High-Speed Compound Rotorcraft Performance and Design

High-speed configurations are among the new emerging concepts that are currently expanding the scope of rotorcraft design. Especially in the field of defense technology research, the capability of a substantial increase in maximum velocity becomes more interesting. For instance, NATO project NGRC is considering this capability for a new medium utility rotorcraft. DLR supports these activities by its continuing defense technology research. In this study the benefits and drawbacks of a high-speed capability for a given mission scenario are analyzed. For that purpose, a contemporary configuration has been modeled, featuring a maximum velocity of 82 m/s (160 KTAS). The high-speed configuration meets with the same mission requirements, but with an increase of about 50% of maximum speed to 125 m/s (242 KTAS). All tasks in this study are conducted with DLRs integrated design environment IRIS. The high-speed configuration features an off-loaded main rotor, a wing, a propeller and a reduction of the rotational speed of the drive train for the extended flight envelope. The reference configuration as well as the high-speed rotorcraft were compared with the focus on flight performance.