• Title/Summary/Keyword: 비균일 익단간극

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Study on the Performance of a Centrifugal Compressor Using Fluid-Structure Interaction Method (유체-구조 연성해석을 이용한 원심압축기 운전익단간극과 성능 예측)

  • Lee, Horim;Kim, Changhee;Yang, Jangsik;Son, Changmin;Hwang, Yoonjei;Jeong, Jinhee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.6
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    • pp.357-363
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    • 2016
  • In this study, we perform a series of aero-thermo-mechanical analyses to predict the running-tip clearance and the effects of impeller deformation on the performance using a centrifugal compressor. During operation, the impeller deformation due to a combination of the centrifugal force, aerodynamic pressure and the thermal load results in a non-uniform tip clearance profile. For the prediction, we employ the one-way fluid-structure interaction (FSI) method using CFX 14.5 and ANSYS. The predicted running tip clearance shows a non-uniform profile over the entire flow passage. In particular, a significant reduction of the tip clearance height occurred at the leading and trailing edges of the impeller. Because of the reduction of the tip clearance, the tip leakage flow decreased by 19.4%. In addition, the polytrophic efficiency under operating conditions increased by 0.72%. These findings confirm that the prediction of the running tip clearance and its impact on compressor performance is an important area that requires further investigation.

NUMERICAL STUDY OF NON-UNIFORM TIP CLEARANCE EFFECTS ON THE PERFORMANCE AND FLOW FIELD IN A CENTRIFUGAL COMPRESSOR (비균일 익단간극이 원심압축기의 성능과 유동에 미치는 영향에 대한 수치해석적 연구)

  • Jung, Y.H.;Park, J.Y.;Choi, M.;Baek, J.H.
    • Journal of computational fluids engineering
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    • v.18 no.1
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    • pp.7-12
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    • 2013
  • This paper presents a numerical investigation of the influences of various non-uniform tip clearances on the performance and flow field in a centrifugal compressor. Numerical simulations were conducted for three centrifugal compressor impellers in which the tip clearance height varied linearly from the leading edge to the trailing edge. The numerical result was compared with the experimental data for validation. Although the performance improved for low tip clearances, a smaller tip clearance at the trailing edge reduced the overall tip leakage flow more effectively than a smaller tip clearance at the leading edge. Therefore, a smaller tip clearance at the trailing edge lowered the mixing loss caused by interactions between the tip leakage flow and the main passage flow.

Prediction of flow field in an axial compressor with a non-uniform tip clearance at the design and off-design conditions (설계점 및 탈설계점에서 비균일 익단 간극을 가지는 축류 압축기의 유동장 예측)

  • Kang, Young-Seok;Park, Tae-Choon;Kang, Shin-Hyoung
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.6
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    • pp.46-53
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    • 2008
  • Flow structures in an axial compressor with a non-uniform tip clearance were predicted by solving a simple prediction method. For more reliable prediction at the off-design condition, off-design flow characteristics such as loss and flow blockage were incorporated in the model. The predicted results showed that flow field near the design condition is largely dependent on the local tip clearance effect. However overall flow field characteristics are totally reversed at off-design condition, especially at the high flow coefficient. The tip clearance effect decreases, while the local loss and flow blockage make a complicated effect on the compressor flow field. The resultant fluid induced Alford's force has a negative value near the design condition and it reverses its sign as the flow coefficient increases and shows a very steep increase as the flow coefficient increases.