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조현철 ( H. C. Jo ),오승우 ( S. W. Oh ),이기훈 ( G. H. Lee ),배영주 ( Y. J. Bae ),박권하 ( K. H. Park ) 한국분무공학회 2002 한국액체미립화학회지 Vol.7 No.2
N/A Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. This study addresses the analysis of the LPG spray behavior near injection nozzle. The LPG spray photographs are compared with sprays of diesel fuel at the same conditions. The LPG spray photos show that the dispersion characteristic depends very sensuously on the ambient pressure soon after injection. The spray angle is very wide in a low ambient pressure condition until the saturated pressure at this test condition, but the angle value is quickly reduced at the condition over the pressure.
김재휘(C. H. Kim),김진환(J. H. Kim),박권하(K. H. Park) 한국자동차공학회 1998 한국 자동차공학회논문집 Vol.6 No.6
In a diesel engine the phenomenon of spray impaction on a combustion chamber wall has been taken as an undesirable matter because of the deposition of fuel on the surfaces, and the subsequent slow evaporation and mixing with air resulting in unburned hydrocarbons. Therefore many researches have concentrated on avoiding fuel impaction on surfaces.<br/> On the contrary done a number of studies using spray wall impactions in a positive way, which makes the droplets smaller, changes the direction into free spaces far from the wall and also improves mixing with air.<br/> In this paper the angle variations of the impaction land surface prepared for the injection spray is analysed as a simulative manner. The spray dispersions, vapor distributions and flow fields are compared with impacting angle variation. The results show more angle give more vapor distribution until 15°.<br/>
나노구리합금첨가 윤활제가 디젤엔진의 성능에 미치는 영향
김대현(D.H.Kim),박권하(K.H.Park),최재성(J.S.Choi) 한국해양대학교 해사산업연구소 2002 海事産業硏究所論文集 Vol.12 No.-
The characteristics of a lubricant is very important when it is used und0r severe running condition. Especially on diesel engines the better lubrication performance is required because of the extreme condition such as high temperature and pressure by combustion process in a cylinder. Many research works for improving a boundary lubrication performance have been executed by using solid lubricant but this general lubricant has not been applied to engine due to the extreme condition of high temperature and pressure in a cylinder. Recently, the solid lubricant which contained a copper nickel alloy has been introduced and studied. In this study, the authors investigated the effects of lubricant which contains the copper nickel alloy nano-powder on a diesel engine performance. The results were manifested to show the increase of maximum torque, and the decrease of cylinder pressure, exhaust gas temperature, scavenging air temperature, CO emission according to running time elapse at various speed and torque on a diesel engine. It was assured that the lubricant which contains the copper nickel alloy nano-powder decreases friction and wear, and simultaneously increases the sealing effect in a cylinder on diesel engines.