Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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A Study on Friction Loss of Engine using Microfluidics Approach

미세유동의 경계면 특성을 적용한 엔진 마찰 손실 연구

  • Park, Cho Hee (School of Mechanical Engineering, Univ. of Ulsan) ;
  • Kim, Bo Hung (School of Mechanical Engineering, Univ. of Ulsan)
  • Received : 2014.05.16
  • Accepted : 2014.09.11
  • Published : 2014.12.01
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Abstract

Reducing the friction of engine parts is an important issue in engine design. The loss of energy in the piston assembly due to mechanical friction ranges from 40 to 55%, and there is an increase in the total energy of about 5% if the friction of the piston can be removed. In order to reduce the friction loss at the level of each engine part, it is necessary to perform a comparative analysis with other engines to determine the important factors affecting the energy loss. Several studies have been performed to analyze the lubrication based on hydrodynamic modeling, since a piston lubrication system has dimensions in the nanoscale to microscale domain. Therefore, it is necessary to determine the correlations between the molecular and continuum systems. In this study, we investigated the friction changes due to the various interactions between molecules in the wall/fluid interface, where a microscopic movement of the oil film occurs along the cylinder liner of the engine.

엔진 마찰 저감은 엔진 개발의 중요한 항목이 되어왔다. 엔진의 기계적 마찰 손실 중 피스톤계의 마찰이 40~55%에 해당하고, 피스톤 부분의 마찰을 제거할 수 있다면 투입되는 전체 에너지의 5% 정도 향상시킬 수 있다. 엔진의 마찰 손실을 감소시키기 위해서 각 요소에서의 마찰 수준, 이에 영향을 미치는 인자에 대한 분석 및 다른 엔진들과의 비교분석이 필요하다. 하지만 기존 연구에서 마찰이 발생하는 윤활막의 연구들이 유체역학 바탕의 모델링에서 수행해 왔으나, 피스톤계의 윤활막이 크게는 마이크로에서 작게는 나노단위의 영역에 해당하므로 분자들간의 상호관계를 고려할 필요가 있다. 따라서, 본 연구에서는 엔진 실린더 라이너를 따라 형성하는 유막의 운동을 미시적으로 접근하여 분자들간의 상호작용에 따른 마찰변화를 제시하고자 한다.

Keywords

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