Swashplateless Helicopter Rotor with Trailing-Edge Flaps

Abstract

A helicopter primary control system with trailing-edge flaps was investigated numerically for its potential to replace a conventional swashplate system. Eliminating the swashplate and associated control system can lead to significant reductions in weight, drag, and cost and an improvement of rotor performance. A comprehensive rotorcraft analysis was developed for analyzing the swashplateless rotor configuration and was implemented to examine the actuation requirements for rotor primary control with trailing-edge flaps. A multicyclic controller was implemented with the swashplateless rotor analysis, and the feasibility of trailing-edge flap performing both primary control and active vibration control was examined. Flap control inputs of a swashplateless rotor are presented at several advance ratios. With optimal selection of blade collective pitch index angle, the flap was shown to be able to trim the rotor with moderate flap inputs. Simulations of flaps performing both primary control and active vibration control were carried out, with the conclusion that trailing-edge flaps are capable of trimming the rotor and minimizing vibratory rotor hub loads simultaneously