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Ioan Pop - One of the best experts on this subject based on the ideXlab platform.

  • Boundary Layer Flow past a continuously moving thin needle in a nanofluid
    Applied Thermal Engineering, 2017
    Co-Authors: Siti Khuzaimah Soid, Anuar Mohd Ishak, Ioan Pop
    Abstract:

    Abstract A steady two-dimensional laminar forced convection Boundary Layer Flow along a horizontal thin needle immersed in a nanofluid is considered. The governing partial differential equations are first reduced to a system of nonlinear ordinary differential equations, before being solved numerically using the Boundary value problem solver (bvp4c) in Matlab, for copper-water nanofluid with Prandtl number Pr  = 6.2 (water). The physical quantities of interest such as the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles are presented. Dual solutions are found when the needle and the free stream move in the opposite directions. It is seen that the solution domain decreases with increasing values of the solid volume fraction parameter. The influences of the needle size and the solid volume fraction parameter on the Flow and heat transfer characteristics as well as on the velocity and temperature profiles are investigated.

  • mixed convection Boundary Layer Flow from a vertical truncated cone in a nanofluid
    International Journal of Numerical Methods for Heat & Fluid Flow, 2014
    Co-Authors: Flavius Pătrulescu, T Grosan, Ioan Pop
    Abstract:

    Purpose – The purpose of this paper is to investigate the steady mixed convection Boundary Layer Flow from a vertical frustum of a cone in water-based nanofluids. The problem is formulated to incorporate three kinds of nanoparticles: copper, alumina and titanium oxide. The working fluid is chosen as water with the Prandtl number of 6.2. The mathematical model used for the nanofluid incorporates the particle volume fraction parameter, the effective viscosity and the effective thermal diffusivity. The entire regime of the mixed convection includes the mixed convection parameter, which is positive for the assisting Flow (heated surface of the frustum cone) and negative for the opposing Flow (cooled surface of the frustum cone), respectively. Design/methodology/approach – The transformed non-linear partial differential equations are solved numerically for some values of the governing parameters. The derivatives with respect to? were discretized using the first order upwind finite differences and the resulting...

  • similarity solution of marangoni convection Boundary Layer Flow over a flat surface in a nanofluid
    Journal of Applied Mathematics, 2013
    Co-Authors: Norihan Md Arifin, Roslinda Mohd Nazar, Ioan Pop
    Abstract:

    The problem of steady Marangoni Boundary Layer Flow and heat transfer over a flat plate in a nanofluid is studied using different types of nanoparticles. The general governing partial differential equations are transformed into a set of two nonlinear ordinary differential equations using unique similarity transformation. Numerical solutions of the similarity equations are obtained using the Runge-Kutta-Fehlberg (RKF) method. Three different types of nanoparticles are considered, namely, Cu, Al2O3, and TiO2, by using water as a base fluid with Prandtl number . The effects of the nanoparticle volume fraction and the constant exponent m on the Flow and heat transfer characteristics are obtained and discussed.

  • Boundary Layer Flow over a moving surface in a nanofluid with suction or injection
    Acta Mechanica Sinica, 2012
    Co-Authors: Norfifah Bachok, Anuar Mohd Ishak, Ioan Pop
    Abstract:

    An analysis is performed to study the heat transfer characteristics of steady two-dimensional Boundary Layer Flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the Flow field and heat transfer characteristics are numerically studied by using an implicit finite difference method. It is found that dual solutions exist when the plate and the free stream move in the opposite directions. The results indicate that suction delays the Boundary Layer separation, while injection accelerates it.

  • marangoni driven Boundary Layer Flow in a nanofluid with suction and injection
    2012
    Co-Authors: A Remeli, Roslinda Mohd Nazar, Fudziah Ismail, Ioan Pop
    Abstract:

    The problem of steady Marangoni Boundary Layer Flow and heat transfer in a nanofluid when the wall is permeable, namely there is a suction or injection effect, is studied using different types of nanoparticles. The mathematical problem reduces to a pair of coupled ordinary differential equations by similarity transformation, which is then solved numerically using the shooting method. Three different types of nanoparticles , namely Cu, Al2O3 and TiO2 are considered by using water as the base fluid with Prandtl number Pr = 6.2. It is found that the imposition of suction is to increase the velocity profiles and to delay the separation of Boundary Layer, while the injection parameter decreases the velocity profiles.

