Impact of new multiple twisted tapes on treatment of solar heat exchangerM. Sheikholeslami, Seyyed Ali Farshad, M. Barzegar Gerdroodbary and Amir H. AlaviEur. Phys. J. Plus, 137 1 (2022) 86DOI: https://doi.org/10.1140/epjp/s13360-021-02157-6