Different Values Of Physical Parameters Research Articles

ANALYSIS OF UNSTEADY FREE CONVECTION OVER A VERTICAL PLATE FOR KEROSENE-BASED NANOFLUID

An analysis of kerosene-based nanofluid flow past a semi-infinite vertical plate is carried out numerically. A set of unsteady, nonlinear governing equations are derived, namely, the momentum, energy, continuity, and concentration equations. The Crank-Nicolson implicit finite difference scheme is used to solve the governing equations. It is unconditionally stable. Based on different values of physical parameters, the velocity, temperature, and concentration profiles across the boundary layer are depicted. Graphs comparing the heat transfer characteristics of Newtonian fluids with local and average, skin friction, Nusselt number, and Sherwood number are provided. With an increasing value of the Prandtl number of kerosene-based nanofluid the local skin friction coefficient decreases while the Nusselt number increases. Furthermore, the Sherwood number decreases as the Prandtl number increases.

Recent progress in Cattaneo-Christov heat and mass fluxes for bioconvectional Carreau nanofluid with motile microorganisms and activation energy passing through a nonlinear stretching cylinder

AimsIn the current study, the flow of Carreau nano-fluid through the stretched cylinder is subject to the influences of activation energy and heat source/sink with the Cattaneo-Christov heat fluxes model studied. Applications in recent times are the purpose of better heat and mass transport nanoparticles used for this purpose because of their better thermal conductivity than normal fluids. Nanofluids are used in medicines like agricultural sprays and with time it is used in the microprocessor for cooling and also used in the refrigeration industry as coolant. MethodologyThe mathematical model was developed by taking these things into account and getting a model of nonlinear partial differential equations for administering this problem. These governing equations system modified into a system of ODE by utilizing appropriate similarity transform. For numerical computation or simulation, the ‘bvp4c’ built-in package of MATLAB is used to implement the shooting technique. Smooth implementation took place by introducing a set of variables to make our system dimensionless. Results/ConclusionGraphical representation depicts the profiles of concentration, velocity, thermal, and microorganism density, and the impacts of various modeling quantities on these profiles are also discussed and elaborated. In tabular analysis, a contrast of computed outcomes with the previously available outcomes shows the accuracy of our computed results at different values of physical parameters. The presence of motile microorganisms improved the heat transfer rate.

Wave propagation in a non-local magneto-thermoelastic medium permeated by heat source

In this paper, we consider the new concept of non-local heat conduction equation to generalized magneto-thermoelastic problem of two dimensional isotropic and homogeneous half-space in presence of heat-flux at the boundary surface. By using the harmonic plane waves, the governing equations are transformed to the vector matrix differential equation which is then solved by eigenvalue method. The analytical closed form solutions for displacement component, temperature distribution and stress components have been made and comparisons are also illustrated graphically with the theory of non-local dual-phase-lag (NLDPL) and non-local Lord-Shulman (NLLS) theory for different values of physical parameters. The significant effects of non-local variables as well as phase lagging parameters on displacements, temperature distribution and stress components are studied by means of graphically and concluding remarks are drawn.

Technical Simulation for the Hydromagnetic Rotating Flow of Carreau Fluid with Arrhenius Energy and Entropy Generation Effects: Semi-Numerical Calculations

The present study aimed to investigate the influence of activation energy on the MHD Boundary layer of Carreau nanofluid using a semi-numerical/analytical technique. The governing formulated system of partial differential equations (PDEs) subject to appropriate boundary conditions is shortened to ordinary differential equations (ODEs) by convenient transformations. Generalized Differential Transform (GDTM) is used and compared with the Runge–Kutta Dahlberg method to find the results of the proposed system. GDTM is chosen to cure and overcome the highly non-linear differentiation parts in the present system of ODEs. Gradients of velocity, temperature, and concentration are computed graphically with different values of physical parameters. The solutions are offered in two cases, the first in the case of non-Newtonian fluid (We=0.2) and the other in the case of base fluid (We=0.2), which is concluded in the same figure. The accuracy of GDTM is tested with many existing published types of research and found to be excellent. It is worth-mentioned that the distribution of velocity growths at high values of power index law relation. This fluid model can be applied in solar energy power generation, ethylene glycol, nuclear reactions, etc.

