The present analysis is concerned to examine the enhancement of heat transfer in natural convection flow of nanofluid through a vertical wavy plate assumed at variable heat flux. The rate of heat transfer in nanofluid flow as compared to pure water can be increased due to increase the density of nanofluid which depends on the density and concentration of nanoparticles. For this analysis, Tiwari and Das model is used by considering two nanoparticles i. e. Al2O3 and Cu are suspended in a base fluid (water). A very efficient implicit finite difference technique converges quadratically is applied on the concerning PDE for numerical solution. The effects of pertinent parameters namely, volume fraction parameter of nanoparticle, wavy surface amplitude, Prandtl number and exponent of variable heat flux on streamlines, isothermal lines, local skin friction coefficient and local Nusselt number are shown through graphs. In this analysis, a maximum heat transfer rate is noted in Cu-water nanofluid through a vertical wavy surface as compared to Al2O3-water and pure water.

The effect of thermal radiation on unsteady mixed convection flow near a forward stagnation point over a cylinder of elliptic cross section is investigated in this paper. The governing equations are transformed into dimensionless partial differential equations by using a suitable transformation and then are solved numerically by using an implicit finite difference scheme known as Keller Box method. The accuracy of the results is verified by comparing the obtained results with the previous studies available in the literature. It is shown that the results are highly accurate and are in good agreement. The separation times for both blunt and slender orientations in the presence of thermal radiation are shown in tabular forms. Moreover, the effects of pertinent parameters including Prandtl number Pr, mixed convection parameter λ, thermal radiation parameter Rd, surface temperature parameter qw and blunt/slender orientation parameter w on the velocity profile, the temperature profile and the Nusselt number are shown graphically. From the present study, it is observed that boundary layer separation occurs early due to thermal radiation and Nusselt number increases for both blunt and slender orientations.