Roslinda Mohd Nazar - One of the best experts on this subject based on the ideXlab platform.

  • similarity solution of marangoni convection Boundary Layer Flow over a flat surface in a nanofluid
    Journal of Applied Mathematics, 2013
    Co-Authors: Norihan Md Arifin, Roslinda Mohd Nazar, Ioan Pop
    Abstract:

    The problem of steady Marangoni Boundary Layer Flow and heat transfer over a flat plate in a nanofluid is studied using different types of nanoparticles. The general governing partial differential equations are transformed into a set of two nonlinear ordinary differential equations using unique similarity transformation. Numerical solutions of the similarity equations are obtained using the Runge-Kutta-Fehlberg (RKF) method. Three different types of nanoparticles are considered, namely, Cu, Al2O3, and TiO2, by using water as a base fluid with Prandtl number . The effects of the nanoparticle volume fraction and the constant exponent m on the Flow and heat transfer characteristics are obtained and discussed.

  • radiation effect on marangoni convection Boundary Layer Flow of a nanofluid
    mathematical sciences, 2012
    Co-Authors: Nor Azian Aini Mat, Roslinda Mohd Nazar, Norihan Md Arifin, Fudziah Ismail
    Abstract:

    Purpose: In this paper, we present a mathematical model for Marangoni convection Boundary Layer Flow with radiation and different types of nanoparticles, namely, Cu, Al2O3, and TiO2 in a water-based fluid. Method: The governing equations in the form of partial differential equations have been reduced to a set of ordinary differential equations by applying suitable similarity transformations, which is then solved numerically using the shooting method. Results: Numerical results are obtained for the surface-temperature gradient or the heat transfer rate as well as the temperature profiles for some values of the governing parameters, namely, the nanoparticle volume fraction φ, the constant exponent β, and thermal radiation parameter Nr. Conclusion: The results indicate that the heat transfer rate at the surface decreases as the thermal radiation parameter Nr increases. MSC: 76N20, fluid mechanics.

  • marangoni driven Boundary Layer Flow in a nanofluid with suction and injection
    2012
    Co-Authors: A Remeli, Roslinda Mohd Nazar, Fudziah Ismail, Ioan Pop
    Abstract:

    The problem of steady Marangoni Boundary Layer Flow and heat transfer in a nanofluid when the wall is permeable, namely there is a suction or injection effect, is studied using different types of nanoparticles. The mathematical problem reduces to a pair of coupled ordinary differential equations by similarity transformation, which is then solved numerically using the shooting method. Three different types of nanoparticles , namely Cu, Al2O3 and TiO2 are considered by using water as the base fluid with Prandtl number Pr = 6.2. It is found that the imposition of suction is to increase the velocity profiles and to delay the separation of Boundary Layer, while the injection parameter decreases the velocity profiles.

  • non isobaric marangoni Boundary Layer Flow for cu al2o3 and tio2 nanoparticles in a water based fluid
    Meccanica, 2011
    Co-Authors: Norihan Md Arifin, Roslinda Mohd Nazar, Ioan Pop
    Abstract:

    In this paper, a non-isobaric Marangoni Boundary Layer Flow that can be formed along the interface of immiscible nanofluids in surface driven Flows due to an imposed temperature gradient, is considered. The solution is determined using a similarity solution for both the momentum and energy equations and assuming developing Boundary Layer Flow along the interface of the immiscible nanofluids. The resulting system of nonlinear ordinary differential equations is solved numerically using the shooting method along with the Runge-Kutta-Fehlberg method. Numerical results are obtained for the interface velocity, the surface temperature gradient as well as the velocity and temperature profiles for some values of the governing parameters, namely the nanoparticle volume fraction φ (0≤φ≤0.2) and the constant exponent β. Three different types of nanoparticles, namely Cu, Al2O3 and TiO2 are considered by using water-based fluid with Prandtl number Pr =6.2. It was found that nanoparticles with low thermal conductivity, TiO2, have better enhancement on heat transfer compared to Al2O3 and Cu. The results also indicate that dual solutions exist when β<0.5. The paper complements also the work by Golia and Viviani (Meccanica 21:200–204, 1986) concerning the dual solutions in the case of adverse pressure gradient.

