Magnetohydrodynamic free convection boundary layer Flow of non-Newtonian tangent hyperbolic fluid from a vertical permeable cone with variable temperature

The nonlinear, non-isothermal steady-state boundary layer flow and heat transfer of an incompressible tangent hyperbolic non-Newtonian (viscoelastic) fluid from a vertical permeable cone with magnetic field are studied. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using the second-order accurate implicit finite difference Keller-box technique. The numerical code is validated with previous studies. The influence of a number of emerging non-dimensional parameters, namely a Weissenberg number (We), rheological power law index (m), surface temperature exponent (n), Prandtl number (Pr), magnetic parameter (M) suction/injection parameter (fw) and dimensionless tangential coordinate (ξ) on velocity and temperature evolution in the boundary layer regime, is examined in detail. Furthermore, the effects of these parameters on surface heat transfer rate and local skin friction are also investigated. It is observed that velocity, surface heat transfer rate and local skin friction are reduced with increasing Weissenberg number, but temperature is increased. Increasing m enhances velocity and surface heat transfer rate but reduces temperature and local skin friction. An increase in non-isothermal power law index (n) is observed to decrease the velocity and temperature. Increasing magnetic parameter (M) is found to decrease the velocity and increase the temperature. Overall, the primary influence on free convection is sustained through the magnetic body force parameter, M, and also the surface mass flux (injection/suction) parameter, fw. The rheological effects, while still prominent, are not as dramatic. Boundary layers (both hydrodynamic and thermal) are, therefore, most strongly modified by the applied magnetic field and wall mass flux effect. The study is pertinent to smart coatings, e.g., durable paints, aerosol deposition processing and water-based solvent thermal treatment in chemical engineering

Radiative and magnetohydrodynamics flow of third grade viscoelastic fluid past an isothermal inverted cone in the presence of heat generation/absorption

A mathematical analysis is presented to investigate the nonlinear, isothermal, steady-state, free convection boundary layer flow of an incompressible third grade viscoelastic fluid past an isothermal inverted cone in the presence of magnetohydrodynamic, thermal radiation and heat generation/absorption. The transformed conservation equations for linear momentum, heat and mass are solved numerically subject to the realistic boundary conditions using the second-order accurate implicit finite-difference Keller Box Method. The numerical code is validated with previous studies. Detailed interpretation of the computations is included. The present simulations are of interest in chemical engineering systems and solvent and low-density polymer materials processing

Simulation of natural convection heat transfer in a 2-D trapezoidal enclosure

Natural convection within trapezoidal enclosures finds significant practical applications. The natural convection flows play a prominent role in the transport of energy in energy-related applications, in case of proper design enclosures to achieve higher heat transfer rates. In the present study, a two-dimensional cavity with adiabatic right side wall is studied. The left side vertical wall is maintained at the constant hot temperature and the top slat wall is maintained at cold temperature. The dimensionless governing partial differential equations for vorticity-stream function are solved using the finite difference method with incremental time steps. The parametric study involves a wide range of Rayleigh number, Ra, 10(3)<ra<10(5) and Prandtl number (Pr=0.025, 0.71 and 10). The fluid flow within the enclosure is formed with different shapes for different Pr values. The flow rate is increased by enhancing the Rayleigh number (Ra=10(4)). The numerical results are validated with previous results. The governing parameters in the present article, namely Rayleigh number and Prandtl number on flow patterns, isotherms as well as local Nusselt number are reported

Entropy generation in magnetohydrodynamic radiative non-Newtonian dissipative convection flow from an inclined plane : numerical study

A theoretical model is developed to study entropy generation in non-Newtonian magnetohydrodynamic thermal convection from an inclined plate as a simulation of electroconductive polymer materials processing of relevance to automotive coating applications. High temperature invokes radiative effects which are analysed with the Rosseland diffusion flux approximation. The Jeffery’s viscoelastic model is deployed to describe the non-Newtonian characteristics of the fluid and provides a good approximation for magnetic polymers, which constitutes a novelty of the present work. The normalized nonlinear boundary value problem is solved computationally with the Keller-Box implicit finite-difference technique. Extensive solutions for velocity, surface temperature, skin friction and heat transfer rate are visualized graphically for various thermophysical parameters. Validation is conducted with earlier published work for the case of a vertical plate in the absence of magnetic field, radiative flux and non-Newtonian effects. The dimensionless entropy generation is obtained via the reduced momentum and energy equations. Bejan number is generally decreased with greater values of Deborah number. Increasing magnetic field reduces entropy generation number whereas it enhances the Bejan number. Increasing Brinkman number (dissipation parameter) is found to enhance the entropy generation number whereas it suppresses the Bejan number

