K. Gangadhar

UNSTEADY FREE CONVECTIVE BOUNDARY LAYER FLOW OF A NANOFLUID PAST A STRETCHING SURFACE USING SPECTRAL RELAXATION METHOD

ABSTRACT An analysis is presented to study the unsteady, two-dimensional nanofluid flow of heat and mass transfer with vanishing nanoparticles flux at the wall in the presence of heat generation or absorption with viscous dissipation. In this analysis, it is assumed as nanoparticle flux is zero on the boundaries. The highly nonlinear differential equations governing the boundary layer flow, heat and mass transfer are numerically solved by spectral relaxation method and validated with MATLAB solver bvp4c. The results are obtained by some values of the physical parameters, namely, the Brownian motion parameter, the thermophoresis parameter, unsteadiness parameter, Eckert number, heat generation or absorption parameter, Prandtl number and Lewis number. Physical features for all relevant parameters on the dimensionless velocity, temperature, nanoparticles volume fraction and heat and mass transfer rates are analysed and discussed. The thermal boundary layer thickness increases with an increase in the thermophoretic parameter. The nanoparticle volume fraction profile significantly descends from the surface with an increase in Brownian motion parameter.

Boundary layer flow of nanofluids to analyse the heat absorption/generation over a stretching sheet with variable suction/injection in the presence of viscous dissipation

ABSTRACT In this investigation, the heat and mass transfer characteristics in boundary layer flow about a stretching sheet in a porous medium filled with TiO2 – water and Al2O3 – water-based nanofluids, in the presence of internal heat generation or absorption and viscous dissipation with variable suction or injection effects is numerically studied. The similarity transformations are used to transform the governing boundary layer equations for momentum, energy and species transfer into a set of non-linear ordinary differential equations which are solved numerically by Keller-box method. The obtained numerical results are validated against results computed by using MATLAB bvp4c routine, and excellent agreement is observed. The impact of various pertinent parameters on velocity, temperature and concentration as well as the friction factor coefficient, local heat and mass transfer rates are derived and discussed through graphs and tables for TiO2 and Al2O3 water-based nanofluids. The present study reveals that an increase in Eckert number (Ec) and heat generation/absorption parameter (Q) significantly decreases local heat transfer rate.

MHD Flow of a Carreau Fluid Past a Stretching Cylinder with Cattaneo-Christov Heat Flux Using Spectral Relaxation Method

A theoretical investigation of a hydromagnetic boundary layer flow of Carreau fluid over a stretching cylinder with surface slippage and temperature jump is presented in this paper. It is assumed that heat transfer characteristics of the flow follows Cattaneo-Christov heat flux model base on conventional Fourier’s law with thermal relaxation time. The spectral relaxation method (SRM) is being utilized to provide the solution of highly nonlinear system of coupled partial differential equations converted into dimensionless governing equations. The behaviour of flow parameters on velocity, temperature distributions are sketched as well as analyzed physically. The result indicates that the temperature distribution decay for higher temperature jump and thermal relaxation parameters respectively.

Slip Flow of an Unsteady Nanofluid Past a Stretching Surface in a Transverse Magnetic Field Using SRM

A theoretical and numerical examination has been completed to talk about the unsteady, two dimensional slip flow of a nanofluid of heat and mass transfer with transverse magnetic field was investigated in this paper. A stretching surface is used to investigate the flow. Obtained nonlinear equations are solved by Spectral Relaxation Method (SRM) technique and the results are verified by comparing the results obtained by using the Matlab in-built boundary value problem solver bvp4c, and the outcomes which are published in previous papers. The outcomes are exhibited pictorially and talked about difference coming about parameters. Expanding heat transfer rate, mass transfer rate and velocity slip raises velocity yet to be diminishes temperature and skin friction (surface shear stress).

Effect of viscous dissipation of a magneto hydrodynamic micropolar fluid with momentum and temperature dependent slip flow

In this paper, MHD flow and heat transfer of electrically conducting micro polar fluid over a permeable stretching surface with slip flow in the existence of viscous dissipation and temperature dependent slip flow are investigated. With the help of similarity transformations, the fundamental equations have been altered into a system of ordinary differential equations. It is difficult to solve these equations methodically. Thats why we used bvp4c MATLAB solver. We found the Numerical values for the wall couple stress, skin-friction coefficient, and the local Nusselt number in addition to the micro rotation, velocity, and temperature reports for diverse values of the principal parameters like thermal slip parameter, material parameter, magnetic parameter, heat generation/absorption parameter, velocity slip parameter and Eckert number It is observed that the values of suction/injection parameters rise corresponding to the lessening in the values of velocity, angular velocity, and temperature. Moreover, the change in the values of the Eckert number is opposite to the change in the values of the local Nusselt number.

MHD micropolar fluid flow over a stretching permeable sheet in the presence of thermal radiation and thermal slip flow: a numerical study

In this manuscript, a mathematical explanation is an attempt at meant for two-dimensional, micropolar fluid flow over a permeable stretching sheet with viscous dissipation in the occurrence of thermal radiation and temperature dependent slip flow. With the similarity transformations, the governing equations have been changed into a scheme of ordinary differential equations. These differential equations are extremely nonlinear which cannot be solved analytically. Thus, bvp4c MATLAB solvers have been used for solving it. Numerical consequences are obtained for the skin-friction coefficient, the couple wall stress and the local Nusselt number with the same as velocity, microrotation and temperature profiles for various values of the governing parameters, namely, material factor, magnetic factor, thermal slip factor, radiation factor, Prandtl number and Eckert number. It is found that magnetic field reduces the fluid velocity and angular velocity, but magnetic field enhances the fluid temperature. Furthermore, fluid temperature increases with increases in thermal slip parameter.