커먼레일시스템의 비증발 디젤 분무에서 분사율과 주변기체의 압력에 따른 주변기체 유입 = Effect of Injecton Rate and Gas Density on Ambient Gas Entrainment of Non-evaporating Transient Diesel Spray from Common-Rail Injection System

다국어 초록 (Multilingual Abstract)

Entrainment of ambient gas is a crucial characteristics of transient diesel spray. Recently, it was found that the mass flow rate of ambient gas into transient diesel spray increased with the distance from the nozzle, i.e., axial momentum flow rate of entrained gas increased along spray axis. This tendency is different from the turbulent jet whose momentum flow rate is independent from axial positions.<br/>
To understand more detailed spray behaviors, it is necessary to quantify the entrainment characteristics of transient diesel sprays under realistic injection and ambient conditions In this study, measured was the entrained velocity of ambient gas into a diesel spray with LDV (Laser Doppler Velocimetry) technlmique. Non-evaporating transient diesel sprays from a common-rail injection system with triangular injection rate profile were observed. The effects of ambient gas density and nozzle hole geometry were assessed with entrainment coefficient.<br/>
There appeared a region where entrainment coefficients were remaining almost constant after onset of entrainment while iIjection rates were changing The effect of common-rail pressure, which altered the slope of injection rate curve, was hardly noticed at this region. Entrainment coefficient increased with ambient gas density, that is, the effect of ambient gas density on entrainment of transient diesel spray is larger than that of turbulent jet whose entrainment coefficient remains constant.<br/>
Non-dimensional distance was defined to reflect the effect of nozzle hole diameter and ambient gas density together. Mean value of entrnainment coefficient was found to increase with non-dimensional distance from the nozzle.<br/>

목차 (Table of Contents)

• ABSTRACT
  
• 1.서론
  
• 2.실험장치 구성 및 조건
  
• 3.결과 및 토의
  
• 4.결론
  
• 후기
  
• 참고문헌