TY - JOUR
TI - Heat transfer for two types of viscoelastic fluid over an exponentially stretching sheet with variable thermal conductivity and radiation in porous medium
AU - Singh Vijendra
AU - Agarwal Shweta
JN - Thermal Science
PY - 2014
VL - 18
IS - 4
SP - 1079
EP - 1093
PT - Article
AB - An Analysis has been carried out to study the boundary layer flow and heat  transfer characteristics of second order fluid and second grade fluid with  variable thermal conductivity and radiation over an exponentially stretching  sheet in porous medium. The basic boundary layer equations governing the flow  and heat transfer in prescribed surface temperature (PST) and prescribed heat  flux (PHF) cases are in the form of partial differential equations. These  equations are converted to non-linear ordinary differential equations using  similarity transformations. Numerical solutions of the resulting boundary  value problem are solved by using the fourth order Runge-Kutta method with  shooting technique for various values of the physical parameters. The effect  of variable thermal conductivity, porosity, Prandtl number, radiation  parameter and viscoelastic parameters on velocity and temperature profiles  (in PST and PHF cases) are analyzed and discussed through graphs. Numerical  values of wall temperature gradient in PST case and wall temperature in PHF  case are obtained and tabulated for various values of the governing  parameters. In this study Prandtl number also treated as variable inside the  boundary layer because it depends on thermal conductivity. The results are  also verified by using finite difference method. [The authors are thankful to  the Council of Scientific and Industrial Research, New Delhi, for providing  financial support through Grant No. 08/043(0005)/2008-EMR-1]