Effects of radiation and heat source on MHD flow of a viscoelastic liquid and heat transfer over a stretching sheet

We study the MHD flow and also heat transfer in a viscoelastic liquid over a stretching sheet in the presence of radiation. The stretching of the sheet is assumed to be proportional to the distance from the slit. Two different temperature conditions are studied, namely (i) the sheet with prescribed surface temperature (PST) and (ii) the sheet with prescribed wall heat flux (PHF). The basic boundary layer equations for momentum and heat transfer, which are non-linear partial differential equations, are converted into non-linear ordinary differential equations by means of similarity transformation. The resulting non-linear momentum differential equation is solved exactly. The energy equation in the presence of viscous dissipation (or frictional heating), internal heat generation or absorption, and radiation is a differential equation with variable coefficients, which is transformed to a confluent hypergeometric differential equation using a new variable and using the Rosseland approximation for the radiation. The governing differential equations are solved analytically and the effects of various parameters on velocity profiles, skin friction coefficient, temperature profile and wall heat transfer are presented graphically. The results have possible technological applications in liquid-based systems involving stretchable materials. © 2005 Elsevier Ltd. All rights reserved

Suction-induced magnetohydrodynamics of a viscoelastic fluid over a stretching surface within a porous medium.

The magnetohydrodynamic (MHD) flow over a stretching sheet of a viscoelastic fluid immersed in a porous medium is studied analytically. The flow is induced by suction and also by an infinite elastic sheet which is stretched along its own plane. The stretching of the sheet is assumed to be proportional to the distance from the slit. The governing equations are reduced to a non-linear ordinary differential equation by means of similarity transformation. The resulting non-linear equation is solved analytically and the streamlines of the flow field are obtained. The effect of various quantities such as suction parameter, Chandrasekhar number and porous parameter on the velocity fields are studied. Results show that the flow field can be divided into a near-field region (boundary-layer region) and a far-field region (free stream region). Suction on the surface plays an important role in the flow development in the near-field whereas the far-field is influenced mainly by stretching. The electromagnetic effect plays exactly the same role as the porous medium, which reduces the horizontal flow velocity resulting from stretching. The flow pattern also exhibits a substantial change as the suction effect increases, and in such case the growth of the near-field region can extend far away from the stretching surface. These results have possible technological applications in liquid-based systems involving stretchable materials

An analytical study of weakly nonlinear dynamics of a Walters’ liquid B around a flexible sheet undergoing super linear stretching.

The paper discusses the boundary layer flow of Walters' liquid B over a stretching sheet. The stretching is assumed to be a quadratic function of the coordinate along the direction of stretching. The study encompasses within its realm both Walters' liquid B and second order liquid. The velocity distribution is obtained by solving the nonlinear governing differential equation. Analytical expressions are obtained for stream function and velocity components as functions of the viscoelastic and stretching related parameters. It is shown that the viscoelasticity goes hand in hand with quadratic stretching in enhancing the lifting of the liquid as we go along the sheet

A New Analytical Procedure for Solving the Non-Linear Differential Equation Arising in the Stretching Sheet Problem

The paper discusses a new analytical procedure for solving the non-linear boundary layer equation arising in a linear stretching sheet problem involving a Newtonian/non-Newtonian liquid. On using a technique akin to perturbation the problem gives rise to a system of non-linear governing differential equations that are solved exactly. An analytical expression is obtained for the stream function and velocity as a function of the stretching parameters. The Clairaut equation is obtained on consideration of consistency and its solution is shown to be that of the stretching sheet boundary layer equation. The present study throws light on the analytical solution of a class of boundary layer equations arising in the stretching sheet proble

An Analytical Study of Weakly Nonlinear Dynamics of a Walters'' Liquid B around a Flexible Sheet undergoing Super Linear Stretching

The paper discusses the boundary layer flow of Walters'' liquid B over a stretching sheet. The stretching is assumed to be a quadratic function of the coordinate along the direction of stretching. The study encompasses within its realm both Walters'' liquid B and second order liquid. The velocity distribution is obtained by solving the nonlinear governing differential equation. Analytical expressions are obtained for stream function and velocity components as functions of the viscoelastic and stretching related parameters. It is shown that the viscoelasticity goes hand in hand with quadratic stretching in enhancing the lifting of the liquid as we go along the sheet

Analytical solution of a Walters' liquid B flow over a linear stretching sheet in a porous medium

This chapter represents the analytical solution of two-dimensional linear stretching sheet problem involving a non-Newtonian liquid and suction by (a) invoking the boundary layer approximation and (b) using this result to solve the stretching sheet problem without using boundary layer approximation. The basic boundary layer equations for momentum, which are non-linear partial differential equations, are converted into non-linear ordinary differential equations by means of similarity transformation. The results reveal a new analytical procedure for solving the boundary layer equations arising in a linear stretching sheet problem involving a non-Newtonian liquid (Walters’ liquid B). The present study throws light on the analytical solution of a class of boundary layer equations arising in the stretching sheet problem

International Field Workshop and Seminar on Composition and Evolution of High-Grade Gneiss Terrains

This field workshop and seminar represented the culmination of a programme·()f work on the basement rocks of Sri Lanka which was embarked on by the Sri Lankan- German consortium some five years ago. The meeting was sponsored by-German Science Foundation, Project 134 of IGCP (Lower Crustal Processes),Institute of Fundamental Studies (IFS), Kandy, Geological Survey Department, -Colombo and Natural Resources, Energy and Science Authority, Colombo. The-conference provided an opportunity for many scientists frum outside Sri Lanka to visit.parts of Sri Lanka. More than 50 scientists attended the meeting including.representatives from Germany, U.K., USSR, Australia, India and Czechoslovakia. This meeting consisted of field trip for 4 days (plus two optional trips) and'seminar for 2 days at I.F.S., Kandy. The field excursions covered part of Highland Complex near Kandy and Wanni-Complex (West Vijayan Gneiss) near Kurunegala. The Highland Complex consists·of quartzites, pelites and marble with basic sills and dykes as well as a major layered intrusion (Kandy Intrusion) and granite gneiss (metagranite). All these rock types ·.are in upper amphibolite to granulite facies and are deformed in four phases