Non-uniform Channel Research Articles

Modeling and interpretation of peristaltic transport of Eyring–Powell fluid through uniform/non-uniform channel with Joule heating and wall flexibility

The primary focus behind this research work is to unfold the characteristics of peristaltic transport of Eyring–Powell fluid through uniform/non-uniform channel. Consideration of wall flexibility as well as Joule heating is one of the key factors of this investigation. Implementation of small Reynolds number and large wavelength concepts leads to a reduction in the complexity of the system. The governing two-dimensional coupled differential equations are simplified after incorporating dimen- sionless variables. Graphical demonstrations for velocity, temperature, concentration profiles have been sketched out under the influence of pertinent flow parameters. Numerical values for the rate of mass as well as heat transfers are presented in tabular form. One of the most important occurrence regarding peristaltic movement namely trapping phenomenon has also been highlighted by means of circulating bolus through contour plots. Noteworthy findings are that for both uniform and non-uniform channels, Eyring–Powell fluid parameters exhibit a tendency to reduce the fluid velocity as well as the temperature of the fluid. Apart from this, another significant observation is that higher values of both velocity and temperature fields are observed in non-uniform channel as compared to uniform channel. Rate of heat transfer is enhanced due to an increment in Eyring–Powell fluid parameters for different types of non-uniform channels. Also for both the kind of channels, the cur- rent study explores that magnetic parameter and Eyring–Powell fluid parameter show a prominent impact on the trapping phenomenon. • Peristaltic transport of Eyring–Powell fluid through uniform/non-uniform channel. • Behaviours of wall flexibility as well as Joule heating are taken into consideration. • Rate of heat transfer is enhanced due to an increment in Eyring–Powell fluid parameters for different types of non-uniform channels. • The results are well described by graphically and tables.

Stamping of Nonuniform Channels. 6. Fibrous Structure in Channel Extrusion. 6.3. Determining the Basic Characteristics of the Fibrous Structure

Stamping of Nonuniform Channels. 6. Fibrous Structure in Channel Extrusion. 6.3. Determining the Basic Characteristics of the Fibrous Structure

Stamping of Nonuniform Channels. 6. Fibrous Structure in Channel Extrusion. 6.2. Formulas and Their Application

Stamping of Nonuniform Channels. 6. Fibrous Structure in Channel Extrusion. 6.2. Formulas and Their Application

Permeability model establishment and experimental verification of a tree-like branching structure with conventional scale

Permeability is usually only used in the study of porous media with micro-scale characteristics. It is a challenge to accurately calculate permeability for T-shaped branching structures with conventional sizes and non-uniform flow channels. To solve this problem, we derived a theoretical model for the equivalent permeability of the T-shaped tree-like branching structure (TLBS) and the entire microchannel plate (EMP) based on the generalized Darcy's law and the principle of series and parallel solution of equivalent permeability. In order to verify the correctness of the proposed theoretical model, six T-shaped TLBSs with different scale ratios were randomly designed. Experimental values of the permeability of all structures were obtained indirectly by measuring the pressure at both ends of the entrance and exit. The experiments showed that the calculated results of the theoretical model are in good agreement with the experimental results. The average relative error between theoretical calculations results and experimental results is only 3% minimum and 12% maximum in the study range. This study demonstrates that the proposed theoretical model of permeability is reasonable for TLBSs with conventional scales. This provides a new perspective for analyzing the fluid transport performance of fractal-like networks with conventional scales.

Influence of variable velocity slip condition and activation energy on MHD peristaltic flow of Prandtl nanofluid through a non-uniform channel

This study is carried out to analyze the problem of mixed convection magnet nanoflow of Prandtl fluid through a non-uniform channel with peristalsis. The external influences of activation energy and non-constant velocity slip are given full consideration. The mentioned fluid is expressed as a governing equations system, and then these equations are converted with non-dimensional parameter values to a system of ordinary differential equations. The converted system of equations is solved in terms of y and then graphs and sketches are offered using the generalized differential transform method. Graphs and results for volume friction as well as velocity profile, concentration, and temperature distributions are obtained. Results show development in the velocity profile of fluid distribution through high values of the non-constant velocity slip effect. The present study is alleged to deliver more opportunities to advance the applications of the drug-carrying system in hypoxic tumor areas with aid of identifying the flow mechanisms.

