Method for calculating the power of a rotor-screw machinesValeriy A. Lebedev, Georgy V. Serga, Irina V. Davydova, Tatiana V. Atoyan, Irina G. Koshlyakova and Alexander V. GordienkoMATEC Web Conf., 226 (2018) 01007DOI: https://doi.org/10.1051/matecconf/201822601007