CALCULATION OF AERODYNAMIC CHARACTERISTICS OF HELICOPTER ROTOR IN HOVER AND AIRFOILS IN NONSTATIONARY FLOW

摘要

Computational fluid dynamics (CFD) methods are used to model the flow features and in the computations of the aerodynamic characteristics of a helicopter rotor. For the purpose of verification and validation of the numerical methods used, techniques to calculate the main rotor flow in two CFD software packages were developed. The results show satisfactory agreement between the three-dimensional calculations of the integral and distributed characteristics of a two-blade rotor model rotating in hover and the data from the experiment carried out using the standard method at TsAGI. A technique to calculate the two-dimensional transonic nonstationary fluctuating flow over a helicopter airfoil with a specified periodic law of variation over time of the incoming flow velocity was suggested. The results for direct and inverse motion of the airfoil are compared. The phenomenon of hysteresis against the free-stream Mach number was revealed.