Entropy generation of magnetohydrodynamic pulsating flow of micropolar nanofluid in a porous channel through Cattaneo–Christov heat flux model with Brownian motion, thermophoresis and heat source/sink

The current article is to address the entropy generation on pulsating hydromagnetic flow of a micropolar nanofluid in a porous channel with the effects of Cattaneo–Christov heat flux and Buongiorno nanofluid model. This model is significant in the field of pressure surges, food processing systems, biomedical engineering, cancer therapeutic, artificial kidney, brain tumors, and nano-drug delivery in the arteries. The governing partial differential equations are converted into the system of ordinary differential equations by deploying the perturbation process then solved numerically by employing the fourth-order Runge–Kutta scheme with the support of the shooting technique. The flow variables like velocity, microrotation, temperature, nanoparticle concentration, entropy generation, and Bejan number are graphically depicted for different values of physical parameters. The heat transfer and mass transfer rates are displayed through a table. The velocity is diminishing with the enhancement of coupling parameter and Hartmann number. The temperature of nanofluid is increasing with the rising values of thermal radiation, Brownian motion, thermophoresis, and heat source while it is reduced with an enhancement of magnetic field, thermal relaxation time, and heat sink parameter. The total entropy generation is diminished by increasing the values of Hartmann number and Brownian motion.

Twin Peak Quasi‐Periodic Oscillations and Stability via Thin‐Shell Formalism of Traversable Wormholes in Symmetric Teleparallel Gravity

AbstractThis article explores the wormhole geometry in the background of symmetric teleparallel gravity or gravity, where is the non‐metricity term, and definite subject for the gravitational interaction. All the energy conditions are investigated for two different generic shape functions. The presence of exotic matter is confirmed due to the violation of the energy conditions. The epicyclic orbits of test particles around wormhole throat for the considered models are discussed. Twin peak Quasi‐periodic oscillations are calculated and presented with the required behavior. We also explore the physical characteristics and stable configuration of thin‐shell developed from the matching of inner obtained solution of wormhole geometry and outer black hole solution in gravity. The stability of shell is discussed by using the speed of sound parameter for both choices of shape functions, i.e., and . It is found that the position of event horizon does not change for different values of the physical parameter for the choice of while it changes for . We explore the proper length, shell energy and entropy of the developed structure for different values of physical parameters.

Response surface methodology (RSM) and artificial neural network (ANN) simulations for thermal flow hybrid nanofluid flow with Darcy-Forchheimer effects

The goal of this study is to examine the radiative properties of a Cu−Al2O3/water hybrid nanofluid with respect to joule heating and suction effects over a stretched sheet. The copper and aluminium oxide nanoparticles are used to increase the thermal impact of water base fluid. The Darcy-Forchheimer theory is used to endorse the inertial and porous media effects and makes the model more interesting from the physical scenario. The partial differential equations (PDEs) are converted to nonlinear ordinary differential equations (ODEs) through similarity transformation and then numerically solved using the shooting technique with the assistance of a built-in function in Maple software. The impacts of relevant parameters on temperature and velocity profiles, as well as local Nusselt number and skin friction, are discussed. A derivative-based sensitivity analysis is performed to determine different values of physical parameters that affect response functions (skin friction coefficient, Nusselt number) under a given set of assumptions. The effect of the suction, magnetic, and permeability parameters on the solutions is observed to be significant. On the decreasing surface, an increase in copper nanoparticle volume fractions induces an improvement in local skin friction and a decrease in local Nusselt number. Moreover, in order to predict the skin friction and local Nusselt number, we employed an artificial neural network (ANN). This study revealed that the ANN method can predict skin friction and local Nusselt number (R2=0.98 and R2=0.99 respectively). As a result, this study is useful for engineers and scientists who want to learn about the features of the flow, its behavior, and how to anticipate it.