  • radiation effects on marangoni Boundary Layer Flow past a flat plate in nanofluid
    International MultiConference of Engineers and Computer Scientists, 2011
    Co-Authors: Rohana Abdul Hamid, Roslinda Mohd Nazar, Norihan Md Arifin, Ioan Pop
    Abstract:

     Abstract— The problem of Marangoni convection Boundary Layer Flow in nanofluid with radiation effects is studied using different types of nanoparticles. The general governing partial differential equations are transformed into a set of two nonlinear ordinary differential equations using unique similarity transformation. Numerical solutions of the similarity equations are obtained using the Runge-Kutta-Fehlberg method. Three different types of nanoparticles, namely Cu, Al2O3, and TiO2 are considered by using water as a base fluid with Prandtl number Pr = 6.2. The effects of radiation parameter on the heat transfer characteristics are discussed.

Anuar Mohd Ishak - One of the best experts on this subject based on the ideXlab platform.

  • Boundary Layer Flow past a continuously moving thin needle in a nanofluid
    Applied Thermal Engineering, 2017
    Co-Authors: Siti Khuzaimah Soid, Anuar Mohd Ishak, Ioan Pop
    Abstract:

    Abstract A steady two-dimensional laminar forced convection Boundary Layer Flow along a horizontal thin needle immersed in a nanofluid is considered. The governing partial differential equations are first reduced to a system of nonlinear ordinary differential equations, before being solved numerically using the Boundary value problem solver (bvp4c) in Matlab, for copper-water nanofluid with Prandtl number Pr  = 6.2 (water). The physical quantities of interest such as the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles are presented. Dual solutions are found when the needle and the free stream move in the opposite directions. It is seen that the solution domain decreases with increasing values of the solid volume fraction parameter. The influences of the needle size and the solid volume fraction parameter on the Flow and heat transfer characteristics as well as on the velocity and temperature profiles are investigated.

  • Boundary Layer Flow over a moving surface in a nanofluid with suction or injection
    Acta Mechanica Sinica, 2012
    Co-Authors: Norfifah Bachok, Anuar Mohd Ishak, Ioan Pop
    Abstract:

    An analysis is performed to study the heat transfer characteristics of steady two-dimensional Boundary Layer Flow past a moving permeable flat plate in a nanofluid. The effects of uniform suction and injection on the Flow field and heat transfer characteristics are numerically studied by using an implicit finite difference method. It is found that dual solutions exist when the plate and the free stream move in the opposite directions. The results indicate that suction delays the Boundary Layer separation, while injection accelerates it.

  • Boundary Layer Flow over a stretching sheet with a convective Boundary condition and slip effect
    2012
    Co-Authors: Wan Mohd, Anuar Mohd Ishak, Rohana Abdul Hamid, Khairy Adly, Wan Mohd Khairy Adly Wan Zaimi, Biliana Bidin, Pusat Pengajian, Sains Matematik
    Abstract:

    The steady laminar Boundary Layer Flow over a stretching sheet with partial slip under a convective surface Boundary condition is investigated. Using a similarity transformation, the governing partial differential equations are reduced into a set of nonlinear ordinary differential equations, before being solved numerically by a shooting method using Maple software. The effects of the governing parameters namely Prandtl number, convective parameter and slip parameter on the fluid Flow and heat transfer characteristics are presented graphically and analyzed.

  • radiation effects on the thermal Boundary Layer Flow over a moving plate with convective Boundary condition
    Meccanica, 2011
    Co-Authors: Anuar Mohd Ishak, Nor Azizah Yacob, Norfifah Bachok
    Abstract:

    The steady laminar Boundary Layer Flow over a moving plate in a moving fluid with convective surface Boundary condition and in the presence of thermal radiation is investigated in this paper. Under certain conditions, the present problem reduces to the classical Blasius and Sakiadis problems. The effects of radiation and convective parameters on the thermal field are thoroughly examined and discussed. Dual solutions are found to exist when the plate and the fluid move in the opposite directions.

  • mhd Boundary Layer Flow due to an exponentially stretching sheet with radiation effect
    Sains Malaysiana, 2011
    Co-Authors: Anuar Mohd Ishak
    Abstract:

    The effect of radiation on magnetohydrodynamic (MHD) Boundary Layer Flow of a viscous fluid over an exponentially stretching sheet was studied. The governing system of partial differential equations was transformed into ordinary differential equations before being solved numerically by an implicit finite-difference method. The effects of the governing parameters on the Flow field and heat transfer characteristics were obtained and discussed. It was found that the local heat transfer rate at the surface decreases with increasing values of the magnetic and radiation parameters

Muhammad Sajid - One of the best experts on this subject based on the ideXlab platform.

