Articles written in Pramana – Journal of Physics

• MHD mixed convection flow of a nanofluid past a stretching surface of variable thickness and vanishing nanoparticle flux

This article aims to present the flow and heat transfer characteristics of a nanofluid past an elastic sheet having variable thickness in the presence of a magnetic field. Vanishing nanoparticle flux at the boundary has been taken into account for the passive control of nanoparticles. Two-phase model for the nanofluid has been considered. With the help of similarity transformations, the governing nonlinear partial differential equations are converted into nonlinear ordinary differential equations along with the appropriate boundary conditions. The reduced equations are then solved numerically. The effects of buoyancy parameter,magnetic parameter, Brownian motion, thermophoresis parameter etc. on velocity, temperature and nanoparticle volume fraction are presented graphically and analysed in detail. Velocity, temperature and nanoparticle volume fraction are decreasing functions of wall thickness parameter for decelerated flow. Due to increasing values of thermophoresis parameter, the rate of heat transfer at the surface reduces while with the increase in the Brownian motion parameter the mass transfer rate at the surface increases.

• Cu–water nanofluid flow with arbitrarily shaped nanoparticles over a porous plate in a porous medium in the presence of slip

The objective of the article is to analyse the forced convection nanofluid flow over a permeable plate in an absorbent medium using slip boundary conditions. A single-phase model for the nanofluid is used with variable shapes of nanoparticles. The partial differential equations (PDEs) of the model are altered into a set ofnon-linear ordinary differential equations (ODEs) by a suitable alteration. To obtain the solutions of the system of equations numerically, Runge–Kutta method is used with a shooting technique. The effects of various parameters,like permeability, suction/injection, nanoparticle volume fraction, velocity slip, thermal slip and nanoparticle shape parameters on velocity and temperature profiles are presented graphically and analysed. In addition, fora clear understanding of the model, the flow and the heat transfer characteristics are presented through graphs and analysed. Fluid velocity is found to increase with the increasing values of permeability of the porous medium,whereas temperature is found to reduce in this case. Temperature is a rising function of the thermal slip parameter, whereas it is a decreasing function of the velocity slip parameter.

• Influence of Thompson and Troian slip on the nanofluid flow past a permeable plate in porous medium

The aim of the present analysis is to study the influence of Thompson and Troian slip on forced convective nanofluid flow over a permeable plate in Darcy porous medium in the presence of zero nanoparticle flux at the boundary. By the appropriate make-over, the foremost partial differential equations (PDEs) are abridged to ordinary differential equations (ODEs) and numerical solutions for the nonlinear equations are subsequently attained by shooting technique. Due to enhanced permeability parameter, speed and concentration of the liquid increase but the width of the momentum boundary layer and temperature reduce. The current analysis discloses that by reducing the width of the boundary level, the rising (velocity) slip parameter forces the fluid speed and concentration to increase while dimensionless temperature reduces for increasing (velocity) slip. Compared to blowing, liquid speed and concentration are superior for suction. With the rise in Brownian motion parameter, concentration diminishes whereas with the rise in thermophoresis parameter, temperature is found to rise. The results achieved in this examination expose various motivating characteristics which demand additional investigation of the problem.

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019