Theoretical and experimental studies of heat transfer in a double-pipe heat exchanger equipped with twisted tape and nanofluidReza Aghayari, Heydar Maddah, Seyed Mohsen Pourkiaei, Mohammad Hossein Ahmadi, Lingen Chen and Mahyar GhazviniEur. Phys. J. Plus, 135 2 (2020) 252DOI: https://doi.org/10.1140/epjp/s13360-020-00252-8