CFD Simulations and Experiments of Flow Fluctuations Around a Steam Control Valve

Morita, Ryo; Inada, Fumio; Mori, M.; Tezuka, Kenichi; Tsujimoto, Yoshinobu

doi:10.1115/1.2375123

Cited by 50 publications

(28 citation statements)

References 5 publications

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“…Unsteady simulation is conducted with three-point backward difference scheme and LU-SGS methods [7]. This combination of the numerical schemes has been adopted for the numerical study of the unsteady flows in the steam control valve [4]. The numerical results show good agreement with experimental results.…”

Section: Methodssupporting

confidence: 51%

“…The numerical results show good agreement with experimental results. Additional validations of the accuracy in space and time are also shown in ref [4].…”

Section: Methodsmentioning

confidence: 99%

“…The asymmetry occurs rather randomly in each test but does not change during the test. In a three-dimensional model, however, the direction of such an asymmetric pattern rotates randomly in circumferential direction without specific frequencies [4].…”

Section: Classification Of Flow Patternsmentioning

confidence: 99%

“…In the study of Araki et al [2], it is reported that there are a self-excited oscillation and a forced oscillation of the valve head. Morita et al [4] carried out experimental and numerical studies with sub-scale cold flow. In these reports, the detailed flow pattern around the valve head are observed with numerical results.…”

Section: Introductionmentioning

confidence: 99%

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A Two-Dimensional Study of Transonic Flow Characteristics in Steam Control Valve for Power Plant

Yonezawa¹,

Terachi²,

Nakajima³

et al. 2010

International Journal of Fluid Machinery and Systems

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A steam control valve is used to control the flow from the steam generator to the steam turbine in thermal and nuclear power plants. During startup and shutdown of the plant, the steam control valve is operated under a partial flow conditions. In such conditions, the valve opening is small and the pressure deference across the valve is large. As a result, the flow downstream of the valve is composed of separated unsteady transonic jets. Such flow patterns often cause undesirable large unsteady fluid force on the valve head and downstream pipe system. In the present study, various flow patterns are investigated in order to understand the characteristics of the unsteady flow around the valve. Experiments are carried out with simplified two-dimensional valve models. Two-dimensional unsteady flow simulations are conducted in order to understand the experimental results in detail. Scale effects on the flow characteristics are also examined. Results show three types of oscillating flow pattern and three types of static flow patterns.

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Section: Methodssupporting

confidence: 51%

“…The numerical results show good agreement with experimental results. Additional validations of the accuracy in space and time are also shown in ref [4].…”

Section: Methodsmentioning

confidence: 99%

Section: Classification Of Flow Patternsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Two-Dimensional Study of Transonic Flow Characteristics in Steam Control Valve for Power Plant

Yonezawa¹,

Terachi²,

Nakajima³

et al. 2010

International Journal of Fluid Machinery and Systems

Self Cite

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“…9,10) In particular, for the MATIS-SC code, some steam experiments were made to validate the code (Fig. 11).…”

Section: Cfd Calculationsmentioning

confidence: 99%

Evaluation of Acoustic- and Flow-Induced Vibration of the BWR Main Steam Lines and Dryer

Morita

Takahashi

Okuyama

et al. 2011

Journal of Nuclear Science and Technology

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The boiling water reactor (BWR-3) steam dryer in the Quad Cities (QC) Unit 2 Nuclear Power Plant was damaged by high-cycle fatigue due to acoustic-induced vibration. The cause of the dryer failure was considered as flow-induced acoustic resonance at the stub pipes of the safety relief valve (SRV) in the main steam lines (MSLs). The acoustic resonance was considered to be generated by the interaction between the sound field and an unstable shear layer across the closed side branches of SRVs. We have started a research program on BWR steam dryers to develop methods of evaluating the loading. Moreover, it is necessary to evaluate the dryer integrity of BWR-5 plants, which are the main type of BWR in Japan.In the present study, we conducted 1/10-scale BWR model tests and analysis to investigate the flowinduced acoustic resonance and acoustic characteristics in MSLs. The test apparatus consisted of a steam dryer, a steam dome, and 4 MSLs with 20 SRV stub pipes. Computational fluid dynamics (CFD) analysis was conducted to evaluate the acoustic source in MSLs. Finite element method (FEM) was applied to calculate the three-dimensional wave equations for acoustic analysis. We demonstrated that large fluctuating pressure occurred in the high-and low-frequency regions. The high-frequency fluctuating pressure was generated by the flow-induced acoustic resonance in the SRV stub pipes. We evaluated the acoustic source (that is, the fluctuating pressure) in MSLs by unsteady CFD calculations, and we evaluated the pressure propagation by acoustic analysis. These results were verified by comparison with the results of scale-model tests, and they showed good agreement with the experimental results. The effects of the difference between the properties of air and steam were numerically investigated, and it was found that the effects on the acoustic resonance in the SRV stub pipes were not significant.

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Ventile

Joos¹,

Polklas²

2018

Handbuch Dampfturbinen

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CFD Simulations and Experiments of Flow Fluctuations Around a Steam Control Valve

Cited by 50 publications

References 5 publications

A Two-Dimensional Study of Transonic Flow Characteristics in Steam Control Valve for Power Plant

A Two-Dimensional Study of Transonic Flow Characteristics in Steam Control Valve for Power Plant

Evaluation of Acoustic- and Flow-Induced Vibration of the BWR Main Steam Lines and Dryer

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