Multibody Simulation of Coupled Aerodynamics and Structural Model of a Helicopter Main Rotor

Abstract

The use of helicopters has been on the rise since their invention, particularly due to their ability to perform axial and hover flights. However, designing a helicopter rotor is a complex process, as it involves understanding the aerodynamics and flexible structures of the rotor. The purpose of this thesis is to develop a kinematic rotor model with structural flexibility in a multibody simulation environment, and to perform maneuvers such as hover and forward flight with the model. The research begins by developing an algorithm using PYTHON to efficiently complete the design, analysis, and post-processing work. The algorithm includes the following steps. First, CAD model of the rotor using Simcenter 3D NX is created. Airfoil profiles are generated using XFOIL software. Then, development of a kinematic multibody model of the rotor using Simcenter 3D Motion software is performed. Flexible models of the rotor blades using the finite element modeling tool of Simcenter 3D are generated. Finally, aerodynamic parameters of the airfoils using XFOIL software are determined and application of these parameters to the blades are performed using blade element theory. To verify the model, a FLIGHTLAB model with similar specifications to the Simcenter 3D model is also generated. In verification analyses, a wind tunnel test data is used in aerodynamic model in FLIGHTLAB and Simcenter 3D models. Hover and forward flight maneuver solutions obtained from the FLIGHTLAB and Simcenter 3D rotor models are compared. Additionally, the thesis examines the effect of various parameters such as twist distribution, wing span, chord length, and material types on the aerodynamic loadings of the rotor blades. This research contributes to the field of helicopter rotor design by providing a novel approach to simulating aerodynamic loading and structural flexibility in a multibody environment. The results of this thesis can be used to improve the design and performance of helicopter rotors in the future.