  • homotopy analysis for Boundary Layer Flow of a micropolar fluid through a porous channel
    Applied Mathematical Modelling, 2009
    Co-Authors: Muhammad Sajid, Z. Abbas, Tasawar Hayat
    Abstract:

    This paper concerns with the Boundary Layer Flow of a micropolar fluid through a porous channel. The Flow occurs due to suction and injection at the walls of the channel. The micropolar fluid fills the space inside the channel. The governing non-linear partial differential equations are reduced to ordinary ones by employing the similarity transformations. Homotopy analysis method (HAM) is adopted to obtain the expressions for velocity and micro-rotation. The series solution is presented and the recurrence formulae for finding the coefficients are given. The convergence of the series solution is discussed. The results are graphically presented and the role of pertinent parameters on the velocity and micro-rotation is discussed.

  • influence of thermal radiation on the Boundary Layer Flow due to an exponentially stretching sheet
    International Communications in Heat and Mass Transfer, 2008
    Co-Authors: Muhammad Sajid
    Abstract:

    The effect of radiation on the Boundary Layer Flow and heat transfer of a viscous fluid over an exponentially stretching sheet is studied. The homotopy analysis method (HAM) is employed to determine the convergent series expressions of velocity and temperature. The physical interpretation to these expressions is assigned through graphs. It is found that the effects of Prandtl and radiation numbers on the temperature are opposite.

  • non similar series solution for Boundary Layer Flow of a third order fluid over a stretching sheet
    Applied Mathematics and Computation, 2007
    Co-Authors: Muhammad Sajid, Tasawar Hayat
    Abstract:

    This study deals with the Boundary Layer Flow of a third-order fluid induced by a stretching sheet. By means of similarity transformation, the governing non-linear partial differential equation is reduced to a non-linear ordinary differential equation. The analytical solution of the problem is obtained using homotopy analysis method (HAM). Finally, the solutions are also compared with the existing results in the literature.

  • homotopy analysis of mhd Boundary Layer Flow of an upper convected maxwell fluid
    International Journal of Engineering Science, 2007
    Co-Authors: Muhammad Sajid
    Abstract:

    The problem of a magnetohydrodynamic (MHD) Boundary Layer Flow of an upper-convected Maxwell (UCM) fluid is considered for the analytical solution using homotopy analysis method (HAM). The non-linear partial differential equations are transformed to an ordinary differential equation first taking Boundary Layer approximations into account and then using the similarity transformations. The analytical solution is presented in the form of an infinite series. The recurrence formulae for finding the coefficients are presented and the convergence is established. The effects of the Deborah number and MHD parameter is discussed on the velocity profiles and the skin friction coefficients. It is found that the results are in excellent agreement with the existing results in the literature for the case of hydrodynamic Flow.

  • mhd Boundary Layer Flow of an upper convected maxwell fluid in a porous channel
    Theoretical and Computational Fluid Dynamics, 2006
    Co-Authors: Z. Abbas, Muhammad Sajid
    Abstract:

    Two-dimensional magnetohydrodynamic (MHD) Boundary Layer Flow of an upper-convected Maxwell fluid is investigated in a channel. The walls of the channel are taken as porous. Using the similarity transformations and Boundary Layer approximations, the nonlinear partial differential equations are reduced to an ordinary differential equation. The developed nonlinear equation is solved analytically using the homotopy analysis method. An expression for the analytic solution is derived in the form of a series. The convergence of the obtained series is shown. The effects of the Reynolds number Re, Deborah number De and Hartman number M are shown through graphs and discussed for both the suction and injection cases.

Tasawar Hayat - One of the best experts on this subject based on the ideXlab platform.

  • hydromagnetic Boundary Layer Flow of williamson fluid in the presence of thermal radiation and ohmic dissipation
    alexandria engineering journal, 2016
    Co-Authors: Anum Shafiq, Tasawar Hayat, A Alsaedi
    Abstract:

    Abstract This paper is concerned with the unsteady two-dimensional Boundary Layer Flow of an incompressible Williamson fluid over an unsteady permeable stretching surface with thermal radiation. Effects of electric and magnetic fields are considered. The nonlinear Boundary Layer partial differential equations are first converted into the system of ordinary differential equations and then solved analytically. Effects of physical parameters such as Weissenberg number, unsteadiness parameter, suction parameter, magnetic parameter, electric parameter, radiation parameter, Prandtl number and Eckert number on the velocity and temperature are graphically analyzed. The expressions of skin friction coefficient and local Nusselt number are presented and examined numerically.

