The Cheng–Minkowycz problem for natural convective boundary layer flow in a porous medium saturated by a nanofluid: A revised model

Abstract

The classical Cheng–Minkowycz problem considers natural convection past a vertical plate in a fluid-saturated porous medium. In our previous work we extended the Cheng–Minkowycz problem to the case when a porous medium is saturated by a nanofluid. We utilized Buongiorno’s nanofluid model that includes the effects of Brownian motion and thermophoresis. The major limitation of our previous model was active control of nanoparticle volume fraction at the boundary. Here we revisited our previous model and extended it to the case when the nanofluid particle fraction on the boundary is passively rather than actively controlled. This makes the model physically more realistic than our previous model as well as models employed by other authors simulating nanofluid flow in porous media.