Research on the additional drag of turboshaft engine inlet under complex aerodynamic interference

Abstract

In response to the complex aerodynamic interference in the inlet flow field of a turboshaft engine and the difficulty in calculating additional drag, a study was conducted based on numerical algorithms to calculate additional drag. Through the numerical calculation of the internal and external interference flow field model of the helicopter rotor and body, the inlet, the integral component of the exit section parameter, and the inner channel drag are extracted, and the calculation model of additional drag based on the momentum balance of the inlet channel and the control body of the pre-inlet tube is established. The calculation and analysis are carried out according to different operating conditions such as flight speed and inlet flow change. The results show that the calculation model of additional drag based on the three-dimensional numerical value of the interference flow field, considering the aerodynamic interference of incoming flow conditions, rotor, and body on the flow field, can realize the additional drag analysis under complex conditions. The downwash flow generated by the rotor affects the inlet front streamlines and additional drag, and the additional drag of the left and right inlets will also be different.