Calculation Method of Correlation Coefficient of Aeroengine Load Spectrum Based on Rainflow Counting Cycle

Abstract

The invention discloses an aero-engine load spectrum correlation coefficient calculating method based on rain flow counting circulation. Load spectrums of all parameters on different flight profiles are counted based on a rain flow counting method; after load circulation with the amplitude smaller than the amplitude threshold is filtered out, the circulation numbers of all the parameters of all the profiles are obtained, the different circulation numbers are obtained for different parameter load spectrums on the same flight profile, the circulation numbers, counted on all the profiles, of different parameters correspond one to one, a series of circulation data can be obtained for each load parameter, and then a correlation coefficient between all the parameters of the load spectrums are calculated. The delay phenomenon between rotation speed and overload value of an engine is eliminated, and the result more conforms to the reality. The correlation coefficient between the normal overload value representing maneuvering circulation and the rotation speed representing pneumatic circulation is close to 1 to a large extent. A basis is further provided for prediction and evaluation of aero-engine service life.

Description

technical field [0001] The invention relates to an aeroengine load spectrum correlation coefficient calculation method based on rainflow counting cycle, and belongs to the technical field of aeroengine load spectrum. Background technique [0002] A few days ago, our country has carried out relatively comprehensive aerial surveys and statistics on the flight mission profiles of various engines, and obtained a large amount of useful information. How to use these mission profiles to compile a reasonable load spectrum and provide a basis for the stress analysis and life design of the engine has become a very prominent problem. In the past, when compiling the engine flight load spectrum in China, only the change of one flight profile parameter was considered, that is, the compilation of the single parameter spectrum. A lot of in-depth and meticulous research work has been done in China on the compilation of single-parameter spectrum. However, the load on most aeroengine compone...

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Problems solved by technology

[0004] However, the existing correlation analysis between maneuvering loads and aerodynamic loads uses each load parameter as a completely random series to calculate the correlation coefficient. Combined with the task segment analysis, it is found that the start time of each engine speed task segment is always earlier than the normal time. The start time of the overload task segment, the time difference between the two ranges from a few seconds to tens of seconds (see attached figure 2 ), the peak time of the engine speed task segment is also earlier than the peak time of the normal overload task segment (as shown in the attached image 3 ), the correlation coefficient between the maneuvering load and the aerodynamic load calculated according to the above method is small

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