Fluid Flow and Transfer Processes, Modeling and Simulation, Mathematical Physics
11
Scopus Publications
Scopus Publications
Axisymmetric Nanofluid Flow with Non-Uniform Magnetic Field Dhanapal Prakash, Elumalai Ragupathi, Narsu Sivakumar, Murugan Muthtamilselvan, Ikhyun Kim Advances in Computational Fluid Dynamics, 2025 The impact of non-uniform external magnetic field on the three-dimensional stagnation-point axisymmetric flow of nanofluid over a flat plate is numerically investigated. The rigid plate is assumed to transfer the heat with the nanofluid by convection. It is assumed that the resultant magnetic field is parallel to the velocity at infinity and the nanofluid occupies the half-space over a rigid uncharged dielectric at rest. The model used for the nanofluid incorporates the Brownian random motion and thermophoretic force. The passively controlled nanofluid model is considered to investigate the flow characteristics. Numerical results of the self-similar governing equations are computed by employing the Runge–Kutta–Fehlberg method along with shooting technique. Also, the non-dimensional form of the ordinary differential equations is solved by the homotopy analysis method, and compared with numerical results. It is found that the exerted magnetic field manipulated the suspended particles and rearranged their concentration in the fluid. In addition, the numerical data has been interpreted as the regression and correlation and these models bring a suitable representation, which is used in engineering problems.
Comparative study of Fe3O4 and Ag nanoparticles in Ethylene-Glycol Casson nanofluid flow around a Howarth's wavy cylinder: Applications of sensors and actuators E. Ragupathi, D. Prakash, M. Muthtamilselvan, Qasem M. Al-Mdallal, Ikhyun Kim International Journal of Thermofluids, 2025 This study investigates the combined effects of non-uniform heat source/sink and Newtonian heating on the time-dependent stagnation point flow of Casson nanofluids over Howarth’s wavy cylinder. A nanofluid composed of an equal mixture of water( H 2 O ) and ethylene glycol(EG) (50%:50%) is used to suspend Iron-Oxide ( Fe 3 O 4 ) and Silver (Ag) nanoparticles, capitalizing on their unique thermal and rheological properties. The Casson fluid model is employed to capture the non-Newtonian behavior of the nanofluid under shear stress conditions. Moreover, non-uniform heat source/sink mechanism is integrated into the energy equation to simulate spatially dependent thermal generation or absorption. Additionally, the Newtonian heating boundary condition, where surface heat flux is proportional to the temperature difference between the surface and ambient fluid-is imposed to reflect realistic convective heating scenarios. The governing partial differential equations are transformed using similarity variables and solved by using Runge–Kutta-Fehlberge(RKF) method along with shooting technique and Homotopy Analysis Method (HAM). The results reveal that both the non-uniform heat source/sink and Newtonian heating significantly influence the thermal and velocity boundary layers. Notably, silver-based nanofluids show superior heat transfer enhancement due to higher thermal conductivity, while iron oxide-based fluids exhibit stronger magnetic responsiveness and moderate thermal performance. The fluid motion is enhanced by rising the values of Casson and unsteady parameter. The heat transfer rate is enhanced by increasing the values of Biot number on the Fe 3 O 4 / H 2 O + EG and Ag / H 2 O + EG based nanofluid. The findings provide useful insights for the development of thermally responsive systems in microscale actuators, thermal sensors, and heat-dissipating components in smart engineering devices.
