ACTA AERONAUTICAET ASTRONAUTICA SINICA >
Investigation of autorotating rotor aerodynamic characteristics based on free wake method
Received date: 2014-12-10
Revised date: 2015-03-13
Online published: 2015-03-20
Supported by
National Natural Science Foundation of China(11202097);Aeronautical Science Foundation of China(2013ZA52014);A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
To investigate autorotating rotor aerodynamic characteristics, a free wake method calculation model which couples blade flapping motion model and trim model of autorotating rotor is established in this paper, and an analysis method for autorotating rotor aerodynamic characteristics is established. Then, this method is verified by a test example of an autorotating rotor based on the method. Lastly, wake geometry and rotor disk induced inflow distribution characteristics of autorotating rotor are investigated by the method. The results indicate that the free wake method calculation model established in this paper can meet the requirement of autorotating rotor aerodynamic characteristics analysis and the model accuracy is higher compared with the traditional approximate inflow model. Autorotating rotor wake moves upward and backward from the rotor disk as time goes on in the forward flight. The distortion of autorotating rotor wake is slightly smaller than powered rotor in the horizontal plane. The distribution of autorotating rotor disk induced inflow is nonuniform. Downwash inflow generally increases gradually from the leading edge to the trailing edge of the rotor disk. Autorotating rotor induced inflow is less than powered rotor near 90° azimuth and at the trailing edge of the rotor disk at the same thrust.
Key words： rotor; wake; blade; flap; trim; aerodynamic characteristics; helicopter
WANG Junchao , TAN Jianfeng , LI Jianbo , XU Ming . Investigation of autorotating rotor aerodynamic characteristics based on free wake method[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2015 , 36(11) : 3540 -3548 . DOI: 10.7527/S1000-6893.2015.0076
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