Numerical modeling of nanofluid exergy loss within tube with multi-helical tapes Xinglong Liu, Zahir Shah, Ikramullah and Mohammed R. Alzahrani Eur. Phys. J. Plus, 137 1 (2022) 152 Published online: 21 January 2022 DOI: 10.1140/epjp/s13360-021-02327-6