Experimental and numerical investigations of convection heat transfer in corrugated channels using alumina nanofluid under a turbulent flow regime

Combining corrugated surfaces and nanofluids technologies have a significant advantage to develop compact heat exchangers in order to produce more efficient and reliable thermal systems. In this paper, the employment of alumina oxide (Al2O3) in water nanofluid for heat transfer enhancement with corrugation is performed numerically and experimentally over Reynolds number ranges of 10,000-30,000. Three corrugated channels, semicircle (SCC), trapezoidal (TCC), and straight (SC) are fabricated and tested with nanofluid Al2O3 volume fractions of 0%, 1%, and 2%. Thermophysical properties of the prepared nanofluid are measured experimentally. Numerically, the governing equations are solved in the computational domain using the finite volume method, and the results are presented in terms of velocity and isotherms contours. The findings clarified that the corrugation profile has a significant impact on heat transfer enhancement compared to the straight profile. Furthermore, heat transfer enhancement increases with increasing the volume fraction of nanoparticles. The new style of trapezoidal corrugated channel has the best heat transfer enhancement. This result may clarify the best use of corrugated channels in heat exchange devices to obtain the required thermal improvement. The numerical results are compared with the corresponding experimental data, and the results are in a good agreement. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.