Peristaltic Transport of Fractional Jeffrey Fluid in a Nonuniform Channel: Role of heat transfer

Peristaltic Transport of Fractional Jeffrey Fluid in a Nonuniform Channel: Role of heat transfer

Stamping of Nonuniform Channels. 6. Fibrous Structure in Channel Extrusion. 6.1. Basic Principles

Stamping of Nonuniform Channels. 6. Fibrous Structure in Channel Extrusion. 6.1. Basic Principles

Hybrid double-diffusivity convection and induced magnetic field effects on peristaltic waves of Oldroyd 4-constant nanofluids in non-uniform channel

The aim of this work is to relate the Soret and Dufour parameters of peristaltic flow in magneto Oldroyd 4-constant nanofluids in non-uniform channel. The discussion explores the numerical modelling of Oldroyd 4-constant nanofluids with convective double diffusion under induced magnetic flux. The use of a low finite Reynolds number and a long wavelength simplify non-linear partial differential equations. Numerical method is applied to solve reduced differential equation. Furthermore, the exact solutions of nanoparticle, temperature and concentration are computed. The graphical and numerical presentation show the significance of different physical parameters. The results reveal the fact that the greater value of Soret number and Brownian motion parameter decreases the concentration nanosolid particle. In addition, molecular kinetic energy transforms into thermal energy by random collision in the process of micro-mixing of nanoliquid resultantly raise the temperature of the liquid. Moreover, the magnetic force function increases due to enhancing electric field and magnetic Reynolds number.

Thermal spreading characteristics of novel radial pulsating heat pipes with diverging nonuniform channels

The heat-spreading performance of a pulsating heat pipe (PHP) can be enhanced by increasing the driving force using a novel channel structure. The objective of this study is to investigate the thermal characteristics of novel radial PHPs with diverging channels under horizontal operation. The heat spreading characteristics of radial PHPs with diverging uniform channels (PHP1) and nonuniform channels (PHP2) were measured and analyzed under various working fluids, filling ratios, and heat inputs. HFE-7100, HFE-7200, and ethanol were used as the working fluids. Furthermore, the flow patterns and pressure variations in the PHPs within a short time frame were analyzed. Based on the measured data for both PHPs, the optimum filling ratio for each working fluid was determined to achieve the maximum performance. In addition, the maximum thermal performances of PHP1 and PHP2 were evaluated, aiming to achieve the lowest thermal resistance and maximum heat flux. Overall, the thermal resistance and heat flux of PHP2 were 5.9–11.7% lower and 20–37.5% higher than those of PHP1, respectively.

Multiple effects of non-uniform channel width along the cathode flow direction based on a single PEM fuel cell: An experimental investigation

Proton exchange membrane (PEM) fuel cell is considered to be one of the promising alternatives to conventional engines in the future as on-board vehicle energy conversion device. In this paper, three single PEM fuel cells with different cathode flow field plates (FFPs), which vary from each other on the channel width along the cathode flow direction, are assembled. Polarization and power density curves, electrochemical impedance spectroscopy (EIS) fitting results are utilized to evaluate the output performance. Moreover, the economic characteristic of three single cells is calculated based on the assumption of parasitic pumping power generated by air compressor. Finally, the durability of three single cells is assessed based on comparison of electrochemical surface area (ECSA) obtained from analysis of cyclic voltammetry (CV) method. The comprehensive experimental results reveal that cell 0.8-1.0-1.2 exhibits better performance under high RH conditions and cell 1.0-1.0-1.0 is more favorable under a low RH condition. The mechanism behind the phenomenon of performance variation is analyzed and attributed to the switching of dominating factor from two-phase flow velocity to spatial availability degree under various conditions of RH.