ANALISIS KEBUTUHAN AIR PADA IRIGASI SANREGO KECAMATAN KAHU KABUPATEN BONE

D.I Sanrego Kecamatan Kahu,Kabupaten Bone pemberian air pada daerah irigasi perlu menyesuaikan dengan air yang tersedia ini berasal dari air hujan serta seperti Sungai dan bendung sanrego, karena itu yang tersedia selalu berubah-ubah dari waktu ke waktu maka di perlukan pengaturan pemberian air sebagai dasar rencana tata tanam. D.I Sanrego Kecamatan Kahu Kabupaten Bone kebutuhan airnya tidak terpenuhi pada musim kemarau. Hal tersebut mendorong perlu adanya analisis kebutuhan air yang memperhatikan faktor tataguna lahan bagi perencanaan pemanfaatan sumber daya air ( Upt Psda Sanrego ). Tujuan penelitian ini Untuk mengetahui ketersediaan air dalam memenuhi kebutuhan air pada Irigasi Sanrego dan tingkat kebutuhan air irigasi pada Irigasi Sanrego. Pada hasil penelitian ini ketersediaan air dalam memenuhi kebutuhan pada Irigasi Sanrego dengan data curah hujan sebesar 2,92 m3 / dtk. Besar rata – rata tingkat kebutuhan air pada Irigasi Sanrego  6,24 m3 /dt

Computation of Eyring-Powell micropolar convective boundary layer flow from an inverted non-isothermal cone : thermal polymer coating simulation

Thermal coating of components with non-Newtonian materials is a rich area of chemical and process mechanical engineering. Many different rheological characteristics can be simulated for such coatings with a variety of different mathematical models. In this work we study the steady-state coating flow and heat transfer of a non-Newtonian liquid (polymer) on an inverted isothermal cone with variable wall temperature. The Eringen micropolar and three-parameter Eyring-Powell models are combined to simulate microstructural and shear characteristics of the polymer. The governing partial differential conservation equations and wall and free stream boundary conditions are rendered into dimensionless form and solved computationally with the KellerBox finite difference method (FDM). Validation with earlier Newtonian solutions from the literature is also included. Graphical and tabulated results are presented to study the variations of fluid velocity, micro-rotation (angular velocity), temperature, skin friction, wall couple stress (micro-rotation gradient) and wall heat transfer rate. With increasing values of the first Eyring-Powell parameter temperatures are elevated, micro-rotation is suppressed and velocities are enhanced near the cone surface but reduced further into the boundary layer. Increasing values of the second Eyring-Powell parameter induce strong flow deceleration, decrease temperatures but enhance micro-rotation values. An increase in non-isothermal power law index suppresses velocities, temperatures and micro-rotations i.e. all transport characteristics are maximum for the isothermal case (n =0). Increasing Eringen vortex viscosity parameter significantly enhances temperatures and also micro-rotations. The present numerical simulations find applications in thermal polymer coating operations and industrial deposition techniques and provide a useful benchmark for more general computational fluid dynamics (CFD) simulations

Melting heat transfer analysis of electrically conducting nanofluid flow over an exponentially shrinking/stretching porous sheet with radiative heat flux under magnetic field

Modern magnetic nanomaterials processing operations are progressing rapidly and require increasingly sophisticated mathematical models for their optimization. Stimulated by such developments, in this article, a theoretical and computational study of steady magnetohydrodynamic (MHD) flow of nanofluid from an exponentially stretching/shrinking permeable sheet with melting (phase change) and radiative heat transfer is presented. Wall transpiration i.e. suction and blowing (injection) is included. Buongiorno’s nanofluid model is deployed which simulates the effects of Brownian motion and thermophoresis. The transport equations and boundary conditions are normalized via similarity transformations and appropriate variables and similarity solutions are shown to depend on the transpiration parameter. The emerging dimensionless nonlinear coupled ordinary differential boundary value problem is solved numerically with the Newton-Fehlberg iteration technique. Validation with special cases from the literature is included. Increasing magnetic field i.e. Hartmann number is observed to elevate nanoparticle concentration and temperature whereas it damps the velocity. Higher values of melting parameter consistently decelerate the boundary layer flow and suppress temperature and nanoparticle concentration. Higher radiative parameter strongly increases temperature (and thermal boundary layer thickness) and weakly accelerates the flow. Increasing Brownian motion reduces nanoparticle concentrations whereas greater thermophoretic body force strongly enhances them. Nusselt number and Sherwood number are decreased with increasing Hartmann number whereas they are elevated with stronger wall suction and melting parameter