Hall effect on MHD Jeffrey fluid flow with Cattaneo–Christov heat flux model: an application of stochastic neural computing

Exploration and exploitation of intelligent computing infrastructures are becoming of great interest for the research community to investigate different fields of science and engineering offering new improved versions of problem-solving soft computing-based methodologies. The current investigation presents a novel artificial neural network-based solution methodology for the presented problem addressing the properties of Hall current on magneto hydrodynamics (MHD) flow with Jeffery fluid towards a nonlinear stretchable sheet with thickness variation. Generalized heat flux characteristics employing Cattaneo–Christov heat flux model (CCHFM) along with modified Ohms law have been studied. The modelled PDEs are reduced into a dimensionless set of ODEs by introducing appropriate transformations. The temperature and velocity profiles of the fluid are examined numerically with the help of the Adam Bashforth method for different values of physical parameters to study the Hall current with Jeffrey fluid and CCHFM. The examination of the nonlinear input–output with neural network for numerical results is also conducted for the obtained dataset of the system by using Levenberg Marquardt backpropagated networks. The value of Skin friction coefficient, Reynold number, Deborah number, Nusselt number, local wall friction factors and local heat flux are calculated and interpreted for different parameters to have better insight into flow dynamics. The precision level is examined exhaustively by mean square error, error histograms, training states information, regression and fitting plots. Moreover, the performance of the designed solver is certified by mean square error-based learning curves, regression metrics and error histogram analysis. Several significant results for Deborah number, Hall parameters and magnetic field parameters have been presented in graphical and tabular form.

Slit flow and thermal analysis of micropolar fluids in a symmetric channel with dynamic and permeable

The mass and thermal flow of micropolar fluid in a channel having permeable and moving walls perpendicular to the flow-direction is considered here. A mathematical formulation for this physical problem is made using the Eringen's micropolar fluid-thermal model. Closed form solutions for temperature, microspin of aciculate particle and velocity are derived using the double perturbation method followed by the similarity transformation for the Newtonian/micropolar fluids. The perturbation parameters are the Reynolds number (that controls the wall-injection/suction) and the wall dilation parameter (that controls the rate of flow through the pores). Usually the no-spin conditions are imposed on studying the micropolar fluid-flows, but we consider no-spin condition in this attempt in order to highlight effect of micropolar spin boundary layer in the vicinity of the walls of the channel. The convergence of the perturbation method is checked, that sounds well. The results obtained for particular case (Newtonian fluid) are compared with alike literature and they are found satisfactory. The results for velocity, temperature, shear stress, thermal transfer rate and spin are presented for different values of physical parameters quantitatively and qualitatively.

Non-similarity method for heat and mass transfer of MHD radiative flow over exponentially stretching sheet

In this paper a modification of existing mathematical model of MHD radiative incompressible fluid-flow over exponentially stretching sheet is given by accumulating equation of mass transfer under an influence of chemical reaction. Using local non-similarity variables method, governing equations for heat and mass transfer of viscous fluid-flow are efficiently remodeled into the system of dimensionless PDE, and later on the obtained system of dimensionless PDE is tack?led numerically using MATLAB built in solver bvp4c. Graphs of temperature, velocity and concentration profiles are explained through variation of different values of physical parameters. Significant effects of several parameters, for example radiation and magnetic parameters, Eckert and Prandtl numbers on local skin-friction coefficient, local Nusselt and Sherwood numbers are computed in tabular form.

Radiative mixed convective flow induced by hybrid nanofluid over a porous vertical cylinder in a porous media with irregular heat sink/source

PurposeHybrid nanofluids have higher mechanical resistance, thermal conductivity, chemical stability, and physical strength when compared to normal nanofluids. Our approach in the current paper is to present a novel exploration comprising radiative mixed convection flow of hybrid nanofluids with irregular heat source/sink effect through a porous vertical cylinder immersed in a porous media. Both opposing and assisting flows are discussed. MethodologyThe transmuted similarity ODEs are numerically worked out utilizing the assist of the bvp4c package in MATLAB for different values of physical parameters. The hybrid nanofluids contain a couple of nanoparticles namely aluminum and copper particles with water as base fluid. FindingsIt was observed that fundamental similarity equations disclose double solutions (first and second branches) for buoyancy assisting and opposing flows. The drag force is enhanced due to the radiation as well as curvature parameters. In addition, the velocity declines due to heat source/sink and radiation parameter. Originality/valueThe writers agree that all numerical outcomes are novel and have not previously been published for the current problem.

