Abstract: A system has a fin with an upstream end, a downstream end, a wall interface (412), a carrier interface (414) offset from the wall interface (412) in a radially inward direction, and an impact surface (418). The impact surface extends between an upstream end of the wall interface and an upstream end of the carrier interface. The impact surface (418) has a substantially flat portion configured to cause flow stagnation. The fin (306) has a side surface (416) extending between the impact surface (418), the wall interface (412), and the carrier interface. The impact surface (418) is joined to the side surface (416) by an edge profile (420) configured to cause turbulence or separation of the fluid flow from the fin.

Abstract: A system has a fin with an upstream end, a downstream end, a wall interface (412), a carrier interface (414) offset from the wall interface (412) in a radially inward direction, and an impact surface (418). The impact surface extends between an upstream end of the wall interface and an upstream end of the carrier interface. The impact surface (418) has a substantially flat portion configured to cause flow stagnation. The fin (306) has a side surface (416) extending between the impact surface (418), the wall interface (412), and the carrier interface. The impact surface (418) is joined to the side surface (416) by an edge profile (420) configured to cause turbulence or separation of the fluid flow from the fin.

Abstract: Rotary motion sensing systems are well-suited for integration in a bearing system of a rotary aircraft to provide information about the operational state of the rotor blades of the aircraft. In some embodiments, sensors are positioned on lateral sides of an elastomeric bearing system and output signals which may be processed to calculate one or more rotor blade operational states. The operational states include, for example, flap angle, lead-lag angle, and pitch angle. In other embodiments, sensors may be distributed along at least a portion of the length of a rotor blade to detect deflection of the rotor blade or its impact with another object. The operational state of the rotor blades may be transmitted to the pilot and/or the flight control computer of the aircraft in order for corrective action to be taken and/or may be stored within a control box for later review.