V. Rajesh

Transient nanofluid flow and heat transfer from a moving vertical cylinder in the presence of thermal radiation: Numerical study

A mathematical model is presented for unsteady free convective flow and heat transfer of a viscous nanofluid from a moving vertical cylinder in the presence of thermal radiation. A range of nanofluids containing nanoparticles of Al2O3, Cu, TiO2 and Ag with nanoparticle volume fraction range less than or equal to 0.04 are considered. The governing partial differential equations with the corresponding initial and boundary conditions are solved numerically by a robust, well-tested, implicit finite difference scheme of Crank–Nicolson type, which is efficient, unconditionally stable and convergent. The obtained results are benchmarked with previously published work for special cases of the problem in order to access the accuracy of the numerical method and found to be in excellent agreement. The influence of significant parameters such as nanoparticle volume fraction, nanofluid type, thermal conduction–radiation parameter and thermal Grashof number on the flow and heat transfer characteristics is discussed. This study is relevant to high-temperature nanofluid materials’ processing, chemical engineering coating operations exploiting nanomaterials and so on.

Unsteady convective flow past an exponentially accelerated infinite vertical porous plate with Newtonian heating and viscous dissipation

Purpose – The purpose of this paper is to consider unsteady free convection flow of a dissipative fluid past an exponentially accelerated infinite vertical porous plate in the presence of Newtonian heating and mass diffusion. Design/methodology/approach – The problem is governed by coupled non-linear partial differential equations with appropriate boundary conditions. A Galerkin finite element numerical solution is developed to solve the resulting well-posed two-point boundary value problem. It is a powerful, stable technique which provides excellent convergence and versatility in accommodating coupled systems of ordinary and partial differential equations. Findings – It is found that the skin friction coefficient increases with increases in either of the Eckert number, thermal Grashof number, mass Grashof number or time whereas it decreases with increases in either of the suction parameter, Schmidt number or the acceleration parameter for both air and water. The skin friction coefficient is also found to...