Thermophoretic particle deposition in a nanofluid flow across a disc with non-fourier heat flux: An investigation using tangent hyperbolic model E. Ragupathi, D. Prakash, M. Muthtamilselvan, Qasem M. Al-Mdallal, Ikhyun Kim Numerical Heat Transfer Part A Applications, 2025 Non-Newtonian nanofluids are attracting the attention of researchers and academics due to the high heat transmission rates that they possess. To improve thermal devices and exchangers, the researchers come up with innovative and expense-effective methods. One of the advanced technological approaches that can be utilized to enhance the thermal performance of devices is the utilization of nanofluids. This non- Newtonian nanofluid possesses the advanced properties of increasing heat transfer and destroying harmful bacteria. For this purpose, the present theoretical work is to explore the heat and thermophoretic particle deposition analysis on the tangent hyperbolic nanofluid flow over the rotating porous disk with presence of non-Fourier heat flux model and nanoparticle aggregation effect. Darcy-Forchheimer fluid model is adopted to develop the fluid flow system. Furthermore, the nanofluid’s viscosity and thermal conductivity are expressed through advanced modeling, employing the modified Krieger-Dougherty model for viscosity and the Maxwell-Bruggeman model for thermal conductivity. The nanoparticles and base fluid involved in this context are Molybdenum disulfide (MoS2) and Water/carboxyl-methyl cellulose (CMC) respectively. The mathematical representation of the fluid flow and energy propagation involves a system of coupled partial differential equations (PDEs). The system of partial differential equations (PDEs) is transformed into non-dimensional ordinary differential equations (ODEs), which are then solved both analytically and numerically using the Homotopy Analysis Method(HAM) and Runge-Kutta-Fehlberg (RKF) method along with shooting technique. Exploring the graphical representation reveals a comprehensive analysis of key factors influencing velocity, temperature, and concentration. Through innovative visualization, these parameters take center stage, providing insights into their intricate interplay and dynamic relationships. The heat transfer rate is enhanced 0.24% and 1.4% by rising the values of thermal relaxation parameter and Weissenberg number. Also, the mass transfer rate is accelerated 0.8% and 0.14% due to enhancing the values of thermophoretic coefficient and thermophoresis parameter.
Dynamics of non-Newtonian methanol conveying aluminium alloy over a rotating disc: consideration of variable nanoparticle radius and inter-particle spacing E Ragupathi, D Prakash, M Muthtamilselvan, Qasem M Al-Mdallal Nanotechnology, 2024 The advancement of non-Newtonian nanofluid innovation is a crucial area of research for physicists, mathematicians, manufacturers, and materials scientists. In engineering and industries, the fluid velocity caused by rotating device and nanofluid has a lot of applications such as refrigerators, chips, heat ex-changers, hybrid mechanical motors, food development, and so on. Due to the tremendous usage of the non-Newtonian nanofluid, the originality of the current study is to explore the influence of nanoparticle radii and inter-particle spacing effects on the flow characteristics of Casson methanol-based aluminium alloy (AA7072) nanofluid through a rotating disc with Joule heating and magnetic dipole. The present problem is modeled in the form of partial differential equations (PDEs), and these PDEs are converted into ordinary differential equations with the help of suitable similarity transformations. The analytical solution to the current modeled problem has been obtained by using the homotopy analysis method (HAM) and numerical solutions are obtained by employing Runge–Kutta–Fehlberg method along with shooting technique. The main purpose of the present research work is to analyze the behavior of the velocity and temperature of the nanofluid for small and large radius of the aluminium alloy (AA7072) nanoparticles and inter-particle spacing. The radial and tangential velocities are enhanced due to rising ferro-hydrodynamic interaction parameter and the skin friction force for radial and tangential directions are enhanced 10.51% and 2.16% when h = 0.5. Also, the heat transfer rate is reduced 18.71% and 16.70% when h = 0.5% and R p = 1.5. In fact, the present results are compared with the published results and they met good agreement.
Entropy analysis of Casson nanofluid flow across a rotating porous disc with nonlinear thermal radiation and magnetic dipole E. Ragupathi, D. Prakash, M. Muthtamilselvan, Kyubok Ahn International Journal of Modern Physics B, 2023 The theme of the current effort is to theoretically analyze the entropy generation and heat transfer aspects of Casson nanofluid flow triggered by rotating porous disc with the presence of magnetic dipole, nonlinear thermal radiation, viscous dissipation and Joule heating. The modeling of the nanofluid can be described with the combination of Brownian motion and thermophoresis by incorporating the passive control boundaries, and the governing PDEs are transformed into a set of highly nonlinear ODEs. The resulting equations are then solved analytically using HAM technique. The present results are compared with previously published results, which are in excellent agreement. The effect of pertinent nondimensional parameters on the entropy generation, hydrodynamic, heat and mass transport aspects is discussed via graphical illustrations. Both radial and tangential velocities are affected by accelerating the values of Hartmann number and porosity parameter. The temperature profile is upsurged by improving the radiation and thermal ratio parameter. Increasing the Casson parameter and Brinkman number leads to improved entropy generation rate. Moreover, skin friction, heat and mass transfer rates are examined with the help of the tables. It is believed that this study can be utilized as coolants by numerous automotive and engineering industries, namely the electronic devices, electrical motor, spin coating, fabrication of spacecraft, thermal insulation, nuclear reactors, etc.
