RT Journal Article ID 168122732e7a580d A1 Wang, G. A1 Fan, Z. L. A1 Zeng, Min A1 Wang, Qiuwang A1 Ozoe, H. T1 NATURAL CONVECTION HEAT TRANSFER IN A NANOFLUID-FILLED HORIZONTAL LAYER WITH SINUSOIDAL WALL TEMPERATURE AT THE BOTTOM BOUNDARY JF Heat Transfer Research JO HTR YR 2018 FD 2018-06-07 VO 49 IS 11 SP 1059 OP 1076 K1 natural convection K1 nanofluids K1 infinite horizontal layer K1 Brownian motion K1 time-periodic boundary temperature AB Transient natural convection heat transfer of a water-based nanofluid in an infinite horizontal layer submitted to the influence of a time-periodic boundary temperature is studied numerically using finite volume approach. The bottom wall temperature of the horizontal layer is varied sinusoidally with time at a constant temperature, while the top wall is cooled at a relatively low temperature. CuO nanoparticles are taken into consideration. The computational region of height 1 and horizontal width 1 is adopted, and numerical computation is performed. By considering Brownian motion, the effects of the Rayleigh number and solid volume fraction on the flow and temperature patterns as well as the heat transfer rate within the horizontal layer are presented. It is found that the time-averaged heat transfer rate decreases with increasing solid volume fraction at low Rayleigh numbers. However, at high Rayleigh numbers, all of the time-averaged Nusselt numbers for the CuO–water nanofluid with different nanoparticle volume fractions are larger than that for pure water, and there is an optimum solid volume fraction which results in the maximum time-averaged heat transfer rate. PB Begell House LK https://www.dl.begellhouse.com/journals/46784ef93dddff27,7ff6027401e57c45,168122732e7a580d.html