MHD natural convection in nanofluid filled square cavity with isothermally heated hexagonal block

This article explores the influence of natural convection heat transfer in a square enclosure with hexagonal block filled by Al2O3-H2O nanofluid in presence of external magnetic field. The two vertical walls of the enclosure are kept at constant cold temperature, Tc, and the top horizontal wall is insulated whereas the remaining walls of the enclosure are maintained high temperature, Th. The governing equations are formulated using Boussinesq approximations and solved numerically employing built-in-finite element method and then presented graphically in terms of streamlines, isotherms, average Nusselt number and average temperature. It is found that the different values of physical parameters: Rayleigh number (Ra = 103 -106), nanoparticle volume fraction (ϕ = 1% -5%) and Hartman number (Ha = 0-100) affects the streamlines, isotherm contours and heat transfer rate. Comparison of the present results with previously published results on the basis of special cases has been performed and found to be a good agreement.

Pulsating electrically conducting flow of Au/SWCNTs-blood micropolar nanofluid in a porous channel with Ohmic heating, thermal radiation

The present article addresses the pulsating hydromagnetic flow of a micropolar nanofluid in a porous channel with the existence of thermal radiation and Joule heating (Ohmic heating). Micropolar fluid is considered as blood (base-fluid) and Au(gold)/SWCNTs(single-walled carbon nanotube) are taken as nanoparticles. The fluid is injected into the channel along with a constant velocity from the bottom wall and is squeezed out at the same rate from the top wall. The perturbation approach can be used to change the governing partial differential equations (PDEs) into ordinary differential equations (ODEs), and are subsequently solved by employing the shooting technique with the help of the Runge-Kutta fourth-order scheme. The flow variables like velocity, microrotation, and temperature of nanofluid are graphically depicted and discussed in detail for different values of physical parameters. The heat transfer rate is calculated and displayed through a table. The comparative results for Au and SWCNTs with blood as base fluid are simulated. Such findings bring out that the velocity of nanofluid decreases over an enhancement of coupling parameter, volume fraction of nanoparticles, and Hartmann number. The temperature of nanofluid is increasing with the rising values of Eckert number, Hartmann number, and radiation parameter while it is reducing with an enhancement of coupling parameter, volume fraction of nanoparticles, and cross-flow Reynolds number. Further, the results revealed that the Nusselt number is increasing with rising values of the radiation parameter and Eckert number.

Numerical approach for enhanced mass transfer of Bio-convection on Magneto-hydrodynamic Carreau fluid flow through a nonlinear stretching surface

The present study deals with an investigation of steady two dimensional flow of Carreau fluid covering both the motile microorganism and nanoparticles through a nonlinear stretching surface. The idea of microorganisms is implied just to stabilize suspended nanoparticles by convection. The governing PDEs (partial differentiable equations) are transform set of nonlinear ODEs (ordinary differentiable equations) using suitable similarity transformation. The higher order nonlinear differential equation is solved by using Runge-Kutta-Felhberg method with shooting technique. The performance of fluid microorganism density, concentration, temperature, velocity in different values of physical parameters are scrutinized. Here the numerical results are presented through graphs and tables. Numerical values of skin friction, local Nusselt, Sherwood and local density numbers are analyzed. This study is relevant to navel microorganisms using few technologies combining with the Nano fluid with Bio-convection.

Cross diffusion and heat generation effects on mixed convection stagnation point MHD Carreau fluid flow in a porous medium

In this study, a two-dimensional mixed convective MHD stagnation point flow of Carreau fluid past an infinite plate in a porous medium is studied. Effects of cross-diffusion, thermal radiation, heat generation, and chemical reaction are considered. The governing partial differential equations are remodelled into ordinary differential equations by using similarity transformation. The HAM is employed to solve the system of ordinary differential equations. Velocity, temperature and concentration are presented with several values of different physical parameters through the graph. It is depicted that, velocity profiles decrease via mixed convection and buoyancy force parameter for Newtonian Carreau fluid, whereas in non-Newtonian Carreau fluid those parameters have reverse effects on it. Thermal radiation and heat generation tend to improve heat transfer process. Magnetic field, mixed convection and buoyancy force parameter tend to improve velocity and concentration gradient, whereas thermal radiation and heat generation have reverse effects on it.

