Mixed convection and entropy generation in a square cavity using nanofluids

Abstract

In this work, two-dimensional mixed convection and entropy generation of water-(Cu, Ag, Al2O3, and TiO2) nanofluids in a square lid-driven cavity containing two heat sources, have been numerically investigated. The upper lid and bottom wall of the cavity are maintained at a cold temperature TC, respectively. The governing equations along with boundary conditions are solved using the finite volume method. Comparisons with the previous results were performed and found to be in excellent agreement. The effects of the solid volume fraction (0≤φ≤0.10), Rayleigh (103≤Ra≤105) and Reynolds (1≤Re≤500) numbers, and different types of nanofluids on the total entropy generation St and on entropy generation due to heat transfer Sh are presented and discussed. Moreover, the heat sources positions have an effect on the total entropy generation and Bejan number. It was found that St and Sh decrease with increase of φ, Ra, and Re.