  • hydromagnetic Boundary Layer Flow of williamson fluid in the presence of thermal radiation and ohmic dissipation
    alexandria engineering journal, 2016
    Co-Authors: Anum Shafiq, Tasawar Hayat, A Alsaedi
    Abstract:

    Abstract This paper is concerned with the unsteady two-dimensional Boundary Layer Flow of an incompressible Williamson fluid over an unsteady permeable stretching surface with thermal radiation. Effects of electric and magnetic fields are considered. The nonlinear Boundary Layer partial differential equations are first converted into the system of ordinary differential equations and then solved analytically. Effects of physical parameters such as Weissenberg number, unsteadiness parameter, suction parameter, magnetic parameter, electric parameter, radiation parameter, Prandtl number and Eckert number on the velocity and temperature are graphically analyzed. The expressions of skin friction coefficient and local Nusselt number are presented and examined numerically.

  • Boundary Layer Flow of third grade nanofluid with newtonian heating and viscous dissipation
    Journal of Central South University, 2015
    Co-Authors: S A Shehzad, Tasawar Hayat, Tariq Hussain, Muhammad Ramzan, A Alsaedi
    Abstract:

    Two-dimensional Boundary Layer Flow of an incompressible third grade nanofluid over a stretching surface is investigated. Influence of thermophoresis and Brownian motion is considered in the presence of Newtonian heating and viscous dissipation. Governing nonlinear problems of velocity, temperature and nanoparticle concentration are solved via homotopic procedure. Convergence is examined graphically and numerically. Results of temperature and nanoparticle concentration are plotted and discussed for various values of material parameters, Prandtl number, Lewis number, Newtonian heating parameter, Eckert number and thermophoresis and Brownian motion parameters. Numerical computations are performed. The results show that the change in temperature and nanoparticle concentration distribution functions is similar when we use higher values of material parameters β1 and β2. It is seen that the temperature and thermal Boundary Layer thickness are increasing functions of Newtonian heating parameter γ. An increase in thermophoresis and Brownian motion parameters tends to an enhancement in the temperature.

  • exact solution for Boundary Layer Flow of casson fluid over a permeable stretching shrinking sheet
    Zamm-zeitschrift Fur Angewandte Mathematik Und Mechanik, 2014
    Co-Authors: Krishnendu Bhattacharyya, Tasawar Hayat, Ahmed Alsaedi
    Abstract:

    In this investigation, the steady Boundary Layer Flow of Casson fluid over a porous stretching/shrinking sheet is studied. The governing equations are transformed using similarity transformations and then solved analytically. In both stretching and shrinking sheet cases, the closed form exact solutions are obtained. The solution is always unique for stretching sheet case. On the other hand, in shrinking sheet case, the solution may exist or may not and if exists it may be unique or may be of dual nature; these all depend on the value of Casson parameter and wall mass transfer parameter. Also, the analysis reveals that for steady Flow of Casson fluid stronger mass suction is needed.

  • melting heat transfer in a Boundary Layer Flow of a second grade fluid under soret and dufour effects
    International Journal of Numerical Methods for Heat & Fluid Flow, 2013
    Co-Authors: Tasawar Hayat, Majid Hussain, Muhammad Awais, S Obaidat
    Abstract:

    Purpose – The Boundary Layer Flow and heat transfer of second grade fluid in a region of the stagnation point over a stretching surface has been examined. Thermal-diffusion (Dufour) and diffusion-thermo (Soret) effects combined with melting heat transfer are also considered. Suitable transformations are employed to convert the partial differential equations representing the conservation of mass, momentum, energy and diffusion into the system of ordinary differential equations. The series solutions for the Flow quantities of interest are presented. Interpretation to velocity, temperature and concentration is assigned. Numerical values of the local Nusselt and Sherwood numbers have been computed. The paper aims to discuss these issues. Design/methodology/approach – Analytic approach homotopy analysis method (HAM) is used to find the convergent solution of melting heat transfer in a Boundary Layer Flow of a second grade fluid under Soret and Dufour effects. Findings – In this article the main findings are as...