http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
고정빈 ( Jung Bin Ko ),구자예 ( Ja Ye Koo ) 한국분무공학회 2004 한국액체미립화학회지 Vol.9 No.4
N/A Vaporization characteristics of a liquid heptane droplet in high-pressure and temperature flow field are numerically studied. Variable thermodynamic and transport properties and high-pressure effects are taken into account in order to consider real gas effects. Droplet vaporization in convective environments was investigated on the basis of droplet vaporization in quiescent and convective environment. In quiescent environments, droplet lifetime is directly proportional to pressure at the subcritical temperature range but it is inversely proportional to pressure at the supercritical temperature range. In convective environment, droplet deformation becomes stronger by increasing Reynolds number due to increase of velocity while droplet deformation is relatively weak at a higher pressure for the same Reynolds number cases.
아음속 횡단 기체 유동장에서 노즐 형상 변화와 분사각 변화가 액적크기와 침투거리에 미치는 영향
이봉수(Bong-Soo Lee),고정빈(Jung-Bin Ko),조우진(Woo-Jin Cho),구자예(Ja-Ye Koo) 한국항공우주학회 2006 韓國航空宇宙學會誌 Vol.34 No.6
횡단 유동장내에서 일어나는 분무 현상에 대하여 분사각 변화에 대한 특성과 단일 노즐 형상에서 노즐의 크기와 길이에 대한 분무 특성을 연구하였다. 노즐은 단일 구멍으로 직경이 0.5 ㎜이고 노즐 대 노즐길이의 비(L/D)는 1.0에서 6.0이며 이미지는 고해상 줌 렌즈를 이용한 CCD 카메라를 통해 얻었으며, SMD와 액적의 속도는 PDPA와 상용 프로그램인 Image Express를 사용하였다. 액체 제트의 궤적은 웨버수와 모멘텀비, 노즐형상 변화(L/D)에 영향을 받아 액주가 후방으로 휘어지는 현상이 나타났다. 분사각이 낮을 때 (θ<90°)에 노즐 형상보다는 웨버수 증가가 액체 제트의 궤적에 더 크게 영향을 미쳤으며, 분사각이 높을 때(θ>90°)에 노즐 형상 변화에 의한 분열점 변화가 액체 제트의 궤적에 더 크게 영향을 미쳤다. The spray characteristics of liquid jet injected into subsonic cross-flow were investigated experimentally. Spray trajectories were captured using CCD camera. Droplet sizes were measured using PDPA and Image Express. The nozzle diameter was 0.5 ㎜, and its length-to-diameter ratios (L/D) ranged from 1.0 to 6.0. Experimental results indicate that the breakup point is delayed by increasing gas momentum ratio and the penetration length is decreased by increasing Weber number. At low injection angle(θ<90°), Weber number is dominant parameter for trajectories, but at high injection angle(θ>90°), L/D is dominant parameter for trajectories rather than Weber number.
횡단류에 분사되는 액체제트의 분무특성에 대한 수치적 연구
이관형(Kwan-Hyung Lee),고정빈(Jung-Bin Ko),구자예(Ja-Ye Koo) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5
The spray characteristics of liquid jet in cross flow are numerically studied. Numerical analysis was carried out using KIVA code, which was modified to be suitable for simulating liquid jet ejected into cross flow. Wave model and Kelvin-Helmholtz(KH)/Rayleigh-Taylor(RT) hybrid model were used for the purpose of analyzing liquid column, ligament, and the breakup of droplet. Numerical results were compared with experimental data in order to verify the reliability of the physical model. Liquid jet penetration length, volume flux, droplet velocity profile and SMD were obtained. Penetration length increases as flow velocity decreases and injection velocity increases. From the bottom wall, the SMD increases as vertical distance increases.
고압 수소 기체 환경에서 액체 산소 액적의 초임계 상태의 기화 특성 수치적 연구
고정빈,구자예 한국항공대학교 항공우주산업기술연구소 2003 航空宇宙産業技術硏究所 硏究誌 Vol.13 No.-
Droplet vaporization at high ambient pressures is studied numerically by formulating one dimensional vaporization model in liquid oxygen and hydrogen. The ambient pressure is supercritical conditions. The modified Soave-Redlich-Kwong state equation is used to consider of the real gas effects in the high pressure condition. Non-ideal thermodynamic and transport property at near critical and supercritical conditions are considered. Several parametric studies are performed by changing ambient pressure and temperature. Droplet lifetime is proportional to ambient pressure and temperature. Temporal spatial distribution of properties are also investigated.