The use of dielectric barrier discharge plasma actuators for hingeless flow control over a 47-deg 1303 unmanned combat air vehicle wing is described. Control was implemented at the wing leading edge to provide longitudinal control without the use of hinged control surfaces.Wind-tunnel tests were conducted at a chord Reynolds number of 4:12 10 and angles of attack ranging from 15 to 35 deg to ev...

Abstract In contrast to analyses with constrained hub speed, the present study includes dynamic response of coupled rotor-drivetrain modes in aeromechanic simulation rotor blade loads. The structural model flexible Bo105 system is aerodynamics modeled by an analytical formulation unsteady element loads combined a generalized wake or free wake, respectively. For two flight states, i. e. cruise a...

The intense nature of the aerodynamic environment surrounding a helicopter can cause excessive deflection rotor blades. Therefore, proper prediction loading and blade are necessary for monitoring health. Compared to rigid blade, dynamics hingeless is particular interest its inherent flexing tendency strong coupling between different degrees-of-freedom motion. With small-angle assumption, deform...

In forward flight, slowing down a rotor alleviates compressibility effects on the advancing side blade tip, extending cruise speed limit, and inducing high-advance-ratio flight regime. Previous wind tunnel tests have shown that an articulated trimmed to zero hub moment generates limited thrust at high advance ratios, because needs be against retreating with significant reverse flow, where is in...

This paper briefly reviews the history and development of compounds, tiltrotors and hingeless rotors. Largely through a quirk of history, the compound has been neglected for over three decades. The mission performance potential of the compound is re-examined based on basic aerodynamic principles and by surveying recent NASA and Army mission design studies. A rational case can be made that the c...