Mixed convective flow stability of nanofluids past a square cylinder by dynamic mode decomposition

The mixed convective flow stability of nanofluids past a square cylinder is investigated by Dynamic Mode Decomposition (DMD). The energy content in the individual modes for Cu-water nanofluids is found to be higher than that of Al2O3-water nanofluids. DMD results showed the fact that Cu-water nanofluids have more small-scale structures of higher frequency modes compared to that of Al2O3-water nanofluids. The most dominant temporal dynamic mode corresponds to the lower-frequency eigenvalue lambda = (0.99374, +/- 0.1117) for Al2O3-water nanofluids and lambda = (0.99451, +/- 0.10464) for Cu-water nanofluids. Energy content in the mean flow of the base fluid at Richardson number of -0.5 is found to be maximum compared to that of nanofluids. (C) 2013 Elsevier Inc. All rights reserved.