Reverse Anslysis And Reconstruction Of Aerodynamic Configuration Of Heliicopter Blade

As a critical component and the main aerodynamic part of helicopter, the rotor blade has a close relationship with the lift force, mobility, quick cruise and hover performance. The traditional aerodynamic shape design of rotor blade is a complex and time-consuming process, in which the balde aerofoil, torsion angle distribution, blade tip shape must be chosen and designed respectively, according to the design requirement of helicopter maneuver performance. In order to shorten the aerodynamic shape design cycle of rotor blade and improve the design reliability, we researched on the aerodynamic shape reverse technology of rotor balde in the paper, including balde aerodynamic shape analyais and model reconstruction. The balde aerodynamic shape design parameters could be obtained by analyzing the actual measurement point cloud data. Meanwhile, the reverse modeling method can be used to build 3D model of the rotor balde. The balde design knowledge and reference and comparative gist for the new type design of rotor blade can be provided. After analyzing the key technology of balde aerodynamic shape and putting forward the implementation method, we developed the aerodynamic shape analysis software system of rotor blade based on actual measurement data. Reaserch works in this paper are summarized as follows:(1) Analyzing and comparing the differences between the common measurement methods and the measurement equipment. Then, the digital measurement scheme for rotor balde was put forward. The rotor balde shape was measured through Tritop system and ATOS 3D Scanning with structured light. At last, the paper researched the measurement data processing method, which includes data merging, nosie elimination, fairing and data reduction.(2) Researching on the critical technique and implementation methods of aerodynamic shape analysis of rotor blade based actual measurement data to meet the application requirement of the reverse design of rotor balde. According to the characteristics of rotor balde structure and the actual measurement data, a set of blade aerodynamic shape analysis scheme and parameter extraction method are put forward, which could be used to idenficy the aerofoil distribution and aerofoil type, and got the distribution of blade chord length, blade twist andle and balde thickness.(3) Researching on the rotor blade reverse modeling technology based on the Imageware and CATIA software, including cross section, curve fitting, curve editing and surface reconstruction, etc. Finally, the accuracy and smoothless of blade surface reconstructed were analyzed.(4) Finally, after deeply studying the key technologies for blade aerodynamic shape analysis, the aerodynamic shape analysis software system of rotor blade based on actual measurement data was developed. And acrossing the balde example analysis, the software system proved to be practical.