Yazar "Awrejcewicz, Jan" seçeneğine göre listele

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    Effect of Magnetic Field with Parabolic Motion on Fractional Second Grade Fluid
    (Mdpi, 2021) Iftikhar, Nazish; Riaz, Muhammad Bilal; Awrejcewicz, Jan; Akgul, Ali
    This paper is an analysis of the flow of magnetohydrodynamics (MHD) second grade fluid (SGF) under the influence of chemical reaction, heat generation/absorption, ramped temperature and concentration and thermodiffusion. The fluid was made to flow through a porous medium. It has been proven in many already-published articles that heat and mass transfer do not always follow the classical mechanics process that is known as memoryless process. Therefore, the model using classical differentiation based on the rate of change cannot really replicate such a dynamical process very accurately; thus, a different concept of differentiation is needed to capture such a process. Very recently, new classes of differential operators were introduced and have been recognized to be efficient in capturing processes following the power law, the decay law and the crossover behaviors. For the study of heat and mass transfer, we applied the newly introduced differential operators to model such flow. The equations for heat, mass and momentum are established in the terms of Caputo (C), Caputo-Fabrizio (CF) and Atangana-Baleanu in Caputo sense (ABC) fractional derivatives. The Laplace transform, inversion algorithm and convolution theorem were used to derive the exact and semi-analytical solutions for all cases. The obtained analytical solutions were plotted for different values of existing parameters. It is concluded that the fluid velocity shows increasing behavior for ? , G(r) and G(m), while velocity decreases for P-r and M. For K-r, both velocity and concentration curves show decreasing behavior. Fluid flow accelerates under the influence of S-r and R. Temperature and concentration profiles increase for S-r and R. Moreover, the ABC fractional operator presents a larger memory effect than C and CF fractional operators.
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    Heat and Flow Control in Cavity with Cold Circular Cylinder Placed in Non-Newtonian Fluid by Performing Finite Element Simulations
    (Mdpi, 2022) Bilal, Sardar; Khan, Noor Zeb; Shah, Imtiaz Ali; Awrejcewicz, Jan; Akgul, Ali; Riaz, Muhammad Bilal
    A study on strategies regarding advancement in heat transfer characteristics in two-dimensional closed domains by placing cold cylinders is conducted. This effort is undertaken due to the fact that active and passive control in heat transmission is connected with provision of temperature differences at different locations of enclosures. Based on the experiments, researchers have concluded that placement of cold cylinder in non-uniformly distributed heat in a cavity is the most effective technique to enrich heat transfer rate, along with reducing the the waste of extra heat generation in processes such as polymer and aero dynamical extrusion, glass cooling, refrigeration, heating and cooling systems. Thus, the prime goal of this work is to outline heat and flow characteristics of non-linear fluid occupied in a square enclosure with adjustment of the cold cylinder. Heat transfer attributes are incorporated by accounting buoyancy forces and forming coupling of molecular diffusion of fluid within the flow domain. Formulation of the problem in dimensionless form is attained by encapsulating the aspects of natural convection in view of principal partial differential equations. Parametric study for governing expressions is computed numerically with the finite element method based on COMSOL Multiphysics version 5.6. Quadric interpolating functions are used to obtain information about velocity and temperature on nodes in elements. Hybrid meshing is manifested for discretization of the domain into rectangular and triangular elements. For the optimized variation in flow structures, prospective parameters are varied from 0.5 <= n <= 1.5, 5 <= Pr <= 35 and 10(2) <= Ra <= 10(6). The achieved results are projected graphically through streamlines, isotherms, and local and average Nusselt numbers. Tabular data for kinetic energy and wall heat flux are also calculated. It is inferred through the analysis that, with uplift in the Rayleigh number ( Ra) elevation in the magnitude of kinetic energy and convective heat transfer arises, whereas the reverse pattern is depicted versus the power-law index ( n)
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    Heat and Mass Transfer Impact on Differential Type Nanofluid with Carbon Nanotubes: A Study of Fractional Order System
    (Mdpi, 2021) Javed, Fatima; Riaz, Muhammad Bilal; Iftikhar, Nazish; Awrejcewicz, Jan; Akguel, Ali
    This paper is an analysis of flow of MHD CNTs of second grade nano-fluid under the influence of first order chemical reaction, suction, thermal generation and magnetic field. The fluid is flowing through a porous medium. For the study of heat and mass transfer, we applied the newly introduced differential operators to model such flow. The equations for heat, mass and momentum are established in the terms of Caputo (C), Caputo-Fabrizio (CF) and Atangana-Baleanu in Caputo sense (ABC) fractional derivatives. This shows the novelty of this work. The equations for heat, mass and momentum are established in the terms of Caputo (C), Caputo-Fabrizio (CF) and Atangana-Baleanu in Caputo sense (ABC) fractional derivatives. The solutions are evaluated by employing Laplace transform and inversion algorithm. The flow in momentum profile due to variability in the values of parameters are graphically illustrated among C, CF and ABC models. It is concluded that fluid velocity showed decreasing behavior for chi, P, PLANCK CONSTANT OVER TWO PI2, Mo, Pr, & ALEPH; and Sc while it showed increasing behavior for Gr, Gm, kappa and Ao. Moreover, ABC fractional operator presents larger memory effect than C and CF fractional operators.
