High-order high-cycle fatigue design of centrifugal impeller under unsteady flow field excitation
FENG Yajuan
LI Jian
WANG Yuehua
XIN Jianqiang
SHUAI Shijin
Abstract：[Objective]The study aims to analyze the causes of blade trailing edge fracture in a centrifugal impeller and propose effective improvement measures to enhance its high-cycle fatigue(HCF)life.[Methods]Firstly,unsteady flow field analysis was employed to identify the radial diffuser as the primary excitation source based on the relation between flow excita-tion and blade resonance.Secondly,dangerous high-order modes within the excitation frequency range were determined through modal analysis and subsequently confirmed by dynamic stress measurement tests.Finally,improvement measures,including reducing blade outlet height,optimizing blade profiles,and adjusting diffuser blade angles,were implemented to mitigate vibra-tion stress.[Results]The results of dynamic stress measurements and long-term engine tests show that the HCF reserve of the improved impeller meets the service requirements.The peak vibration stress was reduced from 120 MPa to 70 MPa.The proposed method provides a valuable reference for the vibration design of aero-engine impellers.
Keywords：Centrifugal impellerHigh mode vibrationUnsteadyDangerous modeVibration stressHigh-cycle fatigue
Publication Date：2026-05-31
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：7( 83-89 )