Study of structural order–disorder thermal dependence dielectric properties for PbHPO4 and PbHAsO4 crystals

By using the statistical Green function theory and extended two sublattice pseudospin lattice coupled mode model Hamiltonian for proton subsystem with mean field approximation on hydrogen bonds have been used to interpret structural phase transition thermal dependence dielectric properties in PbHPO $$_{4}$$ and PbHAsO $$_{4}$$ ferroelectric compounds. By using the retarded thermal Green function theory and Hamiltonian along with Dyson approach, the expressions for ferroelectric soft mode frequency, dielectric permittivity and dielectric tangent loss have been derived. With the putting of the model values of different physical parameters in theoretical derived expressions, the thermal dependence of ferroelectric normal mode frequency, relative permittivity and dielectric loss has been calculated for both ferroelectric compounds in two structural phases. With the help of proper fitting of model parameters, valuable theoretical results for corresponding experimental results have been calculated.

An efficient semi-analytical method for solving the generalized regularized long wave equations with a new fractional derivative operator

In this work, the newly developed optimal perturbation iteration technique with Laplace transform is applied to the generalized regularized long wave equations with a new fractional operator to obtain new approximate solutions. We transform the classical generalized regularized long wave equations to fractional differential form by using the Atangana-Baleanu fractional derivative which is defined with the Mittag-Leffler function. To show the efficiency of the proposed method, a numerical example is given for different values of physical parameters.

The flow behaviour of blood in two-phase time-dependent tapered stenosed artery in the presence of transverse magnetic field

In this study, a tapered stenosed artery is considered to notice the effect of transverse magnetic field applied on blood flow to analyze the behavior of the flow with the help of significant flow attributes. The laminar, incompressible and fully developed flow of blood is studied taking into account the variable viscosity. To resemble the problem to real life situation, flow in core region is assumed to be non-Newtonian and flow in peripheral region is assumed to be Newtonian. The constitutive equation of blood is represented by Bingham plastic model in peripheral region and Herschel–Bulkley model in core region. The simulations are carried out for important flow characteristics such as wall shear stress, volumetric flow rate and axial velocity and the behavior is analyzed. We have reported numerical results for different values of physical parameters of interest. Biological implications of the present model are discussed. It has been observed that the important flow attributes are affected in tapered artery with stenosis and it is possible to stabilize the flow with the help of magnetic field applied externally. It is also noticed that the behaviour of flow attributes found by considering variable viscosity is in good agreement with the literature as compared to constant viscosity.

Dielectric Properties of Deuterated Cesium Dihydrogen Phosphate Crystal

Modified two sublattice pseudospin lattice coupled-mode model Hamiltonian has been applied to study the dielectric properties of deuterated cesium dihydrogen phosphate crystal. With the help of model Hamiltonian and Green’s function theory, the theoretical expressions for normal mode frequency, dielectric constant and loss tangent are derived. By fitting the model values of different physical parameters, the thermal dependence of the above quantities has been calculated. Our theoretical obtained results are well compared with experimental data.

Study of Heat Transfer under the Impact of Thermal Radiation, Ramped Velocity, and Ramped Temperature on the MHD Oldroyd-B Fluid Subject to Noninteger Differentiable Operators

This theoretical study explores the impact of heat generation/absorption with ramp wall velocity and ramp wall temperature on the magnetohydrodynamic (MHD) time-dependent Oldroyd-B fluid over an unbounded plate embedded in a porous surface. The mathematical analysis of fractional governing partial differential equations has been established using systematic and powerful techniques of Laplace transform with its numerical inversion algorithms. The fractionalized solutions have been traced out separately through all fractional differential operators. Nondimensional parameters along with Laplace transformation are used to find the solution of temperature and velocity profiles. Fractional time derivatives are used to analyze the impact of fractional parameters (memory effect) on the dynamics of the fluid. While making a comparison, it is observed that the fractional-order model is the best to explain the memory effect as compared to classical models. The obtained solutions are plotted graphically for different values of physical parameters. Our results suggest that the velocity profile decreases by increasing the effective Prandtl number. Furthermore, the existence of an effective Prandtl number may reflect the control of the thickness of momentum and enlargement of thermal conductivity.