ISBN 9783843955232

978-3-8439-5523-2, Reihe Ingenieurwissenschaften

Constantin Öhrle
Aeromechanic Simulations of a Compound Helicopter Configuration and Noise Reduction through Trim Variation

170 Seiten, Dissertation Universität Stuttgart (2024), Hardcover, A5

Zusammenfassung / Abstract

This thesis presents a detailed aeroacoustic analysis of the Airbus Helicopters’ RACER compound helicopter, with an emphasis on noise reduction through trim variation using its redundant controls. The study begins by describing the advanced tools and methodologies employed for the aeromechanical simulation of the compound helicopter, highlighting enhancements made to support these simulations. Central to this enhancement is a coupling framework that integrates the high-fidelity computational fluid dynamics (CFD) solver FLOWer with the comprehensive analysis (CA) code HOST.

The simulation methods are validated using the X³ compound helicopter, where two distinct flight conditions are simulated and compared against existing flight test data, focusing on flight mechanics, aerodynamics, rotor dynamics, and rotor blade loads.

A significant part of the thesis investigates the novel noise sources introduced by the RACER’s pusher lateral rotors, analyzing simulation accuracy, identifying key noise mechanisms, and conducting a parameter study on the effects of varying lateral rotor thrust and wing lift on noise emissions.

The primary contribution of this work is the in-depth aeroacoustic investigation of the RACER compound helicopter and the optimization of its trim settings for noise reduction. The computational setup is described, and a trim study is conducted for three specific flight conditions relevant to rotorcraft acoustic certification. The analysis of the resulting noise reductions provides valuable insights into achieving quieter operations of compound helicopters through optimized trim configurations.