TY JOUR TI MATHEMATICAL MODELING OF FLAPPING WING MOVEMENTS WHEN INTERACTING WITH A RESISTING MEDIUM KW flapping wing KW lifting force KW wing rotation angle KW effective wing area JO Transport engineering AU Efimov, S.V. AU Emel'yanova, O.V. AU Yacun, S.F. PY 2022 IS 2022 PB Bryansk State Technical University