A computational study of helicopter vibration and rotor shaft power reduction is conducted using actively-controlled trailing-edge flaps (ACFs), implemented in both single and dual flap configurations. Simultaneous vibration reduction and performance enhancement is demonstrated under level flight condition at high advance ratios, where dynamic stall effects are significant. Power reduction is a...

Observational evidence of the location of a dayside high-latitude ionospheric current (DPY current) with respect to the different regimes of the high-latitude magnetosphere is obtained by analyzing data from the magnetometer chain along the west coast of Greenland in conjunction with simultaneous measurements from the newly established incoherent-scatter radar facility at Sondre Stromfjord. The...