Numerical Investigation of Thermal-Hydraulic Performance of Printed Circuit Heat Exchanger with Different Fin Shape Inserts

The printed circuit heat exchanger is one of the most recent important heat exchangers, especially in the nuclear power plant and aerospace applications, due to its very compact geometry and small print foot. This paper presents a 3D numerical investigation of the thermo-hydraulic performance of PCHE with a new non-uniform channel design configuration. The new channel design consists of two different fins and shape inserts: the diamond and biconvex shapes. The influence of two design parameters on the heat exchanger performance was studied and optimized, the longitudinal and transverse pitch length (Pl) and (Pt). Air with constant properties as the working fluid with constant heat flux at the walls envelope. The Reynolds number varied from 200 to 2000. Different Pitch lengths were used (Pl=20, 30, 40, and 50) mm and (Pt=3, 4, and 5) mm. Three performance parameters were studied the Nusselt number, friction factor, and the overall performance evaluation factor. Results show that the thermal performance enhanced with decreasing the pitch lengths, and it was shown that this enhancement was found only at high Reynolds numbers above 1400. The higher enhancement factor was with NACA 0020 airfoil fins at pt=3 mm and pl=20mm of η=2.75 at Re=2000, while the worst performance was obtained with biconvex fins. The main reason behind the enhancement is the disruption of the boundary layer and the good mixing induced in the fluid flow.

Effects of Double Diffusive Convection and Inclined Magnetic Field on the Peristaltic Flow of Fourth Grade Nanofluids in a Non-Uniform Channel.

This study explored the impact of double diffusive convection and inclined magnetic field in nanofluids on the peristaltic pumping of fourth grade fluid in non-uniform channels. Firstly, a brief mathematical model of fourth grade fluid along inclined magnetic fields and thermal and concentration convection in nanofluids was developed. A lubrication approach was used to simplify the highly non-linear partial differential equations. An analytical technique was then used to solve the highly non-linear differential equations. The exact solutions for the temperature, nanoparticle volume fraction and concentration were calculated. Numerical and graphical outcomes were also examined to see the effects of the different physical parameters of the flow quantities. It was noted that as the impact of Brownian motion increased, the density of the nanoparticles also increased, which led to an increase in the nanoparticle fraction. Additionally, it could be observed that as the effects of thermophoresis increased, the fluid viscosity decreased, which lowered the fraction of nanoparticles that was made up of less dense particles.

A Steady-State LDMOST Model Based on Semi-Numerical Regional Approach

This paper presents a high-voltage lateral DMOS transistor (LDMOST) model for steady-state condition.The device modelling method is basically based on a semi-numerical regional approach.The complete model is physical, so that it accounts for unique LDMOST features such as non-uniform channel doping, non-planar drift region and space-charge-limited current flowing.Themodelcalculationsshow good overall agreement withthe measured results.This DMOS transistor model, whichcan beapplicable to a SPICE-like circuit simulator, might be useful in technology CAD of high-voltage power ICs.

Heat Transport Exploration for Hybrid Nanoparticle (Cu, Fe3O4)-Based Blood Flow via Tapered Complex Wavy Curved Channel with Slip Features.

Curved veins and arteries make up the human cardiovascular system, and the peristalsis process underlies the blood flowing in these ducts. The blood flow in the presence of hybrid nanoparticles through a tapered complex wavy curved channel is numerically investigated. The behavior of the blood is characterized by the Casson fluid model while the physical properties of iron (Fe3O4) and copper (Cu) are used in the analysis. The fundamental laws of mass, momentum and energy give rise the system of nonlinear coupled partial differential equations which are normalized using the variables, and the resulting set of governing relations are simplified in view of a smaller Reynolds model approach. The numerical simulations are performed using the computational software Mathematica’s built-in ND scheme. It is noted that the velocity of the blood is abated by the nanoparticles’ concentration and assisted in the non-uniform channel core. Furthermore, the nanoparticles’ volume fraction and the dimensionless curvature of the channel reduce the temperature profile.

Experimental study on sub-cooled flow boiling heat transfer in inclined non-uniform heating tube bundle channel

Since the specific structure of the U-tube, non-uniform heating (NUH) occurs on the shell side of the U-tube steam generator or exchanger. When the above equipment are applied in ocean environments, they may be in an inclined condition. The coupled conditions of NUH and incline can enhance the complexity of the heat transfer on the shell side, especially in terms of the sub-cooled flow boiling, during which the heat transfer mechanism changes. In this paper, sub-cooled flow boiling in a tube bundle channel under the coupled conditions of NUH and incline are performed experimentally. The result shows that the Gungor-Winterson correlation is in good agreement with the experimental data under uniform heating (UH) conditions and the mean relative error is only about 10.05%, while the predicted ability is poor under the coupled conditions of NUH and incline. The heat transfer characteristics are affected by radial heat and mass transfer, convective flow, bubbles behavior, and bubbles migration, which are introduced by the coupled action of NUH and incline. At last, an improved Gungor-Winterson correlation is proposed for UH, NUH, and inclined NUH conditions. Its average relative error is only 5.56% in total, and less than 0.91% of data has a larger deviation than 15%.

