Development and Validation of an Inflow Model for a Coaxial Teetering Rotor System

In this paper, two candidate models describing the inflow of a coaxial rotor system are defined, implemented, and analyzed. As a benchmark, a finite state nonlinear dynamic inflow model is implemented based on potential flow theory. The extension of this approach to a coaxial rotor system is achieved by the superposition of both rotors' pressure potentials. Furthermore, a simpler static simulation model is developed and extended to a coaxial rotor configuration using geometric considerations. The nonlinear inflow models are both integrated into a rotor simulation model, which is part of a full flight envelope helicopter simulation model implemented at the Institute of Flight System Dynamics of the Technical University of Munich. The influence of the inflow dynamic on the overall rotor response as well as the differences between the two implemented approaches are investigated. The models have been evaluated for the coaxial helicopter CoAX 600, developed by edm aerotec GmbH.     «

In this paper, two candidate models describing the inflow of a coaxial rotor system are defined, implemented, and analyzed. As a benchmark, a finite state nonlinear dynamic inflow model is implemented based on potential flow theory. The extension of this approach to a coaxial rotor system is achieved by the superposition of both rotors' pressure potentials. Furthermore, a simpler static simulation model is developed and extended to a coaxial rotor configuration using geometric considerations. Th...     »