Convective-radiative heat transfer in a cavity filled with a nanofluid under the effect of a nonuniformly heated plate

Purpose The purpose of this study is to examine the radiation effect on the natural convective heat transfer of an alumina-water nanofluid in a square cavity in the presence of centered nonuniformly heated plate. Design/methodology/approach The square cavity filled with alumina-water nanofluid has a nonuniformly heated plate placed horizontally or vertically at its center. The plate is heated isothermally with linearly varying temperature. The vertical walls are cooled isothermally with a constant temperature, while the horizontal walls are insulated. The governing equations have been discretized using finite volume method on a uniformly staggered grid system. Simulations were carried out for different values of the heated plate nonuniformity parameter ( = -1, 0 and 1), the nanoparticles solid volume fraction ( = 0.01 - 0.04) and the radiation parameter (R-d = 0 - 2) at the Rayleigh number of Ra = 1e+07. Findings It is found that the total heat transfer rate is enhanced with an increase in the radiation parameter for both the horizontal and vertical plates. The role of nanoparticles addition to the base fluid can have dual effects on the heat transfer rate by augmenting and dampening for the absence of radiation while it dampens the heat transfer rate for the presence of radiation. Originality/value The originality of this work is to analyze steady natural convection in a square cavity filled with a water-based nanofluid in the presence of centered nonuniformly heated plate. The results would benefit scientists and engineers to become familiar with the analysis of convective heat and mass transfer in nanofluids, and the way to predict the properties of nanofluid convective flow in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors, electronics, etc.