Abstract: The two-dimensional unsteady magnetohydrodynamic squeezing flow and heat transfer of Casson fluid between two parallel plates with aligned magnetic field and nonlinear thermal radiation is investigated theoretically. The resulting governing equations are transformed as set of ODEs and solved numerically by using bvp4c Matlab package. The influence of various pertinent parameters on the flow and temperature fields are discussed with the assistance of graphical illustrations. The reduced Nusselt number are presented through graphs. It is seen that increasing values of squeeze number depreciate the flow and temperature fields.
Abstract: This work deals with the effect of thermal buoyancy on momentum and heat transfer characteristics of confined square cylinder submerged in Non Newtonian shear-thinning fluids. In two-dimension, the governing equations are solved by using the commercial code ANSYS-CFX. The effects of thermal buoyancy and power-law index, n, on the non-dimensional Drag coefficient and Nusselt number are studied for the conditions: Ri = 0 to 1, n = 0.3 to 0.9, Re = 40, Pr = 1 and blockage ratio β = 1/4. The detailed flow and temperature field are presented in terms of streamlines and isotherm contours. It is found that for all values of Richardson number increase in the power-law index increases the total drag coefficient and decreases the non-dimensional Nusselt number.
Abstract: Effect of suction/injection on the rate of entropy generation of third grade fluid with convective cooling is analysed in this work. The highly non-linear boundary value problems obtained from the governing equations are solved by Adomian decomposition method (ADM). Some plots are presented to explain the influence of pertinent parameters on fluid motion, temperature, entropy generation and irreversibility ratio. From the results it is shown that suction/injection and third grade fluid parameters reduce fluid velocity across the channel, and increase in suction/injection parameter enhances fluid temperature while convective cooling parameter reduces it. Entropy generation is enhanced by suction/injection parameter at the lower wall but reduces it at the upper wall
Abstract: The combined effects diffusion-thermo, chemical reaction, buoyancy forces, radiative heat flux, velocity slip and magnetic field on an unsteady hydromagnetic mixed convective flow of an electrically conducting fluid with heat and mass transfer over an inclined vertical porous plate embedded in a porous medium is studied. The imposed thermal boundary conditions include prescribed uniform plate surface temperature (PST) and prescribed heat flux (PHF). The governing equations are solved analytically with the help of two term perturbation technique. The influence of various thermophysical parameters on the fluid velocity, temperature and species concentration are presented graphically while numerical values of skin friction, Nusselt and Sherwood numbers are presented in tabular form for different values and discussed. A special case of our results show excellent agreement with the earlier results in the literature.
Abstract: In this paper, a numerical simulation was conducted to investigate the steady laminar natural convective heat transfer and surface radiation from a heated rectangular body in a triangular enclosure. The coupled equations of Navier-stockes and energy are both solved using the finite volume method. The velocity-pressure coupling is insured by the SIMPLER algorithm. The fluid used in this study is a dry air of Prandtl number Pr = 0.71.In such way that, the radiative exchanges are made only through solid walls and which are assumed to be gray and diffuse. The physical parameters characterizing the problem and influencing heat transfer are Rayleigh number Ra, aspect ratio A, height h and width w of the body. The results are presented in terms of isotherms, streamlines and average Nusselt number.
Abstract: The effects of thermal and exponential space dependent heat sources (THS and ESHS) on magneto-nanoliquid flow across a rotating disk with uniform stretching rate along radial direction are scrutinized in this communication. H2O based nanoliquids containing aluminium (AA 7075) and titanium (Ti6Al4V) alloy nanoparticles are considered. The AA7075 is made up of 90% Al, 5-6% Zn, 2-3% Mg, 1-2% Cu with additives such as Fe, Mn and Si etc. The flow is driven due to rotating disk with uniform stretching of the disk. Impacts of Joule and viscous heating are also deployed. The multidegree ordinary differential equations are formed via Von Karman transformations. The obtained non-linear BVP is solved by Runge-Kutta-Fehlberg based shooting approach (RKFS). Graphical illustrations depict the impacts of influential parameters on flow fields. The skin friction and Nusselt number are also calculated. Results pointed out that the thermal boundary layer growth stabilizes due to the influence of ESHS aspect. Velocities of nanofluid are superior than that of nanoliquid. Furthermore, the thermal performance of base liquid is outstanding when we added titanium alloy nanoparticles in comparison with aluminium alloy nanoparticles.
Abstract: This study focuses on the analytical solution for the chemical reaction and melting heat transfer effects on MHD steady two-dimensional laminar viscous incompressible radiating boundary layer flow over a flat plate in the presence of variable fluid properties and Soret effect. The presence of viscous dissipation is also put into consideration at the plate under the influence of uniform transverse magnetic field. A mathematical model is developed to investigate the heat transfer characteristics occurring during the melting process due to a stretching sheet. The model contains nonlinear coupled partial differential equations which have been transformed into a system of ordinary differential equation via suitable similarity variables and then solved analytically by employing the Homotopy analysis method (HAM). The convergence of the series solution is established. The impact of various controlling parameters on the flow, heat and mass transfer characteristics are analyzed and discussed in detail through graphs and tables. The velocity and temperature depreciate with increase in radiation parameter and variable viscosity parameter. It is observed that for rising values of magnetic field parameter, variable viscosity parameter, and Prandtl number, the local skin friction increases while a reverse effect is seen in the case of Grashof number and melting parameter. It is found that the temperature decreases as the thermal radiation and melting parameter increase.
Abstract: The present work focuses on the numerical simulation of isothermal and weakly compressible Poiseuille flow in a planar channel using the Lattice Boltzmann method with multiple times of relaxation (MRT-LBE) coupled to the Finite Difference method (FDM). The active fluid considered is the air under low Mach number assumption. The flow is two-dimensional, laminar and all the physical properties are constants except the density which varies in the sense of the Boussinesq approximation. The effects of the compressibility, the inclination angle and the Reynolds number on the dynamical and thermal fields are studied numerically. The results are presented in terms of streamlines, isotherms and transverse velocity.
Abstract: In the recent years, blood flow through an aorta has been the main focus of many investigators. It shows particular interest in analyzing human aortic stiffness and blood flow behavior. Mainly, an unsteady state is applied for incompressible fluid, which is assumed to be newtonian. Artery is considered an elastic tube and the wall boundaries are isotropic. The analytical modeling of blood involves adopting an asymptotic approach according to a small aspect radio, which is inversely proportional to Reynolds number. The wall has been assumed a thin shell, which generates a small axisymmetric vibration. The mathematical model of the wall is developed using the thin shell theory based on geodesic curvature parameter. In the end, the analytical results simulation is applied to have better understanding of the effects of blood flow behavior over the elasticity aortic wall properties.