Analytische Formulierung der Instationaeren Profilbeiwerte und Deren Anwendung inder Rotorsimulation (Analytic Formulation of Unsteady Profile Aerodynamics and Its Application to Simulation of Rotors)

摘要

A new approach to the modeling of rotor aerodynamics is addressed. The steadystate aerodynamic coefficients for an aerofoil section are described in terms of a set of analytical equations. The periodically varying velocities over the aerofoil section can then be converted into similarly periodic displacements of angle of attack and stall angle of attack. These can then be fed directly into the simulation. It is very important to have models of the blade dynamics and induced velocities of sufficient accuracy. For this reason a modal method is used to describe the blade dynamics and the induced velocities are modeled in terms of a rigid, distorted spiral geometry, developed from measurements. Results show that a good compromise was achieved between the requirements for short computation times and accuracy. This is of particular interest with respect to the calculation and design of higher harmonic control systems.