Fatigue failure of regenerator screens in a high frequency Stirling engine

A high cycle fatigue failure of a low pressure turbine blade was investigated. Strain gauge tests of a running engine indicated a high dynamic response of the blade at the nozzle passing frequency. This could be attributed to the excitation of a bladed disc mode of vibration. A Finite Element analysis of the low pressure turbine blades and discs, together with bench testing of the complete structure, confirmed the existence of a high frequency 2nd Nodal Diameter mode of vibration. The levels of dynamic strain determined through strain gauge tests were found to be sufficient enough to explain the failure at the given location. Having understood the problem, the situation was resolved through the use of Finite Element analysis with a short term modification to the original blade aerofoil to prevent the mode from being excited. An aero/mechanical re-design of both the low pressure turbine rotor and the stator was undertaken to resolve the problem by both returning the blade to avoid high frequency excitation, and also by reducing the forcing effect of the nozzle passing frequency. The new design has been validated through strain gauge tests and endurance tests. A further improvement in performance was also obtained.

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The performance of a high‐frequency thermoacoustic‐Stirling engine

The Journal of the Acoustical Society of America ◽

10.1121/1.4781018 ◽

2003 ◽

Vol 114 (4) ◽

pp. 2328-2328

Author(s):

Kevin J. Bastyr ◽

Robert M. Keolian

Keyword(s):

High Frequency ◽

Stirling Engine

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Fractographic features of fatigue failure of titanium alloys in repeated static tensile loading and high-frequency vibrations

Strength of Materials ◽

10.1007/bf01530036 ◽

1984 ◽

Vol 16 (3) ◽

pp. 395-399

Author(s):

T. Yu. Yakovleva ◽

T. S. Voznyi ◽

V. A. Kuz'menko

Keyword(s):

Titanium Alloys ◽

Fatigue Failure ◽

High Frequency ◽

Tensile Loading ◽

Static Tensile Loading ◽

Static Tensile ◽

High Frequency Vibrations ◽

Fractographic Features

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Study on high frequency vibration-induced fatigue failure of antenna beam in a metro bogie

Engineering Failure Analysis ◽

10.1016/j.engfailanal.2021.105976 ◽

2021 ◽

pp. 105976

Author(s):

Xingwen Wu ◽

Chenxi Xie ◽

Kaicheng Liu ◽

Shengchuan Wu ◽

Zefeng Wen ◽

...

Keyword(s):

Fatigue Failure ◽

High Frequency ◽

High Frequency Vibration ◽

Antenna Beam

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Acoustically Induced Vibration of Drums Excited by Rotating Machinery

Volume 4: Fluid Structure Interaction ◽

10.1115/pvp2005-71380 ◽

2005 ◽

Author(s):

Itsuro Hayashi ◽

Shijie Guo

Keyword(s):

Fatigue Failure ◽

High Frequency ◽

Three Dimensional ◽

Rotating Machinery ◽

Coupled Analysis ◽

Pressure Loading ◽

High Frequency Region ◽

One Dimensional ◽

Material Fatigue ◽

High Frequency Vibrations

Rotating machinery generates pressure pulsations, and the pulsations may cause severe vibrations of drums in high frequency region, resulting in material fatigue failure under certain conditions. Experiments and numerical simulations were performed to investigate the mechanism of the high frequency vibrations of the drums downstream of compressors. The results show that fatigue failure occurs when acoustic diametral modes of a drum are excited by pressure loading. In order to establish practical countermeasures against the vibrations, three-dimensional sound-structural coupled analysis as well as one-dimensional pulsation analysis were conducted. As a result, practical measures such as changing diameter, or thickness of the drums, applying restriction orifice are confirmed effective by using the approach proposed in this study. The validity of the simulation methods incorporating the sensitivity to the fluid conditions is shown.

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