The airfoil of the lifting fuselage of a helicopter-type unmanned aerial vehicle was developed and studied. The paper investigates the flow pattern in different engine operating modes and angles of attack. The flight speed is assumed to be 70 m/s, which is close to the maximum speed of helicopters. For different intake air flow rates, the boundaries of the supercritical modes are obtained, when there is a transition to a separating flow and an abrupt decrease in lifting force. The calculations obtained a lifting force coefficient exceeding Cya = 2.
Knyazev et al. (Mon,) studied this question.