Ch. Venkata Rao

Double dispersion effects on non-Darcy free convective boundary layer flow of a nanofluid over vertical frustum of a cone with convective boundary condition

Abstract In this paper, a numerical analysis is performed to investigate the effects of double dispersion and convective boundary condition on natural convection flow over vertical frustum of a cone in a nanofluid saturated non-Darcy porous medium. In addition, Brownian motion and thermophoresis effects have taken into consideration, and the uniform wall nanoparticle condition is replaced with the zero nanoparticle mass flux boundary condition to execute physically applicable results. For this complex problem, the similarity solution does not exist and hence suitable non-similarity transformations are used to transform the governing equations along with the boundary conditions into non-dimensional form. The Bivariate Pseudo-Spectral Local Linearisation Method (BPSLLM) is used to solve the reduced non-similar, coupled partial differential equations. To test the accuracy of proposed method, the error analysis and convergence tests are conducted. The effect of flow influenced parameters on non-dimensional velocity, temperature, nanoparticle volume fraction, regular concentration field as well as on the surface drag, heat transfer, nanoparticle and regular mass transfer rates are analyzed.

Non-similarity solution for Soret effect on natural convection over the vertical frustum of a cone in a nanofluid using new bivariate pseudo-spectral local linearisation method

In this paper, we present a numerical investigation of a highly coupled and nonlinear system of partial differential equations (PDEs) that model natural convection over the vertical frustum of a cone in a nanofluid in the presence of Soret effect. The system of PDEs are solved using a new numerical approach named as bivariate pseudo-spectral local linearisation method (BPSLLM). The solution method uses the so-called quasilinearisation method to linearise the equations in a sequential manner and applies spectral collocation to discretise all independent variables. To test the accuracy of the proposed method, error analysis and convergence tests are conducted. Further, the accuracy validation is conducted through comparison with asymptotic series solutions for limiting cases of small and large parameters. In order to unravel the interesting features of the problem, the effects of the physical parameters on skin-friction, heat, regular mass and nanoparticle mass transfer characteristics along the vertical frustum of a cone are given and the salient features are discussed.

Effects of Soret, Hall and Ion-slip on mixed convection in an electrically conducting Casson fluid in a vertical channel

Abstract The significance of Soret, Hall and Ion-slip effects on mixed convection flow of an electrically conducting Casson fluid in a vertical channel in the presence of viscous dissipation is analyzed. The system of flow governing equations are converted into the system of non-dimensional equations using appropriate non-dimensional transformations and hence solved analytically by homotopy analysis method. A quantitative comparison is made between homotopy analysis method and Adomian decomposition method and the results are found to be in good agreement. The dimensionless velocity, temperature and species concentration profiles are illustrated graphically and quantitatively with special focus on the Casson fluid, Soret, viscous dissipation, Hall and Ion-slip parameters.