Now showing 1 - 2 of 2
  • Publication
    MHD Stagnation-point flow towards a permeable shrinking/stretching sheet in a porous medium with velocity slip and heat generation/absorption effects
    (Semarak Ilmu Publishing, 2025)
    Hisyam Juwaidi Aziz
    ;
    ; ;
    Adnan Asghar
    ;
    Suliadi Firdaus Sufahani
    ;
    Liaquat Ali Lund
    ;
    Ubaidullah Yashkun
    ;
    Mohammad Ferdows
    The analysis of velocity slip and heat generation/absorption in fluid flow problems is crucial due to their significant impact on fluid behavior and heat transfer characteristics. The findings are vital for understanding and optimizing flow and heat transfer in industrial processes involving shrinking/stretching surfaces. Thus, this study aims to examine dual solutions of MHD stagnation-point flow over a stretching/shrinking sheet with suction/injection, velocity slip, and heat generation/absorption effects. The governing nonlinear partial differential equations are transformed into nonlinear ordinary differential equations using a similarity transformation and solved numerically using the boundary value problem solver bvp4c, a built-in MATLAB software. Dual solutions are found for the shrinking case, while the stretching case yields a unique solution. Increasing suction and slip parameters broadens the range of dual solutions. Results show that suction enhances the skin friction coefficient and heat transfer, whereas velocity slip reduces skin friction but increases heat transfer. Heat generation lowers the local Nusselt number. It is observed that the first solution is stable, while the second is unstable.
  • Publication
    Computational study of magnetite-ethylene glycol–water-based hybrid nanofluid dynamics on an exponential shrinking/stretching Riga surface under radiative heat flux
    (Springer, 2024-10)
    Ubaidullah Yashkun
    ;
    Liaquat Ali Lund
    ;
    ;
    Zahir Shah
    ;
    Mansoor H. Alshehri
    ;
    Narcisa Vrinceanu
    ;
    Elisabeta Antonescu
    The exceptional heat transfer capabilities of hybrid base ferrofluids have attracted numerous researchers, prompting an increase in investigations into these working fluids. In various applications, hybrid base nanofluids have demonstrated superior heat transfer performance. However, further research is needed to expand their range of applications. To address this need, the current study aims to explore the flow of a hybrid base nanofluid (magnetite with ethylene glycol and water as the base fluid) on an exponential shrinking/stretching Riga plate with radiative heat flux. The Riga plate, an electromagnetic actuator, consists of a spanwise-aligned array of alternating electrodes attached to a flat surface and permanent magnets. This setup enables the examination of heat transfer with Hartmann number, thermal radiation, and nanoparticle volume fraction. The governing PDE systems are transformed into ODE systems using similarity transformations, and the developed model is solved numerically using the bvp4c technique in MATLAB software. A comprehensive convergence analysis and comparative investigation of numerical data are conducted to ensure the accuracy of the results. Finally, the effects of physical parameters on skin frictional force, Nusselt number, velocity field, and temperature field are investigated, and the results are presented graphically and discussed in detail. The numerical values for the skin frictional quantity variation along suction with different Hartmann quantity obtained. The critical values Sci,i=1,2, and 3 observed are 2.2396,2.3795, and 2.7714 corresponding to the values of M = 0,0.02, and 0.04, respectively. Research suggests that dual solutions are present within a specific spectrum of suction and stretching/shrinking parameters. Additionally, the stability analysis of these dual solutions indicates that the primary solution is stable.