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    Numerical Study of Natural Convection of Power Law Fluid in a Square Cavity Fitted with a Uniformly Heated T-Fin
    (Mdpi, 2022) Bilal, Sardar; Khan, Noor Zeb; Shah, Imtiaz Ali; Awrejcewicz, Jan; Akgul, Ali; Riaz, Muhammad Bilal
    Flow of a liquid in an enclosure with heat transfer has drawn special focus of researchers due to the abundant thermal engineering applications. So, the aim of present communication is to explore thermal characteristics of natural convective power-law liquid flow in a square enclosure rooted with a T-shaped fin. The formulation of the problem is executed in the form of partial differential expressions by incorporating the rheological relation of the power-law fluid. The lower wall of the enclosure along with the fin is uniformly heated and vertical walls are prescribed with cold temperature. For effective heat transfer within the cavity the upper boundary is considered thermally insulated. A finite element based commercial software known as COMSOL is used for simulations and discretization of differential equations and is executed incorporating a weak formulation. Domain discretization is performed by dividing it into triangular and rectangular elements at different refinement levels. A grid independence test is accomplished for quantities of engineering interest like local and average Nusselt numbers to attain accuracy and validity in results. Variation in the momentum and thermal distributions against pertinent parameters is analyzed through stream lines and isothermal contour plots. Measurement of the heat flux coefficient along with the calculation of kinetic energy against involved parameters is displayed through graphs and tables. After the comprehensive overview of attained results it is deduced that kinetic energy elevates against the upsurging magnitude of the Rayleigh number, whereas contrary behavior is encapsulated versus power-law index n. Elevation in the Nusselt number for the shear thinning case i.e., n=0.5 adheres as compared to Newtonian i.e., n=1 and shear thickening cases i.e., n=1.5. It is perceived that by the upsurging power-law index viscosity augmentations and circulation zones increases. Heat is transferred quickly against Rayleigh number (Ra) due to production of temperature difference in flow domain.
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    On Soliton Solutions of Perturbed Boussinesq and KdV-Caudery-Dodd-Gibbon Equations
    (Mdpi, 2021) Asjad, Muhammad Imran; Ur Rehman, Hamood; Ishfaq, Zunaira; Awrejcewicz, Jan; Akgul, Ali; Riaz, Muhammad Bilal
    Nonlinear science is a fundamental science frontier that includes research in the common properties of nonlinear phenomena. This article is devoted for the study of new extended hyperbolic function method (EHFM) to attain the exact soliton solutions of the perturbed Boussinesq equation (PBE) and KdV-Caudery-Dodd-Gibbon (KdV-CDG) equation. We can claim that these solutions are new and are not previously presented in the literature. In addition, 2d and 3d graphics are drawn to exhibit the physical behavior of obtained new exact solutions.
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    Power Law Kernel Analysis of MHD Maxwell Fluid with Ramped Boundary Conditions: Transport Phenomena Solutions Based on Special Functions
    (Mdpi, 2021) Riaz, Muhammad Bilal; Rehman, Aziz-Ur; Awrejcewicz, Jan; Akgul, Ali
    In this paper, a new approach to find exact solutions is carried out for a generalized unsteady magnetohydrodynamic transport of a rate-type fluid near an unbounded upright plate, which is analyzed for ramped-wall temperature and velocity with constant concentration. The vertical plate is suspended in a porous medium and encounters the effects of radiation. An innovative definition of the time-fractional operator in power-law-kernel form is implemented to hypothesize the constitutive mass, energy, and momentum equations. The Laplace integral transformation technique is applied on a dimensionless form of governing partial differential equations by introducing some non-dimensional suitable parameters to establish the exact expressions in terms of special functions for ramped velocity, temperature, and constant-concentration fields. In order to validate the problem, the absence of the mass Grashof parameter led to the investigated solutions obtaining good agreement in existing literature. Additionally, several system parameters were used, such as as magnetic value M, Prandtl value Pr, Maxwell parameter lambda, dimensionless time tau, Schmidt number Sc, fractional parameter alpha, and Mass and Thermal Grashof numbers Gm and Gr, respectively, to examine their impacts on velocity, wall temperature, and constant concentration. Results are also discussed in detail and demonstrated graphically via Mathcad-15 software. A comprehensive comparative study between fractional and non-fractional models describes that the fractional model elucidate the memory effects more efficiently.
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    Thermophysical Investigation of Oldroyd-B Fluid with Functional Effects of Permeability: Memory Effect Study Using Non-Singular Kernel Derivative Approach
    (Mdpi, 2021) Riaz, Muhammad Bilal; Awrejcewicz, Jan; Rehman, Aziz-Ur; Akgul, Ali
    It is well established fact that the functional effects, such as relaxation and retardation of materials, can be measured for magnetized permeability based on relative increase or decrease during magnetization. In this context, a mathematical model is formulated based on slippage and non-slippage assumptions for Oldroyd-B fluid with magnetized permeability. An innovative definition of Caputo-Fabrizio time fractional derivative is implemented to hypothesize the constitutive energy and momentum equations. The exact solutions of presented problem, are determined by using mathematical techniques, namely Laplace transform with slipping boundary conditions have been invoked to tackle governing equations of velocity and temperature. The Nusselt number and limiting solutions have also been persuaded to estimate the heat emission rate through physical interpretation. In order to provide the validation of the problem, the absence of retardation time parameter led the investigated solutions with good agreement in literature. Additionally, comprehensively scrutinize the dynamics of the considered problem with parametric analysis is accomplished, the graphical illustration is depicted for slipping and non-slipping solutions for temperature and velocity. A comparative studies between fractional and non-fractional models describes that the fractional model elucidate the memory effects more efficiently.