Effects of ramped wall temperature and concentration on viscoelastic Jeffrey’s fluid flows from a vertical permeable cone

In thermo-fluid dynamics, free convection flows external to different geometries such as cylinders, ellipses, spheres, curved walls, wavy plates, cones etc. play major role in various industrial and process engineering systems. The thermal buoyancy force associated with natural convection flows can exert a critical role in determining skin friction and heat transfer rates at the boundary. In thermal engineering, natural convection flows from cones has gained exceptional interest. A theoretical analysis is developed to investigate the nonlinear, steady-state, laminar, non-isothermal convection boundary layer flows of viscoelastic fluid from a vertical permeable cone with a power-law variation in both temperature and concentration. The Jeffery’s viscoelastic model simulates the non-Newtonian characteristics of polymers, which constitutes the novelty of the present work. The transformed conservation equations for linear momentum, energy and concentration are solved numerically under physically viable boundary conditions using the finite-differences Keller-Box scheme. The impact of Deborah number (De), ratio of relaxation to retardation time (λ), surface suction/injection parameter (fw), power-law exponent (n), buoyancy ratio parameter (N) and dimensionless tangential coordinate (Ѯ) on velocity, surface temperature, concentration, local skin friction, heat transfer rate and mass transfer rate in the boundary layer regime are presented graphically. It is observed that increasing values of De reduces velocity whereas the temperature and concentration are increased slightly. Increasing λ enhance velocity however reduces temperature and concentration slightly. The heat and mass transfer rate are found to decrease with increasing De and increase with increasing values of λ. The skin friction is found to decrease with a rise in De whereas it is elevated with increasing values of λ. Increasing values of fw and n, decelerates the flow and also cools the boundary layer i.e. reduces temperature and also concentration. The study is relevant to chemical engineering systems, solvent and polymeric processes

An Inhibitory Antibody Blocks Interactions between Components of the Malarial Invasion Machinery

Host cell invasion by apicomplexan pathogens such as the malaria parasite Plasmodium spp. and Toxoplasma gondii involves discharge of proteins from secretory organelles called micronemes and rhoptries. In Toxoplasma a protein complex comprising the microneme apical membrane antigen 1 (AMA1), two rhoptry neck proteins, and a protein called Ts4705, localises to the moving junction, a region of close apposition between parasite and host cell during invasion. Antibodies against AMA1 prevent invasion and are protective in vivo, and so AMA1 is of widespread interest as a malaria vaccine candidate. Here we report that the AMA1 complex identified in Toxoplasma is conserved in Plasmodium falciparum. We demonstrate that the invasion-inhibitory monoclonal antibody (mAb) 4G2, which recognises P. falciparum AMA1 (PfAMA1), cannot bind when PfAMA1 is in a complex with its partner proteins. We further show that a single completely conserved PfAMA1 residue, Tyr251, lying within a conserved hydrophobic groove adjacent to the mAb 4G2 epitope, is required for complex formation. We propose that mAb 4G2 inhibits invasion by preventing PfAMA1 from interacting with other components of the invasion complex. Our findings should aid the rational design of subunit malaria vaccines based on PfAMA1

Numerical study of radiative Maxwell viscoelastic magnetized flow from a stretching permeable sheet with the Cattaneo–Christov heat flux model

In this article, the Cattaneo-Christov heat flux model is implemented to study non-Fourier heat and mass transfer in the magnetohydrodynamic (MHD) flow of an upper convected Maxwell (UCM) fluid over a permeable stretching sheet under a transverse constant magnetic field. Thermal radiation and chemical reaction effects are also considered. The nonlinear partial differential conservation equations for mass, momentum, energy and species conservation are transformed with appropriate similarity variables into a system of coupled, highly nonlinear ordinary differential equations with appropriate boundary conditions. Numerical solutions have been presented for the influence of elasticity parameter (), magnetic parameter (M2), suction/injection parameter (λ), Prandtl number (Pr), conduction-radiation parameter (Rd), sheet stretching parameter (A), Schmidt number (Sc), chemical reaction parameter (γ_c), modified Deborah number with respect to relaxation time of heat flux (i.e. non-Fourier Deborah number) on velocity components, temperature and concentration profiles using the successive Taylor series linearization method (STSLM) utilizing Chebyshev interpolating polynomials and Gauss-Lobatto collocation. The effects of selected parameters on skin friction coefficient, Nusselt number and Sherwood number are also presented with the help of tables. Verification of the STSLM solutions is achieved with existing published results demonstrating close agreement. Further validation of skin friction coefficient, Nusselt number and Sherwood number values computed with STSLM is included using Mathematica software shooting quadrature