Vibration Characteristics Analysis of Fixed-Pitch Propeller of Aero-piston Engine

• 1、Aviation Engineering Institute, Civil Aviation Flight University of China, Deyang 618307, China

Abstract：Based on basic theory of modal analysis for cyclic symmetrical structure, the vibration characteristic analysis method for integral structure of propeller had been established and verified. In this method, the impacts on vibration characteristic by centrifugal and aerodynamic loads, which generated under the actual working condition of propeller, is taken into account. A two-blade fixed-pitch propeller from an aero-piston engine was selected as an analysis object, after extracting the geometric dimension parameters, a 3-D finite element model of basic repeating sector of propeller structure was established in ANSYS software. Firstly, the vibration frequency and mode of propeller under non-rotating condition were calculated; then, the vibration frequency and mode of propeller under common rotating speed condition with pre-stress were calculated. One hand, the influence of external loads on vibration frequency and mode was analyzed; the other hand, it is found that the symmetrical mode and anti-symmetric mode will appear in the same order vibration of propeller structure. Eccentric mass of the propeller and cylinder gas explosion were considered as the source of exciting force, and the Campbell curve was figured out, which provides a basis for the subsequent structural analysis and troubleshooting. These results provided a convenient vibration characteristic calculation method for integral structure of multi-blade and variable-pitch propellers.

Keywords： engineering mechanics integral structure of propeller vibration characteristics cyclic symmetric structure the modal analysis finite element analysis