Development of a spectrum method for modelling fatigue due to thermal mixing

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)

Abstract

Turbulent mixing of cold and hot fluids can lead to high-cycle thermal fatigue in T-junctions. In this work, a spectrum method for the thermal fatigue modelling was further developed. Estimation of the reference frequency, which determines the frequency range of the temperature spectrum, was considered in particular by utilizing flow mixing data from two T-junctions. Fatigue and crack growth obtained with the method were compared with the sinusoidal (SIN) method and with a computational fluid dynamics (CFD) load. The reference frequency was determined by fitting the model spectrum with temperature spectra obtained from measurements and CFD simulations. A formula for the reference frequency was proposed, which can be used in approximating the frequency also for other flow conditions. The SIN method resulted in over-conservatism in the fatigue and crack growth assessment. Results from the spectrum method agreed quite well with those obtained with the CFD load, showing that the method could result in significant improvement over the SIN method
Original languageEnglish
Pages (from-to)136–146
Number of pages11
JournalNuclear Engineering and Design
Volume331
DOIs
Publication statusPublished - 1 May 2018
MoE publication typeA1 Journal article-refereed

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fatigue
Computational fluid dynamics
Thermal fatigue
Fatigue of materials
Dynamic loads
computational fluid dynamics
Crack propagation
thermal fatigue
dynamic loads
modeling
cracks
turbulent mixing
crack
Temperature
Fluids
Computer simulation
frequency ranges
Hot Temperature
method
cycles

Keywords

  • thermal loads
  • turbulent mixing
  • thermal fatigue
  • crack growth

Cite this

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title = "Development of a spectrum method for modelling fatigue due to thermal mixing",
abstract = "Turbulent mixing of cold and hot fluids can lead to high-cycle thermal fatigue in T-junctions. In this work, a spectrum method for the thermal fatigue modelling was further developed. Estimation of the reference frequency, which determines the frequency range of the temperature spectrum, was considered in particular by utilizing flow mixing data from two T-junctions. Fatigue and crack growth obtained with the method were compared with the sinusoidal (SIN) method and with a computational fluid dynamics (CFD) load. The reference frequency was determined by fitting the model spectrum with temperature spectra obtained from measurements and CFD simulations. A formula for the reference frequency was proposed, which can be used in approximating the frequency also for other flow conditions. The SIN method resulted in over-conservatism in the fatigue and crack growth assessment. Results from the spectrum method agreed quite well with those obtained with the CFD load, showing that the method could result in significant improvement over the SIN method",
keywords = "thermal loads, turbulent mixing, thermal fatigue, crack growth",
author = "Antti Timperi",
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Development of a spectrum method for modelling fatigue due to thermal mixing. / Timperi, Antti.

In: Nuclear Engineering and Design, Vol. 331, 01.05.2018, p. 136–146.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

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AU - Timperi, Antti

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