufacturer tends to focus more on the competitive effects of channel encroachment, leading to a reduction in channel sales. However, this approach only enhances the manufacturer’s agency profit when the retailer’s substitution capability is relatively strong. The manufacturer faces greater competitive pressure from the retailer under asymmetric channel substitution. Although the manufacturer increases the wholesale price and adjusts sales across channels according to the competitive situation, its profits are always lower than in the symmetric substitution case. The presence of a Pareto improvement region in the extended model confirms the robustness of our findings.

Determination of mode strengths in channel waveguide from the complex electric field

We show that the mode strengths of a guided field in an arbitrary asymmetric channel waveguide can be uniquely determined from self-referencing interferometric measurements at the exit plane of the waveguide. This requires knowledge of both the amplitude and phase of the complex electric field distribution. Although the amplitude can be obtained from the measured intensity profile easily, the phase retrieval is usually non-trivial. We develop an innovative, alternative and promising technique, where the complex cross-spectral density (CSD) function is measured using a customized wavefront folding interferometer. We then construct the total electric field (complex valued), from which we can determine the strengths of the allowed modes for an asymmetric strip waveguide. Our retrieval algorithm also provides the phase information (intermodal dispersion) associated with each mode, directly from the measured electric field distribution. Moreover, we experimentally demonstrate the developed scheme for different in-coupling (butt-coupling) conditions, resulting in different modal strength distributions.

Uncertainty analysis of MHD oscillatory flow of ternary nanofluids through a diverging channel: a comparative study of nanofluid composites

PurposeThis study aims to investigate the heat and mass transfer characteristics of a temperature-sensitive ternary nanofluid in a porous medium with magnetic field and the Soret–Dufour effect through a tapered asymmetric channel. The ternary nanofluid consists of Boron Nitride Nanotubes (BNNT), silver (Ag) and copper (Cu) nanoparticles, with a focus on understanding the thermal behaviour and performance across mono, hybrid and tri-hybrid nanofluids. This paper also examines the thermal behaviour of MHD oscillatory nanofluid flow and carries out an uncertainty analysis of the model using the Taguchi method.Design/methodology/approachThe governing equations for this system are transformed into coupled linear partial differential equations using non-similarity transformations and solved numerically with the Crank–Nicolson scheme. The impact of temperature sensitivity at three distinct temperatures (5°C, 20°C and 60°C) is incorporated to analyse variations in viscosity and Prandtl number. The study also examines the combined effects of Soret–Dufour numbers and thermal radiation on heat and mass transfer within the nanofluid.FindingsThe results demonstrate that the inclusion of BNNT, Ag and Cu nanoparticles significantly enhances heat and mass transfer rate, with copper nanoparticles showing superior performance in terms of skin friction and heat transfer rates. The Soret and Dufour effects play critical roles in modulating heat and mass diffusion within tri-hybrid nanofluids. The study reveals that temperature sensitivity alters heat and mass transfer characteristics depending on the temperature range, with pronounced variations at elevated temperatures. The influence of thermal radiation and the Peclet number is found to significantly impact temperature distribution and overall heat transfer performance within the asymmetric channel.Originality/valueTo the best of the authors’ knowledge, this study is the first to analyse the heat and mass diffusion in a ternary nanofluid composed of BNNT, Ag and Cu nanoparticles, considering porous media, oscillatory flow and thermal radiation within a tapered asymmetric channel. The research extends to a novel examination of temperature sensitivity in mono, hybrid and tri-hybrid nanofluids at varying temperature gradients. Furthermore, a comparative analysis of skin friction and heat transfer rates between copper, alumina and ferro composites is presented for optimising the nanofluid performance.

Influence of magnetic field and activation energy on creeping flow of tri-hybrid nanofluid driven by peristaltic pumping in an asymmetric channel with synthetic cilia

In this study we explored the effects of magnetic field and activation energy on creeping flow of Fe3O4-Zn-Ag/blood-based tri-hybrid nanofluid through an asymmetric channel adorned with synthetic cilia. Also incorporated double diffusion, heat and mass transfer effects via Porous medium is considered. The channel walls are covered with cilium that facilitates flow actuation. The mathematical model is formed for the present issue and non dimensionalised by employing the appropriate dimensionless parameters and solved the non linear partial differential equation by using Homotopy Perturbation method. The flow properties are examined for various factors. The concept of trapping has also been described using streamlines. The significant outcome of this study is that, due to ciliated wall velocity declines close to the channel’s walls and it develops at the centre, where as it shows exactly opposite nature to magnetic field. Additionally temperature and concentration increases with activation energy and they shows opposition to magnetic field. By raising the magnetic field and decreasing the cilium filament and eccentricity parameters, the trapped bolus shrinks in size. By incorporating nanoparticles into the basic fluid, nanofluid improves heat transmission. The radiated ternary nanofluid under magnetic field effects may help with cooling by eliminating additional heat from the system.

Unlocking Nanoprecipitation: A Pathway to High Reversibility in Nanofluidic Memristors.

Solid-state nanochannels have emerged as a promising platform for the development of ionic circuit components with analog properties to their traditional electronic counterparts. In the last years, nanofluidic devices with memristive properties have attracted special interest due to their applicability in, for example, the construction of brain-like computing systems. In this work, an asymmetric track-etched nanofluidic channel with memory-enhanced ion transport is reported. The results illustrate that the formation of nanoprecipitates on the channel walls induces memory effects in ion transport, leading to characteristic hysteresis loops in the current-voltage curves, a hallmark of memristive behavior. Notably, these memristive properties are achievable with a straightforward experimental setup that combines an aqueous solvent and a relatively low-soluble inorganic salt. The various conductance states can be rapidly and reversibly tuned over prolonged time scales. Furthermore, under appropriate measurement conditions, the nanofluidic device can alternate between different iontronic regimes and states, encompassing ion current rectification, ON-OFF states, and memristor-like behavior. These findings provide insights into the design and optimization of nanofluidic devices for bioinspired ionic circuit components.

