Measurement and Analysis on Passive Drag Reduction of High-Speed Compound Rotorcraft Fuselage Model

Complex-shaped aircraft have various causes of aerodynamic drag compared to general fixedwing aircraft. In this study, the cause of drag generation of High-Speed Compound Rotorcraft (HCUR) was identified and the drag reduction method was studied. The flow separation area generated around the hub of the model's fuselage was observed through prior research. It was confirmed that the drag force caused by this accounted for about 40% of the total drag force of the model. The flow separation is judged to be a factor that increases the pressure drag of the model. In this study, this drag was solved by reduction of flow separation area and delay of separation generation through shape modification and turbulent flow generation methods. To confirm the effect of drag reduction, CFD analysis and wind tunnel testing were also performed.