Homotopy analysis approach to Ferro-hydrodynamic bio-nanofluid flow over a co-axial rotating discs with Stefan blowing and magnetic dipole E. Ragupathi, D. Prakash, M. Muthtamilselvan, Kyubok Ahn Numerical Heat Transfer Part B Fundamentals, 2023 In this study, the Homotopy Analysis Method (HAM) is employed to investigate the flow of a Ferro-hydrodynamic bio-nanofluid over a co-axial rotating disks with Stefan blowing, magnetic dipole, and hall effects. The heat transport mechanism is modeled by using the Brownian movement and thermophoresis. The governing equations are derived and transformed into nondimensional form using appropriate similarity transformations. The resulting equations are solved analytically using the Homotopy Analysis Method. The obtained results are compared with the existing literature and are found to be in excellent agreement. The effects of various parameters such as Hartmann number (Ha), Ferro-hydrodynamic interaction parameter (B), Stefan blowing effect (fw), Peclet (Pe), and bio-convection Lewis number (Lb) are examined via graphical representation. Moreover, the bio-nanofluid radial velocity field is enhanced by improving the values of hall and Ferro-hydrodynamic interaction parameter (FHD). The temperature profile is diminished due to increasing the values of hall parameter, while the opposite behavior is observed when rising the values of FHD parameter. Increasing the Hartmann number (Ha) lead to decline the radial and tangential velocity, whereas the temperature profile is enhanced. The motile microorganisms filed is significantly affected by bio-Lewis and Peclet numbers. The significance of Stefan blowing is discussed on the hydrodynamic, heat, and mass transport aspects for the instances of fw<0, fw = 0, and fw>0, respectively. Also, the drag coefficient, heat and mass transport, motile microorganisms rates are discussed via tables.
Nanofluid Flow and Heat Transfer in Upright Asymmetrical Channel with Boundary Conditions of Third Kind E. Ragupathi, D. Prakash, S. Kumar, K. Karuppiah Aip Conference Proceedings, 2022 An unsteady magnetic incompressible free convective flow of nanofluid between two rigid, parallel asymmetric plates with the inclusion of additional thermal source is considered. The heat is transferred from the fluid to the plate and vice versa due to thickness of the plate is negligible. It is assumed that nano-liquids are made up with pouring various types of nanoparticles into the water based fluid. Single phase model is adopted to determine the thermo-physical properties of the nano-liquid. The governing equations for the model are solved to analyze the flow and heat transfer characteristics by D-T-M semi analytical and numerical approaches and it was illustrated graphically.
Impact of Thermal Nonequilibrium on Flow Through a Rotating Disk with Power Law Index in Porous Media Occupied by Ostwald-de-Waele Nanofluid E. Ragupathi, D. Prakash, M. Muthtamilselvan, Qasem M. Al-Mdallal Journal of Non Equilibrium Thermodynamics, 2022 The current study is made to analyze the impact of local thermal nonequilibrium (LTNE) on the steady, incompressible, and viscous Ostwald-de-Waele nano-liquid over a rotating disk in a porous medium with the various power law index, due to many remarkable applications, such as aeronautical systems, rotating machineries, air cleaning machineries, electrical power-generating systems, heat exchangers, gas turbines, centrifugal pumps. To describe the modeling of the nano-liquid, Brownian movement and thermophoresis are employed with the passive control boundaries. Three temperature model is adopted to distinguish the temperature among the fluid, particle, and solid. The governing transport equations have been converted to a system of nonlinear coupled ordinary differential equations by employing von Karman transformation. Numerical results of the flow and heat and transfer characteristics of the fluid, particle, and solid are obtained by applying Runge–Kutta–Fehlberg method (RKF) together with the shooting technique. The numerical results in the present work are compared with the published results for the case of thermal equilibrium and found that they are in good agreement. It is observed that the temperature profile significantly varies with the fluid-particle, fluid-solid interphase heat transfer coefficients and the modified thermal capacity ratios.
