Tribology and Lubricants

Korean Tribology Society (한국트라이볼로지학회)
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Comparative Study of the Navier-Stokes Equation & the Reynolds Equation in Spool Valve Analysis Considering Cavitation

캐비테이션을 고려한 스풀밸브 해석에서 Navier-Stokes 방정식과 Reynolds 방정식에 의한 비교 연구

  • Hong, Sung-Ho (School of Mechanical, Aerospace & Systems Engineering, KAIST) ;
  • Son, Sang-Ik (School of Mechanical, Aerospace & Systems Engineering, KAIST) ;
  • Kim, Kyung-Woong (School of Mechanical, Aerospace & Systems Engineering, KAIST)
  • 홍성호 (KAIST 기계항공시스템학부) ;
  • 손상익 (KAIST 기계항공시스템학부) ;
  • 김경웅 (KAIST 기계항공시스템학부)
  • Received : 2013.07.31
  • Accepted : 2013.08.02
  • Published : 2013.10.31
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Abstract

The Reynolds equation is commonly used to investigate the lubrication characteristics of a spool valve. However, the applicability of the Reynolds equation is questionable for analyzing a spool valve because cavitation often occurs in the grooves of the valve and the depth of a groove is much higher than the clearance in most cases. In this study, the validity of the Reynolds equation in the spool valve analysis is investigated by comparing the results obtained from the Reynolds equation and those obtained from the Navier-Stokes equation. The results are compared in terms of the lateral forces, friction forces, and volume flow rates (leakages). A significant difference of more than 20% is found in the lateral forces in cases where cavitation occurs and there are many grooves. Therefore, the Navier-Stokes equation should be used to investigate the lubrication characteristics of a spool valve when cavitation occurs and when the spool valve contains many grooves.

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References

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