Electroosmotic peristaltic transport of magnetohydrodynamic Casson nanofluid in a non-uniform wavy porous asymmetric micro-channel

Magnetohydrodynamics (MHD) have numerous engineering and biomedical applications such as sensors, MHD pumps, magnetic medications, MRI, cancer therapy, astronomy, cosmology, earthquakes, and cardiovascular devices. In view of these applications and current developments, we investigate the magnetohydrodynamic MHD electro-osmotic flow of Casson nanofluid during peristaltic movement in a non-uniform porous asymmetric channel. The effect of thermal radiation, heat source, and Hall current on the Casson fluid peristaltic pumping in a porous medium is taken into consideration. The effect of chemical reactions is also considered. The mass, momentum, energy, and concentration equations were constructed using the proper transformations and dimensionless variables to make them easier for non-Newtonian fluids. A lubricating strategy is used to make the system less complicated. The Boltzmann distribution of electric potential over an electric double layer is studied using the Debye–Huckel approximation. The temperature and concentration equations are addressed using the homotopy perturbation method (HPM), while the exact solution is determined for the velocity field. The study examines the performance of velocity, pressure rise, temperature, concentration, streamlines, Nusselt, and Sherwood numbers for the involved parameters using graphical illustrations and tables. Asymmetric channels exhibit varying behavior, with velocity declining near the left wall and accelerating towards the right wall while enhancing the Casson fluid parameter. The pumping rate boosts in the retrograde region due to the evolution of the permeability parameter value, while it declines in the augment region. The temperature profile optimizes as the value of the heat source parameter gets higher. The concentration profile significantly falls as the chemical reaction parameter rises. The size of the trapped bolus strengthens with a spike in the parameter for the Casson fluid.

An inclined magnetic field and slip effect on heat and mass transfer analysis in the peristaltic flow of immiscible fluid through an asymmetric porous channel

In this work, authors have studied peristaltic flow of immiscible type of couple stress and Newtonian fluid via an asymmetric horizontal channel filled with porous material by taking slippage into account at the channel wall which was ignored in previous published literature under the influence of thermal radiation and magnetic field. The study of peristaltic flow of considered immiscible fluids will play an important role in maximizing system efficiency, reducing energy losses, and improving performance of various fluid transport. In the present problem, the linearized form of governing equations has been solved by direct method with the use of Mathematica 14 software to obtained the closed form solutions of various flow variables. In this work, the impacts of various influencing factors on the model's flow, thermal, and concentration properties have been analyzed graphically. The work presented here leads to the significant result that large Schmidt number values in a porous filled duct reduces the mass diffusivity. Another key finding of this work is that the formation of entropy is reduced when low permeability porous material is used. Our research concludes that entropy creation in the asymmetric porous channel is decreased when the slip length increases on the channel's static borders.

Shadow fading analysis over asymmetric beam channel at 2.1 GHz in outdoor scenarios

AbstractIn this letter, we investigate the radio propagation characteristics in an open outdoor place through a frequency‐domain channel measurement campaign at a frequency band of 2.1 GHz via asymmetric beam patterns. Specifically, we focus on the large‐scale fading characteristics and analyze the transceivers' separation‐dependent and boresight direction‐dependent received power, shadow fading (SF), and SF auto‐correlation properties under the case of perfect beam alignment. Furthermore, the effects of asymmetric beamwidths are also thorough investigated. The measured results reveal that transceivers' beams can reduce the shadow fading variances evidently in contrast to the omnidirectional antennas' case. Besides, it is found that the pattern where mobile receiver (Rx) uses narrow beams and static transmitter (Tx) adopts the omnidirectional antenna yields a high SF auto‐correlation value compared to the other beam patterns. The conclusions help to understand the impacts of variable beamwidths on radio propagation.

A computation analysis with heat and mass transfer for micropolar nanofluid in ciliated microchannel: With application in the ductus efferentes

Inherited heat enhancement capabilities and their significance in the field of medical sciences and industry make nanofluids the focus of research nowadays. Furthermore, due to the remarkable advancements in bionanotechnology and its significance in biomedical fields such as drug delivery systems, cancer tumor therapy, bioimaging, and many others, it has emerged as a key research area. Contribution of cilia for the flow in ductus efferentes of human male reproductive tract is elaborated. A novel mathematical scheme is presented for the heat and mass transfer of MHD micropolar nanofluid transport in an asymmetric channel lined with cilia. The pertinent equations of nanofluid transport are exposed to lubrication approximation theory and solution for the physical problem is examined with efficient bvp4c technique in MATLAB. Fluid rheology is explored with the variations of different transport parameters like Hartmann number, Grashof number, Brownian motion, buoyancy, thermophoresis and Darcy number. It is reported that nanofluid transport is affected with rise in the Lorentz force and show reverse behavior with rising permeability. The temperature of the nanofluid in ciliated microchannel is raised with enhanced value of Hartmann number, Grashof number, Prandtl number, and Darcy number while diffusion phenomenon of nanofluid is slowed down with these parameters. Spinning motion of the nanofluid is enhanced with Grashof number and slow down with nanoparticle Grashof number and different behavior is recorded for Darcy and viscosity parameters in different flow regime. Reported investigation presents crucial findings for ciliary transport of micropolar nanofluid and tackled with appropriate selection of micropolar parameter, Brownian motion parameter, thermophoresis and Grashof number. Moreover, this investigation will be handful for cilia-based actuators which work as micro-mixers in controlling the flow in minute bio-sensors and may prove their worth in micro-pumps employed in various drug-delivery systems.