Unsteady double-diffusive mixed convective boundary layer flow of a three-component nanofluid near stagnation point region

The unsteady double-diffusive mixed convective stagnation-point flow of a water-based nanofluid past avertical flat plate has been studied numerically. Buongiorno’s model is used to incorporate the effects ofBrownian motion and thermophoresis for the nanofluid, when the base fluid of the nanofluid is itself a binaryfluid such as salty water. In addition the thermal energy equations include regular diffusion and crossdiffusionterms.Using the local similarity method, it is shown that a set of suitable similarity transformationsreduces the non-linear coupled PDEs governing on the problem into a set of non-linear coupled ODEs. Theresulting basic equations are solved numerically via an efficient Runge-Kutta fourth-order method withshooting technique. The results demonstrate that for a regular fluid, without nanoparticle and salt, thedimensionless heat transfer rate is smaller than other diffusion cases. Moreover, it is observed that the highestheat transfer rate is obtained for the situation that the thermophoretic effect of nanoparticles is negligible.

Keywords:

Double diffusion , Mixed convective boundary layer flow , Stagnation point , thermophoretic effect , Brownian motion