Terahertz radiation generation from self-focused amplitude modulated gaussian pulse in non-uniform plasma channel

This paper presents an analytical investigation of terahertz generation by self-focused amplitude modulated Gaussian laser beam at modulation frequency in non-uniform plasma channel. Due to intensity variations transverse to the propagating laser, a ponderomotive is generated. Attempts have been made to derive ponderomotive force, which generates transient transverse nonlinear current. The analytical expression for beam width parameter and amplitude of THz radiation have been derived. The self-focusing of amplitude modulated Gaussian laser beam in non-uniform channel and its effect on generated THz amplitude have been studied. It is observed that increase in the value of non-uniformity, self-focusing enhances and shifts towards lower value of propagation distance which further enhance the THz amplitude. In this study, we obtained a normalized power of the order of 10−4times the original power supplied by the laser beam by self-focusing the laser beam.

Stamping of Nonuniform Channels. 5. Calculation Methods for Channel Extrusion. 5.5. Other Methods of Controlling the Extruded Flow

Stamping of Nonuniform Channels. 5. Calculation Methods for Channel Extrusion. 5.5. Other Methods of Controlling the Extruded Flow

Thermal convection in nanofluids for peristaltic flow in a nonuniform channel

A magneto couple stress nanofluid flow along with double diffusive convection is presented for peristaltic induce flow through symmetric nonuniform channel. A comprehensive mathematical model is scrutinized for couple stress nanofluid magneto nanofluids and corresponding equations of motions are tackled by applying small Reynolds and long wavelength approximation in viewing the scenario of the biological flow. Computational solution is exhibited with the help of graphical illustration for nanoparticle volume fraction, solutal concentration and temperature profiles in MATHEMTICA software. Stream function is also computed numerically by utilizing the analytical expression for nanoparticle volume fraction, solutal concentration and temperature profiles. Whereas pressure gradient profiles are investigated analytically. Impact of various crucial flow parameter on the pressure gradient, pressure rise per wavelength, nanoparticle volume fraction, solutal concentration, temperature and the velocity distribution are exhibited graphically. It has been deduced that temperature profile is significantly rise with Brownian motion, thermophoresis, Dufour effect, also it is revealed that velocity distribution really effected with strong magnetic field and with increasing non-uniformity of the micro channel. The information of current investigation will be instrumental in the development of smart magneto-peristaltic pumps in certain thermal and drug delivery phenomenon.

RETRACTED: Concentration-dependent electrical and thermal conductivity effects on magnetoHydrodynamic Prandtl nanofluid in a divergent–convergent channel: Drug system applications

In the early era, thermal energy has a significant concern for all investigations that is caused due to its applications in engineering processes. So, this work introduces a new model for electrical and thermal conductivity effects on MagnetoHydrodynamic (MHD) peristaltic flow of Prandtl nanofluid in a nonuniform channel. Electrical and thermal conductivity is considered a nonconstant in the fluid concentration. Double-diffusivity convection, magnetic field, Joule heat, and thermal convection are taken into consideration. A new model is proposed as a system of partial differential equations. Consequently, it simplified to a strong nonlinear flow system of ordinary differential equations. Semi-numerical solutions of velocity, temperature, concentration, and nanoparticle volume fraction were obtained by the adaptive shooting technique. The main concern of obtaining results is that the nonconstant electrical and thermal conductivity increases the effect of Hartmann number on temperature profile than the others that are found in the case of constant electrical and thermal conductivity. The proposed model is thought to improve electronic applications like refrigerators, heat engines, air conditioning, and heat pump.

Stamping of Nonuniform Channels. 5. Calculation Methods for Channel Extrusion. 5.4. Methods of Controlling the Extruded Flow

Stamping of Nonuniform Channels. 5. Calculation Methods for Channel Extrusion. 5.4. Methods of Controlling the Extruded Flow