Evaluation Method of Turbocharger Turbine Blade Vibration Reliability Index

Abstract

The invention relates to a pressurizing device turbine blade vibration reliability index evaluation method. Probability distribution parameters of pressurizing device turbine blade vibration first order inherent frequency are confirmed by means of finite element simulation or experimental test, the minimum resonance order corresponding to the resonance of the turbine blades is confirmed by utilizing a turbine blade vibration frequency and turbine rotating speed resonance graph, probability distribution parameters of turbine operation rotating speed are confirmed according to an engine use cross section or an experimental cross section, and a law of changing of reliability and a failure rate of turbine blade vibration along with service life index is confirmed according to parameters such as the number of turbine blades, the blade vibration first order inherent frequency, the turbine operation rotating speed and the blade resonance order. The method can confirm reliable service life of turbine blade vibration meeting given reliability requirements reasonably, can guide structural design of a turbine, avoids vibration failure of the blades due to insufficient reliability, and prevents aerodynamic performance of a turbine blade from being lowered due to aimless increase of the dimension of the turbine blade structure.

Description

technical field [0001] The invention belongs to a vibration analysis and structural reliability evaluation method of a supercharger turbine blade, in particular to a vibration reliability index evaluation method of a supercharger turbine blade. Background technique [0002] The turbocharger is a key component for enhancing the engine power and improving its performance. As one of the core parts of the turbocharger, the reliability of the turbocharger determines the reliability and service life of the turbocharger to a large extent. Blade vibration failure is an important failure mode of turbocharger turbine. During the operation of the supercharger, the turbine blades are subjected to periodically changing forces (even if the blades generate forced vibration excitation force), when the frequency of the excitation force is equal to or an integer multiple of the natural frequency of the blades, the blades will resonate . When the blade resonates, the stress will increase sha...

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Problems solved by technology

[0005] The existing reliability evaluation method for the vibration failure mode of the turbine blade usually makes the average value of the first-order natural frequency of the turbine blade greater than several times the rated speed frequency of the turbine (for example, the average value of the first-order natural frequency of the turbine blade is greater than 5 times the rated speed frequency of the turbine) As its reliability evaluation criterion, it cannot comprehensively and objectively reflect the impact of parameters such as the number of blades of the turbine, the dispersion of the natural frequency of the blades, the randomness of the turbine operating speed, the resonance order of the blades, and the life index on the vibration reliability of the turbine blades. , it is impossible to determine the reliability of the turbine corresponding to the blade vibration failure mode, the failure rate and other reliability indicators change with the service life and the turbine life corresponding to the specified reliability index requirements, it is difficult to effectively guide the structural design of the turbine

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